WorldWideScience

Sample records for agroecosystems

  1. The circulation physiology of agroecosystems

    Institute of Scientific and Technical Information of China (English)

    Cao Zhiping; Richard Dawson

    2007-01-01

    This paper represents an effort to enlarge the understanding of the biophysical foundation of agroecosystems by using an analogy with the circulation of the blood in the human body. The circulation function in the human body can be represented as arterial pressure. The factors affecting arterial pressure in the human body have direct counterparts in the cultivation-husbandry system. The relationship between circulation pressure and the factors affecting that pressure in the cultivation-husbandry system are similar to the relationship between the arterial pressure and factors affecting arterial pressure in the human body. Furthermore, circulation resistance in the cultivation-husbandry system can be shown to be analogous to the calculation of peripheral resistance in the human body by Poiseuille's formula.

  2. Governing of Agro-Ecosystem Services

    OpenAIRE

    Bachev, Hrabrin

    2009-01-01

    In this paper we incorporate interdisciplinary New Institutional and Transaction Costs Economics (combining Economics, Organization, Law, Sociology, Behavioral and Political Sciences), and suggest a framework for analysis of mechanisms of governance of agro-ecosystem services. Firstly, we present a new approach for analysis and improvement of governance of agro-ecosystem services. It takes into account the role of specific institutional environment (formal and informal rules, distribution of ...

  3. Agroecosystem functional assessment and its difficulties

    Institute of Scientific and Technical Information of China (English)

    CAO Zhi-Ping; Richard Dawson1

    2004-01-01

    Agroecosystem functional assessment indicators provide a necessary bridge between decision-makers and scientists. The development of acceptable indicators, however, remains a difficult task because the current knowledge and understanding of ecosystems is not sufficient to allow an objective assessment of all ecosystem functions. These difficulties were summarized from three perspectives. First, there are difficulties in individual function assessment. Of the four functions associated with agroecosystems-energy flow, materials cycling, information flow and value flow - data on material cycling and information flow remain difficult to obtain and the indicators relatively immature. Secondly, there are difficulties of integration. During the assessment process, the integration of the agroecosystem functions remains the biggest obstacle. Until now, there has been no practical or effective methodology established to resolve the problem. At present, the makeshift approach has been to weight the various indicators and then add them together. Thirdly, there is the problem of obscure concepts and concept confusion. When assessments of agroecosystems are conducted, concepts such as structure, function, benefit, and resource utilization are used extensively. To date, no logical relationship(either real or implied) has been developed between any of these concepts. Are they causes and results such that the relationship between them is linear, or are they independent from one another such that the relationship is parallel? Thus far, the essence of this question is yet to be explored.

  4. Rice agroecosystem and the maintenance of biodiversity

    International Nuclear Information System (INIS)

    Rice fields are a special type of wetland. They are shallow, constantly disturbed and experience extremes in temperature and dissolved oxygen content. They receive nutrients in the form of fertilizers during rice cultivation. Rice fields; support a variety of flora and fauna that have adapted and adjusted themselves to the extreme conditions. Since rice fields also support populations of wild fish, rice?fish integration should be done in order to optimize land use and provide supplementary income to farmers. Rice?fish farming encourages farmers to judiciously apply pesticides and herbicides in their fields thus helping to control excessive and unwarranted use of these chemicals. Rice fields also support many migratory and nonmigratory bird species and provides habitat for small mammals. Thus the rice agroecosystem helps to maintain aquatic biodiversity. The Muda rice agroecosystem consists of a troika of interconnected ecosystems. The troika consisting of reservoirs, the connecting network of canals and the rice fields; should be investigated further. This data is needed for informed decision-making concerning development and management of the system so that productivity and biodiversity can be maintained and sustained. (Author)

  5. The Long Term Agroecosystem Research Network - Shared research strategy

    Science.gov (United States)

    Agriculture faces tremendous challenges in meeting multiple societal goals, including a safe and plentiful food supply; climate change adaptation and mitigation; supplying sources of bioenergy; improving water, air, and soil quality; and maintaining biodiversity. The Long Term Agroecosystem Research...

  6. The rice agroecosystem of the MUDA irrigation scheme: an overview

    International Nuclear Information System (INIS)

    The Green Revolution technologies were introduced to the Muda area of Malaysia in the late 1960s. These technological innovations have resulted in rapid modification of the crop habitat and triggered a chain reaction in the rice agroecosystem. The impact of these technologies on the pest flora and fauna are significant. Indiscriminate use of pesticides causes disruption of natural enemy equilibrium and other undesirable effects to the farmers and the rice environment. The main emphasis of this paper is focused on the interactions between the various biological factors such as pathogenic microorganisms, arthropods, gastropods, fishes, birds, rodents, weeds, and the physical factors in the rice agroecosystem. The impact of double cropping of rice, the provision of irrigation facilities, the changes of crop establishment methods, and the adoption of pesticides on the rice agroecosystem are found to have far reaching effects on the sustainability of rice production in the Muda area. (Author)

  7. Assessment of federal databases to evaluate agroecosystem productivity

    Energy Technology Data Exchange (ETDEWEB)

    Olson, G.L.; Breckenridge, R.P.; Wiersma, G.B.

    1990-02-01

    Ecological monitoring data that could provide indications of agroecosystem condition, such as soil microbial biomass, biodiversity in the patches or mineralizable-N, are not available on a national scale. This paper discusses the economists' and ecologists' approach to assessing agroecosystem productivity, and the data available to make ecological assessments of agroecosystems on a national level. Models and indices of productivity used by ecologists and economists are briefly discussed in the context of agricultural inputs and outputs. Databases on production, pesticides, fertilizers, water use, water and air quality, land use, soil, labor and machinery are evaluated for their ability to make national trend assessments on how this ecosystem responds to stress. 39 refs., 3 figs., 3 tabs.

  8. Antibiotics in agroecosystems: Introduction to the special section

    Science.gov (United States)

    The presence of antibiotic drug residues, antibiotic resistant bacteria, and antibiotic resistance genes in agroecosystems has become a significant area of research in recent years, and is a growing public health concern. While antibiotics are utilized for human medicine and agricultural practices, ...

  9. The role of arable weed seeds for agroecosystem functioning

    NARCIS (Netherlands)

    Franke, A.C.; Lotz, L.A.P.; Burg, van der W.J.; Overbeek, van L.S.

    2009-01-01

    A literature study was conducted to gather knowledge on the impact of weed seeds on agroecosystem functioning other than effects related to the production of weed seedlings and plants. The results of the review suggested that a larger and more diverse weed seedbank can contribute to the biodiversity

  10. Comparing Energy Use and Efficiency in Central Iowa Agroecosystems

    Science.gov (United States)

    Cox, Rachael; Wiedenhoeft, Mary

    2009-01-01

    Energy is relevant to all areas of human life; energy sustains us through food, drives our transportation, warms and cools our buildings, and powers our electrical gadgets. In nature, ecosystems function by capturing and transforming energy. Agroecosystems are formed when humans manipulate the capture and flow of energy for food, fiber, and fuel…

  11. Long term agro-ecosystem research: The Southern Plains partnership

    Science.gov (United States)

    The USDA Agricultural Research Service (ARS) is coordinating ten well-established research sites as a Long Term Agro-ecosystem Research (LTAR) Network. The goal of the LTAR is to sustain a land-based infrastructure for research, environmental management testing, and education, that enables understan...

  12. Agroecosystem Analysis of the Choke Mountain Watersheds, Ethiopia

    Directory of Open Access Journals (Sweden)

    Mutlu Ozdogan

    2013-02-01

    Full Text Available Tropical highland regions are experiencing rapid climate change. In these regions the adaptation challenge is complicated by the fact that elevation contrasts and dissected topography produce diverse climatic conditions that are often accompanied by significant ecological and agricultural diversity within a relatively small region. Such is the case for the Choke Mountain watersheds, in the Blue Nile Highlands of Ethiopia. These watersheds extend from tropical alpine environments at over 4000 m elevation to the hot and dry Blue Nile gorge that includes areas below 1000 m elevation, and contain a diversity of slope forms and soil types. This physical diversity and accompanying socio-economic contrasts demand diverse strategies for enhanced climate resilience and adaptation to climate change. To support development of locally appropriate climate resilience strategies across the Blue Nile Highlands, we present here an agroecosystem analysis of Choke Mountain, under the premise that the agroecosystem—the intersection of climatic and physiographic conditions with agricultural practices—is the most appropriate unit for defining adaptation strategies in these primarily subsistence agriculture communities. To this end, we present two approaches to agroecosystem analysis that can be applied to climate resilience studies in the Choke Mountain watersheds and, as appropriate, to other agroecologically diverse regions attempting to design climate adaptation strategies. First, a full agroecoystem analysis was implemented in collaboration with local communities. It identified six distinct agroecosystems that differ systematically in constraints and adaptation potential. This analysis was then paired with an objective landscape classification trained to identify agroecosystems based on climate and physiographic setting alone. It was found that the distribution of Choke Mountain watershed agroecosystems can, to first order, be explained as a function of

  13. Assessing and monitoring impacts of genetically modified plants on agro-ecosystems

    DEFF Research Database (Denmark)

    Arpaia, S.; Messéan, A.; Birch, N.A.;

    2014-01-01

    -funded research project AMIGA − Assessing and monitoring Impacts of Genetically modified plants on Agro-ecosystems − aims to address this issue, by providing a framework that establishes protection goals and baselines for European agro-ecosystems, improves knowledge on the potential long term environmental...... focuses on ecological studies in different EU regions, the sustainability of GM crops is estimated by analysing the functional components of the agro-ecosystems and specific experimental protocols are being developed for this scope....

  14. Diversity of methanotrophs in urea-fertilized tropical rice agroecosystem

    OpenAIRE

    Vishwakarma, Pranjali; Dubey, Suresh K.

    2010-01-01

    Laboratory experiments were conducted to study the population size, diversity and methane oxidation potential of methanotrophs in tropical rice agroecosystem under the influence of N-fertilizer. Results indicate that the diversity of methane oxidizing bacteria (MOB) is altered in fertilizer treated soils compared to untreated control. Nevertheless, Type I MOB still dominated in the fertilized soils whereas the diversity of Type II methanotrophs decreases. Control soils have higher MOB populat...

  15. Influence of growing and exploatation of bovins on regional agroecosystems

    OpenAIRE

    Cornel Podar; Ioan Oroian; Friss Zsuzsa; Bianca Damian; I. Macarie; Daniela Ţerbea; Pop, Ioan A

    2011-01-01

    Scientists all over the are concerned regarding the influence of growing ruminants on regional agro-ecosystems due to green house gases resulted (CO 2, CH4, N2O5). Cattle have contributed to environmental pollution in old industrial farming systems, when the cattle number in Romania, reached 8 million, manure evacuation was not solved and manure was accumulating around the farm polluting the soil, water and air. Low density of ruminants existing in the agricultural sector of the country is no...

  16. Long-term Agroecosystem Research in the Northern Great Plains.

    Science.gov (United States)

    Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

    2015-12-01

    The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

  17. Meteorological risks as drivers of innovation for agroecosystem management

    Science.gov (United States)

    Gobin, Anne; Van de Vyver, Hans; Zamani, Sepideh; Curnel, Yannick; Planchon, Viviane; Verspecht, Ann; Van Huylenbroeck, Guido

    2015-04-01

    Devastating weather-related events recorded in recent years have captured the interest of the general public in Belgium. The MERINOVA project research hypothesis is that meteorological risks act as drivers of environmental innovation in agro-ecosystem management which is being tested using a "chain of risk" approach. The major objectives are to (1) assess the probability of extreme meteorological events by means of probability density functions; (2) analyse the extreme events impact of on agro-ecosystems using process-based bio-physical modelling methods; (3) identify the most vulnerable agro-ecosystems using fuzzy multi-criteria and spatial analysis; (4) uncover innovative risk management and adaptation options using actor-network theory and economic modelling; and, (5) communicate to research, policy and practitioner communities using web-based techniques. Generalized Extreme Value (GEV) theory was used to model annual rainfall maxima based on location-, scale- and shape-parameters that determine the centre of the distribution, the deviation of the location-parameter and the upper tail decay, respectively. Likewise the distributions of consecutive rainy days, rainfall deficits and extreme 24-hour rainfall were modelled. Spatial interpolation of GEV-derived return levels resulted in maps of extreme precipitation, precipitation deficits and wet periods. The degree of temporal overlap between extreme weather conditions and sensitive periods in the agro-ecosystem was determined using a bio-physically based modelling framework that couples phenological models, a soil water balance, crop growth and environmental models. 20-year return values were derived for frost, heat stress, drought, waterlogging and field access during different sensitive stages for different arable crops. Extreme yield values were detected from detrended long term arable yields and relationships were found with soil moisture conditions, heat stress or other meteorological variables during the

  18. The use and fate of pesticides in vegetable-based agroecosystems in Ghana

    NARCIS (Netherlands)

    Ntow, W.J.

    2008-01-01

    Use and Fate of Pesticides in Vegetable-based Agroecosystems in Ghana presents the results of a doctoral study conducted on pesticide use in vegetable production in Ghana, West Africa. It covers the various aspects of pesticide use, behavior, and impacts in vegetable-based agroecosystems and presen

  19. STATE AND EFFICIENCY OF MANAGEMENT OF AGROECOSYSTEM SERVICES – THE CASE OF BULGARIA

    Directory of Open Access Journals (Sweden)

    HRABRIN BACHEV

    2010-01-01

    Full Text Available This paper incorporates New Institutional Economics and analyzes the state and efficiency of management of agro-ecosystem services in Bulgaria. Firstly, it presents framework of analyses of management of agro-ecosystem services including: definition of agroecosystem services and its management; specification of management needs and spectrum of governing modes (institutions, market, private, public, hybrid; assessment of efficiency of different form of management in terms of potential to protect eco-rights and investments, assure socially desirable level of agro-ecosystem services, minimize costs, coordinate and stimulate eco-activities, meet preferences and reconcile conflicts of related agents. Secondly, it identifies and assesses the management of agro-ecosystem services in Bulgaria. Transition and EU integration have brought about significant changes in the state and management of agroecosystems services in the country. Newly evolved market, private and public governance have led to a significant improvement of a part of agro-ecosystems services introducing modern ecostandards and public support, enhancing environmental stewardship, disintensifyingproduction, recovering landscape and traditional productions, diversifying quality, products,and services. At the same time, the novel eco-management is associated with new challenges such as unsustainable exploitation, lost biodiversity, land degradation, water and air contamination. Moreover, implementation of EU common policies would have no desired impact on agro-ecosystem services unless special measures are taken to improve management of public programs, and extend public support to dominating small-scale and subsistence farms.

  20. Managing biotic interactions for ecological intensification of agroecosystem

    Directory of Open Access Journals (Sweden)

    Sabrina eGaba

    2014-06-01

    Full Text Available Agriculture faces the challenge of increasing food production while simultaneously reducing the use of inputs and delivering other ecosystem services. Ecological intensification of agriculture is a paradigm shift, which has recently been proposed to meet such challenges through the manipulation of biotic interactions. While this approach opens up new possibilities, there are many constraints related to the complexity of agroecosystems that make it difficult to implement. Future advances, which are essential to guide agricultural policy, require an eco-evolutionary framework to ensure that ecological intensification is beneficial in the long term.

  1. Ant patchiness: a spatially quantitative test in coffee agroecosystems

    Science.gov (United States)

    Philpott, Stacy M.

    2006-08-01

    Arboreal ants form patchy spatial patterns in tropical agroforest canopies. Such patchy distributions more likely occur in disturbed habitats associated with lower ant diversity and resource availability than in forests. Yet, few studies have quantitatively examined these patchy patterns to statistically test if ants are non-randomly distributed or at what scale. Coffee agroecosystems form a gradient of management intensification along which vegetative complexity and ant diversity decline. Using field studies and a spatially explicit randomization model, I investigated ant patchiness in coffee agroecosystems in Chiapas, Mexico varying in management intensity to examine if: (1) coffee intensification affects occurrence of numerically dominant ants, (2) numerical dominants form statistically distinguishable single-species patches in coffee plants, (3) shade trees play a role in patch location, and (4) patch formation or size varies with management intensity. Coffee intensification correlated with lower occurrence frequency of numerically dominant species generally and of one of four taxa examined. All dominant ant species formed patches but only Azteca instabilis was patchy around shade trees. Ant patchiness did vary somewhat with spatial scale and with strata (within the coffee layer vs around shade trees). Patchiness, however, did not vary with management intensity. These results provide quantitative evidence that numerically dominant ants are patchy within the coffee layer at different scales and that shade tree location, but not coffee management intensity, may play a role in the formation of patchy distributions.

  2. [Changes of agroecosystem service value during urbanization of Guangzhou City, South China].

    Science.gov (United States)

    Ye, Yan-Qiong; Li, Yi-Mian; Zhang, Jia-En

    2011-06-01

    Based on the 1996, 2000, 2004, and 2008 statistical data of Guangzhou City, and by the methods of marketing valuation, shadow price, afforestation cost, carbon tax, and industrial oxygen-producing, this paper calculated the related service values of various agroecosystems in Guangzhou, and assessed the changes of agroecosystem service value during the rapid urbanization of the City. In 1996-2008, though the service values of farmland, grassland, and water ecosystems had somewhat increase, the overall agroecosystem service value of Guangzhou decreased, mainly due to the more decrease of forest ecosystem service value which occupied more than 90% of the total service value each year. Over the studied period, the proportion of each individual functional service value to the total service value changed little, and the contribution of each individual functional service value was in the order of climate regulation > gases regulation > product service > waste treatment > soil conservation > biodiversity conservation > recreation and culture > water source retention and storage. The sum of climate regulation and gases regulation service values took over 91% of the total agroecosystem service value. There was a significant negative correlation (R = -0.905, P agroecosystem service value, suggesting that the increase of urbanization rate would lead to a decrease of agroecosystem service value. Therefore, it requires an appropriate reservation of various agroecosystems to maintain the regional sustainable development during urbanization.

  3. [Changes of agroecosystem service value during urbanization of Guangzhou City, South China].

    Science.gov (United States)

    Ye, Yan-Qiong; Li, Yi-Mian; Zhang, Jia-En

    2011-06-01

    Based on the 1996, 2000, 2004, and 2008 statistical data of Guangzhou City, and by the methods of marketing valuation, shadow price, afforestation cost, carbon tax, and industrial oxygen-producing, this paper calculated the related service values of various agroecosystems in Guangzhou, and assessed the changes of agroecosystem service value during the rapid urbanization of the City. In 1996-2008, though the service values of farmland, grassland, and water ecosystems had somewhat increase, the overall agroecosystem service value of Guangzhou decreased, mainly due to the more decrease of forest ecosystem service value which occupied more than 90% of the total service value each year. Over the studied period, the proportion of each individual functional service value to the total service value changed little, and the contribution of each individual functional service value was in the order of climate regulation > gases regulation > product service > waste treatment > soil conservation > biodiversity conservation > recreation and culture > water source retention and storage. The sum of climate regulation and gases regulation service values took over 91% of the total agroecosystem service value. There was a significant negative correlation (R = -0.905, P < 0.01)between urbanization rate and total agroecosystem service value, suggesting that the increase of urbanization rate would lead to a decrease of agroecosystem service value. Therefore, it requires an appropriate reservation of various agroecosystems to maintain the regional sustainable development during urbanization. PMID:21941754

  4. Organochlorine insecticides in African agroecosystems. Report of a final research co-ordination meeting

    International Nuclear Information System (INIS)

    Adverse effects also appear within the agroecosystem itself. Intensive use of broad spectrum insecticides can reduce populations of insect parasites and predators; as a result, pest populations may be inadequately controlled. This, in turn, can lead to the need of more frequent use of pesticides and to the appearance of secondary pests. We are slowly beginning to understand how natural enemies and the other non-target fauna are affected by pesticide use in a few agroecosystems in the developed countries. The knowledge about these matters in developing countries is very rudimentary. The objectives of this programme were to increase the knowledge of how pesticides affect the agroecosystem especially pest-natural enemy interactions and the non-target fauna within and outside African agroecosystem. Chlorinated hydrocarbon pesticides were used as representing the compounds most likely to produce undesirable consequences. This TECDOC reports the accomplishments of the programme which was financed by the Swedish International Development Authority (SIDA). Refs, figs, tabs

  5. Climbing a ladder: a step-by-step approach to understanding the concept of agroecosystem health.

    Science.gov (United States)

    Alkorta, I; Albizu, I; Amezaga, I; Onaindia, M; Buchner, V; Garbisu, C

    2004-01-01

    Population and individual health is linked to agroecosystem health. To comprehend the concept of agroecosystem health, one should climb a ladder consisting of several successive steps, each rung presenting a certain degree of instability (conceptual difficulty and uncertainty) in an advisable but not inevitable order. Here we suggest a ladder consisting of the following concepts: ecosystem, agroecosystem, biodiversity, sustainability, ecosystem health, and agroecosystem health. Although these concepts are to a certain extent well understood and grasped by scientists, politicians, natural resource managers, and environmentalists, some steps are still highly debatable, unclear, and present a considerable degree of reluctance to be defined and understood. Consequently, much empirical and theoretical effort must be made to construct solid conceptual ladders made up of such steps. In this enterprise, a traditional reductionistic approach confining interpretations to narrow scientific disciplines is unadvisable. Holistic, transdisciplinary approaches are required to reach the desired goal.

  6. [A discussion on basic content and evaluation index system of agroecosystem health].

    Science.gov (United States)

    Zhang, Jia'en; Luo, Shiming

    2004-08-01

    Agroecosystem health is the fundament of food security and human health, and becoming one of the hot spots and frontier fields in agricultural ecology study with more and more international concerns, which can be interpreted as a sustainable state and a dynamic process involving good eco-environment, healthy agricultural organisms, rational spatial and temporal structure, clean production pattern, optimal biodiversity and high productivity. Agroecosystem is a kind of typical artificial and natural compound ecosystem. Its health is strongly influenced and controlled by human activities, and usually linked with agro-products quality, food security and biological security. A series of indices including biological, environmental and eco-economic indicators could be integrated to assess the situation and level of agroecosystem health, and some methods including comprehensive index assessment, eco-toxicological assessment and ecological risk assessment could be used for the evaluation of agroecosystem health.

  7. Carbon Sequestration in Dryland and Irrigated Agroecosystems: Quantification at Different Scales for Improved Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Shashi B; Cassman, Kenneth G; Arkebauer, Timothy J; Hubbard, Kenneth G; Knops, Johannes M; Suyker, Andrew E

    2012-09-14

    The overall objective of this research is to improve our basic understanding of the biophysical processes that govern C sequestration in major rainfed and irrigated agroecosystems in the north-central USA.

  8. Aquatic insect populations in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Periodic sampling of aquatic insects was carried out in an experimental plot of the Muda rice agroecosystem. The study which was conducted from August to December 1995, investigated the impact of the pesticides Broadox and Trebon on aquatic insect populations during the rice growing period. The results indicated that there was no significant difference in abundance and diversity of aquatic insects between the treated and non-treated area. The four dominant aquatic insects were from the families; Chironomidae, Dysticidae, Corixidae and Belostomatidae. Water temperature and dissolved oxygen showed changes throughout the rice growing season and the values of these parameters decreased gradually towards the end of the rice growing season in January when the rice plants were maturing. (Author)

  9. [Effect of transgenic plants on biodiversity of agroecosystem].

    Science.gov (United States)

    Nie, Chengrong; Wang, Jianwu; Luo, Shiming

    2003-08-01

    The effect of transgenic plants on the biodiversity of agroecosystem is an important environmental issue. There are many researches in this field at home and abroad recently. This paper reviewed the advances of the researches based on three levels of biodiversity as genetic diversity, species diversity and ecosystem diversity. They included following aspects: the effect of insect-resistant transgenic crops on target pest; the effect of herbicide-resistant transgenic crops on crops and wild weedy relatives; the effect of virus-resistant transgenic crops on virus; and the effect of transgenic crops on non-target organisms. This paper also discussed the effect of transgenic crops on soil ecosystem and crop genetic diversity. Their potential risks included uncontrolled flows of genes to wild relatives; development of herbicide, insect, and virus resistance in wild relatives; reduced crop genetic diversity; and adverse effects on organisms that were not pests, such as beneficial insects.

  10. Influence of growing and exploatation of bovins on regional agroecosystems

    Directory of Open Access Journals (Sweden)

    Cornel Podar

    2011-12-01

    Full Text Available Scientists all over the are concerned regarding the influence of growing ruminants on regional agro-ecosystems due to green house gases resulted (CO 2, CH4, N2O5. Cattle have contributed to environmental pollution in old industrial farming systems, when the cattle number in Romania, reached 8 million, manure evacuation was not solved and manure was accumulating around the farm polluting the soil, water and air. Low density of ruminants existing in the agricultural sector of the country is not significant in terms of pollution. Currently cattle have positive effects on the environment by the use of legumes, grasses and manure production contributing to the increase of agricultural production: crop production (sugar beet, potato and cereals, animal production (milk, meat, leather production and industrial production also (biogas, befouls, alcohol, oil production.

  11. Predicting the global warming potential of agro-ecosystems

    Science.gov (United States)

    Lehuger, S.; Gabrielle, B.; Larmanou, E.; Laville, P.; Cellier, P.; Loubet, B.

    2007-04-01

    Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHG) contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to environmental conditions and crop management. Here, we used two year-round data sets from two intensively-monitored cropping systems in northern France to test the ability of the biophysical crop model CERES-EGC to simulate GHG exchanges at the plot-scale. The experiments involved maize and rapeseed crops on a loam and rendzina soils, respectively. The model was subsequently extrapolated to predict CO2 and N2O fluxes over an entire crop rotation. Indirect emissions (IE) arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. One experimental site (involving a wheat-maize-barley rotation on a loamy soil) was a net source of GHG with a GWP of 350 kg CO2-C eq ha-1 yr-1, of which 75% were due to IE and 25% to direct N2O emissions. The other site (involving an oilseed rape-wheat-barley rotation on a rendzina) was a net sink of GHG for -250 kg CO2-C eq ha-1 yr-1, mainly due to a higher predicted C sequestration potential and C return from crops. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming impact.

  12. Predicting the global warming potential of agro-ecosystems

    Directory of Open Access Journals (Sweden)

    S. Lehuger

    2007-04-01

    Full Text Available Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHG contributing to the global warming potential (GWP of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to environmental conditions and crop management. Here, we used two year-round data sets from two intensively-monitored cropping systems in northern France to test the ability of the biophysical crop model CERES-EGC to simulate GHG exchanges at the plot-scale. The experiments involved maize and rapeseed crops on a loam and rendzina soils, respectively. The model was subsequently extrapolated to predict CO2 and N2O fluxes over an entire crop rotation. Indirect emissions (IE arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. One experimental site (involving a wheat-maize-barley rotation on a loamy soil was a net source of GHG with a GWP of 350 kg CO2-C eq ha−1 yr−1, of which 75% were due to IE and 25% to direct N2O emissions. The other site (involving an oilseed rape-wheat-barley rotation on a rendzina was a net sink of GHG for –250 kg CO2-C eq ha−1 yr−1, mainly due to a higher predicted C sequestration potential and C return from crops. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming impact.

  13. Hierarchical levels in agro-ecosystems: selective case studies on water and nitrogen.

    OpenAIRE

    Ridder, de, N.

    1997-01-01

    The subject of this thesisToday, agronomic research faces the triple challenge to develop knowledge and insight to manage agro-ecosystems which are inherently sustainable, to diminish the undesirable side effects and to meet the increasing demand of food of a still growing world population, without claiming all the available land. Sound management of agro-ecosystems is not solely a matter of the individual farmer, nor of only field and farm level. Local, national and international policy leve...

  14. Adverse effects of lindane in a maize agro-ecosystem in Uganda

    International Nuclear Information System (INIS)

    The impact of lindane, at commercial rates of application, on invertebrate fauna, soil microbial activity, earthworm populations, crop damage and yields in a maize agro-ecosystem was studied and compared with unsprayed control plots of maize using a pitfall trap, D-Vac suction, litter bag, the earthworm formalin expulsion and crop assessment methods. The findings of the study generally portrayed lindane as having very few effects on the maize agro-ecosystem. (author). 5 refs, 9 tabs

  15. Hymenopteran Parasitoids Diversity Associated with Organic and Coventional Agroecosystems in West Sumatera, Indonesia

    OpenAIRE

    Yaherwandi Yaherwandi; Hidrayani Hidrayani

    2014-01-01

    The use of pesticides in agricultural ecosystems does not only cause environmental pollution, but also  impovert  diversity of natural enemies such as parasitoids and predators as well as causes the emergence of pests resistance to pesticides. The study was focused to identify and compare the abundance, diversity and evenness of Hymenopteran parasitoid species  in organic and conventional agroecosystems. This research was conducted in several organic and conventional vegetable agroecosystems ...

  16. Sustainable and resource efficient intensivation of crop production - Perspectives of agro-ecosystem research Policy paper of the DFG Senate Commission on Agroecosystem Research

    NARCIS (Netherlands)

    Wolters, V.; Isselstein, J.; Stützel, H.; Ordon, F.; Haaren, von C.; Schlecht, E.; Wesseler, J.H.H.; Birner, R.; Lützow, von M.; Brüggemann, N.; Diekkrüger, B.; Fangmeier, A.; Flessa, H.; Kage, H.; Kaupenhohann, M.; Kögel-Knabner, I.; Mosandl, R.; Seppelt, R.

    2014-01-01

    With its policy paper the Senate Commission on Agro-ecosystemResearch of the Deutsche Forschungsgemeinschaft(DFG) summarizes potential benefits of basic researchfor the sustainable intensification of crop production. Agro-ecosystems critically contribute to fulfilling the need forincreasing food and

  17. Agro-ecosystem Emergy Evolution and Trend in Hunan Province

    Institute of Scientific and Technical Information of China (English)

    ZHU Yu-lin; LI Ming-jie; HOU Mao-zhang; LI Sha; LONG Yu-zi; WANG Mao-xi

    2012-01-01

    Using the emergy analysis method,we conduct trend analysis of changes in the total emergy,input and output structure,various emergy indicators of agro-ecosystem in Hunan Province during the period 1999-2008.The results show that during the study period,total emergy input basically remained stable,but the emergy input structure was constantly optimized,of which the input of non-renewable industrial assistant emergy increased by 38.4%,from 4.00E +22 sej to 5.53E +22 sej,and the input of renewable organic emergy declined from 1.32E +23 sej to 1.20E + 23 sej;total emergy yield and yield efficiency of this system were promoted dramatically,and in 2008,the total emergy yield reached 1.69E +23 sej,increasing by 23.8% as against that in 1999,the net emergy yield ratio rose from 0.79 to 0.96;since the environmental loading ratio also tended to rise constantly,from 1.12 to 1.79,the sustainability index of this system also experienced the slow downward trend,from 0.71 to 0.54,always less than 1,indicating that the agriculture in Hunan Province is the high consumption-driven ecosystem in general,with obvious features of extensive development.

  18. Biodiversity conservation in tropical agroecosystems: a new conservation paradigm.

    Science.gov (United States)

    Perfecto, Ivette; Vandermeer, John

    2008-01-01

    It is almost certainly the case that many populations have always existed as metapopulations, leading to the conclusion that local extinctions are common and normally balanced by migrations. This conclusion has major consequences for biodiversity conservation in fragmented tropical forests and the agricultural matrices in which they are embedded. Here we make the argument that the conservation paradigm that focuses on setting aside pristine forests while ignoring the agricultural landscape is a failed strategy in light of what is now conventional wisdom in ecology. Given the fragmented nature of most tropical ecosystems, agricultural landscapes should be an essential component of any conservation strategy. We review the literature on biodiversity in tropical agricultural landscapes and present evidence that many tropical agricultural systems have high levels of biodiversity (planned and associated). These systems represent, not only habitat for biodiversity, but also a high-quality matrix that permits the movement of forest organisms among patches of natural vegetation. We review a variety of agroecosystem types and conclude that diverse, low-input systems using agroecological principles are probably the best option for a high-quality matrix. Such systems are most likely to be constructed by small farmers with land titles, who, in turn, are normally the consequence of grassroots social movements. Therefore, the new conservation paradigm should incorporate a landscape approach in which small farmers, through their social organizations, work with conservationists to create a landscape matrix dominated by productive agroecological systems that facilitate interpatch migration while promoting a sustainable and dignified livelihood for rural communities.

  19. Hymenopteran Parasitoids Diversity Associated with Organic and Coventional Agroecosystems in West Sumatera, Indonesia

    Directory of Open Access Journals (Sweden)

    Yaherwandi Yaherwandi

    2014-01-01

    Full Text Available The use of pesticides in agricultural ecosystems does not only cause environmental pollution, but also  impovert  diversity of natural enemies such as parasitoids and predators as well as causes the emergence of pests resistance to pesticides. The study was focused to identify and compare the abundance, diversity and evenness of Hymenopteran parasitoid species  in organic and conventional agroecosystems. This research was conducted in several organic and conventional vegetable agroecosystems in West Sumatera. The tools used for the collection of insects were farmcop, sweep net and yellow pan traps. A total of 717 individuals of Hymenopteran parasitoids belonging to 21 families and 131 species were recorded during the study. A total of 533 individuals collected in organic agroecosystem consisted of 20 families and 85 species of Hymenopteran parasitoids, whereas in conventional agroecosystems there were 184 individuals collected cosisted of 13 families and 46 species of Hymenopteran parasitoids. This study also demonstrated a strong relationship between crops and Hymenopteran parasitoid composition. Species diversity and evenness of Hymenopteran parasitoids were higher in organic than in conventional agroecosystems.

  20. Crop rotational diversity enhances belowground communities and functions in an agroecosystem.

    Science.gov (United States)

    Tiemann, L K; Grandy, A S; Atkinson, E E; Marin-Spiotta, E; McDaniel, M D

    2015-08-01

    Biodiversity loss, an important consequence of agricultural intensification, can lead to reductions in agroecosystem functions and services. Increasing crop diversity through rotation may alleviate these negative consequences by restoring positive aboveground-belowground interactions. Positive impacts of aboveground biodiversity on belowground communities and processes have primarily been observed in natural systems. Here, we test for the effects of increased diversity in an agroecosystem, where plant diversity is increased over time through crop rotation. As crop diversity increased from one to five species, distinct soil microbial communities were related to increases in soil aggregation, organic carbon, total nitrogen, microbial activity and decreases in the carbon-to-nitrogen acquiring enzyme activity ratio. This study indicates positive biodiversity-function relationships in agroecosystems, driven by interactions between rotational and microbial diversity. By increasing the quantity, quality and chemical diversity of residues, high diversity rotations can sustain soil biological communities, with positive effects on soil organic matter and soil fertility.

  1. Agrobiodiversity of Muda Rice Agroecosystem:A case Study in Largest Granary Area of Malaysia

    Institute of Scientific and Technical Information of China (English)

    Amir Shah Ruddin Md Shah; Mashhor Mansor; Shahrul Anuar Mohd Shah; Che Salmah Mohd Rawi; Abu Hassan Ahmad; Ibrahim Jaafar

    2008-01-01

    A survey was carried out at the largest rice cultivation area in Peninsular Malaysia, the Muda rice agroecosystem. The main objective of this study was to document the overall biodiversity associated with this unique agroecosystem by using a combination of sampling techniques in order to record different groups of fauna and flora. The total number of biota recorded and identified from the rice field ecosystem during the study period consisted of 46 species of zooplankton, 81 species of aquatic insects, 5 species of rodents, 7 species of bats, 87 species of birds, 11 species of fishes and 58 species of weeds. A long-term study should be carried out as more species are expected to be recorded when more of the Muda rice agroecosystem area has been sampled to obtain sufficient information on the Muda rice agrobiodiversity.

  2. Production and robustness of a Cacao agroecosystem: effects of two contrasting types of management strategies.

    Directory of Open Access Journals (Sweden)

    Rodolphe Sabatier

    Full Text Available Ecological intensification, i.e. relying on ecological processes to replace chemical inputs, is often presented as the ideal alternative to conventional farming based on an intensive use of chemicals. It is said to both maintain high yield and provide more robustness to the agroecosystem. However few studies compared the two types of management with respect to their consequences for production and robustness toward perturbation. In this study our aim is to assess productive performance and robustness toward diverse perturbations of a Cacao agroecosystem managed with two contrasting groups of strategies: one group of strategies relying on a high level of pesticides and a second relying on low levels of pesticides. We conducted this study using a dynamical model of a Cacao agroecosystem that includes Cacao production dynamics, and dynamics of three insects: a pest (the Cacao Pod Borer, Conopomorpha cramerella and two characteristic but unspecified beneficial insects (a pollinator of Cacao and a parasitoid of the Cacao Pod Borer. Our results showed two opposite behaviors of the Cacao agroecosystem depending on its management, i.e. an agroecosystem relying on a high input of pesticides and showing low ecosystem functioning and an agroecosystem with low inputs, relying on a high functioning of the ecosystem. From the production point of view, no type of management clearly outclassed the other and their ranking depended on the type of pesticide used. From the robustness point of view, the two types of managements performed differently when subjected to different types of perturbations. Ecologically intensive systems were more robust to pest outbreaks and perturbations related to pesticide characteristics while chemically intensive systems were more robust to Cacao production and management-related perturbation.

  3. Production and Robustness of a Cacao Agroecosystem: Effects of Two Contrasting Types of Management Strategies

    Science.gov (United States)

    Sabatier, Rodolphe; Wiegand, Kerstin; Meyer, Katrin

    2013-01-01

    Ecological intensification, i.e. relying on ecological processes to replace chemical inputs, is often presented as the ideal alternative to conventional farming based on an intensive use of chemicals. It is said to both maintain high yield and provide more robustness to the agroecosystem. However few studies compared the two types of management with respect to their consequences for production and robustness toward perturbation. In this study our aim is to assess productive performance and robustness toward diverse perturbations of a Cacao agroecosystem managed with two contrasting groups of strategies: one group of strategies relying on a high level of pesticides and a second relying on low levels of pesticides. We conducted this study using a dynamical model of a Cacao agroecosystem that includes Cacao production dynamics, and dynamics of three insects: a pest (the Cacao Pod Borer, Conopomorpha cramerella) and two characteristic but unspecified beneficial insects (a pollinator of Cacao and a parasitoid of the Cacao Pod Borer). Our results showed two opposite behaviors of the Cacao agroecosystem depending on its management, i.e. an agroecosystem relying on a high input of pesticides and showing low ecosystem functioning and an agroecosystem with low inputs, relying on a high functioning of the ecosystem. From the production point of view, no type of management clearly outclassed the other and their ranking depended on the type of pesticide used. From the robustness point of view, the two types of managements performed differently when subjected to different types of perturbations. Ecologically intensive systems were more robust to pest outbreaks and perturbations related to pesticide characteristics while chemically intensive systems were more robust to Cacao production and management-related perturbation. PMID:24312469

  4. How Should We Be Determining Background and Baseline Antibiotic Resistance Levels in Agroecosystem Research?

    Science.gov (United States)

    Rothrock, Michael J; Keen, Patricia L; Cook, Kimberly L; Durso, Lisa M; Franklin, Alison M; Dungan, Robert S

    2016-03-01

    Although historically, antibiotic resistance has occurred naturally in environmental bacteria, many questions remain regarding the specifics of how humans and animals contribute to the development and spread of antibiotic resistance in agroecosystems. Additional research is necessary to completely understand the potential risks to human, animal, and ecological health in systems altered by antibiotic-resistance-related contamination. At present, analyzing and interpreting the effects of human and animal inputs on antibiotic resistance in agroecosystems is difficult, since standard research terminology and protocols do not exist for studying background and baseline levels of resistance in the environment. To improve the state of science in antibiotic-resistance-related research in agroecosystems, researchers are encouraged to incorporate baseline data within the study system and background data from outside the study system to normalize the study data and determine the potential impact of antibiotic-resistance-related determinants on a specific agroecosystem. Therefore, the aims of this review were to (i) present standard definitions for commonly used terms in environmental antibiotic resistance research and (ii) illustrate the need for research standards (normalization) within and between studies of antibiotic resistance in agroecosystems. To foster synergy among antibiotic resistance researchers, a new surveillance and decision-making tool is proposed to assist researchers in determining the most relevant and important antibiotic-resistance-related targets to focus on in their given agroecosystems. Incorporation of these components within antibiotic-resistance-related studies should allow for a more comprehensive and accurate picture of the current and future states of antibiotic resistance in the environment. PMID:27065388

  5. Ecohydrology of agroecosystems: quantitative approaches towards sustainable irrigation.

    Science.gov (United States)

    Vico, Giulia; Porporato, Amilcare

    2015-02-01

    Irrigation represents one of the main strategies to enhance and stabilize agricultural productivity, by mitigating the effects of rainfall vagaries. In the face of the projected growth in population and in biofuel demands, as well as shifts in climate and dietary habits, a more sustainable management of water resources in agroecosystems is needed. The field of ecohydrology, traditionally focusing on natural ecosystems, has the potential to offer the necessary quantitative tools to assess and compare agricultural enterprises across climates, soil types, crops, and irrigation strategies, accounting for the unpredictability of the hydro-climatic forcing. Here, agricultural sustainability and productivity are assessed with reference to water productivity (defined as the ratio between yield and total supplied water), yields, water requirements, and their variability-a crucial element for food security and resource allocation planning. These synthetic indicators are quantified by means of a probabilistic description of the soil water balance and crop development. The model results allow the interpretation of patterns of water productivity observed in Zea mays (maize) and Triticum aestivum (wheat), grown under a variety of soils, climates, and irrigation strategies. Employing the same modeling framework, the impact of rainfall pattern and irrigation strategy on yield and water requirements is further explored. The obtained standard deviations of yield and water requirements suggest the existence of a nonlinear tradeoff between yield stabilization and variability of water requirements, which in turn is strongly impacted by irrigation strategy. Moreover, intermediate rainfall amounts are associated to the highest variability in yields and irrigation requirements, although allowing the maximum water productivity. The existence of these tradeoffs between productivity, reliability, and sustainability poses a problem for water management, in particular in mesic climates. PMID

  6. PHOSPHORUS BIOGEOCHEMICAL CYCLING IN A SUGAR CANE AGROECOSYSTEM

    Directory of Open Access Journals (Sweden)

    D. Lopez-Hernandez

    2012-01-01

    Full Text Available The annual harvest of sugarcane plantations together with the burning of the crop before harvest, a common practice of management of sugarcane plantations in South America, leads to the loss of significant amounts of nutrients in those agroecosystems. Thus prescribed burning operations could progressively diminish the level of soil organic matter and increase nutrient deficiency in soils of sugar cane agrosystems. This study is an attempt to quantify the P distribution during the period of growth in a plantation of sugar cane (Saccharum officinarum located near San Felipe, Yaracuy State, Central, Venezuela focusing on processes related to the cycling of the element as affected by burning operations. The work was performed in 4.5 ha experimental plots planted with the varieties Puerto Rico (PR 1028 and Venezuela (V 58-4. The principal flows of phosphorus, as well the quantities of this element in the soil-plant components were measured throughout the growing cycle of the crop (third ratoon. The inputs through precipitation (wet and dry were high, that was associated with the intense agricultural (prescribed burning and industrial activities occurring in the area. The annual balance for both varieties was negative (-17.31 and -23.63 kg ha–1 for V 58-4 and PR 1028, respectively. The negative budget is mainly due to the important amounts of P that are exported with the cane stems. The losses must be compensated through fertilization; nonetheless, preliminary results indicated no response to P dressing, suggesting that in the studied mollisols the internal processes e.g., Organic-P (Po mineralization and P solubilization efficiently operate generating important available P levels. It was also found that the burning of the sugar cane plantation plays an important role in the recycling of phosphorus, since 25-28 % of the P requirements of the varieties are reincorporated into the soil from the ashes coming as bulk deposition.

  7. Fruit and Soil Quality of Organic and Conventional Strawberry Agroecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Reganold, John P. [Washington State University; Andrews, Preston K. [Washington State University; Reeve, Jennifer [Washington State University; Carpenter-Boggs, Lynne [Washington State University; Schadt, Christopher Warren [ORNL; Alldredge, J. Richard [Washington State University; Ross, Carolyn [Washington State University; Davies, Neil [Washington State University; Zhou, Jizhong [University of Oklahoma, Norman

    2010-01-01

    Background: Sale of organic foods is one of the fastest growing market segments within the global food industry. People often buy organic food because they believe organic farms produce more nutritious and better tasting food from healthier soils. Here we tested if there are significant differences in fruit and soil quality from 13 pairs of commercial organic and conventional strawberry agroecosystems in California. Methodology/Principal Findings: At multiple sampling times for two years, we evaluated three varieties of strawberries for mineral elements, shelf life, phytochemical composition, and organoleptic properties. We also analyzed traditional soil properties and soil DNA using microarray technology. We found that the organic farms had strawberries with longer shelf life, greater dry matter, and higher antioxidant activity and concentrations of ascorbic acid and phenolic compounds, but lower concentrations of phosphorus and potassium. In one variety, sensory panels judged organic strawberries to be sweeter and have better flavor, overall acceptance, and appearance than their conventional counterparts. We also found the organically farmed soils to have more total carbon and nitrogen, greater microbial biomass and activity, and higher concentrations of micronutrients. Organically farmed soils also exhibited greater numbers of endemic genes and greater functional gene abundance and diversity for several biogeochemical processes, such as nitrogen fixation and pesticide degradation. Conclusions/Significance: Our findings show that the organic strawberry farms produced higher quality fruit and that their higher quality soils may have greater microbial functional capability and resilience to stress. These findings justify additional investigations aimed at detecting and quantifying such effects and their interactions.

  8. The value of producing food, energy, and ecosystem services within an agro-ecosystem

    DEFF Research Database (Denmark)

    Porter, John Roy; Constanza, Robert; Sandhu, Harpinder;

    2009-01-01

    and economic value-transfer methods, the market and nonmarket ES value of a combined food and energy (CFE) agro-ecosystem that simultaneously produces food, fodder, and bioenergy. Such novel CFE agro-ecosystems can provide a significantly increased net crop, energy, and nonmarketed ES compared...... with conventional agriculture, and require markedly less fossil-based inputs. Extrapolated to the European scale, the value of nonmarket ES from the CFE system exceeds current European farm subsidy payments. Such integrated food and bioenergy systems can thus provide environmental value for money for European Union...

  9. Hierarchical levels in agro-ecosystems: selective case studies on water and nitrogen.

    NARCIS (Netherlands)

    Ridder, de N.

    1997-01-01

    The subject of this thesisToday, agronomic research faces the triple challenge to develop knowledge and insight to manage agro-ecosystems which are inherently sustainable, to diminish the undesirable side effects and to meet the increasing demand of food of a still growing world population, without

  10. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    Science.gov (United States)

    Fader, M.; von Bloh, W.; Shi, S.; Bondeau, A.; Cramer, W.

    2015-11-01

    In the Mediterranean region, climate and land use change are expected to impact on natural and agricultural ecosystems by warming, reduced rainfall, direct degradation of ecosystems and biodiversity loss. Human population growth and socioeconomic changes, notably on the eastern and southern shores, will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in turn, require assessments by means of a comprehensive agro-ecosystem and hydrological model. This study presents the inclusion of 10 Mediterranean agricultural plants, mainly perennial crops, in an agro-ecosystem model (Lund-Potsdam-Jena managed Land - LPJmL): nut trees, date palms, citrus trees, orchards, olive trees, grapes, cotton, potatoes, vegetables and fodder grasses. The model was successfully tested in three model outputs: agricultural yields, irrigation requirements and soil carbon density. With the development presented in this study, LPJmL is now able to simulate in good detail and mechanistically the functioning of Mediterranean agriculture with a comprehensive representation of ecophysiological processes for all vegetation types (natural and agricultural) and in a consistent framework that produces estimates of carbon, agricultural and hydrological variables for the entire Mediterranean basin. This development paves the way for further model extensions aiming at the representation of alternative agro-ecosystems (e.g. agroforestry), and opens the door for a large number of applications in the Mediterranean region, for example assessments of the consequences of land use transitions, the influence of management practices and climate change impacts.

  11. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    Directory of Open Access Journals (Sweden)

    M. Fader

    2015-06-01

    Full Text Available Climate and land use change in the Mediterranean region is expected to affect natural and agricultural ecosystems by decreases in precipitation, increases in temperature as well as biodiversity loss and anthropogenic degradation of natural resources. Demographic growth in the Eastern and Southern shores will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in turn, require assessments by means of a comprehensive agro-ecosystem and hydrological model. This study presents the inclusion of 10 Mediterranean agricultural plants, mainly perennial crops, in an agro-ecosystem model (LPJmL: nut trees, date palms, citrus trees, orchards, olive trees, grapes, cotton, potatoes, vegetables and fodder grasses. The model was successfully tested in three model outputs: agricultural yields, irrigation requirements and soil carbon density. With the development presented in this study, LPJmL is now able to simulate in good detail and mechanistically the functioning of Mediterranean agriculture with a comprehensive representation of ecophysiological processes for all vegetation types (natural and agricultural and in a consistent framework that produces estimates of carbon, agricultural and hydrological variables for the entire Mediterranean basin. This development pave the way for further model extensions aiming at the representation of alternative agro-ecosystems (e.g. agroforestry, and opens the door for a large number of applications in the Mediterranean region, for example assessments on the consequences of land use transitions, the influence of management practices and climate change impacts.

  12. Socio-Cultural and Economic Valuation of Ecosystem Services Provided by Mediterranean Mountain Agroecosystems

    NARCIS (Netherlands)

    Bernues, A.; Rodrıguez-Ortega, T.; Ripoll Bosch, R.; Alfnes, F.

    2014-01-01

    The aim of this work was to elucidate the socio-cultural and economic value of a number of ecosystem services delivered by mountain agroecosystems (mostly grazing systems) in Euro-Mediterranean regions. We combined deliberative (focus groups) and survey-based stated-preference methods (choice modell

  13. Measured and CQESTR simulated soil organic carbon changes of dryland agroecosystem under climate change scenarios

    Science.gov (United States)

    The potential effects of global climate change (CC) on C cycling and soil organic carbon (SOC) storage/loss in agroecosystems can be assessed by process-based models such as CQESTR. The CQESTR model was used to simulate the effect of tillage and N fertilization on SOC storage/loss in three long-term...

  14. Insect behavioural ecology and other factors affecting the control efficacy of agro-ecosystem diversification strategies

    NARCIS (Netherlands)

    Potting, R.P.J.; Perry, J.N.; Powell, W.

    2005-01-01

    In the last decade there is an increased interest in the design and use of diversified pest-suppressive agro-ecosystems. A diversification approach aims to manipulate the spatial dynamics of herbivores by adding a trap crop that attracts and retains herbivores in the non-crop area or by adding a dis

  15. Biodiversity and soil quality in agroecosystems: the use of a qualitative multi-attribute model

    DEFF Research Database (Denmark)

    Cortet, J.; Bohanec, M.; Griffiths, B.;

    2009-01-01

    In ecological impact assessment, special emphasis is put on soil biology and estimating soil quality from the observed biological parameters. The aim of this study is to propose a tool easy to use for scientists and decision makers for agroecosystems soil quality assessment using these biological...

  16. Panarchy rules : rethinking resilience of agroecosystems, evidence from Dutch dairy - farming

    NARCIS (Netherlands)

    Apeldoorn, van Dirk F.; Kok, Kasper; Sonneveld, Marthijn P.W.; Veldkamp, Tom (A.)

    2011-01-01

    Resilience has been growing in importance as a perspective for governing social-ecological systems. The aim of this paper is first to analyze a well-studied human dominated agroecosystem using five existing key heuristics of the resilience perspective and second to discuss the consequences of using

  17. Panarchy rules: rethinking resilience of agroecosystems, evidence from Dutch dairy-farming

    NARCIS (Netherlands)

    Apeldoorn, van D.F.; Kok, K.; Sonneveld, M.P.W.; Veldkamp, A.

    2011-01-01

    Resilience has been growing in importance as a perspective for governing social-ecological systems. The aim of this paper is first to analyze a well-studied human dominated agroecosystem using five existing key heuristics of the resilience perspective and second to discuss the consequences of using

  18. Adverse effect of agroecosystem pond water on biological endpoints of common toad (Rhinella arenarum) tadpoles.

    Science.gov (United States)

    Babini, María Selene; Bionda, Clarisa de Lourdes; Salas, Nancy Edith; Martino, Adolfo Ludovico

    2016-08-01

    Chemical prroducts used in farming and wastes from livestock can contaminate pond water in agroecosystems due to runoff. Amphibians using these ponds for breeding are probably exposed to pollutants, and serious consequences might be observed afterward at the population level. Assessment biological endpoints of anuran to water quality give a realistic estimate of the probability of occurrence of adverse effects and provide an early warning signal. In this study, the ecotoxicity of agroecosystem ponds from the south of Córdoba province, Argentina, was investigated. Ponds in four sites with different degrees of human disturbance were selected: three agroecosystems (A1, A2, A3) and a site without crops or livestock (SM). The effect of pond water quality on the biological endpoint of Rhinella arenarum tadpoles was examined using microcosms with pond water from sites. Biological endpoints assessed were as follows: mortality, growth, development, morphological abnormalities (in body shape, gut, and labial tooth row formula), behavior, and blood cell parameters (micronucleus and nuclear abnormalities). Results indicated that water from agroecosystems has adverse effect on early life stage of R. arenarum. High mortality and fewer metamorphs were recorded in the A1 and A3 treatments. Tadpoles and metamorphs from A1 and A2 treatments had lower body condition. Tadpoles from A1 and A3 showed the highest prevalence of morphological abnormalities. The lowest amount of tadpoles feeding and the highest percentage of tadpoles swimming on the surface were observed in treatments with agroecosystem pond water. The higher frequencies of micronuclei and nuclear abnormalities were recorded in tadpoles from A1, A2, and A3 treatments. We check the sensitivity of the biological endpoints of R. arenarum tadpoles like early warning indicators of water quality. We found that the poor water quality of agroecosystem ponds has impact on the health of the tadpoles, and this could affect the

  19. Food resource and temporal partitioning amongst a guild of predatory agroecosystem - inhabiting ant species

    Directory of Open Access Journals (Sweden)

    Vivek Mohan AGARWAL, Neelkamal RASTOGI

    2009-10-01

    Full Text Available Prey diversity and temporal foraging patterns of six abundant, predatory ant species were investigated seasonally in an agroecosystem with two main vegetable crops. Pheidole sp. demonstrated the highest predation success and therefore appears to be the dominant species while Tapinoma melanocephalum showed the lowest success under the natural field conditions. Investigation of prey diversity and temporal activity patterns with the null model tests of niche overlap revealed a significant overlap indicating that the activity periods and prey diversity may not be solely influenced by interactions among the co-existing ant species. However, niche partitioning in the daily peak activity periods was demonstrated during all the three seasons (summer, rainy and winter particularly between Pheidole sp. and T. melanocephalum. Pheidole sp. exhibited a high intensity, broadly extended mono-modal foraging pattern. Camponotus compressus and C. paria showed bi-modality in their foraging activity during the rainy season and mono-modal patterns during summer and winter seasons. Pachycondyla tesserinoda, Tetramorium sp. and T. melanocephalum exhibited peak foraging activities in the morning hours during the summer and rainy seasons. The activity profiles of C. compressus and T. melanocephalum were skewed towards late afternoon hours during the winter season indicating avoidance of foraging activity during the favourable periods when the more aggressive Pheidole sp. is active. In the sponge gourd agroecosystem, the ants captured predominantly hymenopteran, orthopteran and coleopteran insects. While Pheidole sp. hunted mainly the large orthopteran prey, other ant species captured worker ants in the sponge gourd agroecosystem. In the cauliflower agroecosystem, while other species captured prey chiefly belonging to six orders, i.e., Lepidoptera, Hymenoptera, Coleoptera, Hemiptera, Isoptera and Diptera, Pheidole sp. was the only species to also hunt orthopteran prey

  20. Traditional agroecosystems as conservatories and incubators of cultivated plant varietal diversity: the case of fig (Ficus carica L. in Morocco

    Directory of Open Access Journals (Sweden)

    Santoni Sylvain

    2010-02-01

    Full Text Available Abstract Background Traditional agroecosystems are known to host both large crop species diversity and high within crop genetic diversity. In a context of global change, this diversity may be needed to feed the world. Are these agroecosystems museums (i.e. large core collections or cradles of diversity? We investigated this question for a clonally propagated plant, fig (Ficus carica, within its native range, in Morocco, but as far away as possible from supposed centers of domestication. Results Fig varieties were locally numerous. They were found to be mainly highly local and corresponded to clones propagated vegetatively. Nevertheless these clones were often sufficiently old to have accumulated somatic mutations for selected traits (fig skin color and at neutral loci (microsatellite markers. Further the pattern of spatial genetic structure was similar to the pattern expected in natural population for a mutation/drift/migration model at equilibrium, with homogeneous levels of local genetic diversity throughout Moroccan traditional agroecosystems. Conclusions We conclude that traditional agroecosystems constitue active incubators of varietal diversity even for clonally propagated crop species, and even when varieties correspond to clones that are often old. As only female fig is cultivated, wild fig and cultivated fig probably constitute a single evolutionary unit within these traditional agroecosystems. Core collections, however useful, are museums and hence cannot serve the same functions as traditional agroecosystems.

  1. Natural biological control of pest mites in Brazilian sun coffee agroecosystems.

    Science.gov (United States)

    Teodoro, Adenir V; Sarmento, Renato A; Rêgo, Adriano S; da Graça S Maciel, Anilde

    2010-06-01

    Coffee is one of the leading commodities in tropical America. Although plantations are usually established under a canopy of trees in most producing countries in the region, Brazilian coffee is mostly produced under full sun conditions. Such simple, single-crop agroecosystems with intensive agrochemical inputs often suffer with pests like mites. Predatory mites of the family Phytoseiidae are the main natural enemies associated with pest mites in the field. However, these beneficial arthropods struggle to survive in intensive agroecosystems such as coffee monocultures due to unfavorable microclimatic conditions, widespread pesticide use, and lack of alternative food (pollen, nectar). Conservation biological control uses a range of management strategies to sustain and enhance populations of indigenous natural enemies such as predatory mites. We discuss here conservation biological control as a strategy to improve biological control of pest mites by native predatory mites in Brazilian coffee monocultures as well as some related patents.

  2. Energy efficiency / economic in agroecosystems; Eficiencia energetica/economica em agroecossistemas

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Luis Carlos Ferreira de; Bueno, Osmar de Carvalho; Esperancini, Maura Seiko Tsutui [Universidade Estadual Paulista Julio de Mesquita Filho (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas

    2010-07-01

    The energy and economic evaluation of agroecosystems is important in the sense of appraise as maintainable these can be so much of the point of view energy as economic. The objective of the present paper was to show, starting from a case study, the construction of an indicator of energy/economic efficiency, whose results for four existent systems of corn production in the study area presented indexes that varied between 22.4 and 31.6. Of the reading of those values was possible to evaluate that all of the appraised systems show sustainability of long and short term. The proposed indicator if it shows solid in the agroecosystems appreciation concerning the analysis of your energy/economic sustainability. (author)

  3. Biodiversity Indicators for Sustainability Evaluation of Conventional and Organic Agro-ecosystems

    Directory of Open Access Journals (Sweden)

    Concetta Vazzana

    2007-06-01

    Full Text Available Previous studies suggest widespread positive responses of biodiversity to organic farming. However, the effect of organic farming management on biodiversity over time needs to be better understood and this paper aims to compare agricultural biodiversity in a long-term experiment including three different agroecosystem management patterns (old organic, young organic and conventional. The level of agroecosystem sustainability related to plants has been assessed both for the structural and the associated biodiversity, using biodiversity Indicators. The data collected in three years (2003-2005 show that the system under organic agriculture management is better than conventional one for every indicator and it improves each aspect over the time. This trend holds especially for the associated biodiversity while the planned biodiversity can still be improved.

  4. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    OpenAIRE

    Fader, M.; von Bloh, W.; Shi, S; A. Bondeau; Cramer, W.

    2015-01-01

    In the Mediterranean region, climate and land use change are expected to impact on natural and agricultural ecosystems by warming, reduced rainfall, direct degradation of ecosystems and biodiversity loss. Human population growth and socioeconomic changes, notably on the eastern and southern shores, will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in tur...

  5. Valuation of linkages between climate change, biodiversity and productivity of European agro-ecosystems

    OpenAIRE

    Palatnik, Ruslana Rachel; Nunes, Paulo Augusto Lourenço Dias

    2010-01-01

    It is clear that climate change involves changes in temperature and precipitation and therefore directly affects land productivity. However, this is not the only channel for climatic change to affect agro-systems. Biodiversity is subject to climatic fluctuations and in turn may alter land productivity too. Firstly, biodiversity is an input into agro-ecosystems. Secondly, biodiversity supports the functioning of these systems (e.g. the balancing of the nutrient cycle). Thirdly, agro-systems al...

  6. Socio-Cultural and Economic Valuation of Ecosystem Services Provided by Mediterranean Mountain Agroecosystems

    OpenAIRE

    Bernues, A.; Rodriguez-Ortega, T.; Ripoll Bosch, R.; Alfnes, F.

    2014-01-01

    The aim of this work was to elucidate the socio-cultural and economic value of a number of ecosystem services delivered by mountain agroecosystems (mostly grazing systems) in Euro-Mediterranean regions. We combined deliberative (focus groups) and survey-based stated-preference methods (choice modelling) to, first, identify the perceptions of farmers and other citizens on the most important ecosystem services and, second, to value these in economic terms according to the willingness to pay of ...

  7. Ecosystem Service of Shade Trees on Nutrient Cycling and Productivity of Coffee Agro-ecosystems

    OpenAIRE

    Rusdi Evizal; Tohari Tohari; Irfan D. Prijambada; Jaka Widada; Donny Widianto

    2009-01-01

    Shade trees are significant in certification scheme of sustainable coffee production. They play an importance role on ecosystem functioning. This research is aimed to study ecosystem service of shade trees in some coffee agro-ecosystems particularly on nutrient cycling and land productivity. Four agro-ecosys tems of Robusta coffee (Coffea canephora), namely sun coffee (without shade trees), coffee shaded by Michelia champaca, coffee shaded by Gliricidia sepium, and coffee shaded by Erythrina ...

  8. Application of Reduced Corn Cultivation Technology in Agro-Ecosystem of Cazin Municipality

    OpenAIRE

    Mirsad Veladžić; Fatima Muhamedagić; Emdžad Galijašević

    2011-01-01

    Intensive corn cultivation is predominant in current agriculture of the Una-Sana Canton. One of the corn cultivation methods in agro-ecosystem is reduced cultivation. The paper presents the experiment of “Osmak žuti” (eight-row yellow) corn cultivation on two control sites with application of reduced and intensive cultivation in Cazin municipality. The objectives of this research were to examine the possibility of application of reduced corn cultivation; analyze statistical variation elements...

  9. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    OpenAIRE

    M. Fader; von Bloh, W.; Shi, S; A. Bondeau; Cramer, W.

    2015-01-01

    Climate and land use change in the Mediterranean region is expected to affect natural and agricultural ecosystems by decreases in precipitation, increases in temperature as well as biodiversity loss and anthropogenic degradation of natural resources. Demographic growth in the Eastern and Southern shores will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions ...

  10. Energia e sustentabilidade em agroecossistemas Energy and sustainability in agroecosystems

    Directory of Open Access Journals (Sweden)

    Gilberto Vilmar Kozioski

    2000-08-01

    factors, such as those associated to energy use. The objective of this review is to show some data about source and efficiency of energy use in animal and plant production and, moreover, about distribution ofits use in lhe wortd, relating this aspects to lhe sustainability of predominam food systems in the wortd and in Brazil. The main energy source presentty used in the productive process and in the ove rall food chain is derivedfrom petroleum, which worid reserves are limüed and estimated to exhaust around the middie ofthe next century. Moreover, the use of most part of the energy, and consequentiy most offood in the worid is produced and consumed by a small population in afew regions of the Northem Hemisphere. Finally, intensive production systems of animais and plants are more productive, but, on the other hand, are less efficient in te mis of energy use as comparta to less intensive systems. In Brazil, the greater part of plant and animal production come from intensive production systems and, moreover, plant systems are predominanfly of commercial and/or industrial character, m detrimental of alimentary systems. Thus, due to the great dependence of externai inputs, which are energy-expensive and exhaustíble. and to the food dependence and insecurity in Brcail, it is possible to consider Brazilian agroecosystems as fragile and unsustainable, needing a short temi revaluation as to public policies for this sector as well as to research objectives.

  11. AGROECOSYSTEMS SUSTAINABILITY OF CASSAVA PRODUCTION OF PARAÍBA RURAL AREA FROM THE PERSPECTIVE OF BIOGRAM

    Directory of Open Access Journals (Sweden)

    Valdenildo Pedro da Silva

    2015-08-01

    Full Text Available Agriculture modernization resulting from green revolution occurred through means of diverse technological innovations as soluble fertilizers, pesticides, agricultural machinery and genetically modified seeds, aimed at increasing food production. However, the indiscriminate use of these innovations by farmers has been highlighted numerous environmental problems, affecting the productive agricultural system. This technological innovations reality and environmental obstacles, is also been experienced by cassava production in Paraíba rural area. Therefore, this study tried to assess the agroecosystems sustainability of cassava production (Manihot esculenta Crantz of Paraíba Rural Mesoregion, using Sustainable Development Index (S³ method, and its graphical representation, the Biogram. The results showed sustainability differences between the agroecosystems of investigated municipalities, of which Araçagi showed stable levels of sustainability, Araruna and Bananeiras demonstrated unstable levels, and Puxinanã showed the most critical sustainably level. It was concluded that, even the agroecosystems of Araçagi municipality showing better levels of sustainability, when compared with other municipalities assessed, cassava production showed unsustainability situations regarding its technological innovation levels, average yield of cassava production, land in erosion process, water scarcity and lack of social participation.

  12. Migrant farmers as information brokers: agroecosystem management in the transition zone of Ghana

    Directory of Open Access Journals (Sweden)

    Marney E. Isaac

    2014-06-01

    Full Text Available Environmentally induced farmer migration is an important livelihood strategy, yet little is known of the effects on the destination region agroecosystem information networks and management practices. In the forest-savanna transition zone (Brong Ahafo Region of Ghana, where migration from northern regions (migrant and from neighboring regions (settler is active, we chart the role of migrant famers and the type of agroecosystem management practices embedded in information networks using a social networks approach. Based on empirical network data from 44 respondents across three communities, we illustrate a diffuse information network, with variable tie frequency between settlement categories (local, settler, or migrant of farmers. The cohesion of this network is dependent on a few strategic bridging ties initiated by migrant farmers, who are thus centrally positioned to exchange agroecosystem management practices between geographically and socially distant groups. At the individual level, migrant and settler farmers are more likely: (1 to have larger networks with more ties between members of their networks, (2 to be brokers positioned between non-migrant farmers, and (3 to tend (although not statistically significantly to use pro-environmental management regimes, including agroforestry practices, new planting methods, and plot-scale weeding. We conceptualize this phenomenon as extended social and environmental experience and the deployment of social-ecological memory, with migrant farmers as potential agents of innovation and adaptive management.

  13. Landscape Diversity as a Screening Tool to Assess Agroecosystems Sustainability; Preliminary Study in Central Italy

    Directory of Open Access Journals (Sweden)

    Francesco Visicchio

    2007-06-01

    Full Text Available Modernization of agricultural activities has strongly modified agricultural landscapes. Intensive agriculture, with the increased use of inorganic fertiliser and density of livestock, affects water quality discharging nutrients such as nitrogen and phosphorus in water bodies. Nutrients in rivers, subsequently, are excellent indicators to assess sustainability/ land-use intensity in agroecosystems. Landscape, however, is a dynamic system and is the product of interaction amongst the natural environment and human activities, including farming which is a main driving force. At present not much has been investigated on the predictive role of landscape on land-use intensity. Aim of this study is to determine if, in Italian agroecosystem, landscape complexity can be related to land-use intensity. Indexes of landscape complexity (i.e. edge density, number of patches, Shannon’s diversity index, Interspersion-Juxtaposition index derived by processing Corine Land Cover data (level IV, 1:25.000 of Lazio Region, were related with landuse intensity (values of compounds of nitrogen and phosphorus and other parameters found in rivers monitored in accordance to European Directives on Waste Water. Results demonstrate that some landscape indexes were related to some environment parameters. Consequently landscape complexity, with further investigation, could be an efficient screening tool, at large scale, to assess water quality and ultimately agroecosystems sustainability in the absence of monitoring stations.

  14. Characterization of agroecosystems with sheep production in the eastern side of Yucatán, Mexico.

    Directory of Open Access Journals (Sweden)

    Bernardino Candelaria-Martínez

    2015-06-01

    Full Text Available The aim of this study was to characterize and group agroecosystems with sheep production in the eastearn side of Yucatan, Mexico. This study was held from August 2012 to April 2013. A semi-structured questionnaire was applied while interviewing 93% of producers from seven municipalities that have sheep within their agroecosystems. Random sampling, cluster analysis, ANOVA using GLM and comparison of means by Tukey (P>0.05 were performed. Four different groups of agroecosystems with sheep production were obtained: GA (elderly people in charge, middle schooling, and high amount of land, large herds or more years practicing sheep farming, GB middle age people in charge, higher schooling, intermediate amount of land, and intermediate herd size, GC (elderly people in charge, less schooling, low amount of land and reduced herd size, and GD (younger people in charge, high schooling, low amount of land, small herd size and less time performing the activity. Sheep farming was the first, second, and third productive option for 12%, 75% and 11,8% of producers. In some cases, sheep production in the region has been practiced for over 15 years; however it is the economic priority only of a small group of producers. Access to resources determined their level of development and lack of organization among sheep producers is evident.

  15. Meteorological risks are drivers of environmental innovation in agro-ecosystem management

    Science.gov (United States)

    Gobin, Anne; Van de Vyver, Hans; Vanwindekens, Frédéric; Planchon, Viviane; Verspecht, Ann; Frutos de Cachorro, Julia; Buysse, Jeroen

    2016-04-01

    Extreme weather events such as droughts, heat waves and rain storms are projected to increase both in frequency and magnitude with climate change. The research hypothesis of the MERINOVA project is that meteorological risks act as drivers of environmental innovation in agro-ecosystem management which is being tested using a chain of risk approach. The project comprises of five major parts that reflect the chain of risks: the hazard, its impact on different agro-ecosystems, vulnerability, risk management and risk communication. Generalized Extreme Value (GEV) theory was used to model annual maxima of meteorological variables based on a location-, scale- and shape-parameter that determine the center of the distribution, the deviation of the location-parameter and the upper tail decay, respectively. Spatial interpolation of GEV-derived return levels has yielded maps of temperature extremes, precipitation deficits and wet periods. The degree of temporal overlap between extreme weather conditions and sensitive periods in the agro-ecosystem was determined using a bio-physically based modelling framework that couples phenological models, a soil water balance, crop growth and environmental models. 20-year return values for frost, heat stress, drought, waterlogging and field access during different crop stages were related to arable yields. The spatial extent of vulnerability is developed on different layers of spatial information that include inter alia meteorology, soil-landscapes, crop cover and management. The level of vulnerability and resilience of an agro-ecosystem is also determined by risk management. The types of agricultural risk and their relative importance differ across sectors and farm types as elucidated by questionnaires and focus groups. Risk types are distinguished according to production, market, institutional, financial and liability risks. A portfolio of potential strategies was identified at farm, market and policy level. In conclusion, MERINOVA

  16. Panarchy Rules: Rethinking Resilience of Agroecosystems, Evidence from Dutch Dairy-Farming

    Directory of Open Access Journals (Sweden)

    Tom (A.. Veldkamp

    2011-03-01

    Full Text Available Resilience has been growing in importance as a perspective for governing social-ecological systems. The aim of this paper is first to analyze a well-studied human dominated agroecosystem using five existing key heuristics of the resilience perspective and second to discuss the consequences of using this resilience perspective for the future management of similar human dominated agroecosystems. The human dominated agroecosystem is located in the Dutch Northern Frisian Woodlands where cooperatives of dairy farmers have been attempting to organize a transition toward more viable and environmental friendly agrosystems. A mobilizing element in the cooperatives was the ability of some dairy farmers to obtain high herbage and milk yield production with limited nitrogen fertilizer input. A set of reinforcing measures was hypothesized to rebalance nitrogen flows and to set a new equilibrium. A dynamic farm model was used to evaluate the long-term effects of reinforcing measures on soil organic matter content, which was considered the key indicator of an alternative system state. Simulations show that no alternative stable state for soil organic matter exists within a plausible range of fertilizer applications. The observed differences in soil organic matter content and nutrient use efficiency probably represent a time lag of long-term nonequilibrium system development. The resilience perspective proved to be especially insightful in addressing interacting long-term developments expressed in the panarchy. Panarchy created a heterogeneity of resources in the landscape providing local landscape-embedded opportunities for high N-efficiencies. Stopping the practice of grassland renewal will allow this ecological landscape embedded system to mature. In contrast, modern conventional dairy farms shortcut the adaptive cycle by frequent grassland renewals, resulting in high resilience and adaptability. This comes at the cost of long-term accumulated ecological

  17. The Platte River - High Plains Aquifer (PR-HPA) Long Term Agroecosystem Research (LTAR) Network - Data and Technological Resources to Address Current and Emerging Issues in Agroecosystems.

    Science.gov (United States)

    Okalebo, J. A.; Wienhold, B.; Suyker, A.; Erickson, G.; Hayes, M. J.; Awada, T.

    2015-12-01

    The Platte River - High Plains Aquifer (PR-HPA) is one of 18 established Long Term Agroecosystem Research (LTAR) networks across the US. PR-HPA is a partnership between the Institute of Agriculture and Natural Resources at the University of Nebraska-Lincoln (UNL), the USDA-ARS Agroecosystem Management Research Unit (AMRU) in Lincoln, and the USDA-ARS Environmental Management Research Unit (EMRU) in Clay Center, NE. The PR-HPA network encompasses 27,750 ha of research sites with data going back to the early 1900s. A partial list of on-going research projects include those encompassing long-term manuring and continuous corn (Est. 1912), dryland tillage plots (Est. 1970), soil nutrients and tillage (Est. 1983), biofuel feedstock studies (Est. 2001), and carbon sequestration study (Est. 2000). Affiliated partners include the National Drought Mitigation Center (NDMC) that develops measures to improve preparedness and adaptation to climate variability and drought; the High Plains Regional Climate Center (HPRCC) that coordinates data acquisition from over 170 automated weather stations and around 50 automated soil moisture network across NE and beyond; the AMERIFLUX and NEBFLUX networks that coordinate the water vapor and carbon dioxide flux measurements across NE with emphasis on rainfed and irrigated crop lands; the ARS Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet) and the Resilient Economic Agricultural Practices (REAP) project; and the Center for Advanced Land Management Information Technologies (CALMIT) that assists with the use of geospatial technologies for agriculture and natural resource applications. Current emphases are on addressing present-day and emerging issues related to profitability and sustainability of agroecosystems. The poster will highlight some of the ongoing and planned efforts in research pertaining to climate variability and change, water sustainability, and ecological and agronomic challenges associated

  18. Predicting the global warming potential of agro-ecosystems in Europe

    Science.gov (United States)

    Lehuger, S.; Gabrielle, B.; Chaumartin, F.

    2009-04-01

    Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to pedo-climatic conditions and crop management. The biophysical crop model CERES-EGC is designed to predict the productivity and GWP of agro-ecosystems at the plot-scale. Here we applied a Bayesian calibration to its both sub-models of N2O emissions and CO2 fluxes to deal with parameterization and uncertainty analysis. The N2O emission module of CERES-EGC was calibrated against chamber measurements from 7 arable sites in France and the CO2 flux module was calibrated against eddy-covariance measurements from 3 sites in Europe. Measurements from the various sites were assimilated in the posterior probability density functions for the different parameters, using a Bayesian calibration method based on the Metropolis-Hastings algorithm. The model was subsequently extrapolated to predict CO2 and N2O fluxes over entire crop rotations of 3 European experimental sites of the NitroEurope-IP network. Indirect GHG emissions arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming potential. The model would be extrapolated from plot- to regional-scale, with the ultimate goal of generating spatialized GHG inventories. Differentiating the emissions in space would thus make it possible to target critical zones in mitigation scenarios at regional scale.

  19. Ecosystem service trade-offs, perceived drivers, and sustainability in contrasting agroecosystems in central Mexico

    Directory of Open Access Journals (Sweden)

    2015-03-01

    Full Text Available The ability of agroecosystems to provide food ultimately depends on the regulating and supporting ecosystem services that underpin their functioning, such as the regulation of soil quality, water quality, soil erosion, pests, and pollinators. However, there are trade-offs between provisioning and regulating or supporting services, whose nature at the farm and plot scales is poorly understood. We analyzed data at the farm level for two agroecosystems with contrasting objectives in central Mexico: one aimed at staple crop production for self-subsistence and local markets, the other directed to a cash crop for export markets. Bivariate and multivariate trade-offs were analyzed for different crop management strategies (conventional, organic, traditional, crop rotation and their underpinning socioeconomic drivers. There was a clear trade-off between crop yield and soil quality in self-subsistence systems. However, other expected trade-offs between yields and soil quality did not always occur, likely because of the overall good soils of the region and the low to medium input profile of most farms. Trade-offs were highly dependent on farm-specific agricultural practices; organic, traditional, and rotation management systems generally showed smaller trade-offs between yield and soil quality, pest control, and biodiversity than did conventional management systems. Perceived drivers reported by farmers included increasing prices for cash crops, rising costs of inputs, and extreme climatic events (e.g., drought, hail, frost. Farmers did not identify the regulation of soil quality, water quality, soil erosion, pests, or pollinators as important constraints. Although acceptable yields could be maintained irrespective of key regulating and supporting services according to these perceptions, current levels of soil erosion and nutrient runoff are likely to have important negative effects at the watershed scale. Sustainability in both agroecosystems could be

  20. Socio-cultural and economic valuation of ecosystem services provided by Mediterranean mountain agroecosystems.

    Directory of Open Access Journals (Sweden)

    Alberto Bernués

    Full Text Available The aim of this work was to elucidate the socio-cultural and economic value of a number of ecosystem services delivered by mountain agroecosystems (mostly grazing systems in Euro-Mediterranean regions. We combined deliberative (focus groups and survey-based stated-preference methods (choice modelling to, first, identify the perceptions of farmers and other citizens on the most important ecosystem services and, second, to value these in economic terms according to the willingness to pay of the local (residents of the study area and general (region where the study area is located populations. Cultural services (particularly the aesthetic and recreational values of the landscape, supporting services (biodiversity maintenance and some regulating services (particularly fire risk prevention were clearly recognized by both farmers and citizens, with different degrees of importance according to their particular interests and objectives. The prevention of forest fires (≈50% of total willingness to pay was valued by the general population as a key ecosystem service delivered by these agroecosystems, followed by the production of specific quality products linked to the territory (≈20%, biodiversity (≈20% and cultural landscapes (≈10%. The value given by local residents to the last two ecosystem services differed considerably (≈10 and 25% for biodiversity and cultural landscape, respectively. The Total Economic Value of mountain agroecosystems was ≈120 € person(-1 year(-1, three times the current level of support of agro-environmental policies. By targeting and quantifying the environmental objectives of the European agri-environmental policy and compensating farmers for the public goods they deliver, the so-called "green" subsidies may become true Payments for Ecosystems Services.

  1. Socio-cultural and economic valuation of ecosystem services provided by Mediterranean mountain agroecosystems.

    Science.gov (United States)

    Bernués, Alberto; Rodríguez-Ortega, Tamara; Ripoll-Bosch, Raimon; Alfnes, Frode

    2014-01-01

    The aim of this work was to elucidate the socio-cultural and economic value of a number of ecosystem services delivered by mountain agroecosystems (mostly grazing systems) in Euro-Mediterranean regions. We combined deliberative (focus groups) and survey-based stated-preference methods (choice modelling) to, first, identify the perceptions of farmers and other citizens on the most important ecosystem services and, second, to value these in economic terms according to the willingness to pay of the local (residents of the study area) and general (region where the study area is located) populations. Cultural services (particularly the aesthetic and recreational values of the landscape), supporting services (biodiversity maintenance) and some regulating services (particularly fire risk prevention) were clearly recognized by both farmers and citizens, with different degrees of importance according to their particular interests and objectives. The prevention of forest fires (≈50% of total willingness to pay) was valued by the general population as a key ecosystem service delivered by these agroecosystems, followed by the production of specific quality products linked to the territory (≈20%), biodiversity (≈20%) and cultural landscapes (≈10%). The value given by local residents to the last two ecosystem services differed considerably (≈10 and 25% for biodiversity and cultural landscape, respectively). The Total Economic Value of mountain agroecosystems was ≈120 € person(-1) year(-1), three times the current level of support of agro-environmental policies. By targeting and quantifying the environmental objectives of the European agri-environmental policy and compensating farmers for the public goods they deliver, the so-called "green" subsidies may become true Payments for Ecosystems Services. PMID:25036276

  2. Action versus result-oriented schemes in a grassland agroecosystem: a dynamic modelling approach.

    Directory of Open Access Journals (Sweden)

    Rodolphe Sabatier

    Full Text Available Effects of agri-environment schemes (AES on biodiversity remain controversial. While most AES are action-oriented, result-oriented and habitat-oriented schemes have recently been proposed as a solution to improve AES efficiency. The objective of this study was to compare action-oriented, habitat-oriented and result-oriented schemes in terms of ecological and productive performance as well as in terms of management flexibility. We developed a dynamic modelling approach based on the viable control framework to carry out a long term assessment of the three schemes in a grassland agroecosystem. The model explicitly links grazed grassland dynamics to bird population dynamics. It is applied to lapwing conservation in wet grasslands in France. We ran the model to assess the three AES scenarios. The model revealed the grazing strategies respecting ecological and productive constraints specific to each scheme. Grazing strategies were assessed by both their ecological and productive performance. The viable control approach made it possible to obtain the whole set of viable grazing strategies and therefore to quantify the management flexibility of the grassland agroecosystem. Our results showed that habitat and result-oriented scenarios led to much higher ecological performance than the action-oriented one. Differences in both ecological and productive performance between the habitat and result-oriented scenarios were limited. Flexibility of the grassland agroecosystem in the result-oriented scenario was much higher than in that of habitat-oriented scenario. Our model confirms the higher flexibility as well as the better ecological and productive performance of result-oriented schemes. A larger use of result-oriented schemes in conservation may also allow farmers to adapt their management to local conditions and to climatic variations.

  3. Action versus result-oriented schemes in a grassland agroecosystem: a dynamic modelling approach.

    Science.gov (United States)

    Sabatier, Rodolphe; Doyen, Luc; Tichit, Muriel

    2012-01-01

    Effects of agri-environment schemes (AES) on biodiversity remain controversial. While most AES are action-oriented, result-oriented and habitat-oriented schemes have recently been proposed as a solution to improve AES efficiency. The objective of this study was to compare action-oriented, habitat-oriented and result-oriented schemes in terms of ecological and productive performance as well as in terms of management flexibility. We developed a dynamic modelling approach based on the viable control framework to carry out a long term assessment of the three schemes in a grassland agroecosystem. The model explicitly links grazed grassland dynamics to bird population dynamics. It is applied to lapwing conservation in wet grasslands in France. We ran the model to assess the three AES scenarios. The model revealed the grazing strategies respecting ecological and productive constraints specific to each scheme. Grazing strategies were assessed by both their ecological and productive performance. The viable control approach made it possible to obtain the whole set of viable grazing strategies and therefore to quantify the management flexibility of the grassland agroecosystem. Our results showed that habitat and result-oriented scenarios led to much higher ecological performance than the action-oriented one. Differences in both ecological and productive performance between the habitat and result-oriented scenarios were limited. Flexibility of the grassland agroecosystem in the result-oriented scenario was much higher than in that of habitat-oriented scenario. Our model confirms the higher flexibility as well as the better ecological and productive performance of result-oriented schemes. A larger use of result-oriented schemes in conservation may also allow farmers to adapt their management to local conditions and to climatic variations.

  4. Socio-cultural and economic valuation of ecosystem services provided by Mediterranean mountain agroecosystems.

    Science.gov (United States)

    Bernués, Alberto; Rodríguez-Ortega, Tamara; Ripoll-Bosch, Raimon; Alfnes, Frode

    2014-01-01

    The aim of this work was to elucidate the socio-cultural and economic value of a number of ecosystem services delivered by mountain agroecosystems (mostly grazing systems) in Euro-Mediterranean regions. We combined deliberative (focus groups) and survey-based stated-preference methods (choice modelling) to, first, identify the perceptions of farmers and other citizens on the most important ecosystem services and, second, to value these in economic terms according to the willingness to pay of the local (residents of the study area) and general (region where the study area is located) populations. Cultural services (particularly the aesthetic and recreational values of the landscape), supporting services (biodiversity maintenance) and some regulating services (particularly fire risk prevention) were clearly recognized by both farmers and citizens, with different degrees of importance according to their particular interests and objectives. The prevention of forest fires (≈50% of total willingness to pay) was valued by the general population as a key ecosystem service delivered by these agroecosystems, followed by the production of specific quality products linked to the territory (≈20%), biodiversity (≈20%) and cultural landscapes (≈10%). The value given by local residents to the last two ecosystem services differed considerably (≈10 and 25% for biodiversity and cultural landscape, respectively). The Total Economic Value of mountain agroecosystems was ≈120 € person(-1) year(-1), three times the current level of support of agro-environmental policies. By targeting and quantifying the environmental objectives of the European agri-environmental policy and compensating farmers for the public goods they deliver, the so-called "green" subsidies may become true Payments for Ecosystems Services.

  5. Pesticide residues and microbial contamination of water resources in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Studies on the water resources of the Muda rice growing areas revealed evidence of pesticide residues in the agroecosystem. While the cyclodiene endosulfan was found as a ubiquitous contaminant, the occurrence of other organochlorine insecticides was sporadic. The presence of 2,4-D, paraquat and molinate residues was also evident but the occurrence of these herbicides was seasonal. Residue levels of molinate were generally higher than those from the other herbicides. The problem of thiobencarb and carbofuran residues was not encountered. Analyses for microbial contamination revealed that the water resources were unfit for drinking; coliform counts were higher during certain periods of the year than others. (Author)

  6. Nitrous oxide emissions from intensively managed agroecosystems: the role of carbon inputs (Invited)

    Science.gov (United States)

    Castellano, M. J.; Iqbal, J.; Mitchell, D. C.; Basche, A.; Parkin, T.; Miguez, F.; Kaspar, T.

    2013-12-01

    In agroecosystems, many reports demonstrate a positive relationship between N2O emissions and N fertilizer inputs. This relationship has been incorporated into the IPCC model estimate of N2O emissions and implies that inorganic N availability limits N2O emissions. However, evidence indicates that denitrification accounts for most N2O emissions from agroecosystems and N2O production from denitrification requires reduced C in addition to oxidized N. Using two experiments and meta-analysis we highlight the potential importance of reduced carbon availability for N¬2O emissions from agroecosystems. Experiments were conducted in maize-based cropping systems, restored prairies and perennial vegetation buffers in Iowa, USA. These systems have high soil organic C (SOC) concentrations. In the first experiment, a cover crop preceding maize increased N2O emissions despite immobilizing large amounts of NO3. Laboratory incubations of these soils demonstrated that glucose, but not NO3, increased N2O emissions. Because the cover crop had no detectable effect on total or potentially mineralizable SOC, these results indicate that the relatively small cover crop C input increased N2O emissions from this system. In a second experiment that compared land uses (maize, restored prairies, and perennial vegetation buffers) with significant differences in total SOC (2.3, 2.8 and 3.0% C, respectively), 15N tracer application demonstrated the increase in SOC across land uses was associated with more complete denitrification to N2 rather than an increase in N immobilization or N2O emissions. Results from these experiments suggest a complex interaction between NO3 and potentially mineralizable C affects denitrification emissions of N2O and particularly the N2O/(N2+N2O) ratio: although a small plant-based C input increased N2O emissions in a NO3-rich soil, a larger long-term increase in total SOC reduced N2O emissions by decreasing the N2O/(N2+N2O) ratio. Consistent with our cover crop

  7. Soil monitoring in agro-ecosystems of high mountain zone in Quindio

    International Nuclear Information System (INIS)

    Were evaluated soil characteristics in 4 common agro-ecosystems of high mountain zone of Quindio department, soil forest exhibit better indicators that others systems. Low macro porosity and hydraulic conductivity were consequences more important of cattle ranching systems. In pinus plantations were registered lower value of organic matter, pH, interchanging bases, gravimetric moisture and microbial activity CO2. As a result of pinus establishment on pasture ground increase drainable porosity and hydraulic conductivity. In granadilla cultivation were lower organism diversity and structural stability

  8. Assessment of Groundwater Quality of Selected Inland Valley Agro-ecosystems for Irrigation in Southwest Nigeria

    Directory of Open Access Journals (Sweden)

    Olatunji S Aboyeji

    2015-10-01

    Full Text Available The study assessed the quality of groundwater of 6 inland valley (IV agro-ecosystems with a view to establishing their characteristics for cropping in the derived savannah of southwest Nigeria. Water samples were collected in piezometers during the rainy and dry seasons and analysed for physicochemical and heavy metal properties. Major water quality indices and comparison with stipulated standards were used to determine the usability of the waters for irrigation. The study showed that the waters were generally neutral to slightly alkaline, with the dominance structure of the major cations and anions in the order of Na+ > Ca2+ > K+ > Mg2+ and Cl- > SO42- > HCO3- > CO3. The concentration of heavy metals was generally within the recommended limits for most crops grown in the study area. Major water quality indices (sodium adsorption ratio, soluble sodium percentage, total dissolved solids, permeability index, magnesium adsorption ratio, Kelly’s ratio and residual sodium bicarbonate are generally within the levels acceptable for crop irrigation. Kruskal-Wallis H test (two-tailed showed that there was no statistically significant difference in the water quality parameters/indices between the inland valley sites, P = 0.935. The groundwater of inland valley agro-ecosystems of the study area is generally suitable for agricultural utilisation.DOI: http://dx.doi.org/10.5755/j01.erem.71.2.10802

  9. Land Use and Environmental Variability Impacts on the Phenology of Arid Agro-Ecosystems

    Science.gov (United States)

    Romo-Leon, Jose Raul; van Leeuwen, Willem J. D.; Castellanos-Villegas, Alejandro

    2016-02-01

    The overexploitation of water resources in arid environments often results in abandonment of large extensions of agricultural lands, which may (1) modify phenological trends, and (2) alter the sensitivity of specific phenophases to environmental triggers. In Mexico, current governmental policies subsidize restoration efforts, to address ecological degradation caused by abandonments; however, there is a need for new approaches to assess their effectiveness. Addressing this, we explore a method to monitor and assess (1) land surface phenology trends in arid agro-ecosystems, and (2) the effect of climatic factors and restoration treatments on the phenology of abandoned agricultural fields. We used 16-day normalized difference vegetation index composites from the moderate resolution imaging spectroradiometer from 2000 to 2009 to derive seasonal phenometrics. We then derived phenoclimatic variables and land cover thematic maps, to serve as a set of independent factors that influence vegetation phenology. We conducted a multivariate analysis of variance to analyze phenological trends among land cover types, and developed multiple linear regression models to assess influential climatic factors driving phenology per land cover analyzed. Our results suggest that the start and length of the growing season had different responses to environmental factors depending on land cover type. Our analysis also suggests possible establishment of arid adapted species (from surrounding ecosystems) in abandoned fields with longer times since abandonment. Using this approach, we were able increase our understanding on how climatic factors influence phenology on degraded arid agro-ecosystems, and how this systems evolve after disturbance.

  10. Comparison of Soil Biota Between Organic and Conventional Agroecosystems in Oregon, USA

    Institute of Scientific and Technical Information of China (English)

    WU Shan-Mei; HU Dun-Xiao; E. R. INGHAM

    2005-01-01

    Soil samples at 0-10 cm in depth were collected periodically at paired fields in Corvallis, Oregon, USA to compare differences in soil microbial and faunal populations between organic and conventional agroecosystems. Results showed that the organic soil ecosystem had a significantly higher (P < 0.05) average number or biomass of soil bacteria; densities of flagellates, amoebae of protozoa; some nematodes, such as microbivorous and predaceous nematodes and plant-parasitic nematodes; as well as Collembola. Greater numbers of Rhabditida (such as Rhabditis spp.), were present in the organic soil ecosystem while Panagrolaimus spp. were predominant in the conventional soil ecosystem. The omnivores and predators of Acarina in the Mesostigmata (such as Digamasellidae and Laelapid), and Prostigmata (such as Alicorhaiidae and Rhagidiidae), were also more abundant in the organic soil ecosystem. However, fungivorous Prostigmata (such as Terpnacaridae and Nanorchestidae) and Astigmata (such as Acarida) were significantly higher (P < 0.05) in the conventional soil ecosystem, which supported the finding that total fungal biomass was greater in the conventional soil ecosystem. Seansonal variations of the population depended mostly on soil moisture condition and food web relationship.The population declined from May to October for both agroecosystems. However, higher diversities and densities of soil biota survived occurred in the organic soil ecosystem in the dry season.

  11. Environmental Monitoring of Agro-Ecosystem Using Environmental Isotope Tracer Technology

    International Nuclear Information System (INIS)

    This report has provided the counterparts the knowledge and skills on the use of environmental isotope tracer technology for obtaining valuable information on agricultural non-point pollution source in agro-ecosystem. The contamination from agricultural watersheds has been brought into attention as a potential contaminant of streams and tributaries, since majority of them caused water quality degradation, eutrophication of reservoir and negative effect on agro-environment. To prevent the contamination from these watersheds, it is necessary to find out the source of the contamination. However, accurate contaminants outflows from various types of non-point sources have not yet been elucidated due to the fact that the extent of non-point source contaminants related to uncontrollable climatic events and irrigation conditions may differ greatly from place to place and year to year. The dominant use of isotopes in environmental ecosystem research in the last few decades has been to trace sources of waters and solutes. The environmental isotope tracer technology using stable isotopes such as oxygen, hydrogen, carbon, nitrogen, and sulfur has extensively been used for tracing the fate of environmental pollutants and for identification of environmental pollutants sources in agro-ecosystems

  12. Spatial and Temporal Variability of N, P and K Balances for Agroecosystems in China

    Institute of Scientific and Technical Information of China (English)

    SHEN Run-Ping; SUN Bo; ZHAO Qi-Guo

    2005-01-01

    Nitrogen, phosphorus, and potassium balances for agroecosystems in China from 1993 to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and temporal variabilities were analyzed with GIS to estimate the potential impacts of nutrient N, P and K surpluses or deficits to soil, water and air. At the national scale, the N and P balances from 1993 to 2001 showed a surplus, with the nitrogen surplus remaining relatively stable from 1997-2001. Although during this period the P surplus pattern was similar to N, it had smaller values and kept increasing as the use of phosphate fertilizer increased year by year. However, K was deficient from 1993 to 2001 even though from 1999 to 2001 the K deficit decreased. The spatial analysis revealed higher N surpluses in the more developed southeastern provinces and lowest in the western and northern provinces where there was less chemical fertilizer input. The serious K deficit mainly occurred in Shanghai and Beijing municipalities, Jiangsu, Zhejiang and Hubei provinces, and Xinjiang autonomous regions. For the years 1992, 1996 and 2001, N surpluses and K deficits had significant positive spatial correlations with per capita gross domestic product (GDP), per capita gross industrial output value, and per capita net income of rural households. This showed that the level of economic development played an important role on nutrient balances in the agroecosystems.

  13. Species Richness, Community Organization, and Spatiotemporal Distribution of Earthworms in the Pineapple Agroecosystems of Tripura, India

    Directory of Open Access Journals (Sweden)

    Animesh Dey

    2016-01-01

    Full Text Available The impact that plant communities may have on underground faunal diversity is unclear. Therefore, understanding the links between plants and organisms is of major interest. Earthworm population dynamics were studied in the pineapple agroecosystems of Tripura to evaluate the impact of monoculture plantation on earthworm communities. A total of thirteen earthworm species belonging to four families and five genera were collected from different sampling sites. Application of sample-based rarefaction curve and nonparametric richness estimators reveal 90–95% completeness of sampling. Earthworm community of pineapple agroecosystems was dominated by endogeic earthworms and Drawida assamensis was the dominant species with respect to its density, biomass, and relative abundance. Vertical distribution of earthworms was greatly influenced by seasonal variations. Population density and biomass of earthworms peaked during monsoon and postmonsoon period, respectively. Overall density and biomass of earthworms were in increasing trend with an increase in plantation age and were highest in the 30–35-year-old plantation. Significant decrease in the Shannon diversity and evenness index and increase in Simpson’s dominance and spatial aggregation index with an increase in the age of pineapple plantation were recorded. Soil temperature and soil moisture were identified as the most potent regulators of earthworm distribution in the pineapple plantation.

  14. Predictors of leafhopper abundance and richness in a coffee agroecosystem in Chiapas, Mexico.

    Science.gov (United States)

    Burdine, Justin D; Domínguez Martínez, Gabriel H; Philpott, Stacy M

    2014-04-01

    Coffee agroecosystems with a vegetatively complex shade canopy contain high levels of biodiversity. However, as coffee management is intensified, diversity may be lost. Most biodiversity studies in coffee agroecosystems have examined predators and not herbivores, despite their importance as potential coffee pests and coffee disease vectors. We sampled one abundant herbivore group of leafhoppers on an organic coffee farm in Chiapas, Mexico. We sampled leafhoppers with elevated pan traps in high- and moderate-shade coffee during the dry and wet seasons of 2011. The two major objectives were to 1) compare leafhopper abundance and richness during the wet and dry seasons and 2) examine the correlations between habitat characteristics (e.g., vegetation, elevation, and presence of aggressive ants) and leafhopper richness and abundance. We collected 2,351 leafhoppers, representing eight tribes and 64 morphospecies. Leafhopper abundance was higher in the dry season than in the wet season. Likewise, leafhopper richness was higher in the dry season. Several vegetation and other habitat characteristics correlated with abundance and richness of leafhoppers. The number of Inga trees positively correlated with leafhopper abundance, and other significant correlates of abundance included vegetation complexity. Leafhopper richness was correlated with the number of Inga trees. As leafhoppers transmit important coffee diseases, understanding the specific habitat factors correlating with changes in abundance and richness may help predict future disease outbreaks.

  15. Irrigation and Maize Cultivation Erode Plant Diversity Within Crops in Mediterranean Dry Cereal Agro-Ecosystems

    Science.gov (United States)

    Fagúndez, Jaime; Olea, Pedro P.; Tejedo, Pablo; Mateo-Tomás, Patricia; Gómez, David

    2016-07-01

    The intensification of agriculture has increased production at the cost of environment and biodiversity worldwide. To increase crop yield in dry cereal systems, vast farmland areas of high conservation value are being converted into irrigation, especially in Mediterranean countries. We analyze the effect of irrigation-driven changes on the farm biota by comparing species diversity, community composition, and species traits of arable plants within crop fields from two contrasting farming systems (dry and irrigated) in Spain. We sampled plant species within 80 fields of dry wheat, irrigated wheat, and maize (only cultivated under irrigation). Wheat crops held higher landscape and per field species richness, and beta diversity than maize. Within the same type of crop, irrigated wheat hosted lower plant diversity than dry wheat at both field and landscape scales. Floristic composition differed between crop types, with higher frequencies of perennials, cosmopolitan, exotic, wind-pollinated and C4 species in maize. Our results suggest that irrigation projects, that transform large areas of dry cereal agro-ecosystems into irrigated crop systems dominated by maize, erode plant diversity. An adequate planning on the type and proportion of crops used in the irrigated agro-ecosystems is needed in order to balance agriculture production and biodiversity conservation.

  16. Irrigation and Maize Cultivation Erode Plant Diversity Within Crops in Mediterranean Dry Cereal Agro-Ecosystems.

    Science.gov (United States)

    Fagúndez, Jaime; Olea, Pedro P; Tejedo, Pablo; Mateo-Tomás, Patricia; Gómez, David

    2016-07-01

    The intensification of agriculture has increased production at the cost of environment and biodiversity worldwide. To increase crop yield in dry cereal systems, vast farmland areas of high conservation value are being converted into irrigation, especially in Mediterranean countries. We analyze the effect of irrigation-driven changes on the farm biota by comparing species diversity, community composition, and species traits of arable plants within crop fields from two contrasting farming systems (dry and irrigated) in Spain. We sampled plant species within 80 fields of dry wheat, irrigated wheat, and maize (only cultivated under irrigation). Wheat crops held higher landscape and per field species richness, and beta diversity than maize. Within the same type of crop, irrigated wheat hosted lower plant diversity than dry wheat at both field and landscape scales. Floristic composition differed between crop types, with higher frequencies of perennials, cosmopolitan, exotic, wind-pollinated and C4 species in maize. Our results suggest that irrigation projects, that transform large areas of dry cereal agro-ecosystems into irrigated crop systems dominated by maize, erode plant diversity. An adequate planning on the type and proportion of crops used in the irrigated agro-ecosystems is needed in order to balance agriculture production and biodiversity conservation.

  17. Heavy-metal Balances, Part II. Management of cadmium, copper, lead, and zinc in European Agro-Ecosystems

    NARCIS (Netherlands)

    Moolenaar, S.W.

    2000-01-01

    The aim of sustainable heavy-metal management in agro-ecosystems is to ensure that the soil continues to fulfill its functions: in agricultural production, in environmental processes such as the cycling of elements, and as a habitat of numerous organisms. To understand and manage heavy-metal flows e

  18. Energetic efficiency of agroecosystems as an indicator of sustainability; Eficiencia energetica de agroecossistemas como indicador de sustentabilidade

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Osmar de Carvalho [Universidade Estadual Paulista Julio de Mesquita Filho (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas; Colen, Fernando [Universidade Federal de Minas Gerais (ICA/UFMG), Montes Claros, MG (Brazil). Inst. de Ciencias Agrarias; Campos, Alessandro Torres [Universidade Federal de Lavras (DEG/UFLA), MG (Brazil). Dept. de Engenharia

    2010-07-01

    The dependence of modern agriculture in relation to non-renewable energy sources became more pronounced over time. The intensive use of non-renewable energy in agroecosystems, especially fossil fuels, increased the physical output of food and raw materials, reducing the painfulness of work and the improvement of income in the sector. However, complex problems brought individually or in jail, which transformed human life in terms of ecological, social and economic development. It should build indexes in order to relate the inputs and outputs of energy in ecosystems. A breakthrough in the relationship between sustainability and energy analysis of farms is the use of energy efficiency index, the relationship between outputs and inputs of non-renewable energy in agroecosystems. This paper aims to present the energy efficiency of different agroecosystems. The results demonstrate the dependence of agroecosystems in relation to fossil energy sources. It was concluded that it is necessary to make efficient use of exhaustible natural resources, particularly fossil fuels. (author)

  19. Agrodiversity v.2: An educational simulation tool to address some challenges for sustaining functional agrodiversity in agro-ecosystems

    NARCIS (Netherlands)

    Speelman, E.N.; Garcia-Barrios, L.E.

    2010-01-01

    Functional agrodiversity can be useful and even essential for, i.e., the long-term sustainability of agriculture. However, still many aspects of this concept are not well understood. The interplay between species in diverse agro-ecosystems is based on processes as, i.e., competition, facilitation, a

  20. Sustainability indicators, alternative strategies and trade-offs in peasant agroecosystems : analysing 15 case studies from Latin America

    NARCIS (Netherlands)

    Astier, M.; Speelman, E.N.; López-Ridaura, S.; Masera, O.R.; Gonzalez-Esquivel, C.E.

    2011-01-01

    In view of the urgent need to improve agroecosystem sustainability, several efforts have been made to evaluate the effect of alternative strategies on key environmental and socioeconomic variables at the farm, community and regional levels. Most peasant farmers manage complex and diverse agroecosyst

  1. Productivity, Respiration, and Light-Response Parameters of World Grassland and Agroecosystems Derived From Flux-Tower Measurements

    NARCIS (Netherlands)

    Gilmanov, T.G.; Aires, L.; Barsca, V.; Baron, S.; Moors, E.J.; Jacobs, A.

    2010-01-01

    Grasslands and agroecosystems occupy one-third of the terrestrial area, but their contribution to the global carbon cycle remains uncertain. We used a set of 316 site-years of CO2 exchange measurements to quantify gross primary productivity, respiration, and light-response parameters of grasslands,

  2. Effects of synthetic fertilizer on coffee yields and ecosystem services: Soil glomalin and parasitoids in a Costa Rican coffee agroecosystem

    Science.gov (United States)

    We explored the relationships between synthetic fertilizer use, yield, and ecosystem services in a coffee agroecosystem in the Tarrazú region in the central highlands of Costa Rica. Working in nine farms ranging from 0.3 to 2.7ha in the CoopeTarrazú farmers' cooperative, we focused on two important ...

  3. The MERINOVA project: MEteorological RIsks as drivers of environmental inNOvation in Agro-ecosystem management

    Science.gov (United States)

    Gobin, Anne; Van de vijver, Hans; Zamani, Sepideh; Curnel, Yannick; Planchon, Viviane; Verspecht, Ann; Van Huylenbroeck, Guido

    2014-05-01

    Devastating weather-related events have captured the interest of the general public in Belgium. Extreme weather events such as droughts, heat waves and rain storms are projected to increase both in frequency and magnitude with climate change. Since more than half of the Belgian territory is managed by the agricultural sector, extreme events may have significant impacts on agro-ecosystem services and pose severe limitations to sustainable agricultural land management. The research hypothesis of the MERINOVA project is that meteorological risks act as drivers of environmental innovation in agro-ecosystem management. The major objectives are to characterise extreme meteorological events, assess the impact on Belgian agro-ecosystems, characterise their vulnerability and resilience to these events, and explore innovative adaptation options to agricultural risk management. The project comprises of five major parts that reflect the chain of risks: the hazard, its impact on different agro-ecosystems, vulnerability, risk management and risk communication. Impacts developed from physically based models not only provide information on the state of the damage at any given time, but also assist in understanding the links between different factors causing damage and determining bio-physical vulnerability. Socio-economic impacts enlarge the basis for vulnerability mapping, risk management and adaptation options. The perspective of rising risk-exposure is exacerbated further by more limits to aid received for agricultural damage and an overall reduction of direct income support to farmers. The main findings of each of these project building blocks will be communicated. MERINOVA provides for a robust and flexible framework by demonstrating its performance across Belgian agro-ecosystems, and by ensuring its relevance to policy makers and practitioners. A strong expert and end-user network is established to help disseminating and exploiting project results to meet user needs. The

  4. CO2 Fluxes Monitoring at the Level of Field Agroecosystem in Moscow Region of Russia

    Science.gov (United States)

    Meshalkina, Joulia; Mazirov, Ilya; Samardzic, Miljan; Yaroslavtsev, Alexis; Valentini, Riccardo; Vasenev, Ivan

    2014-05-01

    The Central Russia is still one of the less GHG-investigated European areas especially in case of agroecosystem-level carbon dioxide fluxes monitoring by eddy covariance method. The eddy covariance technique is a statistical method to measure and calculate vertical turbulent fluxes within atmospheric boundary layers. The major assumption of the metod is that measurements at a point can represent an entire upwind area. Eddy covariance researches, which could be considered as repeated for the same area, are very rare. The research has been carried out on the Precision Farming Experimental Field of the Russian Timiryazev State Agricultural University (Moscow, Russia) in 2013 under the support of RF Government grant No. 11.G34.31.0079. Arable derno-podzoluvisls have around 1 The results have shown high daily and seasonal dynamic of agroecosystem CO2 emission. Sowing activates soil microbiological activity and the average soil CO2 emission and adsorption are rising at the same time. CO2 streams are intensified after crop emerging from values of 3 to 7 μmol/s-m2 for emission, and from values of 5 to 20 μmol/s-m2 for adsorption. Stabilization of the flow has come at achieving plants height of 10-12 cm. The vegetation period is characterized by high average soil CO2 emission and adsorption at the same time, but the adsorption is significantly higher. The resulted CO2 absorption during the day is approximately 2-5 times higher than emissions at night. For example, in mid-June, the absorption value was about 0.45 mol/m2 during the day-time, and the emission value was about 0.1 mol/m2 at night. After harvesting CO2 emission is becoming essentially higher than adsorption. Autumn and winter data are fluctuate around zero, but for some periods a small predominance of CO2 emissions over the absorption may be observed. The daily dynamics of CO2 emissions depends on the air temperature with the correlation coefficient changes between 0.4 and 0.8. Crop stage, agrotechnological

  5. Energy consumption, greenhouse gas emissions and assessment of sustainability index in corn agroecosystems of Iran

    International Nuclear Information System (INIS)

    The objectives of this study were to assess the energy flow, greenhouse gas (GHG) emission, global warming potential (GWP) and sustainability of corn production systems in Kermanshah province, western Iran. The data were collected from 70 corn agroecosystems which were selected based on randomly sampled method in the summer of 2011. The results indicated that total input and output energy were 50,485 and 134,946 MJ ha−1, respectively. The highest share of total input energy in corn production systems was recorded for N fertilizer, electricity power and diesel fuel with 35, 25 and 20%, respectively. Energy use efficiency and energy productivity were 2.67 and 0.18 kg MJ−1, respectively. Also agrochemical energy ratio was estimated as 40%. Applying chemical inputs produced the following emissions of greenhouse gases: 2994.66 kg CO2, 31.58 kg N2O and 3.82 kg CH4 per hectare. Hence, total GWP was 12,864.84 kg Co2eq ha−1 in corn production systems. In terms of CO2 equivalents 23% of the GWPs came from CO2, 76% from N2O, and 1% from CH4. In this study input and output C equivalents per total GHG and Biomass production were 3508.59 and 10,696.34 kg C ha−1. Net carbon and sustainability indexes in corn production systems were 7187.75 kg C ha−1 and 2.05. Accordingly, efficient use of energy is essential to reduce the greenhouse gas emissions and environmental impact in corn agroecosystems. - Highlights: • Increasing of energy consumption leaded to decreasing energy use efficiency in corn agroecosystems. • Total greenhouse gas (GHG) emission as CO2, N2O and CH4 in corn production systems were 2994.66, 31.58 and 3.82 kg ha-1, respectively. • Global warming potential (GWP) was 12864.84 kg CO2eq ha-1 in corn production systems. • Sustainability index in corn production systems was 2.05. • Reducing use of chemicals fertilizer and diesel fuel are necessary for better management of energy flow, global warming potential and environmental crises

  6. Energy consumption, greenhouse gas emissions and assessment of sustainability index in corn agroecosystems of Iran

    Energy Technology Data Exchange (ETDEWEB)

    Yousefi, Mohammad, E-mail: m.yousefi@pgs.razi.ac.ir [Department of Agronomy and Plant Breeding, Campus of Agriculture and Natural Resources, Razi University, Kermanshah (Iran, Islamic Republic of); Damghani, Abdolmajid Mahdavi [Departments of Agroecology, Environmental Sciences Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Khoramivafa, Mahmud [Department of Agronomy and Plant Breeding, Campus of Agriculture and Natural Resources, Razi University, Kermanshah (Iran, Islamic Republic of)

    2014-09-15

    The objectives of this study were to assess the energy flow, greenhouse gas (GHG) emission, global warming potential (GWP) and sustainability of corn production systems in Kermanshah province, western Iran. The data were collected from 70 corn agroecosystems which were selected based on randomly sampled method in the summer of 2011. The results indicated that total input and output energy were 50,485 and 134,946 MJ ha{sup −1}, respectively. The highest share of total input energy in corn production systems was recorded for N fertilizer, electricity power and diesel fuel with 35, 25 and 20%, respectively. Energy use efficiency and energy productivity were 2.67 and 0.18 kg MJ{sup −1}, respectively. Also agrochemical energy ratio was estimated as 40%. Applying chemical inputs produced the following emissions of greenhouse gases: 2994.66 kg CO{sub 2,} 31.58 kg N{sub 2}O and 3.82 kg CH{sub 4} per hectare{sub .} Hence, total GWP was 12,864.84 kg Co{sub 2}eq ha{sup −1} in corn production systems. In terms of CO{sub 2} equivalents 23% of the GWPs came from CO{sub 2}, 76% from N{sub 2}O, and 1% from CH{sub 4}. In this study input and output C equivalents per total GHG and Biomass production were 3508.59 and 10,696.34 kg C ha{sup −1}. Net carbon and sustainability indexes in corn production systems were 7187.75 kg C ha{sup −1} and 2.05. Accordingly, efficient use of energy is essential to reduce the greenhouse gas emissions and environmental impact in corn agroecosystems. - Highlights: • Increasing of energy consumption leaded to decreasing energy use efficiency in corn agroecosystems. • Total greenhouse gas (GHG) emission as CO{sub 2}, N{sub 2}O and CH{sub 4} in corn production systems were 2994.66, 31.58 and 3.82 kg ha{sup -1}, respectively. • Global warming potential (GWP) was 12864.84 kg CO{sub 2}eq ha{sup -1} in corn production systems. • Sustainability index in corn production systems was 2.05. • Reducing use of chemicals fertilizer and diesel fuel

  7. Hydrogeochemistry of the Overland Flow in Soil at Agroecosystems in Eastern Amazon

    Science.gov (United States)

    Costa, C. F. G. D.; Figueiredo, R. O.; Oliveira, F. D. A.

    2014-12-01

    In the watershed of the Timboteua and Buiuna streams, northeast of Pará state, Amazon, it was characterized the overland flow dissolved material by some hydrogeochemical variables: electrical conductivity (EC), pH, chloride (Cl-), nitrate (NO3-), phosphate (PO43-), and sulfate (SO42-). In two small holder properties three overland flow experimental plots (1m2) were placed in each of the six evaluated ecosystems under similar biophysical conditions, totaling 18 plots. There was also installed three rainwater collectors and two rain gauges in a nearby area. In the rainy season were collected 234 samples of rainwater and overland flow. The evaluation of the measured variables promote the hydrogeochemical characterization of the overland flow at soil under chop-and-mulch and slash-and-burn practices in the different ecosystems found in the familiar agriculture of this watershed, in which it was identified some distinct hydrogeochemical characteristics of the overland flow. The lowest losses of NO3- (variation range = 0.07 to 2.57 μM) was found in agroecosystem - chop-and-mulch, this nutrient obtained higher values in agroecosystem - slash-and-burn (RQ). In agroecosystem (RQ) initially, there was a high value of PO43- (8.87 μM); EC (121 μS cm-1) and a subsequent sharp decline. Secondary successional forest (CP) of 20 years presented in overland flow pH 4.8 and EC 25 μS cm-1 (average 6 months), low loss of NO3- (0.2 μM) and PO43- (0.05 μM), and large range of variation of SO42- (0.7 to 21.5 μM). While Cl- and SO42- overland flow concentrations were affect by the rainfall variation, the increase of NO3- and PO43-concentrations were more related to the ecosystem management, with the first element responding to the presence of nitrogen-fixing species and the second responding to the burning practices. In summary: This study was efficient to characterize the hydrogeochemical of the overland flow and its relation to the altered ecosystems by Amazonian family farming.

  8. Food resource and temporal partitioning amongst a guild of predatory agroecosystem-inhabiting ant species

    Institute of Scientific and Technical Information of China (English)

    Vivek Mohan AGARWAL; Neelkamal RASTOGI

    2009-01-01

    Prey diversity and temporal foraging patterns of six abundant, predatory ant species were investigated seasonally in an ngroeeosystem with two main vegetable crops. Pheidole sp. demonstrated the highest predation success and therefore appears to be the dominant species while Tapinoma melanocephalum showed the lowest success under the natural field conditions. Investigation of prey diversity and temporal activity patterns with the null model tests of niche overlap revealed a significant overlap indicating that the activity periods and prey diversity may not be solely influenced by interactions among the co-existing ant species. However, niche partitioning in the daily peak activity periods was demonstrated during all the three seasons (summer, rainy and winter) particularly between Pheidole sp. and T. melanocephalum. Pheidole sp. exhibited a high intensity, broadly extended mono-modal foraging pattern. Camponotus compressus and C. paria showed bi-modality in their foraging activity during the rainy season and mono-modal patterns during summer and winter seasons. Pachycondyla tesserinoda, Tetramorium sp. and T. melanocephalum exhibited peak foraging activities in the morning hours during the summer and rainy seasons. The activity profiles of C. compressus and T. melanocephalum were skewed towards late afternoon hours during the winter season indicating avoidance of foraging activity during the favourable periods when the more aggressive Phe/do/e sp. is active. In the sponge gourd agroecosystem, the ants captured predominantly hymenopteran, orthopteran and eoleopteran insects. While Pheidole sp. hunted mainly the large orthopteran prey, other ant species captured worker ants in the sponge gourd ngroeeosystem. In the cauliflower ngroecosystem, while other species captured prey chiefly belonging to six orders, i. e., Lepidoptera, Hymenoptera, Coleoptera, Hemiptera, Isoptera and Diptera, Pheidole sp. and P. tesserinoda were the only species to also hunt many orthopteran

  9. Considerations in miniaturizing simplified agro-ecosystems for advanced life support

    Science.gov (United States)

    Volk, T.

    1996-01-01

    Miniaturizing the Earth's biogeochemical cycles to support human life during future space missions is the goal of the NASA research and engineering program in advanced life support. Mission requirements to reduce mass, volume, and power have focused efforts on (1) a maximally simplified agro-ecosystem of humans, food crops, and microbes; and, (2) a design for optimized productivity of food crops with high light levels over long days, with hydroponics, with elevated carbon dioxide and other controlled environmental factors, as well as with genetic selection for desirable crop properties. Mathematical modeling contributes to the goals by establishing trade-offs, by analyzing the growth and development of experimental crops, and by pointing to the possibilities of directed phasic control using modified field crop models to increase the harvest index.

  10. Effects of CO2 gas as leaks from geological storage sites on agro-ecosystems

    DEFF Research Database (Denmark)

    Patil, Ravi; Colls, Jeremy J; Steven, Michael D

    2010-01-01

    Carbon capture and storage in geological formations has potential risks in the long-term safety because of the possibility of CO2 leakage. Effects of leaking gas, therefore, on vegetation, soil, and soil-inhabiting organisms are critical to understand. An artificial soil gassing and response....... This study showed adverse effects of CO2 gas on agro-ecosystem in case of leakage from storage sites to surface....... detection field facility developed at the University of Nottingham was used to inject CO2 gas at a controlled flow rate (1 l min-1) into soil to simulate build-up of soil CO2 concentrations and surface fluxes from two land use types: pasture grassland, and fallow followed by winter bean. Mean soil CO2...

  11. A multivariate analysis for evaluating the environmental and economical aspects of agroecosystem sustainability in central Italy.

    Science.gov (United States)

    Di Felice, Vincenzo; Mancinelli, Roberto; Proulx, Raphaël; Campiglia, Enio

    2012-05-15

    Over the past century farming activity has intensified worldwide, characterized by an increasing dependence on external inputs and on land conversion. Although the intensification of agriculture has increased productivity, the sustainability of agroecosystems has also been compromised. The objective of this study is to build multivariate relationships between farm structural characteristics and farm performance to highlight the relative costs and benefits of four main farming systems in Central Italy: organic, conventional, mixed and non-mixed farms. Results show that the relationship between cropping diversity and agroecological sustainability is associated to a mixed versus non-mixed farm management dichotomy, not to organic or conventional farming practices. The presence of livestock appears to have played an important role as an economic lever for diversifying the farm cropping system. PMID:22265812

  12. Advances in Nitrogen Denitrification and N2O Emission in Agro-ecosystem

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-shu; DING Hong; QIN Sheng-jin

    2011-01-01

    Nitrification and denitrification are two key links of nitrogen flow cycle in soil. N2O and N2, generated from biochemical process of nitrogen, can cause not only the nitrogen losses and reduction of nitrogen use efficiency, but also the boosted concentration of greenhouse gases,severely endangering the environment. Accordingly, nitrification-denitrification has been more and more concerned from whether an agricultural view, or an environmental one. Referring to the related literatures published at home and abroad in recent years, we overviewed the denitrification-caused N loss and N2O emission in various agro-ecosystems, and based on which we put forward countermeasures to reduce the denitrification-caused N loss and N2O emission and its research prospects in the future.

  13. Emergy signature as a basis for sustainability valuation of agro-ecosystems

    DEFF Research Database (Denmark)

    Ghaley, Bhim Bahadur; Montesino San Martin, Manuel; Porter, John Roy

    Traditionally, research and advisory service had focused on increasing crop yield and improving the efficiency of the production systems for bringing down he price of food. However, the environmental and ecological costs are not taken into account which has a significant bearing of the long term ......, moisture and biomass production. The study proposes a need for balance of intensive agriculture to produce enough food and CFE-like systems to maintain the ecosystem services required for the continued provision of food, fodder and energy needs of the growing world population....... the boundaries of the production systems and calculating the emergy indices. The results reveal that the innovative agroecosystems, exemplified by CFE, are less resources demanding and amenable to local environments and helps conserve the ecosystem services in terms of sustainable supply of soil nutrients...

  14. AGRO-ECOSYSTEMS AND SUSTAINABLE DEVELOPMENT OF WATER RESOURCES IN ARGES RIVER BASIN

    Directory of Open Access Journals (Sweden)

    Tatiana Diaconu

    2010-01-01

    Full Text Available Lotic ecosystems, part of the Natural Capital, is one of the key factors functioning of socio - economic development andtheir support. An important role in their sustainable development, is the retention and recycling of nutrients, especiallyN, P and their compounds. The nutrients in lotic and lentic ecosystems are either due to natural biochemical processesor by human impact of pollution or broadcast process and characterize the ecological status of water bodies and thuscan determine the quality of services provided. A special importance have agro-ecosystems, particularly multifunctionallivestock farms. Pathways by which pollutants (especially nutrients and pesticides, and other pollutants to reach bodiesof water are different (surface drainage, percolation, etc..To ensure sustainable development of water resources is necessary for agricultural development to take place in termsof minimizing waste streams and not affect the production and support of NC.

  15. Nutrient Cycling and Balance in Red Soil Agroecosystem and Their Management

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An experiment was conducted in a red soil derived from Quaternary red clay in the Ecological Experiment Station of Red Soil, the Chinese Academy of Sciences, located in Yingtan (28°15' 30" N, 116°55' 30" E), Jiangxi Province. The results show that the major ways of nutrient loss are leaching and nitrogen volatilization. Rationalizing crop distribution, stimulating nutrient recycling, and improving internal nutrient flow are effective measures to decrease nutrient loss and to promote nutrient utilization efficiency. The important ways of regulating nutrient cycling and balance in the agroecosystem of the red soil are to establish optimal eco-agricultural models, practice balanced fertilization and combine the cropping system with the livestock system.

  16. Application of Reduced Corn Cultivation Technology in Agro-Ecosystem of Cazin Municipality

    Directory of Open Access Journals (Sweden)

    Mirsad Veladžić

    2011-03-01

    Full Text Available Intensive corn cultivation is predominant in current agriculture of the Una-Sana Canton. One of the corn cultivation methods in agro-ecosystem is reduced cultivation. The paper presents the experiment of “Osmak žuti” (eight-row yellow corn cultivation on two control sites with application of reduced and intensive cultivation in Cazin municipality. The objectives of this research were to examine the possibility of application of reduced corn cultivation; analyze statistical variation elements (length, circumference and weight of corn cob; and determine cost effectiveness of reduced relative to intensive production. The results indicate extremely high statistically significant difference (p<0.001 for all parameters in both cultivation methods. The cost effectiveness of reduced relative to intensive cultivation of Osmak žuti corn is higher by 36%. The experiment encourages introduction of reduced corn cultivation practice.

  17. Future rainfall variations reduce abundances of aboveground arthropods in model agroecosystems with different soil types

    Directory of Open Access Journals (Sweden)

    Johann G. Zaller

    2014-10-01

    Full Text Available Climate change scenarios for Central Europe predict less frequent but heavier rainfalls and longer drought periods during the growing season. This is expected to alter arthropods in agroecosystems that are important as biocontrol agents, herbivores or food for predators (e.g. farmland birds. In a lysimeter facility (totally 18 3-m2-plots, we experimentally tested the effects of long-term past vs. prognosticated future rainfall variations (15% increased rainfall per event, 25% more dry days according to regionalized climate change models from the Intergovernmental Panel on Climate Change (IPCC on aboveground arthropods in winter wheat (Triticum aestivum L. cultivated at three different soil types (calcaric phaeozem, calcic chernozem and gleyic phaeozem. Soil types were established 17 years and rainfall treatments one month before arthropod sampling; treatments were fully crossed and replicated three times. Aboveground arthropods were assessed by suction sampling, their mean abundances (± SD differed between April, May and June with 20 ± 3 m-2, 90 ± 35 m-2 and 289 ± 93 individuals m-2, respectively. Averaged across sampling dates, future rainfall reduced the abundance of spiders (Araneae, -47%, cicadas and leafhoppers (Auchenorrhyncha, -39%, beetles (Coleoptera, -52%, ground beetles (Carabidae, -41%, leaf beetles (Chrysomelidae, -64%, spring tails (Collembola, -58%, flies (Diptera, -73% and lacewings (Neuroptera, -73% but increased the abundance of snails (Gastropoda, +69%. Across sampling dates, soil types had no effects on arthropod abundances. Arthropod diversity was neither affected by rainfall nor soil types. Arthropod abundance was positively correlated with weed biomass for almost all taxa; abundance of Hemiptera and of total arthropods was positively correlated with weed density. These detrimental effects of future rainfall varieties on arthropod taxa in wheat fields can potentially alter arthropod-associated agroecosystem services.

  18. Challenges in the Measurement of Antibiotics and in Evaluating Their Impacts in Agroecosystems: A Critical Review.

    Science.gov (United States)

    Aga, Diana S; Lenczewski, Melissa; Snow, Daniel; Muurinen, Johanna; Sallach, J Brett; Wallace, Joshua S

    2016-03-01

    Large quantities of antibiotics are used in agricultural production, resulting in their release to agroecosystems through numerous pathways, including land application of contaminated manure, runoff from manure-fertilized fields, and wastewater irrigation of croplands. Antibiotics and their transformation products (TPs) exhibit a wide range of physico-chemical and biological properties and thus present substantive analytical challenges. Advances in the measurement of these compounds in various environmental compartments (plants, manure, soil, sediment, and water) have uncovered a previously unrealized landscape of antibiotic residues. These advanced multiresidue methods, designed to measure sub-ng g concentrations in complex mixtures, remain limited by the inherent intricacy of the sample matrices and the difficultly in eliminating interferences that affect antibiotic detection. While efficient extraction methods combined with high sensitivity analysis by liquid chromatography/mass spectrometry can provide accurate quantification of antibiotics and their TPs, measured concentrations do not necessarily reflect their bioavailable fractions and effects in the environment. Consequently, there is a need to complement chemical analysis with biological assays that can provide information on bioavailability, biological activity, and effects of mixtures. Enzyme-linked immunosorbent assays (ELISA), often used as screening tools for antibiotic residues, may be useful for detecting the presence of structurally related antibiotic mixtures but not their effects. Other tools, including bioreporter assays, hold promise in measuring bioavailable antibiotics and could provide insights on their biological activity. Improved assessment of the ecological and human health risks associated with antibiotics in agroecosystems requires continued advances in analytical accuracy and sensitivity through improvements in sample preparation, instrumentation, and screening technologies.

  19. Bacteria isolated from a sugarcane agroecosystem: their potential production of polyhydroxyalcanoates and resistance to antibiotics

    Directory of Open Access Journals (Sweden)

    Lima Teresa Cristina S. de

    1999-01-01

    Full Text Available In this investigation, a sugarcane agroecosystem at a coastal tableland, in the northeast of Brazil, was screened to obtain bacteria strains able to synthesize poly-b-hydroxyalkanoates (PHA, using sucrose as the main carbon source. The potential to synthesize PHA was tested qualitatively by Sudan Black staining of colonies growing in different carbon sources: sucrose, glucose, fructose, propionate and cellulose. In a typical sugarcane crop management system, the plantation is burned before harvesting and vinasse, a byproduct of alcohol production, is used in a fertirrigation system causing, probably, selective pressures on the microbiota of natural environments. Eightytwo bacteria strains, belonging to 16 different genera and 35 different species, were isolated. The data showed that 11 strains (ca 13%, nine of which belonging to the genus Pseudomonas, presented a strong Sudan Black staining in several carbon sources tested and, simultaneously, showed multiple resistance to antibiotics. Resistance to antibiotics is an advantageous feature for the biotechnological production of PHAs. The total number of isolates with multiple resistance to antibiotics was 73, and 38% of them belong to the genus Pseudomonas. Among the isolates, ca 86% and 43% grew in the presence of 10-100 U/ml of penicillin and/or 100-300 mg/ml of virginiamycin, respectively. These antibiotics are utilized in the alcohol distillery we investigated. The results suggest that some agroecosystem environments could be considered as habitats where bacteria are submitted to nutritional unbalanced conditions, resulting in strains with potential ability to produce PHAs, and also, to an increase in the microbial diversity.

  20. Ecology of Glossina species inhabiting peridomestic agroecosystems in relation to options for tsetse fly control

    International Nuclear Information System (INIS)

    Unbaited blue biconical traps were used to sample populations of Glossina once a week from April 1984 to March 1988 in three peridomestic agroecosystems of the Nsukka area, Nigeria. Serological analysis of 1764 fly midgut contents revealed that G. tachinoides had fed on reptiles, birds and mammals, with the domestic pig accounting for 88.08% of the 730 identifiable bloodmeals. The frequency distribution of flies in various stages of the trophic cycle showed that males and females feed at 2.88 ± 0.42 and 2.43 ± 0.44 day intervals, respectively. Flies were caught in greater numbers in biotopes containing domestic pigs, while the presence of man depressed trap catches. The larger the pig population in an agroecosystem, the larger the G. tachinoides population. However, reduction in the pig population to below five triggered the collapse of one of the G. tachinoides populations, which disappeared following the removal of all the pigs. The fly populations exhibited marked seasonal fluctuations in apparent density, largely caused by routine agronomic practices. These density fluctuations undermine recruitment of new adults into the population, especially during the wet season. It is suggested that tsetse populations in this area, already being kept at low density by routine agricultural procedures, could be further reduced by combining insecticides impregnated traps or targets with insect proofing of the piggeries. Methods aimed at undermining the recruitment of young adults into tsetse populations, capitalizing on naturally occurring sex ratio distortion as well as on maintaining populations of preferred hosts of the tsetse fly at low levels, should form part of integrated tsetse control packages. Selection of sterile male release sites and the number of sterile males to be released in them during sterile insect technique campaigns should take into account the sex ratio dynamics of target tsetse populations. 28 ref, 9 figs, 8 tabs

  1. Understanding soil erosion impacts in temperate agroecosystems: bridging the gap between geomorphology and soil ecology

    Directory of Open Access Journals (Sweden)

    C. Baxter

    2013-04-01

    Full Text Available Soil is a key asset of natural capital, providing a myriad of goods and ecosystem services that sustain life through regulating, supporting and provisioning roles, delivered by chemical, physical and biological processes. One of the greatest threats to soil is accelerated erosion, which raises a natural process to unsustainable levels, and has downstream consequences (e.g. economic, environmental and social. Global intensification of agroecosystems is a major cause of soil erosion which, in light of predicted population growth and increased demand for food security, will continue or increase. Elevated erosion and transport is common in agroecosystems and presents a multi-disciplinary problem with direct physical impacts (e.g. soil loss, other less tangible impacts (e.g. loss of ecosystem productivity, and indirect downstream effects that necessitate an integrated approach to effectively address the problem. Climate is also likely to increase susceptibility of soil to erosion. Beyond physical response, the consequences of erosion on soil biota have hitherto been ignored, yet biota play a fundamental role in ecosystem service provision. To our knowledge few studies have addressed the gap between erosion and consequent impacts on soil biota. Transport and redistribution of soil biota by erosion is poorly understood, as is the concomitant impact on biodiversity and ability of soil to deliver the necessary range of ecosystem services to maintain function. To investigate impacts of erosion on soil biota a two-fold research approach is suggested. Physical processes involved in redistribution should be characterised and rates of transport and redistribution quantified. Similarly, cumulative and long-term impacts of biota erosion should be considered. Understanding these fundamental aspects will provide a basis upon which mitigation strategies can be considered.

  2. Use of N immobilization to tighten the N cycle in conventional agroecosystems.

    Science.gov (United States)

    McSwiney, Claire P; Snapp, Sieglinde S; Gentry, Lowell E

    2010-04-01

    Soils in conventional agroecosystems are purposely held in a nitrogen (N)-saturated state to maximize crop yields. Planting winter annual cover crops when fields are usually fallow has been proposed to ameliorate N losses from soils. In this study we introduced winter annual cover crops into an N rate study with plots fertilized at 0, 34, 67, 101, 134, 168, and 202 kg N/ha in maize (Zea mays L.) to determine how winter annual cover crops affect yields, N2O and NO3- fluxes, and N pools. At the six-leaf stage and during flowering, incorporation of cover crop into soil resulted in a 30% reduction in maize biomass. Three weeks after fertilization, KCl-extractable soil mineral N was 75-87% lower in covercropped soils than in no-cover soils, indicating that N had been immobilized in the covercropped soils. At physiological maturity, there was no difference between cover and no-cover treatments in crop yield, which was maximized at 9 Mg/ha in 2006 and 7 Mg/ha in 2007. Where N rates exceed crop requirements, cover crop incorporation may reduce N exports as NO3- and N2O. Tighter N cycling in conventional agroecosystems could be fostered by matching N rates to the amount of N removed with grain and using N immobilization to retain N and support yields. If N immobilization is viewed as a means for efficient fertilizer N use rather than a process that decreases crop productivity, growers might be more willing to adopt cover-cropping practices.

  3. A survey of pesticide usage in the MUDA rice agroecosystem between 2001 and 2003

    International Nuclear Information System (INIS)

    Pesticides are widely used in rice granary area to protect crops against pests, weeds and diseases. It is the most common chemicals that come in contact with human population, fauna and flora so much so that its misuse may affect human health and agroecosystem. A survey on pesticide usage by rice farmer in the Muda Rice Agroecosystem was carried out between 2001 and 2003 at sir sites that include recycled area (3) and non-recycled area (3). A total of 65 respondents were interviewed using two sets of questionnaire. In 2001, a preliminary questionnaire was used to survey the pesticide input. In 2003, a modified questionnaire was used which also include the pest problem, farmer's background and cost and purchase of pesticide. The most frequently used pesticide per respondent was herbicide (65%), followed by insecticide (33%), fungicides (I %) and molluscicide (1%). The study has identified a total of 32 different types of pesticide that include 15 insecticides, 15 herbicides, 1 fungicide and 1 molluscicide. Results showed that 80% and 78.5% of respondent preferred Rumputax and Nurelle 5050 to control weed and insect, respectively. Most respondents spent RM100-500 per season (58%) to buy pesticide, followed by more than RM1000 (201196), RM600-1000 (15%) and less than RM100 (7%). Results show that 71% of pesticides were bought from shop and only 29% ftom the Muda Agricultural Development Authority (MADA). The farmers' background results showed that 52% of respondents were from 51 years and above age group, 22% (41-50 years), 18% (31-40 years) and 8% (21-30 years). Only 56% of respondents have attended the pesticide application and safety course even though 71% of respondents have been planting rice for more than 21 years. This course should be carried out more often to give a wider impact on crop protection and productivity, including the farmers health. (Author)

  4. Understanding soil erosion impacts in temperate agroecosystems: bridging the gap between geomorphology and soil ecology

    Science.gov (United States)

    Baxter, C.; Rowan, J. S.; McKenzie, B. M.; Neilson, R.

    2013-04-01

    Soil is a key asset of natural capital, providing a myriad of goods and ecosystem services that sustain life through regulating, supporting and provisioning roles, delivered by chemical, physical and biological processes. One of the greatest threats to soil is accelerated erosion, which raises a natural process to unsustainable levels, and has downstream consequences (e.g. economic, environmental and social). Global intensification of agroecosystems is a major cause of soil erosion which, in light of predicted population growth and increased demand for food security, will continue or increase. Elevated erosion and transport is common in agroecosystems and presents a multi-disciplinary problem with direct physical impacts (e.g. soil loss), other less tangible impacts (e.g. loss of ecosystem productivity), and indirect downstream effects that necessitate an integrated approach to effectively address the problem. Climate is also likely to increase susceptibility of soil to erosion. Beyond physical response, the consequences of erosion on soil biota have hitherto been ignored, yet biota play a fundamental role in ecosystem service provision. To our knowledge few studies have addressed the gap between erosion and consequent impacts on soil biota. Transport and redistribution of soil biota by erosion is poorly understood, as is the concomitant impact on biodiversity and ability of soil to deliver the necessary range of ecosystem services to maintain function. To investigate impacts of erosion on soil biota a two-fold research approach is suggested. Physical processes involved in redistribution should be characterised and rates of transport and redistribution quantified. Similarly, cumulative and long-term impacts of biota erosion should be considered. Understanding these fundamental aspects will provide a basis upon which mitigation strategies can be considered.

  5. Use of N immobilization to tighten the N cycle in conventional agroecosystems.

    Science.gov (United States)

    McSwiney, Claire P; Snapp, Sieglinde S; Gentry, Lowell E

    2010-04-01

    Soils in conventional agroecosystems are purposely held in a nitrogen (N)-saturated state to maximize crop yields. Planting winter annual cover crops when fields are usually fallow has been proposed to ameliorate N losses from soils. In this study we introduced winter annual cover crops into an N rate study with plots fertilized at 0, 34, 67, 101, 134, 168, and 202 kg N/ha in maize (Zea mays L.) to determine how winter annual cover crops affect yields, N2O and NO3- fluxes, and N pools. At the six-leaf stage and during flowering, incorporation of cover crop into soil resulted in a 30% reduction in maize biomass. Three weeks after fertilization, KCl-extractable soil mineral N was 75-87% lower in covercropped soils than in no-cover soils, indicating that N had been immobilized in the covercropped soils. At physiological maturity, there was no difference between cover and no-cover treatments in crop yield, which was maximized at 9 Mg/ha in 2006 and 7 Mg/ha in 2007. Where N rates exceed crop requirements, cover crop incorporation may reduce N exports as NO3- and N2O. Tighter N cycling in conventional agroecosystems could be fostered by matching N rates to the amount of N removed with grain and using N immobilization to retain N and support yields. If N immobilization is viewed as a means for efficient fertilizer N use rather than a process that decreases crop productivity, growers might be more willing to adopt cover-cropping practices. PMID:20437954

  6. Energy efficiency of the cotton agroecosystem on familiar agriculture explorations; Eficiencia energetica do agroecossistema algodao em exploracoes agricolas familiares

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Maria Gloria Cabrera [UNESP, Botucatu, SP (Brazil). Faculdade de Ciencias Agronomicas. Programa de Pos-graduacao em Agronomia. Energia na Agricultura]. E-mail: gloriac@fca.unesp.br; Bueno, Osmar de Carvalho [UNESP, Botucatu, SP (Brazil). Faculdade de Ciencias Agronomicas. Dept. de Gestao e Tecnologia Agroindustrial]. E-mail: Osmar@fca.unesp.br

    2006-07-01

    The aim of this study was to assess the energy efficiency indexes per unit of cotton agroecosystem area. As the focal point of this research, family exploitation is analyzed, with the use of the categorization done by the National Program for Strengthening Family Agriculture (Programa Nacional de Fortalecimento da Agricultura Familiar - PRONAF). Use was made of primary and secondary data from three family exploitations in the municipality of Leme/SP, Brazil. To construct the energy expenditure structure of the cotton agro-ecosystem, the mean values obtained were considered, since these agriculturalists present the same technical itinerary and are within the typification proposed in this study. The energy efficiency was obtained through the making of structure by type, source, form and gross energy. (author)

  7. Monitoring for the use of experimental and natural radionuclides in soil-plant complex of agroecosystem near Issyk-Kul

    International Nuclear Information System (INIS)

    In the present work has researched the levels of accumulation experimental and natural radionuclides in the soil-plant and some agricultural plants of agroecosystems near Issyk-Kul. Technological development has caused global environmental problems. Radioactive pollution is harmful problem for human and animal health. Besides all types of technogenic radiation we are exposed, mankind are aware that there in danger because of naturally sources of radioactivity

  8. Assessing and monitoring impacts of genetically modified plants on agro-ecosystems: the approach of AMIGA project

    OpenAIRE

    Arpaia, S.; Messéan, A.; Birch, N. A.; Hokannen, H.; Härtel, S.; van Loon, J.; Lovei, G.; Park, J.; H. Spreafico; Squire, G R; Steffan-Dewenter, I.; Tebbe, C.; van der Voet, H.

    2014-01-01

    The environmental impacts of genetically modified crops is still a controversial issue in Europe. The overall risk assessment framework has recently been reinforced by the European Food Safety Authority(EFSA) and its implementation requires harmonized and efficient methodologies. The EU-funded research project AMIGA − Assessing and monitoring Impacts of Genetically modified plants on Agro-ecosystems − aims to address this issue, by providing a framework that establishes protection goals and b...

  9. Indirect effects of Argentine ant and honeydew-producing insect mutualisms on California red scale in a citrus agroecosystem

    OpenAIRE

    Kizner, Michelle Cara

    2010-01-01

    In San Diego County, a major economic impact of the Argentine ant occurs in citrus agroecosystems, where ants interfere with biological control of key insect pests, especially California red scale. Ant control is considered a critical component of integrated pest management (IPM) of several citrus pests, but IPM recommendations fail to consider quantitative relationships between levels of Argentine ant abundance and those of the economic pests. This serious gap in understanding impedes develo...

  10. Effects of irrigated agroecosystems: 2. Quality of soil water and groundwater in the southern High Plains, Texas

    Science.gov (United States)

    Scanlon, B. R.; Gates, J. B.; Reedy, R. C.; Jackson, W. A.; Bordovsky, J. P.

    2010-09-01

    Trade-offs between water-resource depletion and salinization need to be understood when promoting water-conservative irrigation practices. This companion paper assesses impacts of groundwater-fed irrigation on soil water and groundwater quality using data from the southern High Plains (SHP). Unsaturated zone soil samples from 13 boreholes beneath irrigated agroecosystems were analyzed for water-extractable anions. Salt accumulation in soils varies with irrigation water quality, which ranges from low salinity in the north (median Cl: 21 mg/L) to higher salinity in the south (median Cl: 180 mg/L). Large Cl bulges under irrigated agroecosystems in the south are similar to those under natural ecosystems, but they accumulated over decades rather than millennia typical of natural ecosystems. Profile peak Cl concentrations (1200-6400 mg/L) correspond to irrigation efficiencies of 92-98% with respect to drainage and are attributed to deficit irrigation with minimal flushing. Perchlorate (ClO4) also accumulates under irrigated agroecosystems, primarily from irrigation water, and behaves similarly to Cl. Most NO3-N accumulation is below the root zone. Groundwater total dissolved solids (TDS) have increased by ≤960 mg/L and NO3-N by ≤9.4 mg/L since the early 1960s. Mobilization of salts that have accumulated under irrigated agroecosystems is projected to degrade groundwater much more in the future because of the essentially closed-basin status of the aquifer, with discharge occurring primarily through irrigation pumpage. TDS are projected to increase by an additional 2200 mg/L (median), ClO4 by 21 μg/L, and NO3-N by 52 mg/L. Water and salt balances should be considered in irrigation management in order to minimize salinization issues.

  11. Impacts of biogas projects on agro-ecosystem in rural areas-A case study of Gongcheng

    Institute of Scientific and Technical Information of China (English)

    Jin YANG; Weichao CHEN; Bin CHEN

    2011-01-01

    The rapid growth of agro-ecosystem has been the focus of "New Rural Construction" in China due to intensive energy consumption and environmental pollution in rural areas.As a kind of renewable energy,biogas is helpful for new energy development and plays an important role in the sustainable development of agroecosystem in China.To evaluate the effects of biogas on agro-ecosystem from a systematic angle,we discussed the status quo of household biogas and identified its main factors that may have impacts on agro-ecosystem.An indicator framework covering environmental,social and economic aspects was established to quantify the impacts exerted by biogas project on agro-ecosystem.A case study of Gongcheng was then conducted to evaluate the combined impact of biogas project using the proposed indicator framework.Results showed that there was a notable positive effect brought by the application of biogas,and the integrated benefit has been significantly improved by 60.36%,implying that biogas as a substitute energy source can promote the sustainable level of rural areas.

  12. The unmanaged reproductive ecology of domesticated plants in traditional agroecosystems: An example involving cassavaand a call for data

    Science.gov (United States)

    Elias, Marianne; McKey, Doyle

    2000-05-01

    Although cassava is a strictly vegetatively propagated crop, in many traditional Amazonian agroecosystems, Amerindian farmers recognise volunteer seedlings of cassava and allow them to grow. If their properties are deemed desirable, plants originating from seedlings are included in the harvest of tuberous roots, and their stems are used to prepare cuttings for propagation. Incorporation of these products of spontaneous sexual reproduction appears to be important in origin and maintenance of genetic diversity in this clonally propagated plant. Our observations conducted in an Amerindian village in Guyana suggest that volunteer seedlings arise from a bank of viable seeds stored in soil, and that dispersal and burial of seeds by ants may be important in its constitution. Future investigations of the dynamics of genetic diversity in this crop in traditional agroecosystems must consider the role of the 'wild' sexual reproduction that occurs in parallel with vegetative propagation. We suggest that unmanaged processes of sexual reproduction play important but neglected roles in the evolutionary ecology of many domesticated plants in traditional agroecosystems.

  13. Assessing and monitoring impacts of genetically modified plants on agro-ecosystems: the approach of AMIGA project

    Directory of Open Access Journals (Sweden)

    S. Arpaia

    2014-06-01

    Full Text Available The environmental impacts of genetically modified crops is still a controversial issue in Europe. The overall risk assessment framework has recently been reinforced by the European Food Safety Authority(EFSA and its implementation requires harmonized and efficient methodologies. The EU-funded research project AMIGA − Assessing and monitoring Impacts of Genetically modified plants on Agro-ecosystems − aims to address this issue, by providing a framework that establishes protection goals and baselines for European agro-ecosystems, improves knowledge on the potential long term environmental effects of genetically modified (GM plants, tests the efficacy of the EFSA Guidance Document for the Environmental Risk Assessment, explores new strategies for post market monitoring, and provides a systematic analysis of economic aspects of Genetically Modified crops cultivation in the EU. Research focuses on ecological studies in different EU regions, the sustainability of GM crops is estimated by analysing the functional components of the agro-ecosystems and specific experimental protocols are being developed for this scope.

  14. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    Science.gov (United States)

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  15. The Nitrogen Balance of Three Long-term Agroecosystems on a Boreal Soil in Western Canada

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Shirley M.; Izaurralde, Roberto C.; Janzen, H. H.; Robertson, J. A.; Mcgill, William B.

    2008-09-01

    Nitrogen (N) budgets can be used to quantify the flows of N in agroecosystems and to account for differences in losses and retention of N. The objective of our study was to develop 24-year N budgets for three diverse cropping systems on a boreal soil at Breton, Alberta, Canada: AER an agroecological 8-year rotation, with N inputs from legumes [fababean (Vicia faba L.), red clover (Trifolium pratense L.), alfalfa (Medicago sativa L.)] and manure; CF - a continuous perennial grass legume forage system, with N inputs from fertilizer (18 kg N ha-1 yr-1) and white clover (Trifolium repens L.); and CG - a continuous annual grain system, with N fertilizer (90 kg N ha-1 yr-1). We were able to compile detailed N budgets, demonstrate accumulation of soil N, and attribute differences in N flow and permanence to treatment effects. For AER and CG, net inputs almost exactlymatched gains in soil N. The AER system had the highest N flow and the largest net N accumulation. Soil total N mass to 30 cm depth increased in all systems during 1980 2005, but increases were smaller in CG (0.59 Mg N ha-1) than in AER (1.90 Mg N ha-1) and CF (1.63 Mg N ha-1), showing the effect of legumes, perennial species, and manure in the latter systems. The proportion of total N inputs retained as soil N with organic N inputs in AER (44%) was about twice that with synthetic N fertilizer in CG (23%). The CF system had the lowest productivity and the least N loss to the environment (4 kg N ha-1 yr-1, compared to 28 for AER and 24 for CG). The proportion of N inputs lost to the environment was 16% for AER and 24% for CG. In CF, gains of soil N exceeded apparent net N inputs, perhaps because we under-estimated N inputs from clover. Estimate of legume N input was one of the larger sources of uncertainty. The study affirmed the value of N budgets in evaluating agroecosystem performance, and identified AER and CF as productive and sustainable systems due to their minimal reliance on external N inputs and small

  16. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    Science.gov (United States)

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  17. Spatio-temporal variation in malaria transmission intensity in five agro-ecosystems in Mvomero district, Tanzania

    Directory of Open Access Journals (Sweden)

    Leonard E. G. Mboera

    2010-05-01

    Full Text Available In Africa, malaria is predominantly a rural disease where agriculture forms the backbone of the economy. Various agro-ecosystems and crop production systems have an impact on mosquito productivity, and hence malaria transmission intensity. This study was carried out to determine spatial and temporal variations in anopheline mosquito population and malaria transmission intensity in five villages, representing different agro-ecosystems in Mvomero district, Tanzania, so as to provide baseline information for malaria interventions. The agro-ecosystems consisted of irrigated sugarcane, flooding rice irrigation, non-flooding rice irrigation, wet savannah and dry savannah. In each setting, adult mosquitoes were sampled monthly using Centers for Disease Control and Prevention (CDC light traps from August 2004 to July 2005. A total of 35,702 female mosquitoes were collected. Anopheles gambiae sensu lato was the most abundant (58.9% mosquito species. An. funestus accounted for 12.0% of the mosquitoes collected. There was a substantial village to village variation and seasonality in the density of Anopheles mosquito population, with peaks in May towards the end of the warm and rainy season. Significantly larger numbers of anophelines were collected from traditional flooding rice irrigation ecosystem (70.7% than in non-flooding rice irrigation (8.6%, sugarcane (7.0%, wet savannah (7.3% and dry savannah (6.4%. The overall sporozoite rates for An. gambiae and An. funestus were 3.4% and 2.3%, respectively. The combined overall sporozoite rate (An. gambiae+An. funestus was 3.2%. The mean annual entomological inoculation rate (EIR for An. gambiae s.l. was 728 infective bites per person per year and this was significantly higher in traditional flooding rice irrigation (1351 than in other agro-ecosystems. The highest EIRs for An. gambiae s.l. and An. funestus were observed during May 2005 (long rainy season and December 2004 (short rainy season, respectively. The

  18. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems

    Directory of Open Access Journals (Sweden)

    Marjorie Bonareri Oruru

    2016-01-01

    Full Text Available Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers’ needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF, a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility.

  19. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems.

    Science.gov (United States)

    Oruru, Marjorie Bonareri; Njeru, Ezekiel Mugendi

    2016-01-01

    Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers' needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF), a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility. PMID:26942194

  20. Diversity and Dynamics of Soil Free-Living Nematode Populations in a Mediterranean Agroecosystem

    Institute of Scientific and Technical Information of China (English)

    LIANG Wen-Ju; I.LAVIAN; S.PEN-MOURATOV; Y.STEINBERGER

    2005-01-01

    To determine the effect of agricultural management on the dynamics and functional diversity of soil nematode communities in a carrot field at Kibbutz Ramat Hakovesh, Israel, soil samples from 0-10 cm and 10-20 cm depths were collected during the growing season of carrot. Indices were used to compare and assess the response of soil free-living nematode communities to agricultural management. Eighteen nematode families and 20 genera were observed during the growing period, with Cephalobus, Rhabditidae, Aphelenchus, Tylenchus, and Dorylaimus being the dominant genera/families.During the planting, mid-season and post-harvest periods the total number of nematodes at both depths was significantly lower (P < 0.01) in the carrot treatment than in the control plots, while during the harvest period at both depths total nematodes and bacterivores were significantly higher in the treatment plots (P < 0.01). The values of the maturity index (MI) at both depths were found to be significantly lower in the treatment plots than in the control plots during the pre-planting period (P < 0.05). Overall, WI, MI and PPI were found to be more sensitive indicators than other ecological indices for assessing the response of nematode communities to agricultural management in a Mediterranean agroecosystem.

  1. The Role of the Bacterial Community of an Agroecosystem in Simazine Degradation

    Directory of Open Access Journals (Sweden)

    Anna Barra Caracciolo

    Full Text Available The use of pesticides and fertilizers in agricultural practice is the main source of soil and groundwater contamination. S-Triazines are among the most used herbicides in the world for selective weed control in several types of crops. The homeostatic capability of an agroecosystem to remove a triazinic herbicide, simazine, was assessed in microcosms treated with the herbicide in presence/absence of urea fertilizer. The latter, as well as a fertilizer, is also one of the last by-products before simazine mineralization. The biodegradation, in terms of disappearance of 50% of the initial concentration (DT50, was compared to the degradation and metabolite formation occurring in sterilized soil. Moreover, the bacterial community response was assessed in terms of abundance and community structure by the epifluorescence direct count method and fluorescence in situ hybridization. The results show that the microbial community has a primary role in simazine degradation and that this process is due to the presence of a microbial pool working in succession and of which the metabolism may be modulated by exogenous sources of nitrogen, like urea. The latter influences the degradative pathway with a greater formation and accumulation of the desethyl-simazine metabolite, which is a hazardous contaminant of soil and groundwater ecosystems, as well as its parent compound.

  2. The Role of the Bacterial Community of an Agroecosystem in Simazine Degradation

    Directory of Open Access Journals (Sweden)

    Roberto Ciccoli

    2011-02-01

    Full Text Available The use of pesticides and fertilizers in agricultural practice is the main source of soil and groundwater contamination. S-Triazines are among the most used herbicides in the world for selective weed control in several types of crops. The homeostatic capability of an agroecosystem to remove a triazinic herbicide, simazine, was assessed in microcosms treated with the herbicide in presence/absence of urea fertilizer. The latter, as well as a fertilizer, is also one of the last by-products before simazine mineralization. The biodegradation, in terms of disappearance of 50% of the initial concentration (DT50, was compared to the degradation and metabolite formation occurring in sterilized soil. Moreover, the bacterial community response was assessed in terms of abundance and community structure by the epifluorescence direct count method and fluorescence in situ hybridization. The results show that the microbial community has a primary role in simazine degradation and that this process is due to the presence of a microbial pool working in succession and of which the metabolism may be modulated by exogenous sources of nitrogen, like urea. The latter influences the degradative pathway with a greater formation and accumulation of the desethyl-simazine metabolite, which is a hazardous contaminant of soil and groundwater ecosystems, as well as its parent compound.

  3. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems

    Science.gov (United States)

    Oruru, Marjorie Bonareri; Njeru, Ezekiel Mugendi

    2016-01-01

    Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers' needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF), a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility. PMID:26942194

  4. Seasonal infestations of two stem borers (Lepidoptera: Crambidae) in noncrop grasses of Gulf Coast rice agroecosystems.

    Science.gov (United States)

    Beuzelin, J M; Mészáros, A; Reagan, T E; Wilson, L T; Way, M O; Blouin, D C; Showler, A T

    2011-10-01

    Infestations of two stem borers, Eoreuma loftini (Dyar) and Diatraea saccharalis (F.) (Lepidoptera: Crambidae), were compared in noncrop grasses adjacent to rice (Oryza sativa L.) fields. Three farms in the Texas rice Gulf Coast production area were surveyed every 6-8 wk between 2007 and 2009 using quadrat sampling along transects. Although D. saccharalis densities were relatively low, E. loftini average densities ranged from 0.3 to 5.7 immatures per m(2) throughout the 2-yr period. Early annual grasses including ryegrass, Lolium spp., and brome, Bromus spp., were infested during the spring, whereas the perennial johnsongrass, Sorghum halepense (L.) Pers., and Vasey's grass, Paspalum urvillei Steud., were infested throughout the year. Johnsongrass was the most prevalent host (41-78% relative abundance), but Vasey's grass (13-40% relative abundance) harbored as much as 62% of the recovered E. loftini immatures (during the winter). Young rice in newly planted fields did not host stem borers before June. April sampling in fallow rice fields showed that any available live grass material, volunteer rice or weed, can serve as a host during the spring. Our study suggests that noncrop grasses are year-round sources of E. loftini in Texas rice agroecosystems and may increase pest populations.

  5. A modelling methodology to assess the effect of insect pest control on agro-ecosystems.

    Science.gov (United States)

    Wan, Nian-Feng; Ji, Xiang-Yun; Jiang, Jie-Xian; Li, Bo

    2015-01-01

    The extensive use of chemical pesticides for pest management in agricultural systems can entail risks to the complex ecosystems consisting of economic, ecological and social subsystems. To analyze the negative and positive effects of external or internal disturbances on complex ecosystems, we proposed an ecological two-sidedness approach which has been applied to the design of pest-controlling strategies for pesticide pollution management. However, catastrophe theory has not been initially applied to this approach. Thus, we used an approach of integrating ecological two-sidedness with a multi-criterion evaluation method of catastrophe theory to analyze the complexity of agro-ecosystems disturbed by the insecticides and screen out the best insect pest-controlling strategy in cabbage production. The results showed that the order of the values of evaluation index (RCC/CP) for three strategies in cabbage production was "applying frequency vibration lamps and environment-friendly insecticides 8 times" (0.80) controlling strategy in cabbage production in Shanghai, China. PMID:25906199

  6. Species composition and seasonal abundance of sandflies (Diptera: Psychodidae: Phlebotominae in coffee agroecosystems

    Directory of Open Access Journals (Sweden)

    Jeanneth Perez

    2014-02-01

    Full Text Available The composition and seasonal occurrence of sandflies were investigated in coffee agroecosystems in the Soconusco region of Chiapas, Mexico. Insect sampling was performed on three plantations located at different altitudes: Finca Guadalupe Zajú [1,000 m above sea level (a.s.l.], Finca Argovia (613 m a.s.l. and Teotihuacán del Valle (429 m a.s.l.. Sandflies were sampled monthly from August 2007-July 2008 using three sampling methods: Shannon traps, CDC miniature light traps and Disney traps. Sampling was conducted for 3 h during three consecutive nights, beginning at sunset. A total of 4,387 sandflies were collected during the course of the study: 2,718 individuals in Finca Guadalupe Zajú, 605 in Finca Argovia and 1,064 in Teotihuacán del Valle. The Shannon traps captured 94.3% of the total sandflies, while the CDC light traps and Disney traps captured 4.9% and 0.8%, respectively. More females than males were collected at all sites. While the number of sandflies captured was positively correlated with temperature and relative humidity, a negative correlation was observed between sandfly numbers and rainfall. Five species of sandflies were captured: Lutzomyia cruciata , Lutzomyia texana , Lutzomyia ovallesi , Lutzomyia cratifer / undulata and Brumptomyia sp. Lu. cruciata , constituting 98.8% of the total, was the most abundant species. None of the captured sandflies was infected with Leishmania spp.

  7. Abnormalities in amphibian populations inhabiting agroecosystems in Northeastern Buenos Aires Province, Argentina.

    Science.gov (United States)

    Agostini, M G; Kacoliris, F; Demetrio, P; Natale, G S; Bonetto, C; Ronco, A E

    2013-05-27

    The occurrence of abnormalities in amphibians has been reported in many populations, and its increase could be related to environmental pollution and habitat degradation. We evaluated the type and prevalence of abnormalities in 5 amphibian populations from agroecosystems with different degrees of agricultural disturbance (cultivated and reference areas). We detected 9 types of abnormalities, of which the most frequent were those occurring in limbs. The observed prevalence of abnormality in assessed populations from cultivated and reference areas was as follows: Rhinella fernandezae (37.1 and 10.2%, respectively), Leptodactylus latrans adults (28.1 and 9.2%) and juveniles (32.9 and 15.3%), and Hypsiboas pulchellus (11.6 and 2.8%). Scinax granulatus populations did not show abnormalities. Pseudis minuta, which was only detected in the reference area, exhibited a prevalence of 13.3%. For R. fernandezae, L. latrans, and H. pulchellus, generalized linear mixed models showed that prevalence of abnormalities was significantly higher (p ponds of the cultivated area, no data are currently available on how other factors, such as injuries from predators and parasite infections, vary by land use. Further research will be necessary to evaluate possible causes of abnormalities detected in the present study mainly in the context of factor interactions. PMID:23709469

  8. PROFILE: Tourism Contribution to Agro-Ecosystems Conservation: The Case of Lesbos Island, Greece.

    Science.gov (United States)

    Loumou; Giourga; Dimitrakopoulos; Koukoulas

    2000-10-01

    / The modernization of agriculture and the development of other economic sectors have prompted the abandonment of cultivated areas, which are marginally productive. Specifically, olive groves in Greece are transformed into pastures due to their location in inaccessible mountainous regions where breeding and raising of sheep and goats are the main economic activities. Overgrazing degrades the environment, exhausts natural resources, and prevents natural regeneration. The Greek islands have limited possibilities of development, except for their coastal areas where the growth of tourism is possible.The objective of this study was to investigate the impact of tourism activities on olive tree cultivation and the human population of the island of Lesbos. The presence or absence of tourism is related with the maintenance or abandonment of olive tree cultivation and population changes for each community. A spatial segregation of the island is evident, related to tourist development, olive tree cultivation, and population change. The results of the study demonstrate that in communities where tourism plays an important role olive tree cultivation is preserved and the population is stable. The preservation of the agro-ecosystem is assured while the olive groves remain productive. Simultaneously, the landscape, which provides specific attractions for tourism, is not altered.

  9. Conservation of Agroecosystem through Utilization of Parasitoid Diversity: Lesson for Promoting Sustainable Agriculture and Ecosystem Health

    Directory of Open Access Journals (Sweden)

    DAMAYANTI BUCHORI

    2008-12-01

    Full Text Available For many years, agricultural intensification and exploitation has resulted in biodiversity loss and threaten ecosystem functioning. Developing strategies to bridge human needs and ecosystem health for harmonization of ecosystem is a major concern for ecologist and agriculturist. The lack of information on species diversity of natural enemies and how to utilize them with integration of habitat management that can renovate ecological process was the main obstacle. Parasitoids, a group of natural enemies, play a very important role in regulating insect pest population. During the last ten years, we have been working on exploration of parasitoid species richness, how to use it to restore ecosystem functions, and identifying key factors influencing host-parasitoid interaction. Here, we propose a model of habitat management that is capable of maintaining agricultural biodiversity and ecosystem functions. We present data on parasitoid species richness and distribution in Java and Sumatera, their population structure and its impact toward biological control, relationship between habitat complexes and parasitoid community, spatial and temporal dynamic of parasitoid diversity, and food web in agricultural landscape. Implications of our findings toward conservation of agroecosystem are discussed.

  10. Diversity, abundance and conservation of birds in an agroecosystem in the Ica desert, Peru

    Directory of Open Access Journals (Sweden)

    Letty Salinas

    2013-05-01

    Full Text Available Present work investigates the impact of the agricultural activity in the Peruvian coast on the biodiversity of birds. The study includes the monitoring of birds in asparagus and grapes farms of Ica valley, from January-2004 to January-2006. We evaluated eight types of habitats distributed in a total of 1288 has. Throughout the period of study we registered 93 species of birds. The abundance, richness and diversity were greater in the summers. The greater abundance happened in the habitats of land of asparagus, river brushwood and live fences. The greater richness and diversity happened in January-2006 in alfalfa cultures with huarangos and live fences. The most abundant species were the residents, as Zenaida meloda (6,6 ind./it has, Pygochelidon cyanoleuca (5,9 and the migratory Hirundo rustica (5,9. We registered 12 migratory species. From the conservationist point of view, the number of species catalogued in some degree of threat, at national and international level, is very high. We can emphasize the vulnerable Xenospingus concolor, the Peruvian endemic Colaptes atricollis and the species of desert Geositta peruviana, Sporophila simplex and Burhinus superciliaris. This study demonstrates the importance of agroecosystems in the conservation of the Peruvian Coastal Desert biodiversity, in particular if the enterprise carries out a policy of respect to environment.

  11. Resource use pattern and agroecosystem functioning in Rawanganga micro-watershed in Garhwal Himalaya, India

    Directory of Open Access Journals (Sweden)

    Nagendra Prasad Todaria

    2011-12-01

    Full Text Available Agro-ecological resource use pattern in a traditional hill agricultural watershed in Garhwal Himalaya was analysed along an altitudinal transect. Thirty one food crops were found, although only 0.5% agriculture land is under irrigation in the area. Fifteen different tree species within agroforestry systems were located and their density varied from 30-90 trees/ha. Grain yield, fodder from agroforest trees and crop residue were observed to be highest between 1200 and 1600 m a.s.l. Also the annual energy input- output ratio per hectare was highest between 1200 and 1600 m a.s.l. (1.46.This higher input- output ratio between 1200-1600 m a.s.l. was attributed to the fact that green fodder, obtained from agroforestry trees, was considered as farm produce. The energy budget across altitudinal zones revealed 95% contribution of the farmyard manure and the maximum output was in terms of either crop residue (35% or fodder (55% from the agroforestry component. Presently on average 23%, 29% and 41% cattle were dependent on stall feeding in villages located at higher, lower and middle altitudes respectively. Similarly, fuel wood consumption was greatly influenced by altitude and family size. The efficiency and sustainability of the hill agroecosystem can be restored by strengthening of the agroforestry component. The approach will be appreciated by the local communities and will readily find their acceptance and can ensure their effective participation in the programme.

  12. Diversity of planthoppers associated with the winter rice agroecosystems in southern Yunnan, China.

    Science.gov (United States)

    Hu, Shao-ji; Fu, Da-ying; Liu, Xiao-jun; Zhao, Tao; Han, Zhong-liang; Lü, Jian-ping; Wan, Hai-long; Ye, Hui

    2012-01-01

    A field survey of the overwintering planthoppers (Hemiptera: Delphacidae) associated with the rice agroecosystems in southern Yunnan was carried out during January-February in 2010 and 2011. 22 species of planthoppers were collected and identified, with one species representing the subfamily Stenocraninae and the other 21 species in Delphacinae. Nycheuma cognatum (Muir), Peregrinus maidis (Ashmead), and Pseudosogata vatrenus (Fennah) were new provincial records for Yunnan. The pest species, Sogatella furcifera (Horváth), Nilaparvata lugens (Stål), and Laodelphax striatellus (Fallén) were able to overwinter in part of the survey range. 13 species were listed to be of economic importance. Abandoned rice paddies with dense Poaceae grasses (Poaceae) were the most favorable overwintering habitat. The survey range was divided into four regions and five areas based on natural geographical characteristics. The study demonstrated that winter temperature differentiation, terrains, and habitat differences were three factors affecting planthopper diversity. Planthopper species diversity showed a reductive trend from south to north and reflected a gradient of more severe winter temperatures. In addition, planthopper diversity was influenced by smaller-scale differences in terrain and habitat, as evidenced by greater diversity in the valleys and low-altitude areas as compared to mid-mountain and Karst plain areas. PMID:22958347

  13. Indirect effects of a fungal entomopathogen, Lecanicillium lecanii (Hypocreales: Clavicipitaceae), on a coffee agroecosystem ant community.

    Science.gov (United States)

    Macdonald, A J; Jackson, D; Zemenick, K

    2013-08-01

    Fungal entomopathogens are widely distributed across natural and managed systems, with numerous host species and likely a wide range of community impacts. While the potential for fungal pathogens to provide biological control has been explored in some detail, less is known about their community interactions. Here we investigate the effects of fungal epizootics of the entomopathogen Lecanicillium lecanii (Zimmerman) on a keystone mutualism between Azteca instabilis (F. Smith), a dominant arboreal ant, and the green coffee scale (Coccus viridis Green), as well as broader impacts on a coffee agroecosystem ant community. We hypothesized that seasonal epizootics cause shifts in the foraging ranges of A. instabilis as the ants adapt to the loss of the resource. We further hypothesized that the magnitude of these shifts depends on the availability of alternate resources located in neighboring shade trees. To test these hypotheses, we induced an epizootic in experimental sites, which were compared with control sites. Surveys of ant activity were undertaken pre- and post-epizootic. We found a decrease in foraging activity of A. instabilis and increase in activity of other ant species in the experimental sites post-epizootic. The decrease in abundance of A. instabilis foragers was greater on plants in which an epizootic was induced than in other plants. This relationship was modified by shade tree density where higher shade tree density was associated with larger decreases in A. intabilis foraging activity in coffee plants. These results demonstrate the potential for fungal entomopathogens to influence the structure and diversity of ecological communities. PMID:23905728

  14. Produced water irrigation changes the soil mesofauna community in a semiarid agroecosystem.

    Science.gov (United States)

    Ferreira, Raimundo Nonato Costa; Weber, Olmar Baller; Crisóstomo, Lindbergue Araujo

    2015-08-01

    The scarcity of water in semiarid regions requires alternative sources for irrigation to improve agricultural production. Here, we aimed to evaluate the effects of produced water from oil exploration on the structure of soil mesofauna during the dry and rainy seasons in irrigated sunflower and castor bean fields in a Brazilian semiarid region. Three irrigation treatments were applied on plots cultivated with castor beans and sunflowers: produced water treated by filtration (filtrated) or treated by reverse osmosis (reverse osmosis) and groundwater. The mesofauna under the biofuel crops was collected and identified during the dry and rainy seasons. Although the abundance and richness of the total fauna did not differ between seasons in sunflower plots, the community was altered. In castor beans, the abundance, richness, and community of mesofauna observed in plots irrigated with produced water differed from the groundwater treatment. Irrigation with produced water promotes important changes in soil fauna community that justify their assessment for the maintenance and monitoring of agroecosystems. PMID:26205282

  15. Species composition and seasonal abundance of sandflies (Diptera: Psychodidae: Phlebotominae) in coffee agroecosystems

    Science.gov (United States)

    Pérez, Jeanneth; Virgen, Armando; Rojas, Julio Cesar; Rebollar-Téllez, Eduardo Alfonso; Alfredo, Castillo; Infante, Francisco; Mikery, Oscar; Marina, Carlos Felix; Ibáñez-Bernal, Sergio

    2013-01-01

    The composition and seasonal occurrence of sandflies were investigated in coffee agroecosystems in the Soconusco region of Chiapas, Mexico. Insect sampling was performed on three plantations located at different altitudes: Finca Guadalupe Zajú [1,000 m above sea level (a.s.l.)], Finca Argovia (613 m a.s.l.) and Teotihuacán del Valle (429 m a.s.l.). Sandflies were sampled monthly from August 2007-July 2008 using three sampling methods: Shannon traps, CDC miniature light traps and Disney traps. Sampling was conducted for 3 h during three consecutive nights, beginning at sunset. A total of 4,387 sandflies were collected during the course of the study: 2,718 individuals in Finca Guadalupe Zajú, 605 in Finca Argovia and 1,064 in Teotihuacán del Valle. The Shannon traps captured 94.3% of the total sandflies, while the CDC light traps and Disney traps captured 4.9% and 0.8%, respectively. More females than males were collected at all sites. While the number of sandflies captured was positively correlated with temperature and relative humidity, a negative correlation was observed between sandfly numbers and rainfall. Five species of sandflies were captured: Lutzomyia cruciata , Lutzomyia texana , Lutzomyia ovallesi , Lutzomyia cratifer / undulata and Brumptomyia sp. Lu. cruciata , constituting 98.8% of the total, was the most abundant species. None of the captured sandflies was infected with Leishmania spp. PMID:24271002

  16. Differences in Soil Microbial Biomass and Activity for Six Agroecosystems with a Management Disturbance Gradient

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Jian; FENG Jin-Xia; J. WU; K. PARKER

    2004-01-01

    Different management practices in six agroecosystems located near Goldsboro, NC, USA were conducted including a successional field (SU), a plantation woodlot (WO), an integrated cropping system with animals (IN), an organic farming system (OR), and two cash-grain cropping systems employing either tillage (CT) or no-tillage (NT) to examine if and how microbial biomass and activity differ in response to alterations in disturbance intensity from six land management strategies. Results showed that soil microbial biomass and activity differed, with microbial activity in intermediately disturbed ecosystems (NT, OR, IN) being significantly higher (P < 0.01) than systems with either high or low disturbance intensities. There was also a significant and a highly significant ecosystem effect from the treatments on microbial biomass C (MBC) (P < 0.05) and on microbial activity (respiration) (P < 0.01), respectively. Multiple comparisons of mean respiration rates distinctly separated the six ecosystem types into three groups: CT < NT, SU and WO < OR and IN.Thus, for detecting microbial response to disturbance changes these results indicated that the active component of the soil microbial community was a better indicator than total biomass.

  17. Arthropods in no-tillage soybean agroecosystems: Community composition and ecosystem interactions

    Science.gov (United States)

    House, Garfield J.; Stinner, Benjamin R.

    1983-01-01

    Sampling data are provided and concepts discussed regarding soil and foliage arthropod communities in conventional and no-tillage soybean agroecosystems Soil arthropod communities from the two cropping systems were also compared with that from an adjacent old field. Biweekly arthropod samples were collected from conventional, no-tillage, and old-field systems Soil arthropods were sampled by quadrat and pitfall trap methods, foliage arthropods were collected by sweep net Quadrat sampling revealed that ground beetle number, species diversity, and biomass were significantly higher ( Ptrap data indicated higher densities and species diversity for most major soil macro-arthropod guilds Foliage arthropod guilds from no-tillage treatments showed higher species diversity throughout the growing season than those of conventional tillage, possibly because of greater structural diversity provided by weeds and litter in notillage systems No-tillage systems supported a larger and more diverse arthropod community than conventionally grown soybeans, suggesting a need for pest management strategies that simultaneously consider many variables. Both foliar grazing and leaf nitrogen content were higher in conventional than in no-tillage systems, indicating a possible causal connection between soil tillage and insect herbivory rates

  18. More of the Same: High Functional Redundancy in Stream Fish Assemblages from Tropical Agroecosystems

    Science.gov (United States)

    Casatti, Lilian; Teresa, Fabrício Barreto; Zeni, Jaquelini de Oliveira; Ribeiro, Mariela Domiciano; Brejão, Gabriel Lourenço; Ceneviva-Bastos, Mônica

    2015-06-01

    In this study, we investigated the influence of environmental variables (predictor variables) on the species richness, species diversity, functional diversity, and functional redundancy (response variables) of stream fish assemblages in an agroecosystem that harbor a gradient of degradation. We hypothesized that, despite presenting high richness or diversity in some occasions, fish communities will be more functionally redundant with stream degradation. Species richness, species diversity, and functional redundancy were predicted by the percentage of grass on the banks, which is a characteristic that indicates degraded conditions, whereas the percentage of coarse substrate in the stream bottom was an important predictor of all response variables and indicates more preserved conditions. Despite being more numerous and diverse, the groups of species living in streams with an abundance of grass on the banks perform similar functions in the ecosystem. We found that riparian and watershed land use had low predictive power in comparison to the instream habitat. If there is any interest in promoting ecosystem functions and fish diversity, conservation strategies should seek to restore forests in watersheds and riparian buffers, protect instream habitats from siltation, provide wood debris, and mitigate the proliferation of grass on stream banks. Such actions will work better if they are planned together with good farming practices because these basins will continue to be used for agriculture and livestock in the future.

  19. Assessment of the Maize (Zea mays-Mucuna (Mucuna deeringianum Bort Agroecosystem

    Directory of Open Access Journals (Sweden)

    Carlos E. Aguilar-Jimenez

    2012-01-01

    Full Text Available Problem statement: In Selva de Chiapas, Mexico, the traditional farming technique of slash-fell-burn used on hillside fields has caused severe soil deterioration. Consequently, indigenous farmers reacted by developing several agroecological practices that improve the physical, chemical and biological fertility of the soils. Standing out among these techniques is the use of Mucuna (Mucuna deeringianum Bort. in rotation with maize (Zea mays L. Approach: The objective of this study was to determine the effect of the maize-mucuna system on soil fertility, ecosystem diversity and maize crop yield. The study was conducted in the Tulija Valley, Chiapas, in the autumn-winter growing season (November-April. A completely random design was applied to four periods of consecutive maize-mucuna cropping (0, 5, 10 and 15 years in order to analyze the most significant variables related to soils, weeds, seed bank and yield. Results: The results obtained reveal the higher nutrient concentration in the topsoil (0-15 cm and better crop yield in the treatments with Mucuna rotation. No direct relationship was observed between nutrient content and duration of maize-mucuna system usage. However, the diversity of weeds and similarity of species both diminished where this farming method was used. Conclusion/Recommendations: It was determined that the use of the maize-mucuna agroecosystem helps to increase and maintain agroecological sustainability, supporting this practice that has been adapted and utilized by indigenous Choles for more than 30 years.

  20. Copro-necrophagous beetle (Coleoptera: Scarabaeidae) diversity in an agroecosystem in Yucatan, Mexico.

    Science.gov (United States)

    Reyes Novelo, Enrique; Delfín-González, Hugo; Angel Morón, Miguel

    2007-03-01

    Scarabaeinae are sensitive to structural habitat changes caused by disturbance. We compared copronecrophagous beetle (Scarabaeinae) community structure in three differently managed zones within an agroeco-system of the northern Yucatan Peninsula, Mexico. We placed dung and carrion traps once a month from June 2004 through May 2005. The beetle community included 17 species from the genera Canthon, Canthidium, Deltochilum, Pseudocanthon, Malagoniella, Onthophagus, Phanaeus, Copris, Uroxys, Sisyphus and Ateuchus. The secondary vegetation had a higher beetle diversity than the other two zones. Species richness was highest in the Brosimum alicastrum plantation. The pasture had the lowest species diversity and richness, but exhibited the highest abundance of Scarabaeinae in the dry season. The two zones with extensive tree cover were the most diverse. Roller beetles were dominant over burrower species and small-sized species outnumbered large species. Our data show two important issues: beetle species in the pasture extended their activity to the beginning of the dry season, while abundances dropped in the other, unirrigated zones; and the possibility that the Scarabaeinae living in neotropical forests are opportunistic saprophages and have specialized habits for resources other than dung. The B. alicastrum plantation is beneficial to the entire ranch production system because it functions as a dispersion and development area for stenotopic species limited to tree cover.

  1. Monitoring of the CO2 emission and the contents of microbial biomass in agroecosystems on gray forest soils of the Cisbaikal region under conditions of fluoride pollution

    Science.gov (United States)

    Pomazkina, L. V.

    2015-08-01

    The influence of the technogenic pollution of gray forest soils in the forest-steppe zone of the Cisbaikal region with fluorides emitted by aluminum smelters on the functioning and state of local agroecosystems was studied within the framework of a long-term agroecological monitoring program. Hydrothermic conditions of the growing season during the monitoring period (1997-2012) were compared with the climatic norm (1961-1990). It was found that the adverse effect of the technogenic pollution on the agroecosystem becomes more pronounced during the years with abnormal weather conditions. An increase in the CO2 emission into the atmosphere as a response of the microbial complex to the rise in the air temperatures was characterized by the linear dependence irrespectively of the degree of soil contamination. The methods of systems analysis were applied to generalize the results. The considered agroecosystem was studied as the system of particular components (soil-microorganisms-plants-atmosphere) integrated by the carbon fluxes. The regimes of the agroecosystem functioning and the ecological loads on it were estimated on the basis of data on the fluxes of net mineralized and (re)immobilized carbon. The environmental factors affecting the state and functioning of the agroecosystem were identified.

  2. Carbon balance at represenative agroecosystems of Central European Russia with different crops assessed by eddy covariance method

    Science.gov (United States)

    Yaroslavtsev, Alexis; Meshalkina, Joulia; Mazirov, Ilya

    2016-04-01

    Despite the fact that in Russia cropland's soils carbon loses 9 time higher than forest's soils ones (Stolbovoi, 2002), agroecosystems were not given sufficient attention and most of the papers are devoted to forestry and natural ecosystems. Carbon balance was calculated at the Precision Farming Experimental Fields of the Russian Timiryazev State Agricultural University, Moscow, Russia, for two agroecosystems with different crops from the same crop rotation studied for 2 years. The experimental site has a temperate and continental climate and situated in south taiga zone with Arable Sod-Podzoluvisols (Albeluvisols Umbric). Vertical fluxes of carbon dioxide were measured with eddy covariance technique, statistical method to measure and calculate turbulent fluxes within atmospheric boundary layers (Burba, 2013). Crop rotation included potato, winter wheat, barley and vetch and oat mix. Two fields of the same crop rotation were studied in 2013-2014. One of the fields (A) was used in 2013 for barley planting (Hordeum vulgare L.). The field B was in 2013 used for planting together vetch (Vicia sativa L.) and oats (Avena sativa L.). Inversely oats and vetch grass mixt was sown in 2014 on field A. Winter wheat was sown on field A in the very beginning of September. On the second field (B) in 2014 winter wheat occurred from under the snow in the phase of tillering, after harvesting it in mid of July, white mustard (Sinapis alba) was sown for green manure. Carbon uptake (NEE negative values) was registered only for the field with winter wheat and white mustard; perhaps because the two crops were cultivated on the field within one growing season. Three other cases showed CO2 emission. Great difference in 82 g C m‑2 per year in NEE between two fields with vetch and oat mix was related to higher difference in grass yields. NEE for barley field was positive during the whole year; considering only the growing season, NEE for barley was 100 g C m‑2 lower and was negative

  3. Carbon balance at represenative agroecosystems of Central European Russia with different crops assessed by eddy covariance method

    Science.gov (United States)

    Yaroslavtsev, Alexis; Meshalkina, Joulia; Mazirov, Ilya

    2016-04-01

    Despite the fact that in Russia cropland's soils carbon loses 9 time higher than forest's soils ones (Stolbovoi, 2002), agroecosystems were not given sufficient attention and most of the papers are devoted to forestry and natural ecosystems. Carbon balance was calculated at the Precision Farming Experimental Fields of the Russian Timiryazev State Agricultural University, Moscow, Russia, for two agroecosystems with different crops from the same crop rotation studied for 2 years. The experimental site has a temperate and continental climate and situated in south taiga zone with Arable Sod-Podzoluvisols (Albeluvisols Umbric). Vertical fluxes of carbon dioxide were measured with eddy covariance technique, statistical method to measure and calculate turbulent fluxes within atmospheric boundary layers (Burba, 2013). Crop rotation included potato, winter wheat, barley and vetch and oat mix. Two fields of the same crop rotation were studied in 2013-2014. One of the fields (A) was used in 2013 for barley planting (Hordeum vulgare L.). The field B was in 2013 used for planting together vetch (Vicia sativa L.) and oats (Avena sativa L.). Inversely oats and vetch grass mixt was sown in 2014 on field A. Winter wheat was sown on field A in the very beginning of September. On the second field (B) in 2014 winter wheat occurred from under the snow in the phase of tillering, after harvesting it in mid of July, white mustard (Sinapis alba) was sown for green manure. Carbon uptake (NEE negative values) was registered only for the field with winter wheat and white mustard; perhaps because the two crops were cultivated on the field within one growing season. Three other cases showed CO2 emission. Great difference in 82 g C m-2 per year in NEE between two fields with vetch and oat mix was related to higher difference in grass yields. NEE for barley field was positive during the whole year; considering only the growing season, NEE for barley was 100 g C m-2 lower and was negative. Closed

  4. Long-term agroecosystem research in the central Mississippi river basin: introduction, establishment, and overview.

    Science.gov (United States)

    Sadler, E John; Lerch, Robert N; Kitchen, Newell R; Anderson, Stephen H; Baffaut, Claire; Sudduth, Kenneth A; Prato, Anthony A; Kremer, Robert J; Vories, Earl D; Myers, D Brent; Broz, Robert; Miles, Randall J; Young, Fred J

    2015-01-01

    Many challenges currently facing agriculture require long-term data on landscape-scale hydrologic responses to weather, such as from the Goodwater Creek Experimental Watershed (GCEW), located in northeastern Missouri, USA. This watershed is prone to surface runoff despite shallow slopes, as a result of a significant smectitic clay layer 30 to 50 cm deep that restricts downward flow of water and gives rise to a periodic perched water table. This paper is the first in a series that documents the database developed from GCEW. The objectives of this paper are to (i) establish the context of long-term data and the federal infrastructure that provides it, (ii) describe the GCEW/ Central Mississippi River Basin (CMRB) establishment and the geophysical and anthropogenic context, (iii) summarize in brief the collected research results published using data from within GCEW, (iv) describe the series of papers this work introduces, and (v) identify knowledge gaps and research needs. The rationale for the collection derives from converging trends in data from long-term research, integration of multiple disciplines, and increasing public awareness of increasingly larger problems. The outcome of those trends includes being selected as the CMRB site in the USDA-ARS Long-Term Agro-Ecosystem Research (LTAR) network. Research needs include quantifying watershed scale fluxes of N, P, K, sediment, and energy, accounting for fluxes involving forest, livestock, and anthropogenic sources, scaling from near-term point-scale results to increasingly long and broad scales, and considering whole-system interactions. This special section informs the scientific community about this database and provides support for its future use in research to solve natural resource problems important to US agricultural, environmental, and science policy.

  5. The influence of soil water status on Oryza Sativa Var. MR220 in KADA rice agroecosystem

    International Nuclear Information System (INIS)

    A study to determine the influence of soil water status on rice plant Oryza sativa var. MR220 after panicle initiation stage was carried out at Ladang Merdeka Mulong Lating in the Kemubu Agricultural Development Authority (KADA) area, Kelantan. Five water management treatments imposed on direct seeded rice were; T1. Continuous flooding, T2. Early flooding up to panicle initiation stage followed by saturated (F55-saturated), T3. Early flooding for the first month followed by saturated (F-30 saturated), T4. Continuous saturated, and T5. Continuous field capacity condition throughout the growth stage. The treatments were arranged in Randomized Complete Block Design (RCBD) with four replicates. Results showed significant differences in soil moisture content in the order of T1>T2>T3>T4>T5. Significant differences were also observed in rice plant water content at 68 DAS (days after seeding) in the order of T2>T3>T4>T1>T5. Moisture content also showed significant differences between replicates in the order of R1>R2>R3>R4 and R2>R1>R3>R4; in rice plant and ricefield soil, respectively. Results however showed no significant difference in leaf stomatal conductance due to water stress. Rice plant moisture, soil moisture and leaf stomatal conductance showed no interaction. Published results show that even though overall crop yield was reduced by sheath blight and panicle blast incidence that occur at later stage in 2004-2005 field trials, highest grain yields were obtained from T2 (off season) and T4 (main season). Saturated condition seems to be the most suitable method of growing rice under minimal water input in KADA rice agroecosystem. (Author)

  6. Modeling Sustained Delivery of Agroecosystem Services at a Watershed Scale under Climate Change

    Science.gov (United States)

    Jaradat, A. A.; Starr, J.

    2015-12-01

    The intensive land use and agricultural production systems in the Chippewa River Watershed (CRW) in Minnesota, USA, contribute to inherent environmental problems and have major direct impact on soil conservation, and on several competing agro-ecosystem services (AESs); and may have indirect impact on AESs in the Upper Mississippi River Basin (UMRB). Field-scale indicators of AESs are largely absent in the highly diverse soils of the CRW. Therefore, proxy indicators were developed to assess these services under current (A0) and predicted (A2; 100 years) global climate change (GCC) scenarios. Individual indices were developed for biomass, grain yield, NO3- and NH4-N, soil carbon, runoff, and soil erosion for 132 soil series classified into three land capability classes (LCCs). The indices and a weighted index (Iw) were subjected to multivariate analyses procedures, including distance-weighted least squares, and variance components estimation. Three-D maps delineated contiguous areas of increasing or decreasing AESs in response to projected GCC. Largest significant variance portions in Iw were attributed to GCC scenarios; followed by the interaction of crop rotations and LCCs within conventional and organic cropping systems. The AES were predicted with larger certainty under A2 in organically-managed LCC-1 compared to conventional management. Significantly more runoff and soil erosion are predicted in conventionally-managed LCC-2 and LCC-3 under the same GCC scenario, regardless of soil heterogeneity. The modeling framework and the mapped AES indicators are designed to achieve multiple goals and will be used to support farmers in designing specific crop rotations that are suitable for each of the three LCCs and for major and vulnerable soil series in the watershed. Also, the modeling framework will address sustained delivery of multiple AESs, while enhancing soil conservation, water quality, and environmental protection aspects of farming in the CRW and the UMRB.

  7. Metagenomic Evidence of the Prevalence and Distribution Patterns of Antimicrobial Resistance Genes in Dairy Agroecosystems.

    Science.gov (United States)

    Pitta, Dipti W; Dou, Zhengxia; Kumar, Sanjay; Indugu, Nagaraju; Toth, John Daniel; Vecchiarelli, Bonnie; Bhukya, Bhima

    2016-06-01

    Antimicrobial resistance (AR) is a global problem with serious implications for public health. AR genes are frequently detected on animal farms, but little is known about their origin and distribution patterns. We hypothesized that AR genes can transfer from animal feces to the environment through manure, and to this end, we characterized and compared the resistomes (collections of AR genes) of animal feces, manure, and soil samples collected from five dairy farms using a metagenomics approach. Resistomes constituted only up to 1% of the total gene content, but were variable by sector and also farm. Broadly, the identified AR genes were associated with 18 antibiotic resistances classes across all samples; however, the most abundant genes were classified under multidrug transporters (44.75%), followed by resistance to vancomycin (12.48%), tetracycline (10.52%), bacitracin (10.43%), beta-lactam resistance (7.12%), and MLS efflux pump (6.86%) antimicrobials. The AR gene profiles were variable between farms. Farm 09 was categorized as a high risk farm, as a greater proportion of AR genes were common to at least three sectors, suggesting possible horizontal transfer of AR genes. Taxonomic characterization of AR genes revealed that a majority of AR genes were associated with the phylum Proteobacteria. Nonetheless, there were several members of Bacteroidetes, particularly Bacteroides genus and several lineages from Firmicutes that carried similar AR genes in different sectors, suggesting a strong potential for horizontal transfer of AR genes between unrelated bacterial hosts in different sectors of the farms. Further studies are required to affirm the horizontal gene transfer mechanisms between microbiomes of different sectors in animal agroecosystems. PMID:27046731

  8. Landscape constraints on functional diversity of birds and insects in tropical agroecosystems.

    Science.gov (United States)

    Tscharntke, Teja; Sekercioglu, Cagan H; Dietsch, Thomas V; Sodhi, Navjot S; Hoehn, Patrick; Tylianakis, Jason M

    2008-04-01

    In this paper, we analyze databases [corrected] on birds and insects to assess patterns of functional diversity in human-dominated landscapes in the tropics. A perspective from developed landscapes is essential for understanding remnant natural ecosystems, because most species experience their surroundings at spatial scales beyond the plot level, and spillover between natural and managed ecosystems is common. Agricultural bird species have greater habitat and diet breadth than forest species. Based on a global data base, bird assemblages in tropical agroforest ecosystems were composed of disproportionately more frugivorous and nectarivorous, but fewer insectivorous bird species compared with forest. Similarly, insect predators of plant-feeding arthropods were more diverse in Ecuadorian agroforest and forest compared with rice and pasture, while, in Indonesia, bee diversity was also higher in forested habitats. Hence, diversity of insectivorous birds and insect predators as well as bee pollinators declined with agricultural transformation. In contrast, with increasing agricultural intensification, avian pollinators and seed dispersers initially increase then decrease in proportion. It is well established that the proximity of agricultural habitats to forests has a strong influence on the functional diversity of agroecosystems. Community similarity is higher among agricultural systems than in natural habitats and higher in simple than in complex landscapes for both birds and insects, so natural communities, low-intensity agriculture, and heterogeneous landscapes appear to be critical in the preservation of beta diversity. We require a better understanding of the relative role of landscape composition and the spatial configuration of landscape elements in affecting spillover of functionally important species across managed and natural habitats. This is important for data-based management of tropical human-dominated landscapes sustaining the capacity of communities to

  9. Paisang ( Quercus griffithii): A Keystone Tree Species in Sustainable Agroecosystem Management and Livelihoods in Arunachal Pradesh, India

    Science.gov (United States)

    Singh, Ranjay K.; Singh, Anshuman; Garnett, Stephen T.; Zander, Kerstin K.; Lobsang; Tsering, Darge

    2015-01-01

    In a study of the traditional livelihoods of 12 Monpa and Brokpa villages in Arunachal Pradesh, India using social-ecological and participatory rural appraisal techniques, we found that the forest tree species paisang ( Quercus griffithii, a species of oak) is vital to agroecosystem sustainability. Paisang trees are conserved both by individuals and through community governance, because their leaves play a crucial role in sustaining 11 traditional cropping systems of the Monpa peoples. An Indigenous institution, Chhopa, regulates access to paisang leaves, ensuring that the relationship between paisang and traditional field crop species within Monpa agroecosystems is sustainable. The Monpa farmers also exchange leaves and agricultural products for yak-based foods produced by the transhumant Brokpa, who are primarily yak herders. Yak herds also graze in paisang groves during winter. These practices have enabled the conservation of about 33 landraces, yak breeds, and a number of wild plants. Paisang thus emerged as a culturally important keystone species in the cultures and livelihoods of both Monpa and Brokpa. Ecological and conservation knowledge and ethics about paisang vary with gender, social systems, and altitudes. Labor shortages, however, have already caused some changes to the ways in which paisang leaves are used and yak grazing patterns are also changing in the face of changes in attitude among local landowners. Given new competing interests, incentives schemes are now needed to conserve the ecologically sustainable traditional livelihoods.

  10. Development of the Long-Term Agro-ecosystem Research (LTAR) Network: Current Status and Future Trends

    Science.gov (United States)

    Walbridge, M. R.; Bestelmeyer, B.; Derner, J. D.; Harmel, D.; Heilman, P.; Huggins, D. R.; Kleinman, P. J. A.; Moorman, T.; Mccarty, G.; Pierson, F. B.; Rigby, J.; Robertson, G. P.; Sadler, J.; Sanderson, M.; Steiner, J. L.; Strickland, T.; Wienhold, B.

    2015-12-01

    Long-term research conducted at multiple scales is critical to assessing the effects of key long term drivers (e.g., global population growth; land-use change; increased competition for natural resources; climate variability and change) on our ability to sustain or enhance agricultural production to meet future global demand for agricultural products (e.g., food; feed; fiber; fuel). To address this need, the US Department of Agriculture's Agricultural Research Service (ARS), in collaboration with a broad group of partners, identified and reorganized existing long-term research infrastructure (i.e., benchmark watersheds; experimental ranges; research farms) into a Long-Term Agro-ecosystem Research (LTAR) network, the only long-term research network focused specifically on US agro-ecosystems. In 2014, the initial network of 10 sites was expanded to 18 sites, including 3 sites led wholly or in part by non-USDA entities. Later this year, the LTAR network will make the first near real-time data sets from all 18 sites available on the web. This talk will focus briefly on LTAR establishment history, but primarily on LTAR's current status and next steps, including plans for a final network expansion to complete coverage of key farm resource regions in the continental US. In the broader context of this symposium, this talk will set the stage for discussions of complementary long-term research networks (e.g., LTER; NEON) and potential future collaborations to address questions of mutual interest.

  11. Impact of weed control on arbuscular mycorrhizal fungi in a tropical agroecosystem: a long-term experiment.

    Science.gov (United States)

    Ramos-Zapata, José A; Marrufo-Zapata, Denis; Guadarrama, Patricia; Carrillo-Sánchez, Lilia; Hernández-Cuevas, Laura; Caamal-Maldonado, Arturo

    2012-11-01

    Cover crop species represent an affordable and effective weed control method in agroecosystems; nonetheless, the effect of its use on arbuscular mycorrhizal fungi (AMF) has been scantily studied. The goal of this study was to determine root colonization levels and AMF species richness in the rhizosphere of maize plants and weed species growing under different cover crop and weed control regimes in a long-term experiment. The treatment levels used were (1) cover of Mucuna deeringian (Muc), (2) "mulch" of Leucaena leucocephala (Leu), (3) "mulch" of Lysiloma latisiliquum (Lys), (4) herbicide (Her), (5) manual weeding (CD), (6) no weeding (SD), and (7) no maize and no weeding (B). A total of 18 species of AMF belonging to eight genera (Acaulospora, Ambispora, Claroideoglomus, Funneliformis, Glomus, Rhizophagus, Sclerocystis, and Scutellospora) were identified from trap cultures. Muc and Lys treatments had a positive impact on AMF species richness (11 and seven species, respectively), while Leu and B treatments on the other hand gave the lowest richness values (six species each). AMF colonization levels in roots of maize and weeds differed significantly between treatment levels. Overall, the use of cover crop species had a positive impact on AMF species richness as well as on the percentage of root colonized by AMF. These findings have important implications for the management of traditional agroecosystems and show that the use of cover crop species for weed control can result in a more diverse AMF community which should potentially increase crop production in the long run. PMID:22584877

  12. What does the future hold for semi-arid Mediterranean agro-ecosystems? - Exploring cellular automata and agent-based trajectories of future land use change

    NARCIS (Netherlands)

    Nainggolan, D.; Termansen, M.; Fleskens, L.; Hubacek, K.; Reed, M.S.; Vente, de J.; Boix-Fayos, C.

    2012-01-01

    Exploring how land use and the management of agro-ecosystems may evolve in the future is important for advancing scientific understanding and for informing policy makers and land managers of ways to respond and adapt sustainably to future change. In this paper, we investigate the future land-use tra

  13. Including sugar cane in the agro-ecosystem model ORCHIDEE-STICS

    Science.gov (United States)

    Valade, A.; Vuichard, N.; Ciais, P.; Viovy, N.

    2010-12-01

    With 4 million ha currently grown for ethanol in Brazil only, approximately half the global bioethanol production in 2005 (Smeets 2008), and a devoted land area expected to expand globally in the years to come, sugar cane is at the heart of the biofuel debate. Indeed, ethanol made from biomass is currently the most widespread option for alternative transportation fuels. It was originally promoted as a carbon neutral energy resource that could bring energy independence to countries and local opportunities to farmers, until attention was drawn to its environmental and socio-economical drawbacks. It is still not clear to which extent it is a solution or a contributor to climate change mitigation. Dynamic Global Vegetation models can help address these issues and quantify the potential impacts of biofuels on ecosystems at scales ranging from on-site to global. The global agro-ecosystem model ORCHIDEE describes water, carbon and energy exchanges at the soil-atmosphere interface for a limited number of natural and agricultural vegetation types. In order to integrate agricultural management to the simulations and to capture more accurately the specificity of crops' phenology, ORCHIDEE has been coupled with the agronomical model STICS. The resulting crop-oriented vegetation model ORCHIDEE-STICS has been used so far to simulate temperate crops such as wheat, corn and soybean. As a generic ecosystem model, each grid cell can include several vegetation types with their own phenology and management practices, making it suitable to spatial simulations. Here, ORCHIDEE-STICS is altered to include sugar cane as a new agricultural Plant functional Type, implemented and parametrized using the STICS approach. An on-site calibration and validation is then performed based on biomass and flux chamber measurements in several sites in Australia and variables such as LAI, dry weight, heat fluxes and respiration are used to evaluate the ability of the model to simulate the specific

  14. Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems

    Directory of Open Access Journals (Sweden)

    Vincenzo Tabaglio

    2013-02-01

    absorption capability. The insensitivity of A. theophrasti to BOA was due to reduced accumulation in seedlings. Overall, results confirm that the use of a rye cover crop in a suitable crop rotation represents a sustainable weed management practice permitting a reduction in the amount of herbicides used in agroecosystems, thus limiting the environmental risks of intensive agriculture.

  15. Modeling N2O Emissions From Temperate Agroecosystems: A Literature Review Using Monte Carlo Sampling

    Science.gov (United States)

    Tonitto, C.

    2006-12-01

    In this work, we model annual N2O flux based on field experiments in temperate agroecosystems reported in the literature. Understanding potential N2O flux as a consequence of ecosystem management is important for mitigating global change. While loss of excess N as N2 has no environmental consequences, loss as N2O contributes to the greenhouse effect; over a 100 year time horizon N2O has 310 times the global warming potential (GWP) of CO2. Nitrogen trace gas flux remains difficult to accurately quantify under field conditions due to temporal and spatial limitations of sampling. Trace gas measurement techniques often rely on small chambers sampled at regular intervals. This measurement scheme can undersample stochastic events, such as high precipitation, which correspond to periods of high N trace gas flux. We apply Monte Carlo sampling of field measurements to project N2O losses under different crops and soil textures. Three statistical models are compared: 1) annual N2O flux as a function of process rates derived from temporally aggregated field observations, 2) annual N2O flux incorporating the probability of precipitation events, and 3) annual N2O flux as a function of crop growth. Using the temporally aggregated model, predicted annual N2O flux was highest for corn and wheat, which receive higher fertilizer inputs relative to barley and ryegrass. Within a cropping system, clayey soil textures resulted in the highest N2O flux. The incorporation of precipitation events in the model has the greatest effect on clayey soils. Relative to the aggregated model the inclusion of precipitation events changed predicted mean annual N2O flux from 31 to 49 kg N ha-1 for corn grown on clay loam and shifted the 75% confidence interval (CI) from 20-42 to 38-61 kg N ha-1. In contrast, comparisons between the aggregated and precipitation event models resulted in indistinguishable predictions of mean annual N2O loss for corn grown on silty loam and loam soils. Similarly, application

  16. Atmospheric inorganic nitrogen in dry deposition to a typical red soil agro-ecosystem in southeastern China.

    Science.gov (United States)

    Cui, Jian; Zhou, Jing; Yang, Hao

    2010-06-01

    Atmospheric dry deposition is an important pathway of nitrogen (N) sources input to agro-ecosystems. With the knowledge of increasing agricultural effects by dry N deposition, researchers have paid great attention to this topic. Characteristics of dry N deposition were estimated by a big-leaf resistance analogy model and the Auto-Meteorological Experiment Station (AMES) in a typical red soil agro-ecosystem in southeastern China for two years (2005-2006). Monthly dry deposition velocities (V(d)) were in the range of 0.16-0.36, 0.07-0.17 and 0.07-0.24 cm s(-1) for NH(3), NO(2) and aerosol particles (aerosol NH(4)(+) or NO(3)(-)), respectively, and the V(d) were higher in spring and winter than in summer and autumn. Monthly dry N deposition concentration (C(a)) and inferred deposition flux (F(d)) were in the range of 63.38-261.10, 47.21-278.92, 1.56-7.15, 47.21-278.92 microg N m(-3) and of 1.31-8.60, 0.38-3.67, 0-0.08, 0.01-0.23 kg N ha(-2) for NH(3), NO(2), aerosol NH(4)(+) and aerosol NO(3)(-), respectively. During the study period (2005-2006), the total dry N deposition was 70.55 kg N ha(-1) yr(-1) which equivalent to 1.53.8 kg (urea) ha(-1) yr(-1) or 415.0 kg (ammonium bicarbonate) ha(-1) yr(-1) applied in the red soil agro-ecosystems. In addition, the annual mean N depositions, mean sum of the monthly N depositions were 69.44, 1.12, 53.95 and 16.60 kg N ha(-1) yr(-1) for gaseous N, aerosol N, ammonia N and oxidized N, making up 98.42%, 1.58%, 53.95% and 16.60% of the total dry deposition N (70.50 kg ha(-1) yr(-1)). PMID:20532381

  17. Rice field agroecosystem investigation : environmental and toxicological assessment; Indagine su una risaia campione: analisi ambientali e chimico-tossicologiche

    Energy Technology Data Exchange (ETDEWEB)

    Bari, A.; Minciardi, M.; Rossi, G. [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dip. Ambiente; Bonotto, F.; Paonessa, F.; Troiani, F. [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dip. Energia; Rosa, S. [ENEA, Centro Ricrche Casaccia, Rome (Italy). Dip. Ambiente; Cormegna, M. [Ente Nazionale Risi, Centro Ricerche sul Riso, Castello d`Agogna, Pavia (Italy)

    1995-10-01

    The rice-field agroecosystem, even if deeply anthropically determined, can be considered substitute of the plain wet lands, now almost all disappeared in the part of the territory has been considering. The aim of the research we started was the analysis and the ecological characterization of this environment and the assessment of the effects of the different agronomical practices, relating to the conservation of the biodiversity in a plain wetland. The ENEA Environmental Biology and Nature Conservation Division of Saluggia (VC) and Casaccia (Roma), in co-operation with ENEA ERG-RAD-LAB Division of Saluggia and the Rice Research Center of Castello d`Agogna (PV) associated to Rice National Society, started a preliminary research on a sample rice field, aiming to evaluate, using different methodologies, the destiny of the chemical substances (herbicides, fungicidals, heavy metals and other chemical compounds) introduced through cultivation practices or arrived by irrigation systems.

  18. Mammal assemblage of the agroecosystem constituents of the Várzea River Basin, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Felipe Bortolotto Peters

    2010-12-01

    Full Text Available We provide recent information on the richness of mammals along the agroecosystems of the Rio da Várzea Basin, Rio Grande do Sul, Brazil. We used different field techniques to confirm the occurrence of 46 mammal species in this area. Nine species are threatened in at least one of the three “red lists” at state, national and global levels. Adding the up-to-date results obtained in the field to available data, mainly for conservation units, we present a richness of 85 species recorded for the basin. This number represents about 50% of mammals documented for Rio Grande do Sul state. The results suggest the importance of maintaining protected areas in altered regions, confirming the relevance of inventories of local fauna as a first approach to specific studies addressed to distribution, systematics, cytogenetics, physiology, population and community ecology.

  19. Enhancing the Feed Capacity of Horticulture Agro-Ecosystem Through Technology for Goat Production

    Directory of Open Access Journals (Sweden)

    Simon P Ginting

    2011-09-01

    Full Text Available The availability of feed and their efficiency of use throughout the year represent the most important constraint affecting the productivity of animals in any agro-ecosystems. Beside being the largest contributor to the total production cost, logistically feeds need to be available on a daily basis across the animal’s life time. In order to be competitive, goat production system must be directed toward the optimum utilization of inconventional feedstuffs such as crop residues and agro-industrial by-products. The horticulture crops provide various crop-residues and by products from the processing of its main products. These biomass are potential feedstuffs that could be used to support the production of goats. The processing of passion fruits (Passiflora edulis yield by products such as fruit shells and seeds. These products are good energy and protein sources for growing goats. Oriental radish (Raphanus sativus by-products composed by damaged root parts and culls have high digestible energy and low ether extract content, but have very high moisture content. The pineapple by-products composed by the peel and bagasse of the fruit could be used as energy source for goats. Other horticulture by-products or residues such as citrus pulp, abandoned citrus fruit, forages from Ipomea batatas are of great potential as feeds for goat production. Preserving technology like ensiling could be implemented in utilising those biomass categorized as wet by-products such as pineapple and oriental radish by-products. The technology of complete feed is an effective means in utilizing some of those products with relatively low palatability or to increase its inclusion level in diets. Introducing shade-tolerant forage species as intercrops such as Stenotaphrum secundatum, Brachiaria humidicola and Arachis pintoi in the citrus plantation should increase feed capacity of the area. The multi-purpose trees such as Indigofera sp. and Calliandra calothyrsus both are

  20. Evaluation of an agro--ecosystem model using cosmicray neutron soil moisture

    Science.gov (United States)

    Carr, Benjamin David

    The properties of the land surface affect the interaction of the surface and the atmosphere. The partitioning of absorbed shortwave radiation into emitted radiation, sensible heat flux, latent heat flux, and soil heat flux is determined by the presence of soil moisture. When the land surface is dry, there will be higher sensible heat flux, emitted radiation and soil heat flux. However, when liquid water is present, latent energy will be used to change the phase of water from solid to liquid and liquid to gas. This latent heat flux moves water and energy to a different part of the atmosphere. A contributing factor to soil moisture available for latent heat flux is the water table. With a shallow water table (harvest date, fertilizer application, and tile drainage. Therefore, land surface models, like Agro--IBIS, need to be simulated and evaluated at the field--scale. Agro--IBIS is an agroecosystem model that is able to incorporate changes in vegetation growth as well as management practices, which in turn impact soil moisture available for latent heat flux. Agro--IBIS has been updated with the soil physics of HYDRUS--1D in order to accurately simulate the impact of the water table. In measuring soil moisture, a consistent challenge is the representative scale of the instrument, which is often a point. A newer method of obtaining soil moisture over the field--scale is using a cosmic--ray neutron detector, which is sensitive to a diameter of 700 m and to a depth of ˜ 20 cm. I used soil moisture observed by the cosmic--ray neutron detector in an agricultural field to evaluate estimates made with the Agro--IBIS model over a growing season of maize and a growing season of soybean. Because of the large area observed by the cosmic-ray neutron detector, a soil texture sensitivity analysis was performed using Agro--IBIS to determine the texture that would produce the best hydraulic properties and therefore the best estimate of soil moisture. The maize year results show Agro

  1. Genetic Variability of Stolbur Phytoplasma in Hyalesthes obsoletus (Hemiptera: Cixiidae) and its Main Host Plants in Vineyard Agroecosystems.

    Science.gov (United States)

    Landi, Lucia; Riolo, Paola; Murolo, Sergio; Romanazzi, Gianfranco; Nardi, Sandro; Isidoro, Nunzio

    2015-08-01

    Bois noir is an economically important grapevine yellows that is induced by 'Candidatus Phytoplasma solani' and principally vectored by the planthopper Hyalesthes obsoletus Signoret (Hemiptera: Cixiidae). This study explores the 'Ca. P. solani' genetic variability associated to the nettle-H. obsoletus and bindweed-H. obsoletus systems in vineyard agroecosystems of the central-eastern Italy. Molecular characterization of 'Ca. P. solani' isolates was carried out using polymerase chain reaction/restriction fragment length polymorphism to investigate the nonribosomal vmp1 gene. Seven phytoplasma vmp-types were detected among the host plants- and insect-associated field-collected samples. The vmp1 gene showed the highest polymorphism in the bindweed-H. obsoletus system, according to restriction fragment length polymorphism analysis, which is in agreement with nucleotide sequence analysis. Five vmp-types were associated with H. obsoletus from bindweed, of which one was solely restricted to planthoppers, with one genotype also in planthoppers from nettle. Type V12 was the most prevalent in both planthoppers and bindweed. H. obsoletus from nettle harbored three vmp-types, of which V3 was predominant. V3 was the only type detected for nettle. Our data demonstrate that planthoppers might have acquired some 'Ca. P. solani' profiles from other plant hosts before landing on nettle or bindweed. Overall, the different vmp1 gene rearrangements observed in these two plant hosts-H. obsoletus systems might represent different adaptations of the pathogen to the two host plants. Molecular information about the complex of vmp-types provides useful data for better understanding of Bois noir epidemiology in vineyard agroecosystem. PMID:26470289

  2. On the operationalization of a spatially explicit evaluation of the complexity of land use trajectories in semi-arid Mediterranean agro-ecosystems

    DEFF Research Database (Denmark)

    Nainggolan, Doan

    of the interacting effects of various types of drivers. The thesis highlights conceptual and practical challenges in undertaking an integrated evaluation of land use change complexity. Future policy making should consider the various factors that are jointly shaping agricultural land use trajectories.......This thesis aims to unpack the complexity of trajectories of land use change in semi-arid Mediterranean agro-ecosystems – illustrated using findings from the Torrealvilla catchment in south-eastern Spain. The research looks at multiple dimensions of land use change and addresses the past, present...... for further expansion of irrigated farming, the agent-based scenario analysis indicates the opposite. Overall the thesis confirms that land use changes in Mediterranean agro-ecosystems are indeed complex entailing multiple, contrasting, and perhaps competing trajectories and are the manifestation...

  3. Participation of the fossil energy in cotton agro-ecosystem in family agricultural explorations; Participacao da energia fossil no agroecossistema algodao em exploracoes agricolas familiares

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Osmar de Carvalho; Cabrera Romero, Maria Gloria [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas

    2006-07-01

    With the objective of presenting the participation of the several energy sources employees in the cotton agro-ecosystem, this work is constituted in a contribution regarding the subject of the sustain grow.As the focal point of this research, family exploitation is analyzed, with the use of the categorization done by the National Program for Strengthening Family Agriculture - ('Programa Nacional de Fortalecimento da Agricultura Familiar - PRONAF). Use was made of primary and secondary data from three family exploitations in the municipality of Leme/SP, Brazil. To construct the energy expenditure structure of the cotton agro-ecosystem, the mean values obtained were considered, since these agriculturalists present the same technical itinerary and are within the typification proposed in this study. The results were presented by the energy expenditure structure by type, source, form of energy. Considering the cotton agro-ecosystem from the technical itinerary presented, the input energy equal to 51.961,63 MJ . ha{sup -1} was observed, with a participation of 34,21% and 65,79% of the direct and indirect energy respectively. The studied agro ecosystem fundamentally depended on the industrial source of energy, particularly insecticides (39,71%) and chemical fertilizers (19,88%) and fossil sources (33,80%). It was verified like this that the dependence of the industrial energy and of the fossil energy in the cotton agro ecosystem. In that way, we suggest himself the search of the use of another types of energy that they allow the energy sustainability of this agro-ecosystems in family agricultural systems. (author)

  4. Adapting to change in the Andean Highlands: Practices and strategies to address climate and market risks in vulnerable agro-ecosystems

    OpenAIRE

    University of Missouri

    2007-01-01

    Metadata only record The project is a research and development collaboration between rural communities in the Altiplano and high valleys of Bolivia and Peru, universities and non governmental organizations in the region and the US, and institutions that formulate policy. It will strengthen the capacity of these communities and institutions to conduct research and to develop strategies to adapt to change, to reduce vulnerability and enhance biodiversity of their agro-ecosystems. Our Goal is...

  5. Understanding soil erosion impacts in temperate agroecosystems: bridging the gap between geomorphology and soil ecology using nematodes as a model organism

    OpenAIRE

    Baxter, C.; Rowan, J. S.; McKenzie, B. M.; Neilson, R.

    2013-01-01

    Soil is a key asset of natural capital, providing a myriad of goods and ecosystem services that sustain life through regulating, supporting and provisioning roles, delivered by chemical, physical and biological processes. One of the greatest threats to soil is accelerated erosion, which raises a natural process to unsustainable levels, and has downstream consequences (e.g.~economic, environmental and social). Global intensification of agroecosystems is a recognised major cau...

  6. 农田生物多样性对昆虫的生态调控作用%Effects of ecological regulation of biodiversity on insects in agroecosystems

    Institute of Scientific and Technical Information of China (English)

    周海波; 陈巨莲; 程登发; Frederic Francis; 刘勇; 孙京瑞

    2012-01-01

    With the serious problems of herbivorous insect outbreaks and species extinction caused by monocultured crops in large areas, the wide and heavy use of chemical pesticides has made the destruction and instability of agro-ecosystems to rise. Thus, based on the relationships among biodiversity-agroecosystem-herbivorous insect, studying the impacts of conservation and application of biodiversity on pest control and developing new techniques for ecological manipulation in agroecosystems have become the highlights of research on sustainable agriculture. This paper reviewed the importance and ecological effects of biodiversity on herbivorous insects in agroecosystems, and the prospects and applications of biodiversity in agricultural cultivation was further discussed.%随着农田作物的单一性种植,植食性昆虫暴发、物种流失等问题日益突出,化学农药大量应用于作物有害生物的防治更加剧了对农田生态系统的破坏和不稳定性.因此,从生物多样性-农田生态系统-植食性昆虫的相互关系入手,探讨生物多样性的保护及其在农业有害生物防控上的应用,回归农田生态系统动态平衡的生态调控举措,成为可持续发展农业领域中研究的焦点之一.本文综述了农田生物多样性对昆虫生态影响的重要性及其生态功能,进一步阐述了农田生物多样性在农业生产中的应用及前景.

  7. Changes in species diversity of arboreal spiders in Mexican coffee agroecosystems: untangling the web of local and landscape influences driving diversity

    OpenAIRE

    Zachary Hajian-Forooshani; Gonthier, David J.; Linda Marín; Iverson, Aaron L.; Ivette Perfecto

    2014-01-01

    Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosystems. Understanding what drives the diversity of groups of organisms such as spiders is important from a pragmatic point of view because of the important biocontrol services the...

  8. Tropical Agroecosystems: These habitats are misunderstood by the temperate zones, mismanaged by the tropics.

    Science.gov (United States)

    Janzen, D H

    1973-12-21

    require a great deal of pantropical information exchange. This information exchange will cost a great deal of resource, not only in travel funds and support of on-site study, but in insurance policies for the countries that are willing to take the risk of trying to change from an exploitative agroecosystem to an SYTA. For such an experiment to be sociologically successful, it will require a complete change in tropical educational systems, from emphasizing descriptions of events as they now stand, to emphasizing analysis of why things happen the way they do. This will also be very expensive, not only in retreading the technology and mind-sets of current teaching programs, but in gathering the facts on why the tropics have met their current fate. There is a surfeit of biological and agricultural reports dealing with ecological experiments and generalities which suggest that such and such will be the outcome if such and such form of resource harvest is attempted. It is clear that human desiderata regarding a particular site are often radically different from the needs of the "average" wild animals and plants that formed the basis for such experiments and generalities. A finely tuned SYTA will come close to providing a unique solution for each region. The generalities that will rule it are highly stochastic. The more tropical the region, the more evenly weighted the suboutcomes will be, and thus the more likely each region will be to have a unique overall outcome. For example, it is easy to imagine four different parts of the tropics, each with the same kind of soil and the same climate, with four different, successful SYTA's, one based on paddy rice, one on shelterwood forestry, one on tourism, and one on shifting maize culture. A regional experiment station working holistically toward an SYTA is potentially one of the best solutions available. As currently structured, however, almost all tropical experiment stations are inadequate for such a mission. Most commonly they are

  9. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan

    Science.gov (United States)

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops ( p < 0.05). Cluster analysis revealed four categories of soil arthropods according to abundance, i.e., highly abundant (Collembola, Acarina, Myripoda, Hymenoptera), moderately abundant (Orthoptera, Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface

  10. Evaluating the incorporation of heavy metals to agroecosystem. Role of the productive practices executed by agricultural workers

    International Nuclear Information System (INIS)

    Health risks associated to practical activities in farm and agriculture are increasing all over the world. These risks are depending from technology and chemicals substances abuse. Urban agriculture specifically constitutes a challenge for producers and researchers. Agricultural food production, held inside of the cities, looking for sustainable productions is developed in risky scenarios where it is possible to found environmental pollutants such as heavy metals. Environmental pollutants may to contaminate humans throughout different pathways. The analysis of factors related to agricultural working strategies of urban farm workers, the precedent knowledgement about production places and analytical data related to composition and properties of these sites, are significant criteria for proper management of ecosystems. Qualitative analysis research tool such as expert group criteria is a suitable method for field research in this area. It was determined that the precedent use of soil, the use of fertilizers and phytosanitary products are key elements to be taken into account for successful management of agroecosystems and for health risk prevention related to the possible influence of heavy metals in farm practice

  11. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    Science.gov (United States)

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-07-27

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects.

  12. Integrated evaluation of energy use, greenhouse gas emissions and global warming potential for sugar beet (Beta vulgaris) agroecosystems in Iran

    Science.gov (United States)

    Yousefi, Mohammad; Khoramivafa, Mahmud; Mondani, Farzad

    2014-08-01

    The main aim of this study was to determine and discuss the aggregate of energy use and greenhouse gas emission (CO2, N2O, and CH4) for sugar beet agroecosystems in western of Iran. For this propose data was collected by using questionnaires and face to face interview with 50 farmers. Results showed that total inputs and output energy were 49517.2 and 1095360.0 MJ ha-1, respectively. Energy use efficiency was 22.12. Total CO2, N2O and CH4 emissions due to chemical inputs were 2668.35, 22.92 and 3.49 kg, respectively. In sugar beet farms total global warming potential (GWPs) was 9847.77 kg CO2eq ha-1. In terms of CO2 equivalents, 27% of the GWPs come from CO2, 72% from N2O, and 1% from CH4. In this research input and output carbon were 29340.0 and 2678.6 kg C ha-1, respectively. Hence, carbon efficiency ratio was 10.95.

  13. Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem model

    Directory of Open Access Journals (Sweden)

    J. O. Bash

    2013-03-01

    Full Text Available Atmospheric ammonia (NH3 is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurements indicate that the air–surface exchange of NH3 is bidirectional. However, the effects of bidirectional exchange, soil biogeochemistry and human activity are not parameterized in air quality models. The US Environmental Protection Agency's (EPA Community Multiscale Air-Quality (CMAQ model with bidirectional NH3 exchange has been coupled with the United States Department of Agriculture's (USDA Environmental Policy Integrated Climate (EPIC agroecosystem model. The coupled CMAQ-EPIC model relies on EPIC fertilization timing, rate and composition while CMAQ models the soil ammonium (NH4+ pool by conserving the ammonium mass due to fertilization, evasion, deposition, and nitrification processes. This mechanistically coupled modeling system reduced the biases and error in NHx (NH3 + NH4+ wet deposition and in ambient aerosol concentrations in an annual 2002 Continental US (CONUS domain simulation when compared to a 2002 annual simulation of CMAQ without bidirectional exchange. Fertilizer emissions estimated in CMAQ 5.0 with bidirectional exchange exhibits markedly different seasonal dynamics than the US EPA's National Emissions Inventory (NEI, with lower emissions in the spring and fall and higher emissions in July.

  14. Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem model

    Science.gov (United States)

    Bash, J. O.; Cooter, E. J.; Dennis, R. L.; Walker, J. T.; Pleim, J. E.

    2013-03-01

    Atmospheric ammonia (NH3) is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurements indicate that the air-surface exchange of NH3 is bidirectional. However, the effects of bidirectional exchange, soil biogeochemistry and human activity are not parameterized in air quality models. The US Environmental Protection Agency's (EPA) Community Multiscale Air-Quality (CMAQ) model with bidirectional NH3 exchange has been coupled with the United States Department of Agriculture's (USDA) Environmental Policy Integrated Climate (EPIC) agroecosystem model. The coupled CMAQ-EPIC model relies on EPIC fertilization timing, rate and composition while CMAQ models the soil ammonium (NH4+) pool by conserving the ammonium mass due to fertilization, evasion, deposition, and nitrification processes. This mechanistically coupled modeling system reduced the biases and error in NHx (NH3 + NH4+) wet deposition and in ambient aerosol concentrations in an annual 2002 Continental US (CONUS) domain simulation when compared to a 2002 annual simulation of CMAQ without bidirectional exchange. Fertilizer emissions estimated in CMAQ 5.0 with bidirectional exchange exhibits markedly different seasonal dynamics than the US EPA's National Emissions Inventory (NEI), with lower emissions in the spring and fall and higher emissions in July.

  15. [Characteristics of evapotranspiration and crop coefficient of agroecosystems in semi-arid area of Loess Plateau, Northwest China].

    Science.gov (United States)

    Yang, Fu-Lin; Zhang, Qiang; Wang, Run-Yuan; Wang, Sheng; Yue, Ping; Wang, He-Ling; Zhao, Hong

    2013-05-01

    Evapotranspiration (ET) is an important component of ground surface energy balance and water balance, and closely related to water cycle. By using eddy covariance technique, this paper studied the ET characteristics of agroecosystems in the semi-arid area of Loess Plateau in growth season (from April to September), 2010, and analyzed the relationships between crop coefficient and environmental factors. During the observation period, the diurnal variation of latent heat flux (LE) in each month was similar to single-peak curve, and the peak value (151.4 W x m(-2)) occurred in August. The daytime energy partitioning manner showed a significant seasonal variation, with LE/R(n) heat flux) from April to June, and LE/R(n) > H/R(n) from July to September. The daily ET rate also showed a significant seasonal variation, with the maximum of 4.69 mm x d(-1). The wind speed (W(s)), relative humidity (RH), soil water content (theta), and atmospheric vapor pressure deficit (D) were the major factors affecting the crop coefficient K(c) which was exponentially decreased with increasing W(s), exponentially increased with increasing RH and theta, and linearly decreased with increasing D.

  16. Review of agro-ecosystem services and their values%农田生态系统服务及其价值的研究进展

    Institute of Scientific and Technical Information of China (English)

    谢高地; 肖玉

    2013-01-01

    农田生态系统在人类控制下已逐渐演变成了提供农产品的集约化生产系统.尽管与自然生态系统相比,农田生态系统服务功能有所下降,但其在提供农产品的同时还在向人类提供大量的生态服务.近年来,生态系统服务稀缺性变得越来越突出,农田生态系统的多功能性受到了空前的重视.本文首先明确了农田生物多样性是农田提供多种生态系统服务的基础,然后回顾了2000年以来国内外农田生态系统服务及其价值化领域取得的主要研究进展,包括对农田产品供给、碳汇、土壤保持和养分循环、水调节等功能的评价以及对农田生态系统服务及其价值化的综合研究.与此同时,我们也应该注意到农业生产还对人类社会和自然环境产生了各种消极影响,认识到权衡农田生态系统在农业生产中的各项利弊的重要性.通过对比不同农业生产模式对农田生态系统服务供给的影响,提出未来发展多功能农业将是实现农田对人类福祉最大化的重要方向.最后,文章指出我国发展多功能农业的主要措施是:(1)确保18亿亩耕地在空间上的存在;(2)与森林、草地、湿地、水域等其他自然生态系统在空间上合理配置;(3)在农业区域充分发展以观光休闲功能为主的休闲农业,实现农田生态系统社会文化价值;(4)逐步实施农业生态补偿.%Agro-ecosystem has become an integrated crop production system with significant human disturbances.Compared with natural ecosystems,the crop production function of agro-ecosystem has intensified while impairing other ecosystem services such as gas/water regulation,soil conservation and biodiversity maintenance.In recent years,agro-ecosystem services have become more and more scarce because of large demand by the rapid global development.This has resulted in an increasing concern about the values and services of agro-ecosystems across the globe.This study

  17. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: Food consumption and nutrient recycling by waterbirds in Mediterranean rice fields

    Energy Technology Data Exchange (ETDEWEB)

    Navedo, Juan G., E-mail: jgnavedo@uach.cl [Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Facultad de Ciencias, Campus Isla Teja, 5090000 Valdivia (Chile); Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Hahn, Steffen [Department Bird Migration, Swiss Ornithological Institute, Seerose 1, 6204 Sempach (Switzerland); Parejo, Manuel; Abad-Gómez, José M. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Gutiérrez, Jorge S. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Department of Marine Ecology, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, Texel (Netherlands); Villegas, Auxiliadora; Sánchez-Guzmán, Juan M.; Masero, José A. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain)

    2015-04-01

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food consumption on rice fields by overwintering waterbirds in one of the most important areas for rice production in southwestern Europe and a key area for various migrating and resident waterbird species. Herein, we modelled the nutrient (N and P) recycling in rice fields, and their transport to reservoirs. The energy consumption by waterbirds (96,605 ± 18,311 individuals) on rice fields during winter averaged at 89.9 ± 39.0 kJ·m{sup −2}, with its majority (89.9%) belonging to foraging on rice seeds. Thus, the birds removed about 26% of rice seeds leftover after harvest (estimated in 932.5 ± 504.7 seeds·m{sup −2} in early winter) wherein common cranes and dabbling ducks (four species) were the most important consumers. Waterbirds foraging and roosting in the rice fields recycled more than 24.1 (1.0 kg·ha{sup −1}) of N and an additional 5.0 tons (0.2 kg·ha{sup −1}) of P in the Extremadura's rice fields during winter. Additionally, we estimated that 2.3 tons of N and 550 kg of P were removed from rice fields and transported to reservoirs. The seasonal foraging of wildlife should result in a direct benefit for rice farmers by improving nutrient recycling through defecation by waterbirds with respect to artificial fertilisation. Additionally, rice fields located in the cranes' core wintering areas can provide sufficient food supply to induce habitat shift from their traditional wintering habitat in ‘dehesas’ to rice fields, which causes indirect socioeconomic benefit through reduced acorn consumption by cranes. Our modelling approach may thus be especially helpful for management decisions regarding rice agroecosystems in areas which are also important

  18. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: Food consumption and nutrient recycling by waterbirds in Mediterranean rice fields

    International Nuclear Information System (INIS)

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food consumption on rice fields by overwintering waterbirds in one of the most important areas for rice production in southwestern Europe and a key area for various migrating and resident waterbird species. Herein, we modelled the nutrient (N and P) recycling in rice fields, and their transport to reservoirs. The energy consumption by waterbirds (96,605 ± 18,311 individuals) on rice fields during winter averaged at 89.9 ± 39.0 kJ·m−2, with its majority (89.9%) belonging to foraging on rice seeds. Thus, the birds removed about 26% of rice seeds leftover after harvest (estimated in 932.5 ± 504.7 seeds·m−2 in early winter) wherein common cranes and dabbling ducks (four species) were the most important consumers. Waterbirds foraging and roosting in the rice fields recycled more than 24.1 (1.0 kg·ha−1) of N and an additional 5.0 tons (0.2 kg·ha−1) of P in the Extremadura's rice fields during winter. Additionally, we estimated that 2.3 tons of N and 550 kg of P were removed from rice fields and transported to reservoirs. The seasonal foraging of wildlife should result in a direct benefit for rice farmers by improving nutrient recycling through defecation by waterbirds with respect to artificial fertilisation. Additionally, rice fields located in the cranes' core wintering areas can provide sufficient food supply to induce habitat shift from their traditional wintering habitat in ‘dehesas’ to rice fields, which causes indirect socioeconomic benefit through reduced acorn consumption by cranes. Our modelling approach may thus be especially helpful for management decisions regarding rice agroecosystems in areas which are also important for the conservation of

  19. Effects of CO{sub 2} gas as leaks from geological storage sites on agro-ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Ravi H.; Colls, Jeremy J. [Division of Agricultural and Environmental Sciences, School of Biosciences, University of Nottingham, NG7 2RD, Nottingham (United Kingdom); Steven, Michael D. [School of Geography, University of Nottingham, NG7 2RD, Nottingham (United Kingdom)

    2010-12-15

    Carbon capture and storage in geological formations has potential risks in the long-term safety because of the possibility of CO{sub 2} leakage. Effects of leaking gas, therefore, on vegetation, soil, and soil-inhabiting organisms are critical to understand. An artificial soil gassing and response detection field facility developed at the University of Nottingham was used to inject CO{sub 2} gas at a controlled flow rate (1 l min{sup -1}) into soil to simulate build-up of soil CO{sub 2} concentrations and surface fluxes from two land use types: pasture grassland, and fallow followed by winter bean. Mean soil CO{sub 2} concentrations was significantly higher in gassed pasture plots than in gassed fallow plots. Germination of winter bean sown in gassed fallow plots was severely hindered and the final crop stand was reduced to half. Pasture grass showed stress symptoms and above-ground biomass was significantly reduced compared to control plot. A negative correlation (r = -0.95) between soil CO{sub 2} and O{sub 2} concentrations indicated that injected CO{sub 2} displaced O{sub 2} from soil. Gassing CO{sub 2} reduced soil pH both in grass and fallow plots (p = 0.012). The number of earthworm castings was twice as much in gassed plots than in control plots. This study showed adverse effects of CO{sub 2} gas on agro-ecosystem in case of leakage from storage sites to surface. (author)

  20. Can climate change jeopardize predator control of invasive herbivore species? A case study in avocado agro-ecosystems in Spain.

    Science.gov (United States)

    Montserrat, Marta; Sahún, Rosa María; Guzmán, Celeste

    2013-02-01

    Climate change is one of the most important factors affecting the phenology, distribution, composition and diversity of organisms. In agricultural systems many pests and natural enemies are arthropods. As poikilotherm organisms, their body temperature is highly dependent on environmental conditions. Because higher trophic levels typically have lower tolerance to high temperatures than lower trophic levels, trends towards increasing local or regional temperatures may affect the strength of predator/prey interactions and disrupt pest control. Furthermore, increasing temperatures may create climate corridors that could facilitate the invasion and establishment of invasive species originating from warmer areas. In this study we examined the effect of environmental conditions on the dynamics of an agro-ecosystem community located in southern Spain, using field data on predator/prey dynamics and climate gathered during four consecutive years. The study system was composed of an ever-green tree species (avocado), an exotic tetranychid mite, and two native species of phytoseiid mites found in association with this new pest. We also present a climatological analysis of the temperature trend in the area of study during the last 28 years, as evidence of temperature warming occurring in the area. We found that the range of temperatures with positive per capita growth rates was much wider in prey than in predators, and that relative humidity contributed to explain the growth rate variation in predators, but not in prey. Predator and prey differences in thermal performance curves could explain why natural enemies did not respond numerically to the pest when environmental conditions were harsh.

  1. Greenhouse gas emissions from agro-ecosystems and their contribution to environmental change in the Indus Basin of Pakistan

    Science.gov (United States)

    Iqbal, M. Mohsin; Goheer, M. Arif

    2008-11-01

    There is growing concern that increasing concentrations of greenhouse gases in the atmosphere have been responsible for global warming through their effect on radiation balance and temperature. The magnitude of emissions and the relative importance of different sources vary widely, regionally and locally. The Indus Basin of Pakistan is the food basket of the country and agricultural activities are vulnerable to the effects of global warming due to accelerated emissions of GHGs. Many developments have taken place in the agricultural sector of Pakistan in recent decades in the background of the changing role of the government and the encouragement of the private sector for investment in new ventures. These interventions have considerable GHG emission potential. Unfortunately, no published information is currently available on GHG concentrations in the Indus Basin to assess their magnitude and emission trends. The present study is an attempt to estimate GHG (CO2, CH4 and N2O) emissions arising from different agro-ecosystems of Indus Basin. The GHGs were estimated mostly using the IPCC Guidelines and data from the published literature. The results showed that CH4 emissions were the highest (4.126 Tg yr-1) followed by N2O (0.265 Tg yr-1) and CO2 (52.6 Tg yr-1). The sources of CH4 are enteric fermentation, rice cultivation and cultivation of other crops. N2O is formed by microbial denitrification of NO3 produced from applied fertilizer-N on cropped soils or by mineralization of native organic matter on fallow soils. CO2 is formed by the burning of plant residue and by soil respiration due to the decomposition of soil organic matter.

  2. Characterization of enteropathogenic and Shiga toxin-producing Escherichia coli in cattle and deer in a shared agroecosystem

    Directory of Open Access Journals (Sweden)

    Pallavi eSingh

    2015-04-01

    Full Text Available Shiga toxin-producing Escherichia coli (STEC is an important foodborne pathogen. Cattle are suggested to be an important reservoir for STEC; however, these pathogens have also been isolated from other livestock and wildlife. In this study we sought to investigate transmission of STEC, enterohemorrhagic E. coli (EHEC and enteropathogenic E. coli (EPEC between cattle and white-tailed deer in a shared agroecosystem. Cattle feces were collected from 100 animals in a Michigan dairy farm in July 2012, while 163 deer fecal samples were collected during two sampling periods (March and June. The locations of deer fecal pellets were recorded via geographic information system mapping and microsatellite multi-locus genotyping was used to link the fecal samples to individual deer at both time points. Following subculture to sorbitol MacConkey agar and STEC CHROMagar, the pathogens were characterized by serotyping, stx profiling, and PCR-based fingerprinting; multilocus sequence typing (MLST was performed on a subset. STEC and EHEC were cultured from 12% and 16% of cattle, respectively, and EPEC was found in 36%. Deer were significantly less likely to have a pathogen in March versus June where the frequency of STEC, EHEC, and EPEC was 1%, 6% and 22%, respectively. PCR fingerprinting and MLST clustered the cattle- and deer-derived strains together in a phylogenetic tree. Two STEC strains recovered from both animal species shared MLST and fingerprinting profiles, thereby providing evidence of interspecies transmission and highlighting the importance of wildlife species in pathogen shedding dynamics and persistence in the environment and cattle herds.

  3. The Role of Soil Biological Function in Regulating Agroecosystem Services and Sustainability in the Quesungual Agroforestry System

    Science.gov (United States)

    Fonte, S.; Pauli, N.; Rousseau, L.; SIX, J. W. U. A.; Barrios, E.

    2014-12-01

    The Quesungual agroforestry system from western Honduras has been increasingly promoted as a promising alternative to traditional slash-and-burn agriculture in tropical dry forest regions of the Americas. Improved residue management and the lack of burning in this system can greatly impact soil biological functioning and a number of key soil-based ecosystem services, yet our understanding of these processes has not been thoroughly integrated to understand system functionality as a whole that can guide improved management. To address this gap, we present a synthesis of various field studies conducted in Central America aimed at: 1) quantifying the influence of the Quesungual agroforestry practices on soil macrofauna abundance and diversity, and 2) understanding how these organisms influence key soil-based ecosystem services that ultimately drive the success of this system. A first set of studies examined the impact of agroecosystem management on soil macrofauna populations, soil fertility and key soil processes. Results suggest that residue inputs (derived from tree biomass pruning), a lack of burning, and high tree densities, lead to conditions that support abundant, diverse soil macrofauna communities under agroforestry, with soil organic carbon content comparable to adjacent forest. Additionally, there is great potential in working with farmers to develop refined soil quality indicators for improved land management. A second line of research explored interactions between residue management and earthworms in the regulation of soil-based ecosystem services. Earthworms are the most prominent ecosystem engineers in these soils. We found that earthworms are key drivers of soil structure maintenance and the stabilization of soil organic matter within soil aggregates, and also had notable impacts on soil nutrient dynamics. However, the impact of earthworms appears to depend on residue management practices, thus indicating the need for an integrated approach for

  4. Earth Observation Based Assessment of the Water Production and Water Consumption of Nile Basin Agro-Ecosystems

    Directory of Open Access Journals (Sweden)

    Wim G.M. Bastiaanssen

    2014-10-01

    Full Text Available The increasing competition for water resources requires a better understanding of flows, fluxes, stocks, and the services and benefits related to water consumption. This paper explains how public domain Earth Observation data based on Moderate Resolution Imaging Spectroradiometer (MODIS, Second Generation Meteosat (MSG, Tropical Rainfall Measurement Mission (TRMM and various altimeter measurements can be used to estimate net water production (rainfall (P > evapotranspiration (ET and net water consumption (ET > P of Nile Basin agro-ecosystems. Rainfall data from TRMM and the Famine Early Warning System Network (FEWS-NET RainFall Estimates (RFE products were used in conjunction with actual evapotranspiration from the Operational Simplified Surface Energy Balance (SSEBop and ETLook models. Water flows laterally between net water production and net water consumption areas as a result of runoff and withdrawals. This lateral flow between the 15 sub-basins of the Nile was estimated, and partitioned into stream flow and non-stream flow using the discharge data. A series of essential water metrics necessary for successful integrated water management are explained and computed. Net water withdrawal estimates (natural and humanly instigated were assumed to be the difference between net rainfall (Pnet and actual evapotranspiration (ET and some first estimates of withdrawals—without flow meters—are provided. Groundwater-dependent ecosystems withdraw large volumes of groundwater, which exceed water withdrawals for the irrigation sector. There is a strong need for the development of more open-access Earth Observation databases, especially for information related to actual ET. The fluxes, flows and storage changes presented form the basis for a global framework to describe monthly and annual water accounts in ungauged river basins.

  5. Innovations and Lessons Learned Developing the USDA Long-Term Agroecosystem Research Network Common Observatory Data Repository

    Science.gov (United States)

    Campbell, J. D.; Heilman, P.; Goodrich, D. C.; Sadler, J.

    2015-12-01

    The objective for the USDA Long-Term Agroecosystem Research (LTAR) network Common Observatory Repository (CORe) is to provide data management services including archive, discovery, and access for consistently observed data across all 18 nodes. LTAR members have an average of 56 years of diverse historic data. Each LTAR has designated a representative 'permanent' site as the location's common meteorological observatory. CORe implementation is phased, starting with meteorology, then adding hydrology, eddy flux, soil, and biology data. A design goal was to adopt existing best practices while minimizing the additional data management duties for the researchers. LTAR is providing support for data management specialists at the locations and the National Agricultural Library is providing central data management services. Maintaining continuity with historical observations is essential, so observations from both the legacy and new common methods are included in CORe. International standards are used to store robust descriptive metadata (ISO 19115) for the observation station and surrounding locale (WMO), sensors (Sensor ML), and activity (e.g., re-calibration, locale changes) to provide sufficient detail for novel data re-use for the next 50 years. To facilitate data submission a simple text format was designed. Datasets in CORe will receive DOIs to encourage citations giving fair credit for data providers. Data and metadata access are designed to support multiple formats and naming conventions. An automated QC process is being developed to enhance comparability among LTAR locations and to generate QC process metadata. Data provenance is maintained with a permanent record of changes including those by local scientists reviewing the automated QC results. Lessons learned so far include increase in site acceptance of CORe with the decision to store data from both legacy and new common methods. A larger than anticipated variety of currently used methods with potentially

  6. Greenhouse Gas Emissions from Agro-Ecosystems and Their Contribution to Environmental Change in the Indus Basin of Pakistan

    Institute of Scientific and Technical Information of China (English)

    M. Mohsin IQBAL; M. Arif GOHEER

    2008-01-01

    There is growing concern that increasing concentrations of greenhouse gases in the atmosphere have been responsible for global warming through their effect on radiation balance and temperature. The magnitude of emissions and the relative importance of different sources vary widely, regionally and locally. The Indus Basin of Pakistan is the food basket of the country and agricultural activities are vulnerable to the effects of global warming due to accelerated emissions of GHGs. Many developments have taken place in the agricultural sector of Pakistan in recent decades in the background of the changing role of the government and the encouragement of the private sector for investment in new ventures. These interventions have considerable GHG emission potential. Unfortunately, no published information is currently available on GHC concentrations in the Indus Basin to assess their magnitude and emission trends. The present study is an attempt to estimate GHG (CO2, CH4 and N2O) emissions arising from different agro-ecosystems of Indus Basin. The GHGs were estimated mostly using the IPCC Guidelines and data from the published literature. The results showed that CH4 emissions were the highest (4.126 Tg yr-1) followed by N2O (0.265 Tg yr-1) and CO2 (52.6 Tg yr-1). The sources of CH4 are enteric fermentation, rice cultivation and cultivation of other crops. N2O is formed by microbial denitrification of NO3 produced from applied fertilizer-N on cropped soils or by mineralization of native organic matter on fallow soils. CO2 is formed by the burning of plant residue and by soil respiration due to the decomposition of soil organic matter.

  7. Multi-Seasonal Nitrogen Recoveries from Crop Residue in Soil and Crop in a Temperate Agro-Ecosystem.

    Science.gov (United States)

    Hu, Guoqing; Liu, Xiao; He, Hongbo; Zhang, Wei; Xie, Hongtu; Wu, Yeye; Cui, Jiehua; Sun, Ci; Zhang, Xudong

    2015-01-01

    In conservation tillage systems, at least 30% of the soil surface was covered by crop residues which generally contain significant amounts of nitrogen (N). However, little is known about the multi-seasonal recoveries of the N derived from these crop residues in soil-crop systems, notably in northeastern China. In a temperate agro-ecosystem, 15N-labeled maize residue was applied to field surfaces in the 1st year (2009). From the 2nd to 4th year (2010-2012), one treatment halted the application of maize residue, whereas the soil in the second treatment was re-applied with unlabeled maize residue. Crop and soil samples were collected after each harvest, and their 15N enrichments were determined on an isotope ratio mass spectrometer to trace the allocation of N derived from the initially applied maize residue in the soil-crop systems. On average, 8.4% of the maize residue N was recovered in the soil-crop in the 1st year, and the vast majority (61.9%-91.9%) was recovered during subsequent years. Throughout the experiment, the cumulative recovery of the residue N in the crop increased gradually (18.2%-20.9%), but most of the residue N was retained in the soil, notably in the 0-10 cm soil layer. Compared to the single application, the sequential residue application significantly increased the recovery of the residue N in the soil profile (73.8% vs. 40.9%) and remarkably decreased the total and the initially applied residue derived mineral N along the soil profile. Our results suggested that the residue N was actively involved in N cycling, and its release and recovery in crop and soil profile were controlled by the decomposition process. Sequential residue application significantly enhanced the retention and stabilization of the initially applied residue N in the soil and retarded its translocation along the soil profile.

  8. Multi-Seasonal Nitrogen Recoveries from Crop Residue in Soil and Crop in a Temperate Agro-Ecosystem.

    Directory of Open Access Journals (Sweden)

    Guoqing Hu

    Full Text Available In conservation tillage systems, at least 30% of the soil surface was covered by crop residues which generally contain significant amounts of nitrogen (N. However, little is known about the multi-seasonal recoveries of the N derived from these crop residues in soil-crop systems, notably in northeastern China. In a temperate agro-ecosystem, 15N-labeled maize residue was applied to field surfaces in the 1st year (2009. From the 2nd to 4th year (2010-2012, one treatment halted the application of maize residue, whereas the soil in the second treatment was re-applied with unlabeled maize residue. Crop and soil samples were collected after each harvest, and their 15N enrichments were determined on an isotope ratio mass spectrometer to trace the allocation of N derived from the initially applied maize residue in the soil-crop systems. On average, 8.4% of the maize residue N was recovered in the soil-crop in the 1st year, and the vast majority (61.9%-91.9% was recovered during subsequent years. Throughout the experiment, the cumulative recovery of the residue N in the crop increased gradually (18.2%-20.9%, but most of the residue N was retained in the soil, notably in the 0-10 cm soil layer. Compared to the single application, the sequential residue application significantly increased the recovery of the residue N in the soil profile (73.8% vs. 40.9% and remarkably decreased the total and the initially applied residue derived mineral N along the soil profile. Our results suggested that the residue N was actively involved in N cycling, and its release and recovery in crop and soil profile were controlled by the decomposition process. Sequential residue application significantly enhanced the retention and stabilization of the initially applied residue N in the soil and retarded its translocation along the soil profile.

  9. 气候变化对农田生态系统的影响及其对策研究%Effects of Climate Change on Agro-ecosystem and Its Countermeasures

    Institute of Scientific and Technical Information of China (English)

    孔维财

    2009-01-01

    The cause and status of global climate change and the impact of climate changes on the agro-ecosystem were analyzed. Some coun- termeasures on adapting to the climate change for agro-ecosystem of China in the new situation were put forward.%分析了全球气候变化的起因和现状,以及气候变化对农田生态系统的影响,并针对全球气候变化的新形势,提出了适应气候变化的农业对策.

  10. Effectivity Of Agroedutourism To Strengthen Healthy Agro-Ecosystem Awareness Of Students In Some Elementary Schools In Malang Raya, East Java

    Directory of Open Access Journals (Sweden)

    Hanin Niswatul Fauziah

    2013-07-01

    Full Text Available This research aimed to study the effectivity of agroedutourism to strengthen students’ environmental awareness, especially concerning on importance of rice organic farming system. Eighty three students were invited joining the program. They were the 5th grade of three elementary schools (SDN Ketawanggede 2, SDI Surya Buana and SDN Sumberngepoh 02. It was provided three agroedutourism programs, i.e. two outdoors programs (Farmers’ friends and enemies, Plants for biopesticide and natural attractant, as well as the indoor session called Healthy agroecosystem. Including the programs were joining ecoeco-games and tasting some food (steamed rice-bran brownies, organic red rice milk and zalacca fruits. Effectivity of the programs was evaluated using questionnaire. Data were analyzed by SPSS program using Wilcoxon test (α=0,05. Results showed overall that the agroedutourism increased significantly students cognitive, affective and even their appreciation to agricultural environment. Students of SDN Sumberngepoh 02 showed a highest agro-environmental awareness. While, the highest cognitive improvement was gained by students of SDI Surya Buana (76%, followed by SDN Ketawanggede 2 (62% and SDN Sumberngepoh 02 (47%. The most interesting program was an outdoor namely Farmers’ friends and enemies, while they preferred a steamed rice-bran brownies than the other one. They were exciting joining some eco-games especially predator and prey as well as guest animal name and its role. It seemed that the outdoor programs were more appreciated rather than the indoor one. Keywords: Agroedutourism, awareness, effectivity, healthy agro-ecosystem

  11. Changes in cropland topsoil organic carbon with different fertilizations under long-term agro-ecosystem experiments across mainland China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Topsoil soil organic carbon(SOC) data were collected from long-term Chinese agro-ecosystem experiments presented in 76 reports with measurements over 1977 and 2006.The data set comprised 481 observations(135 rice paddies and 346 dry croplands) of SOC under different fertilization schemes at 70 experimental sites(28 rice paddies and 42 dry croplands).The data set covered 16 dominant soil types found in croplands across 23 provinces of mainland China.The fertilization schemes were grouped into six categories:N(inorganic nitrogen fertilizer only),NP(compound inorganic nitrogen and phosphorus fertilizers),NPK(compound inorganic nitrogen,phosphorus and potassium fertilizers),O(organic fertilizers only),OF(combined inorganic/organic fertilization) and Others(other unbalanced fertilizations such as P only,K only,P plus K and N plus K).Relative change in SOC content was analyzed,and rice paddies and dry croplands soils were compared.There was an overall temporal increase in topsoil SOC content,and relative annual change(RAC,g kg-1 yr-1) ranged -0.14-0.60(0.13 on average) for dry cropland soils and -0.12-0.70(0.19 on average) for rice paddies.SOC content increase was higher in rice paddies than in dry croplands.SOC increased across experimental sites,but was higher under organic fertilization and combined organic/inorganic fertilizations than chemical fertilizations.SOC increase was higher under balanced chemical fertilizations with compound N,P and K fertilizers than unbalanced fertilizations such as N only,N plus P,and N plus K.The effects of specific rational fertilizations on SOC increase persisted for 15 years in dry croplands and 20 years in rice paddies,although RAC values decreased generally as the experiment duration increased.Therefore,the extension of rational fertilization in China’s croplands may offer a technical option to enhance C sequestration potential and to sustain long-term crop productivity.

  12. Relevance of traditional integrated pest management (IPM) strategies for commercial corn producers in a transgenic agroecosystem: a bygone era?

    Science.gov (United States)

    Gray, Michael E

    2011-06-01

    The use of transgenic Bt maize hybrids continues to increase significantly across the Corn Belt of the United States. In 2009, 59% of all maize planted in Illinois was characterized as a "stacked" gene variety. This is a 40% increase since 2006. Stacked hybrids typically express one Cry protein for corn rootworm control and one Cry protein for control of several lepidopteran pests; they also feature herbicide tolerance (to either glyphosate or glufosinate). Slightly more than 50 years has passed since Vernon Stern and his University of California entomology colleagues published (1959) their seminal paper on the integrated control concept, laying the foundation for modern pest management (IPM) programs. To assess the relevance of traditional IPM concepts within a transgenic agroecosystem, commercial maize producers were surveyed at a series of meetings in 2009 and 2010 regarding their perceptions on their use of Bt hybrids and resistance management. Special attention was devoted to two insect pests of corn, the European corn borer and the western corn rootworm. A high percentage of producers who participated in these meetings planted Bt hybrids in 2008 and 2009, 97 and 96.7%, respectively. Refuge compliance in 2008 and 2009, as mandated by the U.S. Environmental Protection Agency (EPA), was 82 and 75.7%, respectively, for those producers surveyed. A large majority of producers (79 and 73.3% in 2009 and 2010, respectively) revealed that they would, or had, used a Bt hybrid for corn rootworm (Diabrotica virgifera virgifera LeConte) or European corn borer (Ostrinia nubilalis Hübner) control even when anticipated densities were low. Currently, the EPA is evaluating the long-term use of seed blends (Bt and non-Bt) as a resistance management strategy. In 2010, a large percentage of producers, 80.4%, indicated they would be willing to use this approach. The current lack of integration of management tactics for insect pests of maize in the U.S. Corn Belt, due primarily to

  13. Factors affecting the abundance of wild rabbit (Oryctolagus cuniculus in agro-ecosystems of the Mount Etna Park

    Directory of Open Access Journals (Sweden)

    Susanna Caruso

    2001-09-01

    Full Text Available Abstract A study on the abundance of Wild rabbit Oryctolagus cuniculus and environmental factors which may affect its occurrence in agro-ecosystems of Mount Etna was carried out in 1998. Density data, collected monthly by pellet counts in 7 sample areas, show a mean value of 9.16 individuals per hectare; in two samples high density values were recorded and the difference compared to other areas was significant. Two peaks of abundance were recorded during the year. No significant correlation was found between rabbit density and the factors considered but altitude and percentage of abandoned cultivation seem to have a certain influence on the occurrence of the species. The main natural predators, Vulpes vulpes and Buteo buteo, do not have any negative effect on rabbit abundance.

  14. Agro-ecosystem and socio-economic role of homegarden agroforestry in Jabithenan District, North-Western Ethiopia: implication for climate change adaptation.

    Science.gov (United States)

    Linger, Ewuketu

    2014-01-01

    Homegarden agroforestry is believed to be more diverse and provide multiple services for household than other monocropping system and this is due to the combination of crops, trees and livestock. The aim of this study was to assess socio-economic and agro-ecological role of homegardens in Jabithenan district, North-western Ethiopia. Two sites purposively and two villages randomly from each site were selected. Totally 96 households; in which 48 from homegarden agroforestry user and 48 from non-tree based garden user were selected for this study. Socio-economic data and potential economic and agro-ecosystem role of homegarden agroforestry over non-tree based garden were collected by using semi-structured and structured questionnaires to the households. Homegarden agroforestry significantly (P agroforestry practice provides good socio-economical and agro-ecological service for farmers which have a higher implication for climate change adaptation than non-tree based garden.

  15. Linking spatial patterns of soil redistribution traced with 137Cs and soil nutrients in a Mediterranean mountain agroecosystem (NE Spain)

    Science.gov (United States)

    Quijano, Laura; Gaspar, Leticia; Navas, Ana

    2016-04-01

    Mediterranean mountain agroecosystems are prone to soil loss mainly due to the accelerated erosion as a consequence of human induced changes from agriculture and grazing practices over the last centuries and the climatic conditions (i.e. irregular and scarce precipitations and drought periods). Soil erosion leads to soil degradation inducing the loss of soil functions. The progressive decline of soil functions thereof soil quality is associated to a decrease of soil productivity and can threat the sustainability of cultivated soils. The use of fallout 137Cs as a soil movement tracer provides useful data to identify areas where loss and gain of 137Cs occurs and that of soil. This study aims to address soil movement and soil nutrient dynamics closely related to the status of soil degradation. A rain-fed cereal field (1.6 ha) representative of Mediterranean mountain agricultural landscapes (42°25'41''N 1°13'8''W) was selected to examine the effects of soil redistribution processes on the spatial variability of soil organic carbon (SOC) and nitrogen (SON) and their relationships with soil properties and topographic characteristics. From the hydrological point of view, the field is isolated due to the effect of landscape features and man-made structures. Climate is continental Mediterranean with an average annual rainfall of 500 mm and soils are Calcisols. The reference inventories of 137Cs and soil nutrients were established from 21 soil samples collected in nearby undisturbed areas under typical Mediterranean vegetation cover. A total of 156 bulk soil samples (30-50 cm depth) and 156 topsoil samples (5 cm) were collected on a 10 m grid. 137Cs and soil nutrients loss and gain areas were identified by comparing the reference inventories with the values of inventories at the sampling points. A new approach to characterize and measure active (ACF) and stable (SCF) carbon fraction contents by using a dry combustion method based on the oxidation temperature of carbon

  16. Wild bees and agroecosystems

    OpenAIRE

    Morandin, Lora

    2005-01-01

    Research in agriculture often focuses on development of new technologies rather than on potential environmental impacts. Pollinators, primarily bees, are essential to agriculture, providing significant yield benefit in over 66% of crop species. Currently, dramatic losses of managed honey bee pollinators in North America along with suspected world-wide losses of wild pollinators are focusing research attention on an impending but still poorly documented pollination crisis. Essential questions ...

  17. Looking beyond fertilizer: Assessing the contribution of nitrogen from hydrologic inputs and organic matter to plant growth in the cranberry agroecosystem

    Science.gov (United States)

    Stackpoole, S.M.; Kosola, K.R.; Workmaster, B.A.A.; Guldan, N.M.; Browne, B.A.; Jackson, R. D.

    2011-01-01

    Even though nitrogen (N) is a key nutrient for successful cranberry production, N cycling in cranberry agroecosystems is not completely understood. Prior research has focused mainly on timing and uptake of ammonium fertilizer, but the objective of our study was to evaluate the potential for additional N contributions from hydrologic inputs (flooding, irrigation, groundwater, and precipitation) and organic matter (OM). Plant biomass, soil, surface and groundwater samples were collected from five cranberry beds (cranberry production fields) on four different farms, representing both upland and lowland systems. Estimated average annual plant uptake (63.3 ?? 22.5 kg N ha-1 year-1) exceeded total average annual fertilizer inputs (39.5 ?? 11.6 kg N ha-1 year-1). Irrigation, precipitation, and floodwater N summed to an average 23 ?? 0.7 kg N ha-1 year-1, which was about 60% of fertilizer N. Leaf and stem litterfall added 5.2 ?? 1.2 and 24.1 ?? 3.0 kg N ha-1 year-1 respectively. The estimated net N mineralization rate from the buried bag technique was 5 ?? 0.2 kg N ha-1 year-1, which was nearly 15% of fertilizer N. Dissolved organic nitrogen represented a significant portion of the total N pool in both surface water and soil samples. Mixed-ion exchange resin core incubations indicated that 80% of total inorganic N from fertilizer, irrigation, precipitation, and mineralization was nitrate, and approximately 70% of recovered inorganic N from groundwater was nitrate. There was a weak but significant negative relationship between extractable soil ammonium concentrations and ericoid mycorrhizal colonization (ERM) rates (r = -0.22, P fertilizer N in order to maximize the benefits of ERM fungi in actively mediating N cycling in cranberry agroecosystems. ?? 2011 Springer Science+Business Media B.V.

  18. Effects of Integrated Pest Management on Pest Damage and Yield Components in a Rice Agro-Ecosystem in the Barisal Region of Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammad Zahangeer eAlam

    2016-03-01

    Full Text Available Recently, recognition of negative environmental impacts associated with overuse of pesticides in the agricultural regions of Bangladesh has made it clear that unsustainable pest-control strategies must change. Integrated Pest Management (IPM was developed for use as a tool in the production of healthy, sustainably grown food. A strategic approach to crop-pest control, IPM aims to minimize pest populations by combining environmentally friendly pest-control methods and economically viable farming practices. This study examined the impact of IPM on insect damage to crop-yield parameters in a rice agro-ecosystem. IPM methods tested were: 1 collection of egg masses; 2 sweeping (using a funnel shaped net to capture insects; 3 perching (installing a branch or pole which serves as a resting place for predatory birds; and 4 Economic Threshold Level (ETL based insecticide application (The ETL is the point at which the value of the crop destroyed exceeds the cost of controlling the pest. We also examined the effects of prophylactic insecticide application and current management practices on rice yield. Rice-yield indicators included number of healthy tillers, number of hills, central leaf drying (Dead Heart, and grain-less panicles (White Head. For two consecutive years, the lowest percentages of Dead Heart (1.23 and 1.55 and White Head (2.06 were found in the IPM-treated plots. Further, the IPM-treated plots had higher yields (7.3-7.5 ton/ha compared with the non-IPM treatments (6.28-7.02 ton/ha. The location of the plots appeared to be non-significant for all measured yield components. The effect of treatment on the percentage of Dead Heart, White Head, number of hills, and yield was statistically significant (p ≤ 0.05. We concluded that IPM is an effective strategy for obtaining high rice yields in sustainable rice agro-ecosystems.

  19. Seasonal and Annual Variations of CO2 Fluxes in Rain-Fed Winter Wheat Agro-Ecosystem of Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    WANG Wen; LIAO Yun-cheng; GUO Qiang

    2013-01-01

    To accurately evaluate the carbon sequestration potential and better elucidate the relationship between the carbon cycle and regional climate change, using eddy covariance system, we conducted a long-term measurement of CO2 fluxes in the rain-fed winter wheat field of the Chinese Loess Plateau. The results showed that the annual net ecosystem CO2 exchange (NEE) was (-71.6±5.7) and (-65.3±5.3) gCm-2y-1 for 2008-2009 and 2009-2010 crop years, respectively, suggesting that the agro-ecosystem was a carbon sink (117.4-126. 2gCm-2yr-1). However, after considering the harvested grain, the agro-ecosystem turned into a moderate carbon source. The variations in NEE and ecosystem respiration (Reco) were sensitive to changes in soil water content (SWC). When SWC ranged form 0.15 to 0.21 m3 m-3, we found a highly significant relationship between NEE and photosynthetically active radiation (PAR), and a highly significant relationship between Reco and soil temperature (Ts). However, the highly significant relationships were not observed when SWC was outside the range of 0.15-0.21 m3 m-3. Further, in spring, the Reco instantly responded to a rapid increase in SWC after effective rainfall events, which could induce 2 to 4-fold increase in daily Reco, whereas the Reco was also inhibited by heavy summer rainfall when soils were saturated. Accumulated Reco in summer fallow period decreased carbon fixed in growing season by 16-25%, indicating that the period imposed negative impacts on annual carbon sequestration.

  20. Relação entre macrofauna edáfica e atributos químicos do solo em diferentes agroecossistemas = Relationship between edaphic macrofauna and soil chemical attributes in different agroecosystems

    OpenAIRE

    Lima, S.S.; Aquino, A.M. de; Carvalho Leite, L.F.; Velasquezo, E.; Lavelle, Patrick

    2010-01-01

    The objective of this study was to evaluate land use effects on the abundance and diversity of invertebrate macrofauna and its relationship with the soil chemical characteristics in different agroecosystems. Five systems were studied: ecological based system at three years of adoption (ES3), agroforestry systems at six (AFS6) and ten years of adoption (AFS10), slash and burn agriculture (SBA), and native forest (NF). In each system, five samples were collected in the form of soil monoliths (2...

  1. The impact of land-use and global change on water-related agro-ecosystem services in the midwest US

    Science.gov (United States)

    VanLoocke, Andrew D.

    Humans have and are likely to continue to dramatically alter both the global landscape through the conversion of natural ecosystems into agriculture, and the atmosphere through the combustion of biomass and fossil fuels to meet the need for food and energy. Associated with these land use and global changes are major alterations in the biogeochemical cycles of carbon, water, and nitrogen, which have important implications on the growth and function of ecosystems and the services they provide for humanity. This dissertation investigates the impacts on water-related agro-ecosystem services associated with increasing concentrations of the tropospheric pollutant ozone ([O 3]) and land use change for cellulosic feedstocks in the Midwestern United States. This study focused on quantifying changes in water-related agro-ecosystem services including direct changes to water quantity, water use efficiency (WUE) that links the carbon cycle to water, and water quality that links the nitrogen cycle to water. In the context of these land-use and global changes and the associated changes in water-related agro-ecosystem services, the goals of this research are to: 1) determine the concentration at which soybean latent heat flux (lambdaET) is sensitive to O3, test whether decreases in lambda ET are linked with the concentration of O3, and find whether an increase in O3 has an impact on WUE 2) determine the regional distribution of water use and WUE for Miscanthus x giganteus (miscanthus) and Panicum virgatum (switchgrass) two of the leading candidate cellulosic feedstocks, relative to Zea mays L. (maize), the current dominant ethanol feedstock 3) determine the change in streamflow in the Mississippi-Atchafalya River Basin (MARB) and the export of dissolved inorganic nitrogen (DIN) to the Gulf of Mexico hypoxic region associated with large-scale production of miscanthus and switchgrass. Micrometeorological measurements were made at the Soybean Free Air Concentration Enrichment

  2. Reduced tillage and cover crops as a strategy for mitigating atmospheric CO2 increase through soil organic carbon sequestration in dry Mediterranean agroecosystems.

    Science.gov (United States)

    Almagro, María; Garcia-Franco, Noelia; de Vente, Joris; Boix-Fayos, Carolina; Díaz-Pereira, Elvira; Martínez-Mena, María

    2016-04-01

    The implementation of sustainable land management (SLM) practices in semiarid Mediterranean agroecosystems can be beneficial to maintain or enhance levels of soil organic carbon and mitigate current atmospheric CO2 increase. In this study, we assess the effects of different tillage treatments (conventional tillage (CT), reduced tillage (RT), reduced tillage combined with green manure (RTG), and no tillage (NT)) on soil CO2 efflux, aggregation and organic carbon stabilization in two semiarid organic rainfed almond (Prunus dulcis Mill., var. Ferragnes) orchards located in SE Spain Soil CO2 efflux, temperature and moisture were measured monthly between May 2012 and December 2014 (site 1), and between February 2013 and December 2014 (site 2). In site 1, soil CO2 efflux rates were also measured immediately following winter and spring tillage operations. Aboveground biomass inputs were estimated at the end of the growing season in each tillage treatment. Soil samples (0-15 cm) were collected in the rows between the trees (n=4) in October 2012. Four aggregate size classes were distinguished by sieving (large and small macroaggregates, free microaggregates, and free silt plus clay fraction), and the microaggregates occluded within macroaggregates (SMm) were isolated. Soil CO2efflux rates in all tillage treatments varied significantly during the year, following changes during the autumn, winter and early spring, or changes in soil moisture during late spring and summer. Repeated measures analyses of variance revealed that there were no significant differences in soil CO2 efflux between tillage treatments throughout the study period at both sites. Average annual values of C lost by soil respiration were slightly but not significantly higher under RT and RTG treatments (492 g C-CO2 m-2 yr-1) than under NT treatment (405 g C-CO2 m-2 yr-1) in site 1, while slightly but not significantly lower values were observed under RT and RTG treatments (468 and 439 g C-CO2 m-2 yr-1

  3. Adopt to sustain: The effect of biophysical and socioeconomic context on the ability of two contrasting U.S. agroecosystems to respond to changes

    Science.gov (United States)

    Papanicolaou, T.

    2015-12-01

    Increased demand for food, feed, fuel and fiber in U.S. agroecosystems has deleterious effects on the environment. Gauging the responses of these agroecosystems in the presence of extreme events and new market demands requires a fresh approach. This approach requires better comprehension of the interactions and feedback processes that either sustain or deplete both natural (e.g., soil productivity) and human (e.g., net income) capital. Because soil quality defines land productivity and long-term prosperity, we focus on the cascading effects that soil quality has on other ecosystem properties, profit, farmer decision making in mitigating soil degradation, and development of environmental policies. We argue that land use decision-making must not only be strictly based on socioeconomic and environmental criteria, but should also consider farmer/ farm characteristics, personal beliefs, and the support network that is needed for promoting and implementing conservation practices. Current approaches for adopting conservation do not fit into this paradigm. We develop an Agent Based Model Framework that incorporates novel aspects of ecological, socioeconomic and behavioral modeling to facilitate interactions of the farmer and its land through a multi-objective, maximization utility function. This function is continuously informed and updated by the improved modeling framework. This study is developing measures of sustainability for lags, hysteresis, tipping points, and adaptive capacity. We examine the complex relationship between farmer decision-making and the landscape in two contrasting systems in Iowa and Tennessee with unique distributions of characteristics in terms of climate, soil properties, and landscape patterns that regulate not only the type of farming practiced, but also the degree of soil erosion in each system. Central to this investigation is identifying and quantifying trade-offs among non-pecuniary and pecuniary objectives given alternative scenarios

  4. Efectos de diferentes agroecosistemas en la dinámica de nitrógeno, fósforo y potasio en un cultivo de tomate Effects of different agro-ecosystems in the dynamic of nitrogen, phosphorous, and potassium in the tomato crop

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Bouzo

    Full Text Available El objetivo de este trabajo fue evaluar la dinámica del nitrógeno, fósforo y potasio en cultivos de tomate y suelos en diferentes agroecosistemas. El trabajo consistió en estudiar el efecto de tres agroecosistemas: agrícola (T1, natural (T2 y hortícola (T3. Estos agroecosistemas se caracterizaron por la secuencia de los cultivos de maíz y trigo durante 8 años (T1, vegetación natural de gramíneas (T2 y rotaciones de cultivos hortícolas durante 20 años (T3. El estudio fue realizado en Santa Fe, Argentina (31° 15' S, 60° 50' W entre 2009 y 2010, habiéndose utilizado un cultivar de tomate híbrido redondo de crecimiento indeterminado. La concentración de N-NO3- en los suelos tuvo un valor alto (The objective ofthis research was to evaluate the dynamics of nitrogen, phosphorous, and potassium in tomato crops and in different soils of agro-ecosystems. The research consisted of studying the effect of three agro-ecosystems: 1 agricultural (T1, natural (T2 and horticultural (T3. These agro-ecosystems are characterized by the sequence of the maize and wheat crops during 8 years (T1, natural vegetation of grasses (T2, and rotation of horticultural crops during 20 years (T3. The study was done in Santa Fe, Argentina (31° 15' S, 60° 50' W between 2009 and 2010, having used a hybrid tomato crop, round with indeterminate growth. The concentration of N-NO3- in the soils had a high value (< 65 ppm at the beginning of the crop in the three agro-ecosystems. The concentration of P was also very high (< 250 ppm in the horticultural agro-ecosystem (T3 and less than the rest, with approximately 50 ppm for T1 and 150 ppm for T2. The same occurred in this agro-ecosystem with K. The natural agro-ecosystem (T2 was the one that had the lowest concentration of P in the soil. The concentrations of N, P, and K resulted with highly significant differences (p≤ 0.01 in the concentrations of the stalks of the plants coming from the three agro-ecosystems

  5. Understanding soil erosion impacts in temperate agroecosystems: bridging the gap between geomorphology and soil ecology using nematodes as a model organism

    Science.gov (United States)

    Baxter, C.; Rowan, J. S.; McKenzie, B. M.; Neilson, R.

    2013-11-01

    Soil is a key asset of natural capital, providing a myriad of goods and ecosystem services that sustain life through regulating, supporting and provisioning roles, delivered by chemical, physical and biological processes. One of the greatest threats to soil is accelerated erosion, which raises a natural process to unsustainable levels, and has downstream consequences (e.g.~economic, environmental and social). Global intensification of agroecosystems is a recognised major cause of soil erosion which, in light of predicted population growth and increased demand for food security, will continue or increase. Transport and redistribution of biota by soil erosion has hitherto been ignored and thus is poorly understood. With the move to sustainable intensification this is a key knowledge gap that needs to be addressed. Here we highlight the erosion-energy and effective-erosion-depth continuum in soils, differentiating between different forms of soil erosion, and argue that nematodes are an appropriate model taxa to investigate impacts of erosion on soil biota across scales. We review the different known mechanisms of soil erosion that impact on soil biota in general, and nematodes in particular, and highlight the few detailed studies, primarily from tropical regions, that have considered soil biota. Based on the limited literature and using nematodes as a model organism we outline future research priorities to initially address the important interrelationships between soil erosion processes and soil biota.

  6. Atmospheric deposition, resuspension and root uptake of plutonium in corn and other grain-producing agroecosystems near a nuclear fuel facility

    International Nuclear Information System (INIS)

    Plutonium released to the environment may contribute to dose to humans through inhalation or ingestion of contaminated foodstuffs. Plutonium contamination of agricultural plants may result from interception and retention of atmospheric deposition, resuspension of Pu-bearing soil particles to plant surfaces, and root uptake and translocation to grain. Plutonium on vegetation surfaces may be transferred to grain surfaces during mechanical harvesting. Data obtained from corn grown near the US Department of Energy's H-Area nuclear fuel chemical separations facility on the Savannah River Site was used to estimated parameters of a simple model of Pu transport in agroecosystems. The parameter estimates for corn were compared to those previously obtained for wheat and soybeans. Despite some differences in parameter estimates among crops, the relative importances of atmospheric deposition, resuspension and root uptake were similar among crops. For even small deposition rates, the relative importances of processes for Pu contamination of corn grain should be: transfer of atmospheric deposition from vegetation surfaces to grain surfaces during combining > resuspension of soil to grain surfaces > root uptake. Approximately 3.9 x 10-5 of a year's atmospheric deposition is transferred to grain. Approximately 6.2 x 10-9 of the Pu inventory in the soil is resuspended to corn grain, and a further 7.3 x 10-10 of the soil inventory is absorbed by roots and translocated to grains

  7. Seasonal sex ratio distortion in Glossina tachinoides Westwood populations inhabiting peridomestic agro-ecosystems of the Nsukka area, Anambra state, Nigeria, in relation to the sterile insect technique

    International Nuclear Information System (INIS)

    Glossina tachinoides Westwood populations inhabiting Nsukka peridomestic agro-ecosystems were sampled for sex composition with unbaited blue biconical traps deployed in a cross-section of the biotopes from 06:30 to 18:30 h weekly from April 1983 to March 1987. The sex ratio deviated significantly from 1:1 in favour of males at two locations and in favour of females at a third location. Samples from biotopes where domestic pigs were usually present contained either equal proportions of both sexes or higher proportions of females in contrast to those from biotopes where pigs were scarce or absent, which invariably contained very high proportions of males. There was a marked seasonal difference in the monthly sex ratio, with samples containing higher proportions of females during the wet season (April to October) than in the dry season (November to March). This seasonal variation in sex ratio distortion was significantly correlated with seasonal fluctuations in 'fly apparent density'. These findings are discussed in the light of literature on the sex ratio in tsetse fly populations and their application in the sterile insect technique for tsetse fly control/eradication. (author). 29 refs, 3 figs, 3 tabs

  8. Evaluation of a regional air-quality model with bi-directional NH3 exchange coupled to an agro-ecosystem model

    Directory of Open Access Journals (Sweden)

    J. E. Pleim

    2012-08-01

    Full Text Available Atmospheric ammonia (NH3 is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurements indicate that the air-surface exchange of NH3 is bi-directional. However, the effects of bi-directional exchange, soil biogeochemistry and human activity are not parameterized in air quality models. The US Environmental Protection Agency (EPA's Community Multiscale Air-Quality (CMAQ model with bi-directional NH3 exchange has been coupled with the United States Department of Agriculture (USDA's Environmental Policy Integrated Climate (EPIC agro-ecosystem model's nitrogen geochemistry algorithms. CMAQ with bi-directional NH3 exchange coupled to EPIC connects agricultural cropping management practices to emissions and atmospheric concentrations of reduced nitrogen and models the biogeochemical feedback on NH3 air-surface exchange. This coupled modeling system reduced the biases and error in NHx (NH3 + NH4+ wet deposition and in ambient aerosol concentrations in an annual 2002 Continental US (CONUS domain simulation when compared to a 2002 annual simulation of CMAQ without bi-directional exchange. Fertilizer emissions estimated in CMAQ 5.0 with bi-directional exchange exhibits markedly different seasonal dynamics than the US EPA's National Emissions Inventory (NEI, with lower emissions in the spring and fall and higher emissions in July.

  9. Changes in species diversity of arboreal spiders in Mexican coffee agroecosystems: untangling the web of local and landscape influences driving diversity

    Directory of Open Access Journals (Sweden)

    Zachary Hajian-Forooshani

    2014-11-01

    Full Text Available Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosystems. Understanding what drives the diversity of groups of organisms such as spiders is important from a pragmatic point of view because of the important biocontrol services they offer to agriculture. Spiders in coffee are somewhat enigmatic because of their positive or lack of response to agricultural intensification. In this study, we provide the first analysis, to our knowledge, of the arboreal spiders in the shade trees of coffee plantations. In the Soconusco region of Chiapas, Mexico we sampled across 38 sites on 9 coffee plantations. Tree and canopy connectedness were found to positively influence overall arboreal spider richness and abundance. We found that different functional groups of spiders are responding to different local and landscape factors, but overall elevation was most important variable influencing arboreal spider diversity. Our study has practical management applications that suggest having shade grown coffee offers more suitable habitat for arboreal spiders due to a variety of the characteristics of the shade trees. Our results which show consistently more diverse arboreal spider communities in lower elevations are important in light of looming global climate change. As the range of suitable elevations for coffee cultivation shrinks promoting arboreal spider diversity will be important in sustaining the viability of coffee.

  10. Changes in species diversity of arboreal spiders in Mexican coffee agroecosystems: untangling the web of local and landscape influences driving diversity.

    Science.gov (United States)

    Hajian-Forooshani, Zachary; Gonthier, David J; Marín, Linda; Iverson, Aaron L; Perfecto, Ivette

    2014-01-01

    Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosystems. Understanding what drives the diversity of groups of organisms such as spiders is important from a pragmatic point of view because of the important biocontrol services they offer to agriculture. Spiders in coffee are somewhat enigmatic because of their positive or lack of response to agricultural intensification. In this study, we provide the first analysis, to our knowledge, of the arboreal spiders in the shade trees of coffee plantations. In the Soconusco region of Chiapas, Mexico we sampled across 38 sites on 9 coffee plantations. Tree and canopy connectedness were found to positively influence overall arboreal spider richness and abundance. We found that different functional groups of spiders are responding to different local and landscape factors, but overall elevation was most important variable influencing arboreal spider diversity. Our study has practical management applications that suggest having shade grown coffee offers more suitable habitat for arboreal spiders due to a variety of the characteristics of the shade trees. Our results which show consistently more diverse arboreal spider communities in lower elevations are important in light of looming global climate change. As the range of suitable elevations for coffee cultivation shrinks promoting arboreal spider diversity will be important in sustaining the viability of coffee.

  11. 农地流转对农业生态系统的影响%Impact of farmland transfer on agro-ecosystem

    Institute of Scientific and Technical Information of China (English)

    程相友; 信桂新; 陈荣蓉; 李承桧

    2016-01-01

    Farmland transfer, supported by both the national and local governments, has largely promoted the transformation of agricultural management and modernization. Specifically, the increasing scope and scale of farmland transfer dramatically changed the industrial structure and input-output of agriculture. Thus farmland transfer has a significant effect on the agro-ecosystem. To assess eco-environmental effects of the transformation of the mode of agricultural management due to farmland transfer, this study analyzed three aspects of farmland transfer ― production efficiency, environmental impact and overall sustainability of agro-ecosystems. This was done in a case study of Rongchang County in Chongqing, China. To do that, the input-output of ordinary farmers and agricultural contractors, which respectively represented the agricultural management patterns before and after farmland transfer, was analyzed. The emergy evaluation method used proved to be effective in analyzing the efficiency and sustainability of ecosystems. Emergy evaluation method overcame the weakness of traditional methods of energy analysis as it integrated different forms of energy into a common physical basis known as solar emergy. This method took multiple important factors into consideration (e.g., natural resources, labor and ecosystem services), generally neglected in other similar methods. The results showed that the input for purchasing resources decreased by 70.48%while emergy output increased by 2.15% after farmland transfer. Thus emergy yield ratio (EYR) changed from 0.01 before farmland transfer to 0.04 after that, which represented an increase of 300.00%. This increase was mainly due to agricultural machinery input rather than labor force input, which lowered the overall input and increased the efficiency of production. For a single input item, when its’ renewability factor was less than that of the ecosystem, decreasing input reduced the environmental loading ratio (ELR); for the

  12. Changes in species diversity of arboreal spiders in Mexican coffee agroecosystems: untangling the web of local and landscape influences driving diversity.

    Science.gov (United States)

    Hajian-Forooshani, Zachary; Gonthier, David J; Marín, Linda; Iverson, Aaron L; Perfecto, Ivette

    2014-01-01

    Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosystems. Understanding what drives the diversity of groups of organisms such as spiders is important from a pragmatic point of view because of the important biocontrol services they offer to agriculture. Spiders in coffee are somewhat enigmatic because of their positive or lack of response to agricultural intensification. In this study, we provide the first analysis, to our knowledge, of the arboreal spiders in the shade trees of coffee plantations. In the Soconusco region of Chiapas, Mexico we sampled across 38 sites on 9 coffee plantations. Tree and canopy connectedness were found to positively influence overall arboreal spider richness and abundance. We found that different functional groups of spiders are responding to different local and landscape factors, but overall elevation was most important variable influencing arboreal spider diversity. Our study has practical management applications that suggest having shade grown coffee offers more suitable habitat for arboreal spiders due to a variety of the characteristics of the shade trees. Our results which show consistently more diverse arboreal spider communities in lower elevations are important in light of looming global climate change. As the range of suitable elevations for coffee cultivation shrinks promoting arboreal spider diversity will be important in sustaining the viability of coffee. PMID:25392751

  13. Progress and perspectives in studies on agro-ecosystem carbon cycle model%农田生态系统碳循环模型研究进展和展望

    Institute of Scientific and Technical Information of China (English)

    刘昱; 陈敏鹏; 陈吉宁

    2015-01-01

    Agro-ecosystem, as the most active and controllable carbon pool in terrestrial ecosystem carbon cycle, can lead to substantial changes in the atmospheric CO2 concentration, thus affecting remarkably the global climate. The carbon cycle in agro-ecosystem is a complex process, which is influenced by factors such as climate, plants, soil properties and farm management. It is recognized that a model approach has an advantage in estimating spatiotemporal changes in carbon storage. Carbon cycle models are considered to be the most effective means to study carbon cycle. This paper emphasized on the carbon cycle process of agro-ecosystem, introduced the transference and the mechanism of carbon cycle between different carbon pools, identified characteristics of different models in association with carbon cycle of agro-ecosystem from 1960s, summarized and analyzed the application of international carbon models and others invented and developed in China in the agro-ecosystem. During these years, several models, such as RothC, CENTURY, DNDC, EPIC and APSIM have been widely used to estimate carbon changes at national or global scales. These models provide understanding of carbon flow through food webs and explore the role of carbon storage in the whole agro-ecosystem. They also allow analysis of environmental risks and provide a guide to know more about the relationship among carbon, nitrogen and water cycle. More recently, some new carbon models have been developed in China for simulating the carbon budget of agro-ecosystems. For example, the Agro-C can simulate crop net primary production via Crop-C sub model and changes in soil organic carbon via Soil-C sub model under various conditions of climate, soil, and agricultural practices, which makes it possible to extrapolate the model to a wider domain. Validation of the Soil-C sub model suggested that an inappropriate simplification of the carbon flow between various C pools may introduce errors into the estimates. Carbon loss

  14. Impact of currently used or potentially useful insecticides for canola agroecosystems on Bombus impatiens (Hymenoptera: Apidae), Megachile rotundata (Hymentoptera: Megachilidae), and Osmia lignaria (Hymenoptera: Megachilidae).

    Science.gov (United States)

    Scott-Dupree, C D; Conroy, L; Harris, C R

    2009-02-01

    Pest management practices may be contributing to a decline in wild bee populations in or near canola (Brassica napus L.) agroecosystems. The objective of this study was to investigate the direct contact toxicity of five technical grade insecticides--imidacloprid, clothianidin, deltamethrin, spinosad, and novaluron--currently used, or with potential for use in canola integrated pest management on bees that may forage in canola: common eastern bumble bees [Bombus impatiens (Cresson); hereafter bumble bees], alfalfa leafcutting bees [Megachile rotundata (F.)], and Osmia lignaria Cresson. Clothianidin and to a lesser extent imidacloprid were highly toxic to all three species, deltamethrin and spinosad were intermediate in toxicity, and novaluron was nontoxic. Bumble bees were generally more tolerant to the direct contact applications > O. lignaria > leafcutting bees. However, differences in relative toxicities between the three species were not consistent, e.g., whereas clothianidin was only 4.9 and 1.3x more toxic, deltamethrin was 53 and 68x more toxic to leafcutting bees than to bumble bees and O. lignaria, respectively. Laboratory assessment of direct contact toxicity, although useful, is only one measure of potential impact, and mortality under field conditions may differ greatly depending on management practices. Research conducted using only honey bees as the indicator species may not adequately reflect the risk posed by insecticides to wild bees because of their unique biology and differential susceptibility. Research programs focused on determining nontarget impact on pollinators should be expanded to include not only the honey bee but also wild bee species representative of the agricultural system under investigation. PMID:19253634

  15. The Influence of Culture on Agroecosystem Structure: A Comparison of the Spatial Patterns of Homegardens of Different Ethnic Groups in Thailand and Vietnam.

    Science.gov (United States)

    Timsuksai, Pijika; Rambo, A Terry

    2016-01-01

    Different ethnic groups have evolved distinctive cultural models which guide their interactions with the environment, including their agroecosystems. Although it is probable that variations in the structures of homegardens among separate ethnic groups reflect differences in the cultural models of the farmers, empirical support for this assumption is limited. In this paper the modal horizontal structural patterns of the homegardens of 8 ethnic groups in Northeast Thailand and Vietnam are described. Six of these groups (5 speaking Tai languages and 1 speaking Vietnamese) live in close proximity to each other in separate villages in Northeast Thailand, and 2 of the groups (one Tai-speaking and one Vietnamese-speaking) live in different parts of Vietnam. Detailed information on the horizontal structure of homegardens was collected from samples of households belonging to each group. Although each ethnic group has a somewhat distinctive modal structure, the groups cluster into 2 different types. The Tai speaking Cao Lan, Kalaeng, Lao, Nyaw, and Yoy make up Type I while both of the Vietnamese groups, along with the Tai speaking Phu Thai, belong to Type II. Type I gardens have predominantly organic shapes, indeterminate boundaries, polycentric planting patterns, and multi-species composition within planting areas. Type II homegardens have geometric shapes, sharp boundaries, lineal planting patterns, and mono-species composition of planting areas. That the homegardens of most of the Tai ethnic groups share a relatively similar horizontal structural pattern that is quite different from the pattern shared by both of the Vietnamese groups suggests that the spatial layout of homegardens is strongly influenced by their different cultural models.

  16. The Influence of Culture on Agroecosystem Structure: A Comparison of the Spatial Patterns of Homegardens of Different Ethnic Groups in Thailand and Vietnam.

    Science.gov (United States)

    Timsuksai, Pijika; Rambo, A Terry

    2016-01-01

    Different ethnic groups have evolved distinctive cultural models which guide their interactions with the environment, including their agroecosystems. Although it is probable that variations in the structures of homegardens among separate ethnic groups reflect differences in the cultural models of the farmers, empirical support for this assumption is limited. In this paper the modal horizontal structural patterns of the homegardens of 8 ethnic groups in Northeast Thailand and Vietnam are described. Six of these groups (5 speaking Tai languages and 1 speaking Vietnamese) live in close proximity to each other in separate villages in Northeast Thailand, and 2 of the groups (one Tai-speaking and one Vietnamese-speaking) live in different parts of Vietnam. Detailed information on the horizontal structure of homegardens was collected from samples of households belonging to each group. Although each ethnic group has a somewhat distinctive modal structure, the groups cluster into 2 different types. The Tai speaking Cao Lan, Kalaeng, Lao, Nyaw, and Yoy make up Type I while both of the Vietnamese groups, along with the Tai speaking Phu Thai, belong to Type II. Type I gardens have predominantly organic shapes, indeterminate boundaries, polycentric planting patterns, and multi-species composition within planting areas. Type II homegardens have geometric shapes, sharp boundaries, lineal planting patterns, and mono-species composition of planting areas. That the homegardens of most of the Tai ethnic groups share a relatively similar horizontal structural pattern that is quite different from the pattern shared by both of the Vietnamese groups suggests that the spatial layout of homegardens is strongly influenced by their different cultural models. PMID:26752564

  17. An Approach for Simulating Soil Loss from an Agro-Ecosystem Using Multi-Agent Simulation: A Case Study for Semi-Arid Ghana

    Directory of Open Access Journals (Sweden)

    Biola K. Badmos

    2015-07-01

    Full Text Available Soil loss is not limited to change from forest or woodland to other land uses/covers. It may occur when there is agricultural land-use/cover modification or conversion. Soil loss may influence loss of carbon from the soil, hence implication on greenhouse gas emission. Changing land use could be considered actually or potentially successful in adapting to climate change, or may be considered maladaptation if it creates environmental degradation. In semi-arid northern Ghana, changing agricultural practices have been identified amongst other climate variability and climate change adaptation measures. Similarly, some of the policies aimed at improving farm household resilience toward climate change impact might necessitate land use change. The heterogeneity of farm household (agents cannot be ignored when addressing land use/cover change issues, especially when livelihood is dependent on land. This paper therefore presents an approach for simulating soil loss from an agro-ecosystem using multi-agent simulation (MAS. We adapted a universal soil loss equation as a soil loss sub-model in the Vea-LUDAS model (a MAS model. Furthermore, for a 20-year simulation period, we presented the impact of agricultural land-use adaptation strategy (maize cultivation credit i.e., maize credit scenario on soil loss and compared it with the baseline scenario i.e., business-as-usual. Adoption of maize as influenced by maize cultivation credit significantly influenced agricultural land-use change in the study area. Although there was no significant difference in the soil loss under the tested scenarios, the incorporation of human decision-making in a temporal manner allowed us to view patterns that cannot be seen in single step modeling. The study shows that opening up cropland on soil with a high erosion risk has implications for soil loss. Hence, effective measures should be put in place to prevent the opening up of lands that have high erosion risk.

  18. Estimating NH3 emissions from agricultural fertilizer application in China using the bi-directional CMAQ model coupled to an agro-ecosystem model

    Directory of Open Access Journals (Sweden)

    X. Fu

    2015-01-01

    Full Text Available Atmospheric ammonia (NH3 plays an important role in atmospheric chemistry. China is one of the largest NH3 emitting countries with the majority of NH3 emissions coming from the agricultural practices, such as fertilizer application and livestock. The current NH3 emission estimates in China are mainly based on pre-defined emission factors that lack the temporal or spatial details, which are needed to accurately predict NH3 emissions. In this study, we estimate, for the first time, the NH3 emission from the agricultural fertilizer application in China online using an agricultural fertilizer modeling system coupling a regional air quality model (the Community Multi-Scale Air Quality model, CMAQ and an agro-ecosystem model (the Environmental Policy Integrated Climate model, EPIC, which improves the spatial and temporal resolution of NH3 emission from this sector. Cropland area data of 14 crops from 2710 counties and the Moderate Resolution Imaging Spectroradiometer (MODIS land use data are combined to determine the crop distribution. The fertilizer application rate and method for different crop are collected at provincial or agriculture-regional level. The EPIC outputs of daily fertilizer application and soil characteristics are inputed into the CMAQ model and the hourly NH3 emission are calculated online with CMAQ running. The estimated agricultural fertilizer NH3 emission in this study is about 3 Tg in 2011. The regions with the highest modeled emission rates are located in the North China Plain. Seasonally, the peak ammonia emissions occur from April to July.Compared with previous researches, this method considers more influencing factors, such as meteorological fields, soil and the fertilizer application, and provides improved NH3 emission with higher spatial and temporal resolution.

  19. Using Cosmic-rays to Evaluate Estimates of Root-zone Soil Water from an Agro-ecosystem Model at a Field Site with a Shallow Water Table

    Science.gov (United States)

    Carr, B. D.; Soylu, M. E.; Patton, J. C.; Hornbuckle, B. K.; Kucharik, C. J.

    2013-12-01

    Row-crop agriculture dominates the Corn Belt of the United States both in terms of economics (more than $100 billion in crops harvested each year) and biogeochemical cycles (e.g. more than 75% of Iowa is under cultivation). Hence, future weather and climate models should have dynamic vegetation in order to correctly account for feedbacks among row-crop agriculture, weather, and climate. Although the land surface may seem homogeneous, there are significant differences between fields, such as management practices (e.g. tillage, fertilizer, hybrid, planting date, tile drainage), soil type, and topography. Future simulations of weather and climate must consider changes in management. For example, with the proposed changes in the Energy Independence and Security Act (EISA) of 2007, the amount of croplands used for biofuels is projected to increase substantially in the next ten years. Therefore, we claim that these dynamic vegetation models need to function and be evaluated at the field scale ( 1 km), the scale at which changes in management occur, in order to realistically estimate variables like soil moisture, latent heat flux, and carbon and nitrogen dynamics. In this presentation, we focus on Agro-IBIS, an agro-ecosystem model that explicitly addresses seasonal changes in water, energy, carbon, and nitrogen cycles due to crop growth. Recently, Agro-IBIS has received an important update: improved soil physics through full coupling with HYDRUS-1D. HYDRUS-1D is a physically-based representation of water flow in the vadose zone and allows for the specification and use of a variable water table depth as the lower boundary condition. This enhancement is noteworthy because in many parts of the Corn Belt the water table is close to the surface through the majority of the year. We hypothesize that these changes will improve the simulation of soil moisture and latent heat flux and consequently refine estimates of crop growth and carbon and nitrogen dynamics. We will evaluate

  20. Agricultural crops and soil treatment impacts on the daily and seasonal dynamics of CO2 fluxes in the field agroecosystems at the Central region of Russia

    Science.gov (United States)

    Mazirov, Ilya; Vasenev, Ivan; Meshalkina, Joulia; Yaroslavtsev, Alexis; Berezovskiy, Egor; Djancharov, Turmusbek

    2015-04-01

    The problem of greenhouse gases' concentrations increasing becomes more and more important due to global changes issues. The main component of greenhouse gases is carbon dioxide. The researches focused on its fluxes in natural and anthropogenic modified landscapes can help in this problem solution. Our research has been done with support of the RF Government grants # 11.G34.31.0079 and # 14.120.14.4266 and of FP7 Grant # 603542 LUC4C in the representative for Central Region of Russia field agroecosystems at the Precision Farming Experimental Field of Russian Timiryazev State Agrarian University with cultivated sod podzoluvisols, barley and oats - vetch grass mix (Moscow station of the RusFluxNet). The daily and seasonal dynamics of the carbon dioxide have been studied at the ecosystem level by the Eddy covariance method (2 stations) and at the soil level by the exposition chamber method (40 chambers) with mobile infra red gas analyzer (Li-Cor 820). The primary Eddy covariance monitoring data on CO2 fluxes and water vapor have been processed by EddyPro software developed by LI-COR Biosciences. According to the two-year monitoring data the daily CO2 sink during the vegetation season is usually approximately two times higher than its emission at night. Seasonal CO2 fluxes comparative stabilization has been fixed in case the plants height around 10-12 cm and it usually persist until the wax ripeness phase. There is strong dependence between the soil CO2 emission and the air temperature with the correlation coefficient 0.86 in average (due to strong input of the soil thin top functional subhorizon), but it drops essentially at the end of the season - till 0.38. The soil moisture impact on CO2 fluxes dynamics was less, with negative correlation at the end of the season. High daily dynamics of CO2 fluxes determines the protocol requirements for seasonal soil monitoring investigation with less limitation at the end of the season. The accumulated monitoring data will be

  1. Soil carbon storage and N{sub 2}O emissions from wheat agroecosystems as affected by free-air CO{sub 2} enrichment (FACE) and nitrogen treatments. Final Report - February 12, 1999

    Energy Technology Data Exchange (ETDEWEB)

    S. W. Leavitt; A. D. Matthias; T. L. Thompson; R. A. Rauschkolb

    1999-02-17

    Rising atmospheric CO{sub 2} concentrations have prompted concern about response of plants and crops to future elevated CO{sub 2} levels, and particularly the extent to which ecosystems will sequester carbon and thus impact the rate of rise of CO{sub 2} concentrations. Free-air CO{sub 2} enrichment (FACE) experimentation was used with wheat agroecosystems for two growing seasons to assess effects of CO{sub 2} and soil nitrogen. Over 20 researchers on this experiment variously examined plant production and grain yield, phenology, length of growing season, water-use efficiency ecosystem production, below ground processes (eg, root and microbial activity, carbon and nitrogen cycling), etc.

  2. Big Data Initiatives for Agroecosystems

    Science.gov (United States)

    NAL has developed a workspace for research groups associated with the i5k initiative, which aims to sequence the genomes of all insesct species known to be important to worldwide agriculture, food safety, medicine, and energy production; all those used as models in biology; the most abundant in worl...

  3. THREATS TO BIOTOPES IN AGROECOSYSTEMS

    Directory of Open Access Journals (Sweden)

    Kazimierz Sporek

    2014-06-01

    Full Text Available One of the conditions of the species continuity is a natural living space (habitat, in which the species achieves its basic needs. Large area of agriculture and forestry monoculture are not conducive to existence of game animals. Permanent devastation of game preserves, windbreaks, liquidation of foraging sites and shelterbelts force the wild animals to feed in the field and forest crops. In modern agrotechnique – the usage of plant protection products deprives the wild species (eg the hare of forage, on the other hand it causes contamination of food absorbed by animals. Not only does it disorganise the trophic pyramide, but also can cause permanent damage to the organism – environment networks system, which is essential for proper circulation of matter and energy in ecosystems. The aim of the study is to draw attention to the effects of the changes in the biotypes caused by agriculture.

  4. Escoamento superficial em Latossolo Amarelo distrófico típico sob diferentes agroecossistemas no nordeste paraense Runoff in Oxisol under different agroecosystems in the northeast part of Pará State

    Directory of Open Access Journals (Sweden)

    Cristiane F. G. da Costa

    2013-02-01

    Full Text Available Na bacia dos igarapés Timboteua e Buiuna, no Estado do Pará, avaliou-se a influência das mudanças de uso da terra e do manejo do solo sobre as taxas de escoamento superficial. Foram estabelecidas 18 parcelas experimentais (1 m² sendo três em cada um dos seis agroecossistemas avaliados, a saber: i Capoeira de 20 anos (CP; ii Sistema agroflorestal / derruba-e-queima (SQ; iii Sistema agroflorestal / corte-e-trituração (ST; iv Cultivo de mandioca / corte-e-trituração - Roça (RT; v Cultivo de mandioca / derruba-e-queima - Roça (RQ; vi Pastagem / derruba-e-queima (PQ. Adicionalmente foram instalados, na mesma localidade, dois pluviômetros e três coletores de água de chuva (CH para monitoramento da precipitação. Em 26 datas ao longo da estação chuvosa de 2010, foram coletadas 234 amostras, obtendo-se alta correlação entre volumes precipitado e escoado. O agroecossistema de Pastagem (PQ degradada apresentou o maior valor de 54,53% do total de escoamento superficial medido nesta pesquisa, e o SAF, que estava em recuperação de 7 anos após uma queima, o menor valor de 1,11%. O escoamento superficial decresceu dos agroecossistemas de menor para os sistemas de maior percentagem de material orgânico.In the watershed of the Timboteua and Buiuna streams in the State of Pará, the effect of land use change and soil management on the runoff rates was evaluated. Eighteen experimental plots (1 m² were established, three in each one of the six evaluated agroecosystems as follows: i 20 years Secondary vegetation ("Capoeira" (CP, ii Agroforestry system / slash-and-burn (SQ, iii Agroforestry system / chop-and-mulch (ST, iv Cassava crop / chop-and-mulch (RT, v Cassava crop / slash-and-burn (RQ, vi Cattle pasture / slash-and-burn (PQ. Nearby these plots two rain gauges and three rainwater collectors for monitoring of precipitation were also installed. Along 2010 rainy season 234 samples were collected on 26 different dates. A strong correlation

  5. Energy efficiency of physic nut agroecosystems: comparative between the dried and irrigated system; Eficiencia energetica do agroecossistema pinhao-manso: comparativo entre os sistemas de cultivo de sequeiro e irrigado

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, Michelle Sato [Universidade Federal de Mato Grosso do Sul (CPCS/UFMS), Chapadao do Sul, MS (Brazil)], E-mail: msfrigo@nin.ufms.br; Bueno, Osmar de Carvalho; Esperancini, Maura Seiko Tsuitsui [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Gestao e Tecnologia Agroindustrial; Frigo, Elisandro Pires [Universidade do Oeste Paulista (CCET/UNIOESTE), Cascavel, PR (Brazil). Centro de Ciencias Exatas e Tecnologicas; Klar, Antonio Evaldo [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural

    2009-07-01

    The physic nut have been a major object of study oil seeds to produce biofuel, but their productive characteristics and the energy expenditure for their production are largely unknown to national both and international conditions. The purpose of this study was to evaluate the efficiency of the physic nut agroecosystem in two different production systems: irrigated and dried. The plantations areas were selected of the company NNE Minas Agro Florestal Ltda. of Janauba/MG. The preparation of the study began with the restoration of the route through the technical oral report provided by the company. Ten operations were identified in the irrigated system and six operations in the dried system. The methodology adopted was based on literature review. The energy balance was 2,141.66 MJ. ha{sup -1} for the irrigation system and 319.30 MJ. ha{sup -1} for the dried. The energy efficiency index for the irrigation system was 2.77 and was not possible to calculate the dried system because this indicator does not use fossil sources. It was concluded that in both systems were used larger amounts of energy to produce than the energy obtained by the final product. (author)

  6. 显花植物在提高节肢动物天敌控制害虫中的生态功能%Ecological Functions of Flowering Plants on Conservation of the Arthropod Natural Enemies of Insect Pests in Agroecosystem

    Institute of Scientific and Technical Information of China (English)

    朱平阳; 吕仲贤; Geoff Gurr; 郑许松; Donna Read; 杨亚军; 徐红星

    2012-01-01

    由于农业集约化生产引起的非作物生境减少和农业化学品的过量使用减弱了农田生态系统中害虫天敌的自然控制作用。合理而有效地利用显花植物可以为害虫天敌提供食物来源和庇护场所,从而能有效地提高天敌对害虫的自然控制能力、减少化学农药的使用量。本文综述了显花植物对天敌种群的促进作用及其在果园、蔬菜和粮食作物等害虫防治中应用的最新进展,同时对进一步利用显花植物提高农业生态系统稳定性的发展方向进行了讨论。%Intensive crop production and overuse of agrochemicals, including fertilizer and pesticides, has resulted in reduction of non-crop habitats, simplification of farm landscape, sharp decline of biodiversity, and decrease of the biological control capacities of arthropod natural enemies of insect pests in agroecosystem. Effective and rational utilization of flowering plants that provide food sources and shelters for natural enemies can strongly improve natural control function and may reduce application of chemical pesticides. This review presented the nutritional function of plant flowers for natural enemies, and the practical applications of flowering plants in agroecosystems such as orchards, vegetable gardens and food crops. Prospective in utilization of flowering plants and potential agricultural measures for maximizing natural control of insect pests in agroecosystem was also discussed.

  7. Soil attributes under agroecosystems and forest vegetation in the coastal tablelands of northestern Brazil Atributos de solo de agroecossistemas e coberturas florestais dos tabuleiros costeiros do nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    João Bosco Vasconcellos Gomes

    2012-12-01

    Full Text Available This study evaluated the changes occurred in a set of soil attributes, particularly those related to the dynamics of soil organic carbon (SOC, as a function of the replacement of native forest for agricultural ecosystems of regional importance in the coastal tablelands of Northeastern Brazil (orange, coconut, eucalyptus and sugarcane. Six commercial sites under these agroecosystems were compared to neighboring areas of native forest in five areas along this region (Coruripe, Umbaúba, Acajutiba, Cruz das Almas and Nova Viçosa. Soil samples were taken from 0-5 and 5-20 cm depth and analyzed for particle size distribution, bulk density, organic C (OC, particulate organic matter, C in soil solution, microbial biomass C, total cation exchange capacity and water stable aggregates. Linear correlation and multivariate techniques were used for data analysis. The values of base saturation and Al saturation for the 0-20 cm depth layer were also calculated. In all the studied areas, soils under native forest presented better status of physical and chemical attributes than their agroecosystem counterparts, especially in the 0-5 cm layer. For both layers, OC content was the attribute most strongly correlated with the overall changes in all attributes. Unexpectedly, the OC content showed no significant correlation with the sum of silt and clay contents. The set of variables investigated in this study is sensitive to differentiate the quality of soils under perennial and semi-perennial land uses from their counterparts under natural vegetation in the landscapes of the coastal tablelands of Northeastern Brazil.Este trabalho avaliou as alterações de um conjunto de atributos de solos dos tabuleiros costeiros do Nordeste do Brasil, em especial os relacionados à dinâmica do C orgânico (CO, em função da substituição da vegetação florestal nativa por agroecossistemas de importância regional (laranja, coco, eucalipto e cana-de-açúcar. Seis s

  8. Soil Carbon Storage and N{sub 2}O Emissions from Wheat Agroecosystems as Affected by Free-Air CO{sub 2} Enrichment (FACE) and Nitrogen Treatments. Annual Progress Report - Year 1: August 1, 1996 to July 31, 1997 [Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Leavitt, S.W.; Matthias, A.; Thompson, T.L.

    1999-02-17

    Rising atmospheric CO{sub 2} concentrations have prompted concern about response of plants and crops to future elevated CO{sub 2} levels, and particularly the extent to which ecosystems will sequester carbon and thus impact the rate of rise of CO{sub 2} concentrations. Free-air CO{sub 2} enrichment (FACE) experimentation was used with wheat agroecosystems for two growing seasons to assess effects of CO{sub 2} and soil nitrogen. Over 20 researchers on this experiment variously examined plant production and grow yield, phenology, length of growing season, water-use efficiency, ecosystem productivity, below ground processes (root and microbial activity, carbon and nitrogen cycling), etc.

  9. A simplified method for the assessment of carbon balance in agriculture: an application in organic and conventional micro-agroecosystems in a long-term experiment in Tuscany, Italy

    Directory of Open Access Journals (Sweden)

    Giulio Lazzerini

    2014-06-01

    Full Text Available Many research works propose sophisticated methods to analyse the carbon balance, while only a few tools are available for the calculation of both greenhouse gas emissions and carbon sequestration with simplified methods. This paper describes a carbon balance assessment conducted at farm level with a simplified methodology, which includes calculations of both CO2 emissions and carbon sequestration in crop rotations. This carbon balance was tested in the Montepaldi Long Term Experiment (MOLTE trial in central Italy, where two agroecosystems managed with two different farming practices (organic vs conventional are compared. Both in terms of CO2eq emissions and carbon sequestration, this simplified method applied in our experiment provided comparable results to those yielded by complex methodologies reported in the literature. With regard to the crop rotation scheme applied in the reference period (2003-2007, CO2 emissions from various farm inputs were found to be significantly lower (0.74 Mg ha-1 in the organically managed system than in the conventionally managed system (1.76 Mg ha-1. The same trend was observed in terms of CO2eq per unit of product (0.30 Mg kg-1 in the organic system and 0.78 Mg kg-1 in the conventional system. In the conventional system the sources that contributed most to total emissions were direct and indirect emissions associated with the use of fertilisers and diesel fuel. Also the stock of sequestered carbon was significantly higher in the organic system (27.9 Mg ha-1 of C than in the conventional system (24.5 Mg ha-1 of C. The carbon sequestration rate did not show any significant difference between the two systems. It will be necessary to test further this methodology also in commercial farms and to validate the indicators to monitor carbon fluxes at farm level.

  10. A Multi-Year Comparison of No-Till Versus Conventional-Till Effects on the Carbon Balance in a Corn/Soybean Agro-Ecosystem Using Eddy Covariance

    Science.gov (United States)

    Joo, E.; Slattery, R.; Meyers, T. P.; Bernacchi, C.

    2015-12-01

    Dramatic increases in atmospheric CO2 concentrations since the industrial revolution are in large part due to the release of carbon previously stored in the soil. No-till strategies have been proposed as a means to mitigate agricultural contributions to atmospheric carbon by decreasing emissions and sequestering carbon in agricultural soils while increasing water use efficiency and soil quality. However, the effects of no-till versus conventional-till practices on carbon sequestration often vary due to difficulty in quantifying soil carbon as soil properties change with management. Eddy covariance (EC) offers a more accurate method of continuously measuring the total carbon budget and does so without relying on physical soil carbon measurements. The majority of agricultural land in the Midwestern United States is farmed using the corn/soybean rotation, making it an ideal agro-ecosystem to examine the potential of adopting no-till practices on carbon and water balances. In this study, we use EC to compare carbon and water fluxes between continuous no-till and conventional-till corn/soybean sites over several years in east central Illinois. This allows the determination and comparison of 1) net ecosystem exchange (NEE) and net biome production (NEE after accounting for grain usage); 2) water use efficiency; and 3) response to climatic variation, both at short and long time scales, between the two tillage systems. We hypothesize that both carbon uptake and water use efficiency will improve with no-till practices, which in turn will improve crop responses to environmental factors such as drought and heat stress.

  11. Relação entre macrofauna edáfica e atributos químicos do solo em diferentes agroecossistemas Relationship between edaphic macrofauna and soil chemical attributes in different agroecosystems

    Directory of Open Access Journals (Sweden)

    Sandra Santana de Lima

    2010-03-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito do uso do solo sobre a densidade e a diversidade da macrofauna invertebrada, bem como a relação dessa com atributos químicos do solo em diferentes agroecossistemas. Foram estudados cinco agroecossistemas: sistema ecológico com três anos de adoção (SE3, sistemas agroflorestais com seis (SAF6 e dez (SAF10 anos de adoção; agricultura de corte e queima (ACQ, e floresta nativa (FN. Em cada sistema, foram coletadas aleatoriamente cinco amostras solo, em forma de blocos (25x25 cm, na profundidade de 10 cm, nas épocas seca (outubro, 2006 e chuvosa (maio, 2007. A relação entre os atributos químicos e a macrofauna edáfica, nos diferentes sistemas de uso do solo, foi determinada por meio da análise da coinércia. Maior abundância da macrofauna foi observada na época chuvosa. Os sistemas SE3, SAF6 e SAF10 apresentaram maior riqueza de espécies e índices de Shannon e Pielou, independentemente da época de coleta. O manejo agroflorestal favoreceu a ocorrência de "engenheiros do ecossistema". Os sistemas agroflorestais propiciam melhores características químicas do solo e aumentos na abundância e riqueza da macrofauna invertebrada do solo.The objective of this study was to evaluate land use effects on the abundance and diversity of invertebrate macrofauna and its relationship with the soil chemical characteristics in different agroecosystems. Five systems were studied: ecological based system at three years of adoption (ES3, agroforestry systems at six (AFS6 and ten years of adoption (AFS10, slash and burn agriculture (SBA, and native forest (NF. In each system, five samples were collected in the form of soil monoliths (25x25 cm at 10 cm depth, during the dry (October 2006 and rainy seasons (May 2007. The relationship between edaphic macrofauna and chemical attributes in the different land use systems was determined by coinertia analysis. The highest abundance of macrofauna was observed in

  12. CARACTERIZACIÓN Y EVALUACIÓN DE AGROECOSISTEMAS A ESCALA PREDIAL. UN ESTUDIO DE CASO: CENTRO AGROPECUARIO PAYSANDÚ (MEDELLÍN, COLOMBIA CHARACTERIZATION AND EVALUATION OF AGROECOSYSTEMS ON A FARM SCALE A STUDY CASE: THE PAYSANDÚ FARMING CENTER.

    Directory of Open Access Journals (Sweden)

    Juan Camilo de los Rios Cardona

    2004-12-01

    Full Text Available Se caracteriza y evalúa el estado, condición y tendencia, de los Agroecosistemas (AE del Centro Agropecuario Paysandú de la Universidad Nacional de Colombia, Sede Medellín, mediante la parametrización y análisis de las variadas Receptividad Tecnológica (RT e Intensidad Tecnológica (IT, con base en la propuesta metodológica de Vélez y Gastó (1979, en cuanto a la diversidad de AE y de usos, manejo y acogida tecnológica, dotación en tecnoestructura e hidroestructura, potencial productivo y servicios a la sociedad local regional y nacional. Los resultados muestran que la mayor parte del área del Centro (72% tiene RT Muy Baja, la cual no admite el establecimiento de Sistemas de Manejo Agrotecnológico (SMA Mecanizados Avanzados. Sin embargo, el 69.8% del área es manejada con SMA adecuados para las restricciones que impone la RT. El 62% del área del Centro, principalmente bajo cobertura de pradera para ganadería de leche, es manejada con SMA avanzado. Como producto de la interacción entre RT y los SMA utilizados, se encontraron seis AE, de los cuales, tres, que representan el 69,8% del área ( 100,2 ha., se manejan con tecnologías adecuadas a sus condiciones biofísicas o de receptividad tecnológica (IT Adecuada, y los otros tres, que representan el 28,57% del área ( 41,3 ha., son manejados con tecnologías que no se corresponden con sus condiciones de RT (IT tradicional, lo que conlleva al deterioro de sus condiciones biofísicas y ecológicas.The state, condition, and tendencies of the agro-ecosystems (AE of the Paysandú Farming Center of the Universidad Nacional de Colombia, Sede Medellín were characterized and evaluated by means of parameterization and analysis of the various Technological Receptivity (RT, after the Spanish initials and Technological Intensity (IT, based upon a methodological proposal of Vélez and Gastó (1999, in terms of AE diversity and of the uses, management, and technological acceptance

  13. Microorganismos asociados a la rizosfera de jitomate en un agroecosistema del valle de Guasave, Sinaloa, México Rhizosphere microorganisms associated to tomato in an agroecosystem from Guasave Valley, Sinaloa, Mexico

    Directory of Open Access Journals (Sweden)

    Jesús Damián Cordero-Ramírez

    2012-09-01

    diversity of culturable and non-culturable microorganisms associated to tomato (Solanum lycopersicum L. in an agroecosystem from Sinaloa. Genomic DNA from rhizospheric soil was extracted and a hypervariable region on the rDNA was amplified using universal oligonucletides directed to amplify prokaryotic and eukaryotic rDNA. Sequence analysis of 194 and 384 rDNA clones of prokaryotic and eukaryotic origin respectively showed that for eukaryotes, the most abundant phylum was Ascomycota (59%, followed by Chlorophyta (21% and Basidiomycota (12%, while for Prokaryotes, the phylum Firmicutes (45% was the most abundant followed by Proteobacteria (14.7% and Gemmatimonadetes (13.1%. This contribution represents the most complete characterization of the microorganism diversity associated to tomato rhizosphere. The work discusses the role that species belonging to genera from prokaryotic (Bacillus and Paenibacillus or eukaryotic origin (Alternaria identified on this work, could play in the rhizosphere of tomato and the biological control of phytopathogens in this species.

  14. Spider management in agroecosystems: Habitat manipulation

    Science.gov (United States)

    Mansour, Fadel; Richman, David B.; Whitcomb, W. H.

    1983-01-01

    Based on the literature and on work conducted in Israel, the management of spider populations through habitat manipulation was found to be very helpful in controlling pest insects in various crops. Spiders were found to be reduced or eliminated by non-selective insecticides, although some resistance has been noted

  15. Pilot analysis of global ecosystems: Agroecosystems

    NARCIS (Netherlands)

    Wood, S.; Sebastian, K.; Scherr, S.J.

    2000-01-01

    A joint study by International Food Policy Research Institute and World Resources Institute with Analytical Contributions from Niels H. Batjes, ISRIC; Andrew Farrow, CIAT; Jean Marc Faurès, FAO; Günther Fischer, IIASA; Gerhard Heilig, IIASA; Julio Henao, IFDC; Robert Hijmans, CIP; Freddy Nachtergael

  16. Landscape Structure and Biological Control in Agroecosystems

    OpenAIRE

    Thies, Carsten; Tscharntke, Teja

    1999-01-01

    Biological pest control has primarily relied on local improvements in populations of natural enemies, but landscape structure may also be important. This is shown here with experiments at different spatial scales using the rape pollen beetle (Meligethes aeneus), an important pest on oilseed rape (Brassica napus). The presence of old field margin strips along rape fields was associated with increased mortality of pollen beetles resulting from parasitism and adjacent, large, old fallow habit...

  17. Landscape structure and biological control in agroecosystems

    Science.gov (United States)

    Thies; Tscharntke

    1999-08-01

    Biological pest control has primarily relied on local improvements in populations of natural enemies, but landscape structure may also be important. This is shown here with experiments at different spatial scales using the rape pollen beetle (Meligethes aeneus), an important pest on oilseed rape (Brassica napus). The presence of old field margin strips along rape fields was associated with increased mortality of pollen beetles resulting from parasitism and adjacent, large, old fallow habitats had an even greater effect. In structurally complex landscapes, parasitism was higher and crop damage was lower than in simple landscapes with a high percentage of agricultural use. PMID:10436158

  18. Modelling Soil respiration in agro-ecosystems

    Science.gov (United States)

    Delogu, Emilie; LeDantec, Valerie; Mordelet, Patrick; Buysse, Pauline; Aubinet, Marc; Pattey, Elizabeth

    2013-04-01

    A soil respiration model was developed to simulate soil respiration in crops on a daily time step. The soil heterotrophic respiration component was derived from Century (Parton et al., 1987). Soil organic carbon is divided into three major components including active, slow and passive soil carbon. Each pool has its own decomposition rate coefficient. Carbon flows between these pools are controlled by carbon inputs (crop residues), decomposition rate and microbial respiration loss parameters, both of which are a function of soil texture, soil temperature and soil water content. The model assumes that all C decompositions flows are associated with microbial activity and that microbial respiration occurs for each of these flows. Heterotrophic soil respiration is the sum of all these microbial respiration processes. To model the soil autotrophic respiration component, maintenance respiration is calculated from the nitrogen content and assuming an exponential relationship to account for temperature dependence (Ryan et al., 1991). Growth respiration is calculated assuming a dependence on both growth rate and construction cost of the considered organ (MacCree et al., 1982) A database, made of four different soil and climate conditions in mid-latitude was used to study the two components of the soil respiration model in wheat fields. Soil respiration were measured in three winter wheat fields at Lamasquère (43°49'N, 01°23'E, 2007) and Auradé (43°54'N, 01°10'E, 2008), South-West France and Lonzée (50°33'N, 4°44'E, 2007), Belgium, and in a spring wheat field at Ottawa (45°22'N, 75°43'W, 2007, 2011), Ontario, Canada. Manual closed chambers were used in the French sites. The Belgium and Canadian sites were equipped with automated closed chamber systems, which continuously collected 30-min soil respiration exchanges. All the sites were also equipped with eddy flux towers. When eddy flux data were collected over bare soil, the net ecosystem exchange (NEE) was equal to soil respiration exchange. These NEE data were used to validate the model. The carbon pools in the model needed to be initialized at each site, by running iteratively simulations of a same climatic year in a given wheat field, until equilibrium was reached. The model performance was evaluated by comparing simulated and measured soil respiration values. The predicted heterotrophic soil respiration compared well with the seasonal dynamic fluxes at each site. The measured values of heterotrophic soil respiration were also well calculated by the model. Then, the autotrophic soil respiration was validated. The parameterization of the Root/Shoot ratio dynamic was a key factor to retrieve the seasonal dynamic of observed root+rhizosphere respiration during vegetation growth period. Finally, the total soil respiration model was validated on independent datasets from calibration, of four wheat crops and could be used as a prediction model for comparison between different scenario of irrigation, ploughing, or crop rotation.

  19. Intercroppingenhancesagroecosystemservicesandfunctioning:Current knowledgeandperspectives*%间套作强化农田生态系统服务功能的研究进展与应用展望*

    Institute of Scientific and Technical Information of China (English)

    李隆

    2016-01-01

     ecological principles. Previous studies have shown that intercropping enhanced not only cropproductivity,butalsotheutilizationefficienciesofresources,includingabove-ground(e.g.,land,thermal,radiationandspace)andbelow-ground(e.g.,waterandnutrients)resources.Recenteffortshavemadesomeprogressesonintercroppingresearch.Here, we reviewed the potential of intercropping to strength ecosystem services and functions at the agroecosystem level,prospective research directions and highlight practical uses in modern agriculture. Intercropping increased biodiversity,productivity and stability of agroecosystems. At the same time, intercropping enhanced water use by isolating the time formaximum water requirements of one species from the other, and spatial complementarity by hydraulic lift of water. TheenhancementofnitrogenacquisitionwasattributedtonichedifferentiationofNresourcesinwhichcerealsacquiredmoremineralNfromthesoil,whilelegumesfixedmoreNfromairN2.ThiswasbecausethatcerealswasmorecompetitivethanlegumesandmineralNcompetitionincreasedsymbioticN2fixationoflegumes.SomePmobilizedspeciesfacilitatedtheconversionofsoilunavailablePintoavailableP,whichbenefitednotonlythespeciesbutalsotheneighboringimmobilizedotherspecies.E.g.,therootsoffababeanreleasedcarboxylatesorprotontodissolvesparinglysolublePinsoils.AlsotherootsofchickpeareleasedphytaseorphosphatasetodecomposeorganicPinthesoil,whichincreasedavailablesoilP.Therewereinterspecificfacilitationsofiron(Fe)andzinc(Zn)nutrientsinintercroppingofdicotyledonousornon-graminaceousmonocotyledonous(strategyIforFeacquisitionandnon-FeorZnmobilization)speciesandgraminaceousmonocotyledonous(strategy Ⅱ forFeacquisitionand Fe or Zn mobilization) species, which benefited micronutrient

  20. Processo analítico hierárquico na identificação de áreas favoráveis ao agroecossistema cafeeiro em escala municipal Analytical hierarchical process to identify favorable areas to the coffee crop agroecosystem at municipal scale

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Barros

    2007-12-01

    Full Text Available O objetivo deste trabalho foi delimitar áreas favoráveis ao agroecossistema cafeeiro, em quatro municípios do Estado de Minas Gerais, pela aplicação do processo analítico hierárquico (AHP. Uma função de ponderação aritmética foi obtida, com base nas premissas de favorabilidade à cafeicultura, considerando-se as seguintes variáveis: solo, declividade, orientação de vertentes, altimetria e as possíveis áreas de preservação permanente. Essa função permitiu combinar as condições adequadas ao cultivo do café e ressaltar as áreas com maior favorabilidade. Foi verificado que os quatro municípios diferem entre si quanto à favorabilidade ao agroecossistema cafeeiro; porém, ao se considerar apenas as áreas cultivadas com café, foi verificado que os municípios de Boa Esperança e Cristais não diferem entre si.The objective of this work was to delimitate favorable areas to the coffee agroecosystem, in four municipalities of Minas Gerais State, Brazil, using the analytical hierarchical process (AHP. An arithmetic pondering function was obtained, based on the favorability premises to coffee crop production, with regard to the following variables: soil, slope, slope aspect, altimetry, and areas that should be under permanent protection. This function allowed to combine the adequate conditions to coffee crop cultivation and gave emphasis to the most favorable areas. It was observed that all four municipalities were different in terms of their favorability to the coffee agroecosystem; however, when considering only the coffee cultivated areas, it was observed that the municipalities of Boa Esperança and Cristais were not significantly different.

  1. Simulação do impacto da mudança climática sobre a água disponível do solo em agroecossistemas de trigo, soja e milho em Santa Maria, RS Simulation of the impact of the climate change on the fraction of transpirable soil water in wheat, soybean, and maize agroecosystems at Santa Maria, RS, Brazil

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2006-04-01

    Full Text Available O impacto de uma possível mudança climática sobre a água disponível em agroecossistemas é um assunto de interesse no planejamento do agronegócio. O objetivo deste estudo foi simular o impacto da mudança climática sobre o balanço de água no solo em agroecossistemas de trigo, soja e milho em Santa Maria, RS. Foram criados cenários meteorológicos dobrando-se a quantidade de CO2 com diferentes aumentos de temperatura do ar com e sem aumento de precipitação pluvial. A água disponível no solo foi representada pela fração de água transpirável no solo pelas plantas (FATS e calculada com modelos matemáticos disponíveis na literatura. Os resultados mostraram que o aumento de temperatura diminui a FATS e esta diminuição é mais preocupante nas culturas de verão (soja e milho do que na cultura do trigo.The impact of the projected climate change on soil water is an important and relevant issue for planning rural activities. The objective of this study was to simulate the fraction of transpirable soil water (FTSW in wheat, soybean and maize agroecosystems under climate change scenarios in Santa Maria, RS. Air temperature and rainfall were modified to generate climate change scenarios. FTSW was simulated with models available in the literature. The results showed that an increase in air temperature decreases FTSW and this decrease is more evident in soybean and maize than in wheat agroecosystems.

  2. A review of agricultural water-saving research at Luancheng Agro-Ecosystem Experimental Station of Chinese Academy of Sciences over the last 30 years%中国科学院栾城农业生态系统试验站农田节水研究过去、现在和未来

    Institute of Scientific and Technical Information of China (English)

    张喜英

    2011-01-01

    本文回顾了中国科学院栾城农业生态系统试验站(以下简称栾城试验站)建站初期20世纪80年代以来在农田节水方面开展的研究.20世纪80年代以作物优化灌溉制度为研究重点,解决生产实际问题;20世纪90年代围绕土壤-植物-大气系统水分传输和界面调控开展了系统研究,为农田节水措施的形成提供理论基础和技术途径;近10年来进一步深化了农田节水生理生态研究,并根据多年研究积累,形成了综合节水技术模式,进行推广应用.未来栾城试验站农田节水工作将更加突出多学科渗透交叉,以提高农田水分利用效率和效益为目标,加强基础研究和节水技术的示范应用.%Farmland water-saving research was conducted since the establishment of Luancheng Agro-Ecosystem Experimental Station, Chinese Academy of Sciences (simplified as Luancheng Station). In 1980s, the research was concentrating on optimizing irrigation scheduling to reduce irrigation application for practical use. During that period, farmers usually irrigated winter wheat 7 to 10 times per season. By application an optimized irrigation scheduling, irrigation number was reduced to 5 per season without penalties to yield. In 1990s, the research was changed to fundamental studies of water movement in field. Water transfer and regulation mechanisms in soil-plant-atmosphere continuum were the research focuses during that period, resulting improved understanding of the principles and potential in water-saving. Extensive root sampling was carried out to study the pattern of root growth and soil water utilization. Root distribution down the soil profile was then modified to allow the crop to use soil water more efficiently. Evapotranspiration (ET) and soil evaporation were determined from long term data for different growing stages of winter wheat and summer maize to provide basis for crop-water relation studies. The results showed that seasonal soil water

  3. Diversidad, fluctuación poblacional y plantas huésped de escolitinos (Coleoptera: Curculionidae asociados con el agroecosistema cacao en Tabasco, México Diversity, dynamic population and host plants of bark and ambrosia beetles (Coleoptera: Curculionidae associated to the cocoa agroecosystem in Tabasco, Mexico

    Directory of Open Access Journals (Sweden)

    Manuel Pérez-De La Cruz

    2009-12-01

    Full Text Available Se estudió la diversidad de escolitinos asociados con el agroecosistema cacao en Tabasco, México durante el año 2007. Los insectos adultos fueron recolectados en 4 localidades con trampas de alcohol etílico, trampas de atracción luminosa y captura directa sobre sus plantas huésped. Se recolectaron 19 263 ejemplares, pertenecientes a 51 especies y 26 géneros. Araptus hymenaeae y Cnesinus squamosus son nuevos registros para México. La máxima diversidad de insectos capturados con los 3 métodos de recolecta se obtuvo en El Bajío (H'=2.45 y Dmg=4.83, la mínima en Río Seco (H'=2.29 y Km. 21 (Dmg=3.85, y el máximo valor de equidad (J lo obtuvo El Bajío (0.67. El índice de similitud de Sorensen (Is mostró que los sitios de estudio tienden a presentar la misma composición de especies. Los índices de diversidad, equidad y similitud, aplicados a la fauna de escolitinos capturados con cada uno de los métodos empleados, mostraron diferencias, excepto en las trampas de alcohol. La fluctuación presenta picos poblacionales marcados al inicio y al final del año de estudio. Las plantas en las que se recolectó el mayor número de especies fueron Theobroma cacao (16 y Swietenia macrophylla (13.The bark and ambrosia beetle diversity in cocoa agroecosystems was studied during 2007 in Tabasco, Mexico. Adult insects were gathered in 4 localities with ethanol and light traps and by direct collecting in their host plants. 19 263 specimens were gathered, belonging to 51 species and 26 genera. Araptus hymenaeae and Cnesinus squamosus are new records for Mexico. The maximum diversity of insects captured with the 3 collecting methods was obtained in El Bajío (H'=2.45 and Dmg=4.83, the minimum in Río Seco (H'=2.29 and Km. 21 (Dmg=3.85, and the maximum value of justness (J was obtained in El Bajío (0.67. The Sorensen similarity index (Is showed that the study places present the same species composition. The diversity, justness and similarity indices

  4. Challenges of reducing excess nitrogen in Japanese agroecosystems.

    Science.gov (United States)

    Yagi, Kazuyuki; Minami, Katsuyuki

    2005-09-01

    Fertilizer N use in Japan has decreased by about 30% from 1960 to 2000, while keeping a little increase in cereal yields. This has resulted in a significant increase in apparent nitrogen use efficiency, in particular for rice. On the other hand, national N load on the environment associated with the production and consumption of domestic and imported agricultural products has almost tripled during this period, mainly due to the dramatic increase of imports of food and feedstuffs. The environmental problems, including water and air pollution, caused by the excessive loads of N are serious public concerns and there is an urgent need to minimize N losses from agricultural production. In order to meet the necessity for reducing the environmental impacts by excess N, political and technological measures have been taken at regional and country levels. In recent years, the Japanese government has embarked on a series of policies to encourage transition to an environmentally conscious agriculture. Promoting proper material circulation with reducing fertilizer impact and utilizing biomass and livestock wastes is emphasized in these policies. The effectiveness of environmental assessment and planning for reducing regional and national N load has been discussed. Implementation of environmentally friendly technologies and management, both conventional and innovational, have been developed and adopted in Japanese agriculture. The effectiveness of conventional technologies in reducing environmental reactive N has been re-evaluated. Innovative technologies, such as use of controlled availability fertilizers and livestock wastes compost pellets, are being investigated and extended. A comprehensive approach that applies political and technological measures with closer co-operation is necessary to control reactive N in the environment.

  5. Estimation of Nitrogen Fertilizer Use Efficiency in Dryland Agroecosystem

    Institute of Scientific and Technical Information of China (English)

    LI Shi-qing; LI Sheng-xiu

    2001-01-01

    A field trial was carried out to study the nitrogen fertilizer recovery by four crops in succession in manurial loess soil in Yangling. The results showed that the nitrogen fertilizer not only had the significant effects on the first crop , but also had longer residual effects, even on the fourth crop. The average apparent nitrogen fertilizer recovery by the first crop was 31.7%, and the accumulative nitrogen recovery by the 4 crops was high as 62.3%, and the latter was double as the former. It is quite clear that the nitrogen fertilizer recovery by the first crop was not reliable for estimating the nitrogen fertilizer unless the residual effect of nitrogen fertilizer was included.

  6. Carbon emissions and sinks in agro-ecosystems of China

    Institute of Scientific and Technical Information of China (English)

    林而达; 李月娥; 郭李萍

    2002-01-01

    Besides ruminant animals and their wastes, soil is an important regula ting medium in carbon cycling. The soil can be both a contributor to climate cha nge and a recipient of impacts. In the past, land cultivation has generally resu lted in considerable depletion of soil organic matter and the release of greenho use gases (GHGs) into the atmosphere. The observation in the North-South Transec t of Eastern China showed that climate change and land use strongly impact all s oil processes and GHG exchanges between the soil and the atmosphere. Soil manage ment can restore organic carbon by enhancing soil structure and fertility and by doing so mitigating the negative impacts of atmospheric greenhouses on climate. A wide estimation carried out in China shows that carbon sequestration potentia l is about 77.2 MMt C/a (ranging from 26.1—128.3 MMt C/a) using proposed IPCC a ctivities during the next fifty years.

  7. Soil Health Management under Hill Agroecosystem of North East India

    Directory of Open Access Journals (Sweden)

    R. Saha

    2012-01-01

    Full Text Available The deterioration of soil quality/health is the combined result of soil fertility, biological degradation (decline of organic matter, biomass C, decrease in activity and diversity of soil fauna, increase in erodibility, acidity, and salinity, and exposure of compact subsoil of poor physicochemical properties. Northeast India is characterized by high soil acidity/Al+3 toxicity, heavy soil, and carbon loss, severe water scarcity during most parts of year though it is known as high rainfall area. The extent of soil and nutrient transfer, causing environmental degradation in North eastern India, has been estimated to be about 601 million tones of soil, and 685.8, 99.8, 511.1, 22.6, 14.0, 57.1, and 43.0 thousand tones of N, P, K, Mn, Zn, Ca, and Mg, respectively. Excessive deforestation coupled with shifting cultivation practices have resulted in tremendous soil loss (200 t/ha/yr, poor soil physical health in this region. Studies on soil erodibility characteristics under various land use systems in Northeastern Hill (NEH Region depicted that shifting cultivation had the highest erosion ratio (12.46 and soil loss (30.2–170.2 t/ha/yr, followed by conventional agriculture system (10.42 and 5.10–68.20 t/ha/yr, resp.. The challenge before us is to maintain equilibrium between resources and their use to have a stable ecosystem. Agroforestry systems like agri-horti-silvi-pastoral system performed better over shifting cultivation in terms of improvement in soil organic carbon; SOC (44.8%, mean weight diameter; MWD (29.4%, dispersion ratio (52.9%, soil loss (99.3%, soil erosion ratio (45.9%, and in-situ soil moisture conservation (20.6% under the high rainfall, moderate to steep slopes, and shallow soil depth conditions. Multipurpose trees (MPTs also played an important role on soil rejuvenation. Michelia oblonga is reported to be a better choice as bioameliorant for these soils as continuous leaf litter and root exudates improved soil physical behaviour and SOC considerably. Considering the present level of resource degradation, some resource conservation techniques like zero tillage/minimum tillage, hedge crop, mulching, cover crop need due attention for building up of organic matter status for sustaining soil health.

  8. Sustainable management of heavy metals in agro-ecosystems.

    OpenAIRE

    Moolenaar, S.W.

    1998-01-01

    In 1993, the Netherlands Organization for Scientific Research (NWO) launched a priority research program on 'Sustainability and Environmental Quality'. Within this program, the METALS subprogram focusses on the accumulation of metals in economy (e.g., zinc in gutters) and the environment (e.g., soil), the mechanisms behind these processes, the associated risks, the possibilities for a sustainable management of metal flows, and their consequences for society and environment. This Ph.D. thesis ...

  9. The Biogeochemical Cycling of Nitrogen in Annual and Perennial Agroecosystems

    Science.gov (United States)

    Fortuna, A.; Cogger, C.

    2010-12-01

    Organic agricultural systems are dependent upon fertilizer amendments that undergo ammonification prior to the release of plant available nitrogen (N) as ammonium. Ammonia may be further transformed via nitrification to nitrate resulting in greater potential for leaching or volatilization. Additions of plant residue and animal amendments contribute to soil N and carbon pools improving soil quality and the potential for release of ammonium. Therefore, agricultural systems that relay on organic inputs as fertilizer sources must be monitored to insure stored nutrients are released during plant uptake to prevent N losses. Our experimental design allows us to determine the effects of several organic cropping systems and fertility regimes on plant available N, nitrification potential and nitrifier gene copy number g-1 dry soil across season in a grass ley and two annual systems receiving chicken manure or compost. Nitrification potentials measured via the shaken slurry method, KCl extractable N and ammonia oxidizing bacteria (AOB) and archaea (AOA) gene copy numbers g-1 dry soil measured via quantitative PCR were monitored. Nitrification potentials measured in March revealed increases in nitrification where compost had historically been applied (7.78 vs. 5.26 ± 0.856). Treatment affects were significant in June the closest date to application of amendments and when ammonification from soil N was optimal. Animal amendments were added yearly in annual systems (31.0 ± 2.91) vs every three years in the ley pasture (12.9 ± 2.91) resulting in a management effect. Copy numbers of AOB (2.69 x 108 ± 4.94 x 107) were greatest in plots receiving compost vs chicken manure. Preliminary measurements of AOA gene copy numbers reveal a similar trend to that of AOB. But, gene copy numbers of AOA (105 to 106) were lower than those of AOB. Nitrification potentials were not different across treatments in September, 11.8 ± 2.28. This research will contribute to the development of novel cropping systems and land-use managements that maintain and promote efficient N cycling.

  10. Challenges of reducing excess nitrogen in Japanese agroecosystems

    Institute of Scientific and Technical Information of China (English)

    Kazuyuki; YAGI; Katsuyuki; MINAMI

    2005-01-01

    Fertilizer N use in Japan has decreased by about 30% from 1960 to 2000, while keeping a little increase in cereal yields. This has resulted in a significant increase in apparent nitrogen use efficiency, in particular for rice. On the other hand, national N Icad on the environment associated with the production and consumption of domestic and imported agricultural products has almost tripled during this period, mainly due to the dramatic increase of imports of food and feedstuffs. The environmental problems, including water and air pollution, caused by the excessive loads of N are serious public concerns and there is an urgent need to minimize N losses from agricultural production. In order to meet the necessity for reducing the environmental impacts by excess N, political and technological measures have been taken at regional and country levels. In recent years, the Japanese government has embarked on a series of policies to encourage transition to an environmentally conscious agriculture. Promoting proper material circulation with reducing fertilizer impact and utilizing biomass and livestock wastes is emphasized in these policies. The effectiveness of environmental assessment and planning for reducing regional and national N Icad has been discussed. Implementation of environmentally friendly technologies and management, both conventional and innovational, have been developed and adopted in Japanese agriculture. The effectiveness of conventional technologies in reducing environmental reactive N has been re-evaluated. Innovative technologies, such as use of controlled availability fertilizers and livestock wastes compost pellets, are being investigated and extended.A comprehensive approach that applies political and technological measures with closer cooperation is necessary to control reactive N in the environment.

  11. Biodiversity and Seasonal Changes of the Microbiome in Chernozem Agroecosystem

    Science.gov (United States)

    Kutovaya, Olga; Chernov, Timofey; Tkhakakhova, Azida; Ivanova, Ekaterina

    2016-04-01

    Studies of the influence of different agricultural technologies on the soil microbiome are widespread; they are important for understanding the dependence of the microbiome on environmental and soil factors and solution of practical problems related to the control of biochemical processes in soils used in agriculture. The seasonal variability (spring-summer-autumn) of the taxonomic structure of prokaryotic microbiomes in chernozems was studied using sequencing of the 16S rRNA gene. The DNA preparation was used as the matrix for a polymerase chain reaction with the use of a pair of universal primers to the variable region V4 of the 16S rRNA gene - F515 (GTGCCAGCMGCCGCGGTAA) and R806 (GGACTACVSGGGTATCTAAT). The preparation of the samples and sequencing were made on a GS Junior. The samples were collected from the topsoil (0-20 cm) horizons of a long-term fallow and croplands differing in the rates of application of mineral fertilizers (NPK). The results of the weighted UniFrac analysis show that the microbiomes of the fallow and field were distinctly distinguished and that the type of land use significantly affected the structure of the microbial community. The most sensitive to the type of land use were the representatives of the Firmicutes, Gemmatiomonades, and Verrucomicrobia phyla. The type of vegetation and aeration of the root-dwelling soil layer seem to be key factors of this influence. The microbiomes analyzed also differed by seasons: in the autumn samples, they were closer to the spring ones than to the summer ones. This fact evidences that the seasonal differences in the microbiomes are not simple gradual temporal changes; they reflect the influence of some ecological factors transforming the phylogenetic structure of prokaryotic communities. As the seasonal shift was equally expressed in the microbiomes of the field and fallow, it is logical to assume that it was caused by the factors common for two systems of land use. Statistically sensitive to seasonal environmental changes were representatives of the Taumarchaeota, Acidobacteria, Bacteroides, Firmicutes, and Verrucomicrobia groups. The differences in the structure of the soil prokaryotic communities were more significant between seasons than those related to different systems of land use. It is noteworthy that the UniFrac analysis did not practically reveal differences in the prokaryotic communities between the fertilized and unfertilized arable soils, since it was difficult to distinguish them from the differences related to the natural heterogeneity of the soil samples (replicates) analyzed. It is probably related to the high buffer capacity and the high adaptive potential of chernozems. In this experiment, even taking into account the 30-year history, the application of fertilizers is a less significant factor affecting the structure of the microbiome than the type of land use or seasonal climate changes. The phylogenetic diversity estimated by the Shannon index, the number of the operating taxonomic units found, and the Chao1 index little depends on the rate of the fertilizers applied and the type of land use; however, one can mention a rather higher diversity of the microbiomes in the summer and autumn periods compared to the spring one.

  12. Emergy Analysis of Agro-ecosystem in Poyang Lake Area

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    By using emergy analysis theory and methods, we conduct quantitative analysis on the input and output of emergy, and sustainable development of agro-ecological system in Poyang Lake Area. The results show that compared with the national average, the environmental loading ratio is relatively low in this area; the net emergy yield rate is high; the sustainable development ability is strong. Finally according to the results of emergy analysis, corresponding countermeasures are put forward as follows: develop agriculture based on the existing rich natural resources; increase technological inputs; develop circular agriculture; promote sustainable agricultural development.

  13. Distinct soil bacterial communities revealed under a diversely managed agroecosystem.

    Directory of Open Access Journals (Sweden)

    Raymon S Shange

    Full Text Available Land-use change and management practices are normally enacted to manipulate environments to improve conditions that relate to production, remediation, and accommodation. However, their effect on the soil microbial community and their subsequent influence on soil function is still difficult to quantify. Recent applications of molecular techniques to soil biology, especially the use of 16S rRNA, are helping to bridge this gap. In this study, the influence of three land-use systems within a demonstration farm were evaluated with a view to further understand how these practices may impact observed soil bacterial communities. Replicate soil samples collected from the three land-use systems (grazed pine forest, cultivated crop, and grazed pasture on a single soil type. High throughput 16S rRNA gene pyrosequencing was used to generate sequence datasets. The different land use systems showed distinction in the structure of their bacterial communities with respect to the differences detected in cluster analysis as well as diversity indices. Specific taxa, particularly Actinobacteria, Acidobacteria, and classes of Proteobacteria, showed significant shifts across the land-use strata. Families belonging to these taxa broke with notions of copio- and oligotrphy at the class level, as many of the less abundant groups of families of Actinobacteria showed a propensity for soil environments with reduced carbon/nutrient availability. Orders Actinomycetales and Solirubrobacterales showed their highest abundance in the heavily disturbed cultivated system despite the lowest soil organic carbon (SOC values across the site. Selected soil properties ([SOC], total nitrogen [TN], soil texture, phosphodiesterase [PD], alkaline phosphatase [APA], acid phosphatase [ACP] activity, and pH also differed significantly across land-use regimes, with SOM, PD, and pH showing variation consistent with shifts in community structure and composition. These results suggest that use of pyrosequencing along with traditional analysis of soil physiochemical properties may provide insight into the ecology of descending taxonomic groups in bacterial communities.

  14. Sustainable management of heavy metals in agro-ecosystems.

    NARCIS (Netherlands)

    Moolenaar, S.W.

    1998-01-01

    In 1993, the Netherlands Organization for Scientific Research (NWO) launched a priority research program on 'Sustainability and Environmental Quality'. Within this program, the METALS subprogram focusses on the accumulation of metals in economy (e.g., zinc in gutters) and the environment (e.g., soil

  15. Potential Impacts of Climate Change on Agro-ecosystems

    Directory of Open Access Journals (Sweden)

    György Várallyay

    2007-03-01

    Full Text Available Human activities lead to changes in the global environment at virtually unprecedented rates, with potentially severe consequences to our future life. Changes in the gas composition of the atmosphere – as the consequence of CO2, CH4 and other “greenhouse gases” concentration rise – may lead to a rise of temperature with heterogeneous spatial and temporal distribution, to alterations in the global circulation processes, and to a serious rearrangement in atmospheric precipitation, in some places to increasing aridity. These modifications are refl ected sensitively by ecosystems, manifested by the changes in natural vegetation and land use pattern with considerable alterations in soil processes and – consequently – in soil properties and soil functions.

  16. Potential Impacts of Climate Change on Agro-ecosystems

    OpenAIRE

    György Várallyay

    2007-01-01

    Human activities lead to changes in the global environment at virtually unprecedented rates, with potentially severe consequences to our future life. Changes in the gas composition of the atmosphere – as the consequence of CO2, CH4 and other “greenhouse gases” concentration rise – may lead to a rise of temperature with heterogeneous spatial and temporal distribution, to alterations in the global circulation processes, and to a serious rearrangement in atmospheric precipitation, in some places...

  17. Metagenomics and other Methods for Measuring Antibiotic Resistance in Agroecosystems

    Science.gov (United States)

    Background: There is broad concern regarding antibiotic resistance on farms and in fields, however there is no standard method for defining or measuring antibiotic resistance in environmental samples. Methods: We used metagenomic, culture-based, and molecular methods to characterize the amount, t...

  18. Agroecosystem Analysis of the Choke Mountain Watersheds, Ethiopia

    OpenAIRE

    Mutlu Ozdogan; Benjamin F. Zaitchik; Belay Simane

    2013-01-01

    Tropical highland regions are experiencing rapid climate change. In these regions the adaptation challenge is complicated by the fact that elevation contrasts and dissected topography produce diverse climatic conditions that are often accompanied by significant ecological and agricultural diversity within a relatively small region. Such is the case for the Choke Mountain watersheds, in the Blue Nile Highlands of Ethiopia. These watersheds extend from tropical alpine environments at over 4000 ...

  19. 灌溉对农田温室效应贡献及土壤碳储量影响研究进展%Advances in Research on the Effects of Irrigation on the Greenhouse Gases Emission and Soil Carbon Sequestration in Agro-ecosystem

    Institute of Scientific and Technical Information of China (English)

    齐玉春; 郭树芳; 董云社; 彭琴; 贾军强; 曹丛丛; 孙良杰; 闫钟清; 贺云龙

    2014-01-01

    countries and regions. Water management is one of the important measures that mitigate the emissions of nitrous oxide (N2O) and methane (CH4). Both the emission amount and the emission pathway of N2O and CH4are significantly affected by the soil water condition. There usually exists marked trade-off relationship between CH4 effluxes and N2O effluxes when soil moisture changes, so the comprehensive evaluation indicators such as global warming potentials (GWPs) are more conducive to reflect the actual change in greenhouse effect contribution of agricultural soil exactly. There exist various possibilities in the effect of irrigation on soil organic C (SOC) pool, such as increase, decrease, or no significant changes, and the responses of SOC to irrigation also vary a lot under different climate and soil conditions. In general, the stimulated effects of irrigation on SOC are more significant in relatively dry regions than in humid regions. Meanwhile, SOC in different forms often shows different response sensitivities and variation trends to irrigation. The effect evaluation of irrigation measures should be considered from the multiple perspectives of water-saving, increasing SOC pool and enhancing the utilization efficiency of liable organic C. To sum up, there still exists large uncertainties in the effects of irrigation on soil greenhouse gas emission and SOC in agro-ecosystem up to now. The future study should be focused on following contents: (1) to strengthen the comparison study of different irrigation patterns, especially the study on the spatial differences of greenhouse gases emission under different irrigation patterns; (2) to pay more attention to the comprehensive effect of different greenhouse gases and the ecosystem carbon budget; (3) to developin-situ field research for both long period and short period; (4) to probe into the microbiology driving mechanism of irrigation on farmland greenhouse effect and soil C sequestration.%农田碳库是全球碳库最活跃

  20. Understanding rice adaptation to varying agro-ecosystems: trait interactions and quantitative trait loci

    OpenAIRE

    Dixit, Shalabh; Grondin, Alexandre; Lee, Cheng-Ruei; Henry, Amelia; Olds, Thomas-Mitchell; Kumar, Arvind

    2015-01-01

    Background Interaction and genetic control for traits influencing the adaptation of the rice crop to varying environments was studied in a mapping population derived from parents (Moroberekan and Swarna) contrasting for drought tolerance, yield potential, lodging resistance, and adaptation to dry direct seeding. A BC2F3-derived mapping population for traits related to these four trait groups was phenotyped to understand the interactions among traits and to map and align QTLs using composite i...

  1. Earthworms, soil aggregates and organic matter decomposition in agro-ecosystems in The Netherlands.

    OpenAIRE

    Marinissen, J.C.Y.

    1995-01-01

    The relationships between earthworm populations, soil aggregate stability and soil organic matter dynamics were studied at an experimental farm in The Netherlands.Arable land in general is not favourable for earthworm growth. In the Lovinkhoeve fields under conventional management earthworm populations were brought to the verge of extinction in a few years. Main causes are soil fumigation against nematodes and unfavourable food conditions. Organic matter inputs and N-contents of the organic m...

  2. Building climate resilience into perennial agroecosystems for adaptation to climate change

    Science.gov (United States)

    Adapting to future climate changes will require resilient agricultural systems. Resiliency can be thought of as the ability of an ecosystem to bounce back and persist after a disturbance or shock. Stressors or perturbations may be more severe in the future because of human-induced climate change. On...

  3. Including sugar cane in the agro-ecosystem model ORCHIDEE-STICS: calibration and validation

    Science.gov (United States)

    Valade, A.; Vuichard, N.; Ciais, P.; Viovy, N.

    2011-12-01

    Sugarcane is currently the most efficient bioenergy crop with regards to the energy produced per hectare. With approximately half the global bioethanol production in 2005, and a devoted land area expected to expand globally in the years to come, sugar cane is at the heart of the biofuel debate. Dynamic global vegetation models coupled with agronomical models are powerful and novel tools to tackle many of the environmental issues related to biofuels if they are carefully calibrated and validated against field observations. Here we adapt the agro-terrestrial model ORCHIDEE-STICS for sugar cane simulations. Observation data of LAI are used to evaluate the sensitivity of the model to parameters of nitrogen absorption and phenology, which are calibrated in a systematic way for six sites in Australia and La Reunion. We find that the optimal set of parameters is highly dependent on the sites' characteristics and that the model can reproduce satisfactorily the evolution of LAI. This careful calibration of ORCHIDEE-STICS for sugar cane biomass production for different locations and technical itineraries provides a strong basis for further analysis of the impacts of bioenergy-related land use change on carbon cycle budgets. As a next step, a sensitivity analysis is carried out to estimate the uncertainty of the model in biomass and carbon flux simulation due to its parameterization.

  4. Soil plant transfer coefficient of 14C-carbofuran in brassica sp. vegetable agroecosystem

    International Nuclear Information System (INIS)

    The soil plant transfer coefficient or f factor of 14C-carbofuran pesticide was studied in outdoor lysimeter experiment consisting of Brassica sp. vegetable crop, riverine alluvial clayey soil and Bungor series sandy loam soil. Soil transfer coefficients at 0-10 cm soil depth were 4.38 ± 0.30, 5.76 ± 1.04, 0.99 ± 0.25 and 2.66 ± 0.71; from IX recommended application rate in alluvial soil, 2X recommended application rate in alluvial soil, IX recommended application rate in Bungor soil and 2X recommended application rate in Bungor soil, respectively. At 0-25 cm soil depth, soil plant transfer coefficients were 8.96 ± 0.91, 10.40 ± 2.63, 2.34 ± 0.68 and 619 ±1.40, from IX recommended application rate in alluvial soil, 2X recommended application rate in alluvial soil, IX recommended application rate in Bungor soil and 2X recommended application rate in Bungor soil, respectively. At 77 days after treatment (DAT), the soil plant transfer coefficient was significantly higher in riverine alluvial soil than Bungor soil whereas shoot and root growth was significantly higher in Bungor soil than in riverine alluvial soil. At both 0-10 cm Brassica sp. rooting depth and 0-25 cm soil depth, the soil plant transfer coefficient was significantly higher in 2X recommended application rate of 14C-carbofuran as compared to IX recommended application rate, in both Bungor and riverine alluvial soils. (Author)

  5. Nutrient flows and balances in urban and peri-urban agroecosystems of Kano, Nigeria

    NARCIS (Netherlands)

    Abdulkadir, A.; Leffelaar, P.A.; Agbenin, J.O.; Giller, K.E.

    2013-01-01

    Nutrient balances are useful indicators to assess the sustainability of farming systems. This study study investigates inflow and outflow of major nutrients in urban and periurban production systems in Kano, Nigeria. To this end, 16 households representing three different urban and peri-urban (UPA)

  6. Nutrient flows in urban and peri-urban agroecosystems in three West African cities

    NARCIS (Netherlands)

    Abdulkadir, A.

    2012-01-01

    Key words: Sustainability, CATPCA, two-step cluster analysis, farm types, nutrient balances, West Africa, gross margin, NUTMON/MONQI. Urban and peri-urban agriculture (UPA) is defined as the cultivation of crops and keeping livestock within and around cities. In addition to providing the cities&rsq

  7. Complex agro-ecosystems for food security in a changing climate.

    Science.gov (United States)

    Khumairoh, Uma; Groot, Jeroen Cj; Lantinga, Egbert A

    2012-07-01

    Attempts to increase food crop yields by intensifying agricultural systems using high inputs of nonrenewable resources and chemicals frequently lead to de-gradation of natural resources, whereas most technological innovations are not accessible for smallholders that represent the majority of farmers world wide. Alternatively, cocultures consisting of assemblages of plant and animal species can support ecological processes of nutrient cycling and pest control, which may lead to increasing yields and declining susceptibility to extreme weather conditions with increasing complexity of the systems. Here we show that enhancing the complexity of a rice production system by adding combinations of compost, azolla, ducks, and fish resulted in strongly increased grain yields and revenues in a season with extremely adverse weather conditions on East Java, Indonesia. We found that azolla, duck, and fish increased plant nutrient content, tillering and leaf area expansion, and strongly reduced the density of six different pests. In the most complex system comprising all components the highest grain yield was obtained. The net revenues of this system from sales of rice grain, fish, and ducks, after correction for extra costs, were 114% higher than rice cultivation with only compost as fertilizer. These results provide more insight in the agro-ecological processes and demonstrate how complex agricultural systems can contribute to food security in a changing climate. If smallholders can be trained to manage these systems and are supported for initial investments by credits, their livelihoods can be improved while producing in an ecologically benign way. PMID:22957173

  8. Soil fertility management and insect pests: Harmonizing soil and plant health in agroecosystems

    OpenAIRE

    Altieri, M.A.; Nicholls, C.

    2003-01-01

    Metadata only record Cultural methods such as crop fertilization can affect susceptibility of plants to insect pests by altering plant tissue nutrient levels. Research shows that the ability of a crop plant to resist or tolerate insect pests and diseases is tied to optimal physical, chemical and mainly biological properties of soils. Soils with high organic matter and active soil biology generally exhibit good soil fertility. Crops grown in such soils generally exhibit lower abundance of s...

  9. Analysing integration and diversity in agro-ecosystems by using indicators of network analysis

    NARCIS (Netherlands)

    Rufino, M.C.; Hengsdijk, H.; Verhagen, A.

    2009-01-01

    Diversity of farming activities may increase income stability and reduce risks to resource-poor households, while integration¿using the outputs of one activity as input in another activity¿may reduce dependency on external resources. In practice, diversity and integration are poorly defined, and the

  10. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems

    OpenAIRE

    Marjorie Bonareri Oruru; Ezekiel Mugendi Njeru

    2016-01-01

    Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers’ needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up wi...

  11. Environmental assessment of agro-ecosystems. An integrated approach to manage agri-environmental risks.

    OpenAIRE

    Gabrielle, Benoit

    2006-01-01

    Les « révolutions vertes » des 50 dernières années ont permis à l'agriculture de répondre à une demande croissante pour ses produits, grâce aux progrès génétiques et à l'apport de produits de synthèse (engrais et pesticides). Ces derniers ont en effet permis de s'affranchir de contraintes qui limitaient auparavant la croissance des plantes cultivées. Cette évolution rapide des pratiques agricoles n'a toutefois pas été sans conséquences pour les écosystèmes en général, mettant en danger le...

  12. Phosphorus in agroecosystems on gray forest soils in the opolie regions of Central Russia

    Science.gov (United States)

    Nikitishen, V. I.; Lichko, V. I.; Kurganova, E. V.

    2008-08-01

    Long-term stationary field experiments revealed a poor supply of gray forest soils with available phosphorus, which provides no more than half the amount necessary for optimum nutrition of plants. It was found that agricultural crops with different capacities to assimilate phosphates from the soil and fertilizers have strong requirements for phosphorus fertilizers and abruptly increase their utilization in the production process with increasing level of nitrogen nutrition. Crops with the optimum level of nitrogen nutrition uptake a double amount of phosphorus compared to crops depleted in nitrogen. Clover and barley have an increased capacity to mobilize soil phosphates from the lower horizons at an extremely low content of available forms of them in the plow layer. Winter wheat and corn are characterized by an active uptake of phosphorus applied with fertilizer and its efficient utilization in the production process if the nitrogen supply is not a limiting factor. The level of phosphorus nutrition of subsequent rotation crops increases due to the enrichment of the root-inhabited soil layer with phosphorus from clover root and harvest residues. Based on the data about the unacceptably abrupt decrease in the application of mineral fertilizers in Russian agriculture (90% of fertilizers are exported now), it is shown that the export of fertilizers should be limited at the state level, because chemicals, and primarily phosphorus fertilizers, should be considered strategic resources for internal use only.

  13. Cover crop effects on soil microbial communities and enzyme activity in semiarid agroecosystems

    Science.gov (United States)

    The objective of this study was to compare a fallow-winter wheat (Triticum aestivum L.) rotation to several cover crop-winter wheat rotations under dryland and irrigated conditions in the semiarid US High Plains. We carried out a study that included two sites (Sidney, NE, and Akron, CO), and three s...

  14. EVOLUTION OF SOME COMPONENTS OF AGROECOSYSTEMS PRODUCTIVITY FROM VINGA PLAIN IN WATER STRESS SITUATIONS

    Directory of Open Access Journals (Sweden)

    Daniel Dicu

    2011-12-01

    Full Text Available The researches are inscribed on line of substantiation of durable agricultural system, having as main objective the prominence of quantitative and qualitative modifications made on agro-system level under the effect of no-tillage system for wheat, maize and soybeans. The experimental field is placed on a cambic chernozem, with a medium content of clay, dominant in the Prodagro West Arad agro-centre and representative for a large surface in the Banat-Crisana Plain. The passing to no-till system change the structure of technological elements, through less soil works, so the impact on agro-system is different comparing with conventional tillage, first less the intervention pressure on agro-system ant secondly appear new interactions, new equilibriums and disequilibriums. Considering the evolution of soil humidity, the observations made monthly (by taking soil samples and laboratory determinations for the three cultures showed that in the no-till system, there are more uniform values in the soil profile, and in the variants where the deep work of soil was made it could be observed a low increase of the water volume in the soil.

  15. Environmental Fate of Soil Applied Neonicotinoid Insecticides in an Irrigated Potato Agroecosystem

    OpenAIRE

    Huseth, Anders S.; Groves, Russell L.

    2014-01-01

    Since 1995, neonicotinoid insecticides have been a critical component of arthropod management in potato, Solanum tuberosum L. Recent detections of neonicotinoids in groundwater have generated questions about the sources of these contaminants and the relative contribution from commodities in U.S. agriculture. Delivery of neonicotinoids to crops typically occurs as a seed or in-furrow treatment to manage early season insect herbivores. Applied in this way, these insecticides become systemically...

  16. Impact of Cover Cropping and Landscape Positions on Nitrous Oxide Emissions in Northeastern Agroecosystems

    Science.gov (United States)

    Han, Z.; Walter, M. T.; Drinkwater, L. E.

    2015-12-01

    Studies investigating agricultural nitrous oxide (N2O) emissions tend to rely on plot-scale experiments. However, to understand the impacts of agricultural practices at a larger scale, it is essential to consider the variability of landscape characteristics along with management treatments. This study compared N2O emissions from a fertilizer-based, conventionally managed farm and an organically managed farm that uses legume cover crops as a primary nutrient source. The objective of the study was to assess how management regimes and slope positions interact to impact N2O emissions and soil characteristics. The field experiment was conducted in two adjacent grain farms in upstate New York that both have been under consistent management for 20 years. In the organic farm, red clover was frost-seeded into a winter grain (spelt), and then incorporated in the spring as a nutrient source for the subsequent corn plants. In contrast, the conventionally managed farm used inorganic fertilizer as the nutrient source. Gas measurement was conducted at two landscape positions at both farms: 1) shoulder and 2) toeslope positions. Comparable N2O emissions were found in the clover-corn phase in the organic site and the bare fallow-corn phase in the conventional site. The spelt-corn phase in the organic farm had the lowest N2O emissions. Soil nitrate concentration was the best predictor for seasonal average N2O emissions. The impact of landscape position on N2O emissions was only found in the conventional site, which was driven by higher denitrfication at toeslopes. In the organic farm, such effect was confounded by higher clover biomass at shoulder slopes. Our study shows that the impact of landscape characteristics on N2O emissions could differ across sites based on the complex interplay between environmental conditions and management.

  17. Diversity and habitat preferences of Carabidae and Staphylinidae (Coleoptera in two agroecosystems

    Directory of Open Access Journals (Sweden)

    Ivan Carlos Fernandes Martins

    2012-01-01

    Full Text Available The present study had as objective determine the diversity and abundance of adults Carabidae and Staphylinidae in two areas, constituted by forest fragment and soybean/corn crops under conventional tillage and no-tillage systems and to analyze the distribution and preference of those beetles for the habitat. The beetles were sampled with 48 pitfall traps. In both experimental areas, two parallel transects of pitfall traps were installed. Each transect had 100 m in the crop and 100 m in the forest fragment. Four traps were close to each other (1 m in the edge between the crop and the forest fragment, the other traps were installed each 10 m. The obtained data were submitted to the faunistic analysis and the preference of the species by habitat was obtained by cluster analysis. The results demonstrated that the type of crop system (conventional tillage or no-tillage might have influenced the diversity of species of Carabidae and Staphylinidae. The cluster analysis evidenced that the carabids may prefer a specific habitat. In the present study, the distribution of carabids and staphylinids in the three habitats showed that these beetles have potential to be dispersed at great distances inside the crop.

  18. Mechanisms for increased soil C storage with increasing temporal and spatial plant diversity in Agroecosystems

    Science.gov (United States)

    Tiemann, L. K.; Grandy, S.; Marin-Spiotta, E.; Atkinson, E. E.

    2012-12-01

    Generally, there are positive relationships between plant species diversity and net primary production and other key ecosystem functions. However, the effects of aboveground diversity on soil microbial communities and ecosystem processes they mediate, such as soil C sequestration, remain unclear. In this study, we used an 11-y cropping diversity study where increases in diversity have increased crop yields. At the experimental site, temporal diversity is altered using combinations of annual crop rotations, while spatial diversity is altered using cover crop species. We used five treatments ranging in diversity from one to five species consisting of continuous corn with no cover crop or one cover crop and corn-soy-wheat rotations with no cover, one cover or two cover crop species. We collected soils from four replicate plots of each treatment and measured the distribution of mega- (>2 mm), macro- (0.25-2 mm), and micro- (0.053-0.25 mm) aggregates. Within each aggregate size class, we also measured total soil C and N, permanganate oxidizable C (POXC), extracellular enzyme activities (EEA), and microbial community structure with phospholipid fatty acid (PLFA) analysis. We use these data to address the impacts of both rotational and cover crop diversity on soil physical structure, associated microbial community structure and activity and soil C storage. As spatial diversity increased, we found concurrent increases in mega-aggregate abundance as well as increasing soil C in the mega- and micro-aggregates but not macro-aggregates. The proportion of total soil C in each aggregate size class that is relatively labile (POXC) was highest in the micro-aggregates, as was enzyme activity associated with labile C acquisition across all levels of diversity. Enzyme activity associated with more recalcitrant forms of soil C was highest in the mega-aggregate class, also across all diversity levels; however, the ratio of labile to recalcitrant EEA increased with increasing diversity in the mega- and micro-aggregates. In addition, soil N increased with diversity such that microbial C:N EEA simultaneously decreased in mega-aggregates. We also found that cropping diversity has created distinctive soil microbial communities, highlighted by variation in the abundance of gram positive bacteria and Actinomycetes. Further research will help us determine how these changes in community structure with increasing diversity are related to concomitant changes in aggregation and enzyme activities. We suggest that the additional organic matter inputs from cover crops in the high diversity treatments have increased aggregation processes and C pools. While microbial activity has also increased in association with this increased C availability, the activity of recalcitrant and N-acquiring enzymes has declined, suggesting an overall decrease in SOM mineralization with possible increased SOM stabilization. The addition of crop species in rotation (temporal diversity) had minimal influence on any of the measured parameters. We thus conclude that spatial diversity is a more important driver of soil structure and microbial activity, likely due to the high quality organic matter inputs derived from the leguminous cover crops; however, spatial diversity alone did not lead to the same level of C storage potential as mixtures of temporal and spatial diversity.

  19. Residues and accumulation of molinate in rice crops and aquatic weeds in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Plant and soil residue levels and its accumulation in rice crops and rice aquatic weed plants were studied. Molinate residue levels in rice, weeds and soil were not significantly different between the recycled and the non-recycled area, even though they were higher in the non-recycled area. In the rice plant, the residue level at 10 DAT (days after treatment) was significantly higher than 30 DAT in the recycled area. In rice aquatic weed plants, the residue level was significantly higher at 10 DAT as compared to 30 DAT in the non-recycled area. Molinate residue levels in soil at 10 DAT and 30 DAT were similar. Molinate accumulated (ratio of molinate concentration in plant over soil) more in the rice crop as compared to rice aquatic weeds at 10 DAT, in both the recycled and the non-recycled areas. (Author)

  20. A modelling methodology to assess the effect of insect pest control on agro-ecosystems

    OpenAIRE

    Nian-Feng Wan; Xiang-Yun Ji; Jie-Xian Jiang; Bo Li

    2015-01-01

    The extensive use of chemical pesticides for pest management in agricultural systems can entail risks to the complex ecosystems consisting of economic, ecological and social subsystems. To analyze the negative and positive effects of external or internal disturbances on complex ecosystems, we proposed an ecological two-sidedness approach which has been applied to the design of pest-controlling strategies for pesticide pollution management. However, catastrophe theory has not been initially ap...

  1. Evaluating the benefits of organic farming in rice agroecosystems in the Philippines

    OpenAIRE

    Mendoza, T.C.

    2004-01-01

    Metadata only record Organic rice farming utilized only 33% (39 USD ha(-1)) of the cash capital required to grow a hectare of rice when compared with conventional farm which spent 118 USD ha(-1). This much reduced cash capital expense in organic rice farming relieved women from the burden of sourcing credit to finance crop establishment. Women are in-charge of family finances. Cooperation among members of the family (husband, wife, children) enabled them to cope with the increased labor re...

  2. Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems

    OpenAIRE

    Vincenzo Tabaglio; Adriano Marocco; Margot Schulz

    2013-01-01

    The allelopathic potential of rye (Secale cereale L.) is mainly due to phytotoxic benzoxazinones, compounds that are produced and accumulated in young tissues to different degrees depending on cultivar and environmental influences. Living rye plants exude low levels of benzoxazinones, while cover crop residues can release from 12 to 20 kg ha–1. This paper summarizes the results obtained from several experiments performed in both controlled and field environments, in which rye was used as a co...

  3. Arbuscular Mycorrhizal (AM) Diversity in Prosopis cineraria (L.) Druce Under Arid Agroecosystems

    Institute of Scientific and Technical Information of China (English)

    Neelam Verma; Jagadish Chandra Tarafdar; Krishna Kant Srivastava; Jitendra Panwar

    2008-01-01

    Arbuscular mycorrhizal (AM) fungi associated with Prosopis cineraria (Khejri) were assessed for their qualitative and quantitative distribution from eight districts of Rajasthan. A total of three species of Acaulospora, one species of Entrophospora, two species of Gigaspora, twenty-one species of Glomus, seven species of Sclerocystis and three species of Scutellospora were recorded. A high diversity of AM fungi was observed and it varied at different study sites. Among these six genera, Glomus occurred most frequently. Glomus fasciculatum, Glomus aggregatum, and Glomus mosseae were found to be the most predominant AM fungi in infecting Prosopis cineraria. Acaulospora, G. fasciculatum, Sclerocystis was found in all the fields studied, while Scutellospora species were found only in few sites. A maximum of thirty-six AM fungal species were isolated and identified from Jodhpur, whereas only thirteen species were found from Jaisalmer. Spores of Glomus fasciculatum were found to be most abundant under Prosopis cineraria.

  4. Soil types will alter the response of arable agroecosystems to future rainfall patterns

    Science.gov (United States)

    Zaller, J. G.; Schwarz, T.; Hall, R.; Ziss, E.; von Hohberg und Buchwald, C.; Hösch, J.; Baumgarten, A.

    2012-04-01

    Regional climate change scenarios for eastern Austria (pannonian region) predict fewer but heavier rains during the vegetation period without substantial changes in the total annual amount of rainfall. While many studies investigated the effects of rainfall patterns on ecosystem properties, very little is known on how different soil types might alter ecosystem responses. In order to test this, we conducted an experiment at the AGES lysimeter station using 18 3 m2 lysimeters where we simultaneously manipulated rainfall patterns according to regional climate scenarios (current vs. prognosticated rain) on the three main soil types of the region (sandy calcaric phaeozem, gleyic phaeozem and calcic chernozem). Lysimeters were cultivated according to good farming practice using crop varieties and crop rotations typically for the region. Here, we present results of the response of field peas (Pisum sativum) on important agricultural parameters. Lysimeters under progn. rain showed lower crop cover than under curr. rain while soil types had no effect. Total aboveground biomass production (comprising crops plus weeds) was significantly lower under progn. rain; sandy calcaric phaeozem showed the lowest plant biomass. Pea yields under progn. rain were substantially lower than under curr. rain; again, yields under sandy soils were lower than under the other two soil types. Root growth was significantly higher in progn. rain than in curr. rain; there was a trend towards less root growth in the gleyic soils. Mycorrhization of roots was not influenced by soil types, however under progn. rain colonization rates were lower than under curr. rain. Weed establishment and growth was increased under progn. rain in gleyic soils but decreased in the other soil types. Weed biomass was not affected by rainfall, however sandy soils had less weed biomass than the other soil types. Abundance of the insect pest pea moth (Cydia nigricana) was almost twice as high under progn. rain than under curr. rain, soil types had only little influence on this pest species. These results show that (i) changes in rainfall patterns predicted for the near future due to human-induced global climate changes will substantially affect crop production and management in the study region, and (ii) the influence of different soil types in altering ecosystem responses should be considered when trying to scale-up experimental results derived at the plot level to the landscape level.

  5. Agroecosystem research in Uppsala, Sweden and Naiman, China:Some observations 1987-2014

    Institute of Scientific and Technical Information of China (English)

    Olof Andrn; XueYong Zhao; Thomas Ktterer; Martin Bolinder

    2016-01-01

    The recent economic progress in China has stimulated scientific research in sandy lands in Inner Mongolia, where the Institute of Desert Research, Chinese Academy of Sciences (now CAREERI) has a leading position. Economic progress naturally creates financial resources for research, and also a dire need for solutions to emerging environmental problems following development, where wind-blown dust from Inner Mongolia adds to the severe particle air pollution in many Chinese cities. This paper presents selected results and observations made during Chinese–Swedish cooperation projects spanning 25 years. Results and experiences from sandy land research concerning climate, vegetation, root dynamics, soil carbon balances,etc. are briefly presented. The evolution of the Naiman Desertification Research Station, 520 km northeast of Beijing, from 1988 to 2013 is duly noted and commented. An overview of the ICBM soil carbon model concept follows and a few recommendations for future scientific advancement in Chinese arid lands are given.

  6. Natural Enemies of the Frankliniella Complex Species (Thysanoptera: Thripidae) in Ataulfo Mango Agroecosystems.

    Science.gov (United States)

    Rocha, Franklin H; Infante, Francisco; Castillo, Alfredo; Ibarra-Nuñez, Guillermo; Goldarazena, Arturo; Funderburk, Joe E

    2015-01-01

    A field survey was conducted in Ataulfo mango (Mangifera indica L.) orchards in Chiapas, Mexico, with the objective of determining the natural enemies of the Frankliniella complex species (Thysanoptera: Thripidae). Seven species of this genus feed and reproduce in large numbers during the mango flowering. Two representative orchards were selected: the orchard "Tres A" characterized by an intensive use of agrochemicals directed against thrips, and the orchard "La Escondida" that did not spray insecticides. During mango flowering, five inflorescences were randomly collected every 5 d in both orchards, for a total of 18 sampling dates. Results revealed the presence of 18 species of arthropods that were found predating on Frankliniella. There were 11 species in the families Aeolothripidae, Phlaeothripidae, Formicidae, Anthocoridae and Chrysopidae; and seven species of spiders in the families Araneidae, Tetragnathidae, and Uloboridae. Over 88% of predators were anthocorids, including, Paratriphleps sp. (Champion), Orius insidiosus (Say), Orius tristicolor (White), and O. perpunctatus (Reuter). The orchard that did not spray insecticides had a significantly higher number of predators suggesting a negative effect of the insecticides on the abundance of these organisms.

  7. Methyl salicylate attracts natural enemies and reduces populations of soybean aphids (Hemiptera: Aphididae) in soybean agroecosystems.

    Science.gov (United States)

    Mallinger, Rachel E; Hogg, David B; Gratton, Claudio

    2011-02-01

    Methyl salicylate, an herbivore-induced plant volatile, has been shown to attract natural enemies and affect herbivore behavior. In this study, methyl salicylate was examined for its attractiveness to natural enemies of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and for its direct effects on soybean aphid population growth rates. Methyl salicylate lures were deployed in plots within organic soybean [Glycine max (L.) Merr.] fields. Sticky card traps adjacent to and 1.5 m from the lure measured the relative abundance of natural enemies, and soybean aphid populations were monitored within treated and untreated plots. In addition, exclusion cage studies were conducted to determine methyl salicylate's effect on soybean aphid population growth rates in the absence of natural enemies. Significantly greater numbers of syrphid flies (Diptera: Syrphidae) and green lacewings (Neuroptera: Chrysopidae) were caught on traps adjacent to the methyl salicylate lure, but no differences in abundance were found at traps 1.5 m from the lure. Furthermore, abundance of soybean aphids was significantly lower in methyl salicylate-treated plots. In exclusion cage studies, soybean aphid numbers were significantly reduced on treated soybean plants when all plants were open to natural enemies. When plants were caged, however, soybean aphid numbers and population growth rates did not differ between treated and untreated plants suggesting no effect of methyl salicylate on soybean aphid reproduction and implicating the role of natural enemies in depressing aphid populations. Although aphid populations were reduced locally around methyl salicylate lures, larger scale studies are needed to assess the technology at the whole-field scale.

  8. Small mammal populations of an agroecosystem in the Atlantic Forest domain, southeastern Brazil.

    Science.gov (United States)

    D'Andrea, P S; Gentile, R; Maroja, L S; Fernandes, F A; Coura, R; Cerqueira, R

    2007-02-01

    This study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. The study was conducted in a rural area of the Atlantic Forest, in Sumidouro, Rio de Janeiro State, Brazil. The population sizes, age structure and reproduction were studied for the four most common species in the study area. The overall diversity was 1.67 and ranged between 0.8 to 1.67. The species richness was 13 considering the whole study. The most abundant species were the rodents Nectomys squamipes (n = 133), Akodon cursor (n = 74), Oligoryzomys nigripes (n = 25) and the marsupials Didelphis aurita (n = 58) and Philander frenatus (n = 50). Seven other rodents were captured once: Necromys lasiurus, Akodon montensis, Sooretamys angouya, Oecomys catherine, Oxymycterus judex, Euryzygomatomys spinosus and Trinomys iheringi. There were higher peaks for diversity and species richness during the winter (dry) months, probably due to higher food availability. The marsupials had a seasonal reproduction with highest population sizes at the end of the rainy seasons. Nectomys squamipes reproduced mostly during rainy periods. Akodon cursor reproduced predominantly in the winter with the highest population peaks occurring during this season. The analysis of the population dynamics of the rodent species indicated that no species behaved as an agricultural pest, probably due to the heterogeneous landscape of high rotativity of vegetable cultivation. Rodent populations were more susceptible to the removal procedure than marsupial ones.

  9. Environmental fate of soil applied neonicotinoid insecticides in an irrigated potato agroecosystem.

    Science.gov (United States)

    Huseth, Anders S; Groves, Russell L

    2014-01-01

    Since 1995, neonicotinoid insecticides have been a critical component of arthropod management in potato, Solanum tuberosum L. Recent detections of neonicotinoids in groundwater have generated questions about the sources of these contaminants and the relative contribution from commodities in U.S. agriculture. Delivery of neonicotinoids to crops typically occurs as a seed or in-furrow treatment to manage early season insect herbivores. Applied in this way, these insecticides become systemically mobile in the plant and provide control of key pest species. An outcome of this project links these soil insecticide application strategies in crop plants with neonicotinoid contamination of water leaching from the application zone. In 2011 and 2012, our objectives were to document the temporal patterns of neonicotinoid leachate below the planting furrow following common insecticide delivery methods in potato. Leaching loss of thiamethoxam from potato was measured using pan lysimeters from three at-plant treatments and one foliar application treatment. Insecticide concentration in leachate was assessed for six consecutive months using liquid chromatography-tandem mass spectrometry. Findings from this study suggest leaching of neonicotinoids from potato may be greater following crop harvest in comparison to other times during the growing season. Furthermore, this study documented recycling of neonicotinoid insecticides from contaminated groundwater back onto the crop via high capacity irrigation wells. These results document interactions between cultivated potato, different neonicotinoid delivery methods, and the potential for subsurface water contamination via leaching.

  10. Elevated carbon dioxide does not offset loss of soil carbon from a corn-soybean agroecosystem

    International Nuclear Information System (INIS)

    The potential for storing additional C in U.S. Corn Belt soils - to offset rising atmospheric [CO2] - is large. Long-term cultivation has depleted substantial soil organic matter (SOM) stocks that once existed in the region's native ecosystems. In central Illinois, free-air CO2 enrichment technology was used to investigate the effects of elevated [CO2] on SOM pools in a conservation tilled corn-soybean rotation. After 5 and 6 y of CO2 enrichment, we investigated the distribution of C and N among soil fractions with varying ability to protect SOM from rapid decomposition. None of the isolated C or N pools, or bulk-soil C or N, was affected by CO2 treatment. However, the site has lost soil C and N, largely from unprotected pools, regardless of CO2 treatment since the experiment began. These findings suggest management practices have affected soil C and N stocks and dynamics more than the increased inputs from CO2-stimulated photosynthesis. - Soil carbon from microaggregate-protected and unprotected fractions decreased in a conservation tilled corn-soybean rotation despite increases in primary production from exposure to atmospheric CO2 enrichment.

  11. Greenhouse cultivation mitigates metal-ingestion-associated health risks from vegetables in wastewater-irrigated agroecosystems.

    Science.gov (United States)

    Cao, Chun; Chen, Xing-Peng; Ma, Zhen-Bang; Jia, Hui-Hui; Wang, Jun-Jian

    2016-08-01

    Wastewater irrigation can elevate metal concentrations in soils and crops and increase the metal-associated health risks via vegetable ingestion in arid and semiarid northwestern China. Here, we investigated the As, Cd, Cr, Cu, Ni, Pb, and Zn concentrations in four vegetable species from Dongdagou and Xidagou farmlands in Baiyin, Gansu, China. We evaluated the effects of irrigation type (Dongdagou: industrial wastewater; Xidagou: domestic wastewater) and cultivation mode (open field and greenhouse) on the vegetable metal concentration, metal partitioning, soil-to-plant bioconcentration factor (BCF), and the health risk index. All stream waters, soils, and vegetables were found most severely polluted by As and Cd, with higher severity in the industrial-wastewater-irrigated Dongdagou than the domestic-wastewater-irrigated Xidagou. All vegetables had higher or, at least, comparable metal mass allocated in the shoot than in the root. Greenhouse cultivation could reduce metal-ingestion-associated health risks from edible vegetable biomass by decreasing the soil to plant bioaccumulation (BCF) and the metal concentration. This effect was always significant for all vegetables within Xidagou, and for carrot within Dongdagou. This mitigation effect of greenhouse cultivation could be attributed to the metal sorption by a higher level of soil organic matter and faster growth rate over metal uptake rate in greenhouses compared to open fields. Such mitigation effect was, however, insignificant for leafy vegetables within Dongdagou, when much more severely polluted water for irrigation was applied in greenhouses compared to open fields within Dongdagou. The present study highlights greenhouse cultivation as a potential mitigating approach to providing less-polluted vegetables for residents in the severely polluted area in addition to the source pollution control.

  12. Characterization of urban and peri-urban agroecosystems in three West African cities

    NARCIS (Netherlands)

    Abdulkadir, A.; Dossa, L.H.; Lompo, D.J.P.; Abdu, N.; Keulen, van H.

    2012-01-01

    Systems of urban and peri-urban agriculture (UPA) take many forms in terms of integration of different activities, production intensities and production orientations. The present study is aimed at a refined characterization of the diversity in terms of production orientation, resource endowments and

  13. Context-dependency of arbuscular mycorrhizal fungi on plant-insect interactions in an agroecosystem

    Directory of Open Access Journals (Sweden)

    Nicholas A Barber

    2013-09-01

    Full Text Available Plants interact with a variety of other community members that have the potential to indirectly influence each other through a shared host plant. Arbuscular mycorrhizal fungi (AMF are generally considered plant mutualists because of their generally positive effects on plant nutrient status and growth. AMF may also have important indirect effects on plants by altering interactions with other community members. By influencing plant traits, AMF can modify aboveground interactions with both mutualists, such as pollinators, and antagonists, such as herbivores. Because herbivory and pollination can dramatically influence plant fitness, comprehensive assessment of plant-AMF interactions should include these indirect effects. To determine how AMF affect plant-insect interactions, we grew Cucumis sativus (Cucurbitaceae under five AMF inoculum treatments and control. We measured plant growth, floral production, flower size, and foliar nutrient content of half the plants, and transferred the other half to a field setting to measure pollinator and herbivore preference of wild insects. Mycorrhizal treatment had no effect on plant biomass or floral traits but significantly affected leaf nutrients, pollinator behavior, and herbivore attack. Although total pollinator visitation did not vary with AMF treatment, pollinators exhibited taxon-specific responses, with honey bees, bumble bees, and Lepidoptera all responding differently to AMF treatments. Flower number and size were unaffected by treatments, suggesting that differences in pollinator preference were driven by other floral traits. Mycorrhizae influenced leaf K and Na, but these differences in leaf nutrients did not correspond to variation in herbivore attack. Overall, we found that AMF indirectly influence both antagonistic and mutualistic insects, but impacts depend on the identity of both the fungal partner and the interacting insect, underscoring the context dependency of plant-AMF interactions.

  14. Modelling the impact of soil erosion on element transfer processes in agro-ecosystems

    Science.gov (United States)

    Shi, Pu; Della Peruta, Raniero; Keller, Armin; Schulin, Rainer

    2014-05-01

    Soil erosion is the main cause for loss of soil fertility worldwide. It can lead to degradation of soil structure, pollution of water bodies, decrease in crop productivity, and excessive accumulation of nutrients and trace elements in locations where eroded sediments are re-deposited. Research into the element transfer in fields and landscapes associated with erosion has hitherto focused on the assessment of element mobilization and nutrient export into aquatic ecosystems. Less is known about the role of erosion in element redistribution within terrestrial environments. Hence, we are developing a GIS-linked model that describes and visualizes areal patterns of particle-bound element transfer processes at the field to catchment scale, adapting and combining existing process-based mechanistic models of soil erosion, soil hydrology, sediment transport, crop growth, soil nutrient turnover and soil pollutant dynamics. The model will be tested in a case study of selected catchment in the framework of the Swiss National Research Program 'Sustainable Use of Soil as a Resource' (NRP 68). The goal is to create a tool that can be used to aid monitoring nutrient and pollutant fluxes associated with erosion in agricultural landscapes, in particular to identify hot spots of excessive pollutant accumulation related to the deposition of eroded sediments on agricultural land for different scenarios of land use and climate change, and to support the evaluation of land management strategies aiming to control them.

  15. Earthworms, soil aggregates and organic matter decomposition in agro-ecosystems in The Netherlands.

    NARCIS (Netherlands)

    Marinissen, J.C.Y.

    1995-01-01

    The relationships between earthworm populations, soil aggregate stability and soil organic matter dynamics were studied at an experimental farm in The Netherlands.Arable land in general is not favourable for earthworm growth. In the Lovinkhoeve fields under conventional management earthworm populati

  16. Nitrate, phosphate, and ammonium loads at subsurface drains: agroecosystems and nitrogen management.

    Science.gov (United States)

    Hernandez-Ramirez, Guillermo; Brouder, Sylvie M; Ruark, Matthew D; Turco, Ronald F

    2011-01-01

    Artificial subsurface drainage in cropland creates pathways for nutrient movement into surface water; quantification of the relative impacts of common and theoretically improved management systems on these nutrient losses remains incomplete. This study was conducted to assess diverse management effects on long-term patterns (1998-2006) of NO, NH, and PO loads (). We monitored water flow and nutrient concentrations at subsurface drains in lysimeter plots planted to continuous corn ( L.) (CC), both phases of corn-soybean [ (L.) Merr.] rotations (corn, CS; soybean, SC), and restored prairie grass (PG). Corn plots were fertilized with preplant or sidedress urea-NHNO (UAN) or liquid swine manure injected in the fall (FM) or spring (SM). Restored PG reduced NO eightfold compared with fields receiving UAN (2.5 vs. 19.9 kg N ha yr; soils recorded high but episodic losses in certain years. Compared with the average of all other treatments, CCSM increased NH in the spring of 1999 (217 vs. 680 g N ha yr), while CCFM raised PO in the winter of 2005 (23 vs. 441 g P ha yr). Our results demonstrate that fall manuring increased nutrient losses in subsurface-drained cropland, and hence this practice should be redesigned for improvement or discouraged. PMID:21712592

  17. Environmental Fate of Soil Applied Neonicotinoid Insecticides in an Irrigated Potato Agroecosystem

    Science.gov (United States)

    Huseth, Anders S.; Groves, Russell L.

    2014-01-01

    Since 1995, neonicotinoid insecticides have been a critical component of arthropod management in potato, Solanum tuberosum L. Recent detections of neonicotinoids in groundwater have generated questions about the sources of these contaminants and the relative contribution from commodities in U.S. agriculture. Delivery of neonicotinoids to crops typically occurs as a seed or in-furrow treatment to manage early season insect herbivores. Applied in this way, these insecticides become systemically mobile in the plant and provide control of key pest species. An outcome of this project links these soil insecticide application strategies in crop plants with neonicotinoid contamination of water leaching from the application zone. In 2011 and 2012, our objectives were to document the temporal patterns of neonicotinoid leachate below the planting furrow following common insecticide delivery methods in potato. Leaching loss of thiamethoxam from potato was measured using pan lysimeters from three at-plant treatments and one foliar application treatment. Insecticide concentration in leachate was assessed for six consecutive months using liquid chromatography-tandem mass spectrometry. Findings from this study suggest leaching of neonicotinoids from potato may be greater following crop harvest in comparison to other times during the growing season. Furthermore, this study documented recycling of neonicotinoid insecticides from contaminated groundwater back onto the crop via high capacity irrigation wells. These results document interactions between cultivated potato, different neonicotinoid delivery methods, and the potential for subsurface water contamination via leaching. PMID:24823765

  18. [Effect of biopreparations on dynamics of the number of bacteria and phytopathogenic fungi in potato agroecosystem].

    Science.gov (United States)

    Patyka, N V; Borodaĭ, V V; Zhitkevich, N V; Khomenko, E V; Gnatiuk, T T; Koltunov, V A; Patyka, V F

    2012-01-01

    Application of biological preparations such as Phytotsid and Planryz favoures the growth of the general number of soil's bacteria population compared with control by 13.0-36.1% in the variant of potato variety Scarbnytsya and by 4.5-24.6% of potato variety Oberig. It also decreases 1.2-1.8 times the number of soil phytopathogens--Fusarium and Alternaria. During the application of Rovral Akvaflo the Shenon's ecological index of species biodiversity was lower than during the bioprepation application. One could observe a decrease of species biodiversity and dominance of dark pigmentation in fungi--Alternaria sp., Cladosporium sp., Phoma sp., Doratomyces sp., and pigmented bacteria.

  19. Potential impact of climatic changes on floristic evolution of phytocoenoses in mediterranean agroecosystems

    Directory of Open Access Journals (Sweden)

    Stefano Benvenuti

    2011-02-01

    Full Text Available In order to predict the potential agronomic scenarios of the future, the probable involvements of climatic changes on weed dynamics were analyzed. In this perspective the several climatic parameters were examined and overlapped to the biological characteristics of the different species to predict both: weed evolution and the sustainability of the relative management. Thermal and CO2 increasing favour the weed ruderality in terms of seed quantity and velocity of seed set. In addition the increasing of stress factors (thermal, drought, UV-B, etc. favour the de-specialization trend as typically occurs in the most persistent weeds. Adverse climatic dynamics, even due to events of opposite biological action (for example drought and flooding, appears to have a synergistic impact with the agronomic disturbances. Indeed these additive disturbances increase the selective pressure of the phytocoenoses and play a crucial role in the allowing survival only to the “segetal” weeds as well it occurs from the origin of agriculture. Consequently, the different degree of resilience induces a decreasing of the phytocoenoses complexity. This biodiversity reduction appears to increase the risk of exotic weed invasion overall regards to species from warmer and more arid environments (potentially even parasite species. Their invasivity could be increased by biotic or abiotic stress factors that are not present in their native environment. The fate of rare weeds appears to go to their extinction, overall if their dynamics is linked to fragile mutualistic interaction as it occurs in the case of entomogamous species. Indeed such simultaneous presence (flora and pollinator fauna is mined by the progressive differences between photoperiod and thermoperiod and the consequent de-synchronization of their phenological phases. This virtual weed evolution through the increasing of the richness of self- and wind-pollinated weeds will involve both: 1 the agricultural landscape degradation; 2 a worse human health because of atmosphere rich of allergenic pollen. In conclusion, weed phytocoenoses appear to be less vulnerable of the relative crops to the climatic injuries. This higher crop vulnerability will increase the pesticides use as well as already predicted regards to entomologic and phytopatologic aspects. Finally, an agronomic strategy of the future was hypothized. This is based on the germplasm utilization of the wild types in order to increase the environmental crop plasticity in the predicted climatic scenarios.

  20. Potential impact of climatic changes on floristic evolution of phytocoenoses in mediterranean agroecosystems

    Directory of Open Access Journals (Sweden)

    Stefano Benvenuti

    Full Text Available In order to predict the potential agronomic scenarios of the future, the probable involvements of climatic changes on weed dynamics were analyzed. In this perspective the several climatic parameters were examined and overlapped to the biological characteristics of the different species to predict both: weed evolution and the sustainability of the relative management. Thermal and CO2 increasing favour the weed ruderality in terms of seed quantity and velocity of seed set. In addition the increasing of stress factors (thermal, drought, UV-B, etc. favour the de-specialization trend as typically occurs in the most persistent weeds. Adverse climatic dynamics, even due to events of opposite biological action (for example drought and flooding, appears to have a synergistic impact with the agronomic disturbances. Indeed these additive disturbances increase the selective pressure of the phytocoenoses and play a crucial role in the allowing survival only to the “segetal” weeds as well it occurs from the origin of agriculture. Consequently, the different degree of resilience induces a decreasing of the phytocoenoses complexity. This biodiversity reduction appears to increase the risk of exotic weed invasion overall regards to species from warmer and more arid environments (potentially even parasite species. Their invasivity could be increased by biotic or abiotic stress factors that are not present in their native environment. The fate of rare weeds appears to go to their extinction, overall if their dynamics is linked to fragile mutualistic interaction as it occurs in the case of entomogamous species. Indeed such simultaneous presence (flora and pollinator fauna is mined by the progressive differences between photoperiod and thermoperiod and the consequent de-synchronization of their phenological phases. This virtual weed evolution through the increasing of the richness of self- and wind-pollinated weeds will involve both: 1 the agricultural landscape degradation; 2 a worse human health because of atmosphere rich of allergenic pollen. In conclusion, weed phytocoenoses appear to be less vulnerable of the relative crops to the climatic injuries. This higher crop vulnerability will increase the pesticides use as well as already predicted regards to entomologic and phytopatologic aspects. Finally, an agronomic strategy of the future was hypothized. This is based on the germplasm utilization of the wild types in order to increase the environmental crop plasticity in the predicted climatic scenarios.

  1. IMPACT OF BT ( BACILLUS THURINGIENSIS ) CROPS ON BAT ACTIVITY IN SOUTH TEXAS AGROECOSYSTEMS

    Science.gov (United States)

    The widespread adoption of transgenic insecticidal crops raises concerns that nontarget species may be harmed and food webs disrupted. The goal of this research is to determine how transgenic Bt (Bacillus thuringiensis) crops impact the activity of Brazilian freetailed bats (Tada...

  2. Nutrient flows in urban and peri-urban agroecosystems in three West African cities

    OpenAIRE

    Abdulkadir, A.

    2012-01-01

    Key words: Sustainability, CATPCA, two-step cluster analysis, farm types, nutrient balances, West Africa, gross margin, NUTMON/MONQI. Urban and peri-urban agriculture (UPA) is defined as the cultivation of crops and keeping livestock within and around cities. In addition to providing the cities’ demand of fresh vegetables, crops and livestock products, it plays an important role in the livelihoods of the urban farmers. With the rapid urbanization in sub-Saharan Africa, UPA provides food...

  3. Estimating total nitrogen deposition in agroecosystems in northern China during the wheat cropping season

    Institute of Scientific and Technical Information of China (English)

    Christie; PETER; Fangmeier; ANDREAS

    2010-01-01

    Atmospheric nitrogen (N) deposition has been poorly documented in northern China, an intensive agricultural and industrial region with large emissions of NHx and NOy. To quantify N deposition, total airborne N deposition was determined at three agricultural sites using a manual integrated total nitrogen input (ITNI) system during growth of winter wheat (Triticum aestivum L.) and Italian ryegrass (Lolium multiflorum Lam.) from September 2005 to May 2006. Total estimated N deposition averaged 54.9 and 43.2 kg N/hm2 across the three sites when wheat was grown to flowering and maturing, respectively. The average value was 50.2 kg N/hm2 when ryegrass was the indicator plant. Both indicator species gave similar total airborne N input results. The intermediate level of N supplied resulted in the highest N deposition, and the ratio of N acquired from deposition to total N content of the whole system decreased with increasing N supply to the roots. The contribution of atmospheric N to the total N content of the wheat and ryegrass sand culture systems ranged from 10% to 24%.

  4. Analysis and classification of data sets for calibration and validation of agro-ecosystem models

    DEFF Research Database (Denmark)

    Kersebaum, K C; Boote, K J; Jorgenson, J S;

    2015-01-01

    to their relevance for modelling and possible uncertainties. Examples are given for data sets of the different classes. The framework helps to assemble high quality data bases, to select data from data bases according to modellers requirements and gives guidelines to experimentalists for experimental design...

  5. Establishing a tracer-based sediment budget to preserve wetlands in Mediterranean mountain agroecosystems (NE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Navas, Ana, E-mail: anavas@eead.csic.es [Department of Soil and Water, Estación Experimental de Aula Dei, EEAD-CSIC, Avda. Montañana 1005, 50059 Zaragoza (Spain); López-Vicente, Manuel, E-mail: mvicente@eead.csic.es [Department of Soil and Water, Estación Experimental de Aula Dei, EEAD-CSIC, Avda. Montañana 1005, 50059 Zaragoza (Spain); Gaspar, Leticia, E-mail: leticia.gaspar@plymouth.ac.uk [School of Geography, Earth and Environmental Science, Plymouth University, Plymouth, Devon PL4 8AA (United Kingdom); Palazón, Leticia, E-mail: lpalazon@eead.csic.es [Department of Soil and Water, Estación Experimental de Aula Dei, EEAD-CSIC, Avda. Montañana 1005, 50059 Zaragoza (Spain); Quijano, Laura, E-mail: lquijano@eead.cisc.es [Department of Soil and Water, Estación Experimental de Aula Dei, EEAD-CSIC, Avda. Montañana 1005, 50059 Zaragoza (Spain)

    2014-10-15

    Mountain wetlands in Mediterranean regions are particularly threatened in agricultural environments due to anthropogenic activity. An integrated study of source-to-sink sediment fluxes was carried out in an agricultural catchment that holds a small permanent lake included in the European NATURA 2000 Network. More than 1000 yrs of human intervention and the variety of land uses pose a substantial challenge when attempting to estimate sediment fluxes which is the first requirement to protect fragile wetlands. To date, there have been few similar studies and those that have been carried out have not addressed such complex terrain. Geostatistical interpolation and GIS tools were used to derive the soil spatial redistribution from point {sup 137}Cs inventories, and to establish the sediment budget in a catchment located in the Southern Pyrenees. The soil redistribution was intense and soil erosion predominated over soil deposition. On the areas that maintained natural vegetation the median soil erosion and deposition rates were moderate, ranging from 2.6 to 6 Mg ha yr{sup −1} and 1.5 to 2.1 Mg ha yr{sup −1}, respectively. However, in cultivated fields both erosion and deposition were significantly higher (ca. 20 Mg ha yr{sup −1}), and the maximum rates were always associated with tillage practices. Farming activities in the last part of the 20th century intensified soil erosion, as evidenced by the 1963 {sup 137}Cs peaks in the lake cores and estimates from the sediment budget indicated a net deposition of 671 Mg yr{sup −1}. Results confirm a siltation risk for the lake and provide a foundation for designing management plans to preserve this threatened wetland. This comprehensive approach provides information useful for understanding processes that influence the patterns and rates of soil transfer and deposition within fragile Mediterranean mountain wetlands subjected to climate and anthropogenic stresses. - Highlights: • Soil erosion threatens long-term sustainability of mountain wetlands and agriculture. • {sup 137}Cs was applied for estimation of soil redistribution in a complex catchment. • A tracer derived sediment budget identified main sources causing lake siltation. • Fallout tracer and GIS provided information useful for wetland preservation. • Vegetation strips around fields would reduce siltation from tillage erosion.

  6. Habitat management for conservation of pollinators in agro-ecosystems of Central Spain

    OpenAIRE

    Barbir, Jelena

    2014-01-01

    La gestión de hábitat orientada a la conservación de polinizadores en los agro-ecosistemas requiere una selección de especies vegetales atendiendo fundamentalmente a dos criterios: i) el potencial atractivo de sus flores a los polinizadores; y ii) la simplicidad en su manejo agronómico. Además de estas premisas, es necesario considerar la capacidad invasora de estas especies vegetales, debido a que algunas de las más atractivas pueden resultar invasoras en determinados agro-ecosistemas. Por l...

  7. THE EFFECT OF SEED TREATMENT ON THE MAIN PATHOGENS PRESENT IN WHEAT AGROECOSYSTEMS.

    Science.gov (United States)

    Stef, R; Grozea, I; Puia, C; Carabet, A; Vlad, M; Manea, D

    2014-01-01

    Wheat crop (Triticum aestivum L.) from Poaceae family is affected by many diseases that cause yield losses. The present paper addresses a topic of economic, agrotechnics and social importance of wheat crop (occupying the first place among the Romanian cultivated crop, feeding 35 to 40% of world population). The study had as main objective product testing like Yunta 246 FS (imidacloprid 233 g/l + tebuconazol 13 g/l), Team Micorriza Plus (Glomus intraradices 150 spore/g + Glomus mosseae 150 spore/g + organic matter 56% and Rhizosphere Bacteria 107 UFC/g) and Condor (Trichoderma spp. 1 x 109 spore/g + Glomus sp. 10 spore/g + Rhizosphere Bacteria 1 x 107 UFC/g and organic matter 7%) applied in the pathosystem wheat/pathogens. The research was conducted in the western part of Romania, in 2010-2012, experience was placed after Latin rectangle method with 10 variants (they are different by product and dose applied) and the data were statistically interpreted. Results showed the presence of pathogens Septoria tritici, Drechslera tritici repentis and Drechslera teres in experimental variants. Statistical analysis showed that the most effective chemical mixture was imidacloprid + tebuconazol at the highest dose tested (3 l/t). Regarding the non-chemical product testing, the product Condor gave positive results. The highest values of quality parameters (protein and gluten) were obtained in the variants treated with Yunta 246 FS.

  8. A stochastic empirical model for heavy-metal balnces in Agro-ecosystems

    NARCIS (Netherlands)

    Keller, A.N.; Steiger, von B.; Zee, van der S.E.A.T.M.; Schulin, R.

    2001-01-01

    Mass flux balancing provides essential information for preventive strategies against heavy-metal accumulation in agricultural soils that may result from atmospheric deposition and application of fertilizers and pesticides. In this paper we present the empirical stochastic balance model, PROTERRA-S,

  9. Analysis of biological qualities of land in traditional and conventional agro-ecosystems

    Directory of Open Access Journals (Sweden)

    Eugen Skura

    2013-12-01

    Full Text Available Land constitutes the most important natural resource from the perspective of environmental and human life, for many ecological functions and socio-economical performs. The provision of continuous recycling of nutrients for plants, water retention, storage of carbon reserves, filtering many potential pollutant substances, are some of the key ecological functions of soil. Production of biomass, the supply of food for man and animals, production of fibers for industry, the plant for agro-industrial use of those medical, constitute social functions - economic land which affect the welfare of everyday human life. These important ecological and economic functions not depend only on land use, but also its qualities, and in particular the biological qualities. Biological qualities of the land, which determine the level of fertility, primarily depend on management practices of agricultural systems. In conventional systems of agriculture, unlike traditional systems, soil fertility is really threatened, due to the accumulation of pollutant substances used and their impact on soil micro-flora. Protecting biological qualities of land remains a perennial target of agricultural systems more to ensure its functioning for a long period of time, to support life on earth.

  10. Biochemical Impact of Fodder Galega (Galega orientalis Lam. on Agro-ecosystems

    Directory of Open Access Journals (Sweden)

    Ligita Baležentienė

    2011-12-01

    Full Text Available Multifunctional allelochemicals activities stimulate an increase in an employment spectrum of biologically active compounds in biological farming. The understanding of the allelochemical action mechanisms makes it possible to use these compounds to enhance crop production and develop a more sustainable agriculture, including weed and pest control through crop rotations, residue management and a variety of approaches in bio-control. The aim of this research was to establish and to compare the total amount of phenolic compounds and allelopathic activity of the aqueous extracts produced of different shoot parts (leaves, stems, blossoms and seed and roots of new crop, namely fodder galega at their different growth stages. Biochemical impact of the aqueous extracts produced of fodder galega ground part and roots on the germination data of the test–object subjected significantly on the galega growth stage and extract concentration. The biochemical effect of all tested extracts and concentrations had the same tendency to inhibit the test–object seed germination. The extracts of the ground part were more toxic than those of roots and had a stronger suppressive effect on the test–plant germination. Phenols concentration and conventional coumarine unit (CCU content increased evenly in dependence on total phenols concentration at all plant development stages accordingly to the extracts concentration gradient. Phenols concentration as well as their activity of ground part and roots increased from shooting to flowering stage.

  11. Ecological Complexity in a Coffee Agroecosystem: Spatial Heterogeneity, Population Persistence and Biological Control

    OpenAIRE

    Heidi Liere; Doug Jackson; John Vandermeer

    2012-01-01

    BACKGROUND: Spatial heterogeneity is essential for the persistence of many inherently unstable systems such as predator-prey and parasitoid-host interactions. Since biological interactions themselves can create heterogeneity in space, the heterogeneity necessary for the persistence of an unstable system could be the result of local interactions involving elements of the unstable system itself. METHODOLOGY/PRINCIPAL FINDINGS: Here we report on a predatory ladybird beetle whose natural history ...

  12. Ecological complexity in a coffee agroecosystem: spatial heterogeneity, population persistence and biological control.

    Directory of Open Access Journals (Sweden)

    Heidi Liere

    Full Text Available BACKGROUND: Spatial heterogeneity is essential for the persistence of many inherently unstable systems such as predator-prey and parasitoid-host interactions. Since biological interactions themselves can create heterogeneity in space, the heterogeneity necessary for the persistence of an unstable system could be the result of local interactions involving elements of the unstable system itself. METHODOLOGY/PRINCIPAL FINDINGS: Here we report on a predatory ladybird beetle whose natural history suggests that the beetle requires the patchy distribution of the mutualism between its prey, the green coffee scale, and the arboreal ant, Azteca instabilis. Based on known ecological interactions and the natural history of the system, we constructed a spatially-explicit model and showed that the clustered spatial pattern of ant nests facilitates the persistence of the beetle populations. Furthermore, we show that the dynamics of the beetle consuming the scale insects can cause the clustered distribution of the mutualistic ants in the first place. CONCLUSIONS/SIGNIFICANCE: From a theoretical point of view, our model represents a novel situation in which a predator indirectly causes a spatial pattern of an organism other than its prey, and in doing so facilitates its own persistence. From a practical point of view, it is noteworthy that one of the elements in the system is a persistent pest of coffee, an important world commodity. This pest, we argue, is kept within limits of control through a complex web of ecological interactions that involves the emergent spatial pattern.

  13. Influences of agricultural management practices on Arbuscular Mycorrhiza Fungal symbioses in Kenyan agro-ecosystems

    NARCIS (Netherlands)

    Muriithi-Muchane, M.N.

    2013-01-01

    Conservation agriculture (CA) and integrated soil fertility management (ISFM) practices are receiving increased attention as pathways to sustainable high-production agriculture in sub-Saharan Africa. However, little is known about the effects of these practices on arbuscular mycorrhizal fungi (AMF).

  14. Deep soil layer is fundamental for evaluating carbon accumulation in agroecosystems

    Science.gov (United States)

    Dal Ferro, Nicola; Morari, Francesco; Simonetti, Gianluca; Polese, Riccardo; Berti, Antonio

    2015-04-01

    Soil organic carbon (SOC) is essential to secure key ecosystem services such as the provision of food and other biomass production, the filtering, buffering and transformation capacity and the climate regulation. It has been estimated that approximately 57% of the globally emitted C (8.7 Gt y-1) to the atmosphere is adsorbed by biospheric C pools, ascertaining the potential soil C sink capacity of managed ecosystems at 55 to 78 Gt, of which only 50 to 66% attainable. Therefore it is essential the full knowledge of soil management practices that can affect SOC dynamics and, in turn, climate change. Several studies focussed on the evaluation of the best cropping management practices to accumulate C in the soil profile. Nevertheless, in most cases soil analyses were made in the topsoil (generally in the 0-30 cm layer), ignoring the effect of C translocation in the deeper soil profile as a result of tillage practices, crop root deepening etc. In this context, in a long-term experiment established in the early 1960s, we quantified the SOC accumulation within the soil profile (0-90 cm) and evaluate the effects of different cropping system on SOC dynamics. The experiment is located at the experimental farm of the University of Padova, in northeastern Italy. The trial compares four rotations with three levels of mineral fertilisation and with or without organic fertilisation. The rotations considered are: continuous crops (grain maize, forage maize, winter wheat and permanent meadow); two-year (maize-wheat); four-year (sugarbeet, soybean, wheat, maize) and six-year (maize, sugarbeet, maize, wheat, alfalfa, alfalfa) with different levels of mineral, organic and mixed fertilisations. Crops with superficially developed rooting systems (e.g. permanent meadow) highly increased SOC only in the topsoil. This effect was enhanced by the contribution of organic amendment-C. Root-derived carbon played a pivotal role also in the deepest soil profile (60-90 cm) by increasing the SOC translocation. Considering the whole profile, the highest C accumulation was observed in cropping systems with high biomass production and deep rooting systems. Results indicated that for estimating the effects of cropping systems and agricultural practices on C accumulation, analyses in the topsoil can be misleading and it is necessary to consider the whole profile.

  15. Impact of Irrigated Agroecosystems on Groundwater Resources in the US High Plains and North China Plain

    Science.gov (United States)

    Scanlon, B. R.; Longuevergne, L.; Cao, G.; Shen, Y.; Gates, J. B.; Reedy, R. W.; Zheng, C.

    2010-12-01

    Overabstraction of groundwater for irrigation in semiarid regions is depleting the worlds’ largest aquifers at much greater rates than these aquifers are being replenished by recharge. This study evaluates groundwater sustainability in the US High Plains (US HP) and North China Plain (NCP) where intensive irrigation has resulted in large water table declines. A variety of approaches were used to evaluate impacts of irrigation on groundwater resources, including GRACE satellite data, unsaturated zone profiling, and groundwater quantity and quality data. Cultivation (40% of area) and irrigation (12%) are less intensive in the US HP than in the NCP (80% cultivated, 50% irrigated). Irrigation is estimated to consume ~97% of groundwater resources in the US HP and ~70% in the NCP. Although only ~10% of groundwater resources has been consumed in the US HP (330 km3 out of 3,900 km3), the problem lies in the uneven spatial distribution. Groundwater depletion is greatest in the Central High Plains (CHP) where water table declines of up to 1.5 m/yr have been recorded in individual wells and regional declines of up to 30 m have been found over a 7,000 km2 area since irrigation began in the 1950s to 1960s. This depletion indicates an irrigation deficit of ~75 mm/yr over 60 yr (specific yield 15%). Recharge rates in the CHP are extremely low (median ~10 mm/yr) with reductions in groundwater storage exceeding recharge by ~10 times. High correlations between GRACE and measured water storage changes (R = 0.7 - 0.8) show that the satellite can accurately track regional changes in water storage. Groundwater in the NCP has declined from a depth of ~1 m in the 1960s to 20 to 40 m in the Piedmont region since expansion of irrigation beginning in the 1970s. Groundwater level declines in individual hydrographs range from 0.5 to 1.0 m/yr, indicating irrigation deficits ranging from 100 to 200 mm/yr (specific yield 20%). Lower groundwater storage changes from GRACE satellites relative to the monitoring well network are attributed to regional overestimation of groundwater level declines from monitoring wells in urban regions. Many strategies are being evaluated to move towards more sustainable water resource management. Transfer of water from the Yangste River to the NCP should relieve some of the water stress in the region. Other proposed approaches include more efficient irrigation, deficit irrigation, mulching, crop rotation, and no irrigation. Future system management needs to consider tradeoffs between water consumption, crop yield, and lifespan of these aquifers.

  16. Entomopathogenic fungi Metarhizium spp. in the soil environment of an agroecosystem

    DEFF Research Database (Denmark)

    Steinwender, Bernhardt Michael

    several sympatric species and genotypes. The isolated species and their genotypes were evaluated for ecological traits including UVB tolerance, temperature dependent in vitro growth, virulence and conidia production on infected cadavers, and mycelial growth from insect cadavers into the surrounding soil......Species of the entomopathogenic fungal genus Metarhizium are found worldwide predominantly in the soil environment where they infect a broad spectrum of insects, but also associate with plant roots. To increase performance of Metarhizium as biological control agents against pests, fundamental...... samples with “insect baits” and from the roots of several crop plants using selective media. The resulting isolates were separated into genotypes by applying microsatellite markers and DNA regions of these genotypes were sequenced. The study showed a highly complex Metarhizium community that comprised...

  17. Genetic variability of wheat M3 mutant population in tropical agroecosystem

    International Nuclear Information System (INIS)

    The success of developing new varieties tolerant to abiotic stress in a plant breeding programs is mainly determined by the availability of genetic variation, the accuracy of selection method and the ability of the breeder to identify genotypes tolerant to a particular stress. The objective of this research is to study genetic variability of M3 wheat population derived from gamma irradiation in term of their tolerance to high temperatures at different elevation. The results showed that appearance of M3 population at > 1000 m asl was generally better than that of 1000 m asl (Cipanas). (author)

  18. HYDROLOGY AND GROUNDWATER NUTRIENT CONCENTRATIONS IN A DITCH-DRAINED AGRO-ECOSYSTEM

    Science.gov (United States)

    Loss of nitrogen (N) and phosphorus (P) from agricultural fields is a major water pollution concern in the Chesapeake Bay watershed. Even though movement of N and P in groundwater from fields to commonly occurring open drainage ditches is an important loss pathway, it has not been studied well enoug...

  19. Molossid bats in an African agro-ecosystem select sugarcane fields as foraging habitat

    DEFF Research Database (Denmark)

    Noer, Christina Lehmkuhl; Dabelsteen, Torben; Bohmann, Kristine;

    2012-01-01

    Two coexisting species of African molossids, the little free-tailed bat, Chaerephon pumilus, and the Angolan free-tailed bat, Mops condylurus, were studied in the lowveld of Swaziland. Nine C. pumilus and five M. condylurus, all non-lactating females, were radio-tracked in order to investigate...

  20. Quantification of ant manure deposition in a tropical agroecosystem: Implications for host plant nitrogen acquisition

    DEFF Research Database (Denmark)

    Pinkalski, Christian Alexander Stidsen; Damgaard, Christian; Jensen, Karl-Martin Vagn;

    2015-01-01

    Ants are functionally important organisms in most terrestrial ecosystems. Being ubiquitous and abundant, ant communities can affect the availability of resources to both primary and secondary consumers. As nitrogen is a limiting nutrient for plant growth in most terrestrial ecosystems, deposition...

  1. Agro(EcoSystem Services—Supply and Demand from Fields to Society

    Directory of Open Access Journals (Sweden)

    Benjamin Burkhard

    2016-04-01

    Full Text Available Land use—with a special focus on agriculture—is increasingly influenced by globalization and external driving forces, causing farmers to seek opportunities to develop efficient, large-scale production systems.[...

  2. Barcode haplotype variation in North American agroecosystem ladybird beetles (Coleoptera: Coccinellidae

    Science.gov (United States)

    DNA barcodes have proven invaluable in identifying and distinguishing insect pests, for example for determining the provenance of exotic invasives, but relatively few insect natural enemies have been barcoded. We used Folmer et al.’s universal invertebrate primers (1994), and those designed by Heber...

  3. Central Russia agroecosystem monitoring with CO2 fluxes analysis by eddy covariance method

    Directory of Open Access Journals (Sweden)

    Joulia Meshalkina

    2015-07-01

    Full Text Available The eddy covariance (EC technique as a powerful statistics-based method of measurement and calculation the vertical turbulent fluxes of greenhouses gases within atmospheric boundary layers provides the continuous, long-term flux information integrated at the ecosystem scale. An attractive way to compare the agricultural practices influences on GHG fluxes is to divide a crop area into subplots managed in different ways. The research has been carried out in the Precision Farming Experimental Field of the Russian Timiryazev State Agricultural University (RTSAU, Moscow in 2013 under the support of RF Government grant # 11.G34.31.0079, EU grant # 603542 LUС4С (7FP and RF Ministry of education and science grant # 14-120-14-4266-ScSh. Arable Umbric Albeluvisols have around 1% of SOC, 5.4 pH (KCl and NPK medium-enhanced contents in sandy loam topsoil. The CO2 flux seasonal monitoring has been done by two eddy covariance stations located at the distance of 108 m. The LI-COR instrumental equipment was the same for the both stations. The stations differ only by current crop version: barley or vetch and oats. At both sites, diurnal patterns of NEE among different months were very similar in shape but varied slightly in amplitude. NEE values were about zero during spring time. CO2 fluxes have been intensified after crop emerging from values of 3 to 7 µmol/s∙m2 for emission, and from 5 to 20 µmol/s∙m2 for sink. Stabilization of the fluxes has come at achieving plants height of 10-12 cm. Average NEE was negative only in June and July. Maximum uptake was observed in June with average values about 8 µmol CO2 m−2 s−1. Although different kind of crops were planted on the fields A and B, GPP dynamics was quite similar for both sites: after reaching the peak values at the mid of June, GPP decreased from 4 to 0.5 g C CO2 m-2 d-1 at the end of July. The difference in crops harvesting time that was equal two weeks did not significantly influence the daily GPP patterns. Cumulative assimilation of CO2 at the end of the growing season was about 150 g C m−2 for both sites. So the difference in NEE was the consequence of essentially higher respiration rates in case of vetch and oats (about 350 g C m−2 comparing to barley (250 g C m−2 that needs additional research. The results have shown high daily and seasonal dynamic of CO2 emission too as a result of different and contrasted conditions: crop type, crop development stage, soil moisture and air temperature. Obtained unique for Russian agriculture data are useful for land-use practices environmental assessment, for soil organic carbon dynamics analysis and agroecological evaluation.

  4. Nitrogen cycle model of agroecosystem in the karst region of Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    CHEN Ye; LIAN Bin

    2010-01-01

    According to the transport theory of soil solutes and the conditions of soil, geology and climate in the karst region of Guizhou Province, a numerical simulation model of edaphic nitrogen element transport under field conditions is initially established. In this model, NO-3 and NH+4 are regarded as soil solutes. Transformation mechanisms such as biological release, bio-immobilization, ammonium adsorption-desorption, nitration-denitrification and factors of crop root uptaking are considered in this model. It is hoped that the data from this model could directly be used to guide agricultural production in this region and offer feasible ways to improve the use of nitrogen element, sustainable development of agriculture in karst mountainous areas and natural environment.

  5. Environmental fate of soil applied neonicotinoid insecticides in an irrigated potato agroecosystem.

    Science.gov (United States)

    Huseth, Anders S; Groves, Russell L

    2014-01-01

    Since 1995, neonicotinoid insecticides have been a critical component of arthropod management in potato, Solanum tuberosum L. Recent detections of neonicotinoids in groundwater have generated questions about the sources of these contaminants and the relative contribution from commodities in U.S. agriculture. Delivery of neonicotinoids to crops typically occurs as a seed or in-furrow treatment to manage early season insect herbivores. Applied in this way, these insecticides become systemically mobile in the plant and provide control of key pest species. An outcome of this project links these soil insecticide application strategies in crop plants with neonicotinoid contamination of water leaching from the application zone. In 2011 and 2012, our objectives were to document the temporal patterns of neonicotinoid leachate below the planting furrow following common insecticide delivery methods in potato. Leaching loss of thiamethoxam from potato was measured using pan lysimeters from three at-plant treatments and one foliar application treatment. Insecticide concentration in leachate was assessed for six consecutive months using liquid chromatography-tandem mass spectrometry. Findings from this study suggest leaching of neonicotinoids from potato may be greater following crop harvest in comparison to other times during the growing season. Furthermore, this study documented recycling of neonicotinoid insecticides from contaminated groundwater back onto the crop via high capacity irrigation wells. These results document interactions between cultivated potato, different neonicotinoid delivery methods, and the potential for subsurface water contamination via leaching. PMID:24823765

  6. Environmental fate of soil applied neonicotinoid insecticides in an irrigated potato agroecosystem.

    Directory of Open Access Journals (Sweden)

    Anders S Huseth

    Full Text Available Since 1995, neonicotinoid insecticides have been a critical component of arthropod management in potato, Solanum tuberosum L. Recent detections of neonicotinoids in groundwater have generated questions about the sources of these contaminants and the relative contribution from commodities in U.S. agriculture. Delivery of neonicotinoids to crops typically occurs as a seed or in-furrow treatment to manage early season insect herbivores. Applied in this way, these insecticides become systemically mobile in the plant and provide control of key pest species. An outcome of this project links these soil insecticide application strategies in crop plants with neonicotinoid contamination of water leaching from the application zone. In 2011 and 2012, our objectives were to document the temporal patterns of neonicotinoid leachate below the planting furrow following common insecticide delivery methods in potato. Leaching loss of thiamethoxam from potato was measured using pan lysimeters from three at-plant treatments and one foliar application treatment. Insecticide concentration in leachate was assessed for six consecutive months using liquid chromatography-tandem mass spectrometry. Findings from this study suggest leaching of neonicotinoids from potato may be greater following crop harvest in comparison to other times during the growing season. Furthermore, this study documented recycling of neonicotinoid insecticides from contaminated groundwater back onto the crop via high capacity irrigation wells. These results document interactions between cultivated potato, different neonicotinoid delivery methods, and the potential for subsurface water contamination via leaching.

  7. Heavy-metal balances of agro-ecosystems in the Netherlands.

    NARCIS (Netherlands)

    Moolenaar, S.W.; Lexmond, Th.M.

    1998-01-01

    Heavy-metal flows (Cd, Cu, Pb, and Zn) of arable, dairy and mixed farming systems in the Netherlands were studied, and farm-gate and field-scale balances calculated. On the field-scale, static and dynamic balances were distinguished. By determining the characteristic metal flows, it became possible

  8. Genomic Regulation of the Response of an Agroecosystem to Elements of Global Change

    Energy Technology Data Exchange (ETDEWEB)

    DeLucia, Evan, H.

    2011-06-03

    This document outlines some of the major accomplishments from this project: (1) New tools for analyzing and visualizing microarray data from soybean gene expression experiments; (2) Physiological, biochemical, and gene array evidence that acclimation of carbon metabolism to elevated CO{sub 2} is governed in significant part by changes in gene expression associated with respiratory metabolism; (3) Increased carbon assimilation in soybeans grown at elevated CO{sub 2} altered pools of carbohydrates and transcripts that control growth and expansion of young leaves; (4) Growth at elevated CO{sub 2} increases the abundance of transcripts controlling cell wall polysaccharide synthesis but not transcripts controlling lignin synthesis; (5) The total antioxidant capacity of soybeans varies among cultivars and in response to atmospheric change; (6) Accelerated leaf senescence at elevated O{sub 3} coincides with reduced abundance of transcripts controlling protein synthesis; (7) Growth under elevated CO{sub 2} increases the susceptibility of soybean to insect herbivores by increasing insect lifespan and fecundity through altered leaf chemistry and by defeating molecular induction of plant defenses; (8) Exposure to elevated CO{sub 2} and O{sub 3} alters flavonoid metabolism in soybean; (9) Exposure to elevated CO{sub 2} or O{sub 3} conferred resistance to soybean mosaic virus by cross inducing defense- and stress-related signaling pathways; and (10) Exposure to elevated CO{sub 2} accelerates decomposition by changing chemical and biotic properties of the soil.

  9. Greenhouse cultivation mitigates metal-ingestion-associated health risks from vegetables in wastewater-irrigated agroecosystems.

    Science.gov (United States)

    Cao, Chun; Chen, Xing-Peng; Ma, Zhen-Bang; Jia, Hui-Hui; Wang, Jun-Jian

    2016-08-01

    Wastewater irrigation can elevate metal concentrations in soils and crops and increase the metal-associated health risks via vegetable ingestion in arid and semiarid northwestern China. Here, we investigated the As, Cd, Cr, Cu, Ni, Pb, and Zn concentrations in four vegetable species from Dongdagou and Xidagou farmlands in Baiyin, Gansu, China. We evaluated the effects of irrigation type (Dongdagou: industrial wastewater; Xidagou: domestic wastewater) and cultivation mode (open field and greenhouse) on the vegetable metal concentration, metal partitioning, soil-to-plant bioconcentration factor (BCF), and the health risk index. All stream waters, soils, and vegetables were found most severely polluted by As and Cd, with higher severity in the industrial-wastewater-irrigated Dongdagou than the domestic-wastewater-irrigated Xidagou. All vegetables had higher or, at least, comparable metal mass allocated in the shoot than in the root. Greenhouse cultivation could reduce metal-ingestion-associated health risks from edible vegetable biomass by decreasing the soil to plant bioaccumulation (BCF) and the metal concentration. This effect was always significant for all vegetables within Xidagou, and for carrot within Dongdagou. This mitigation effect of greenhouse cultivation could be attributed to the metal sorption by a higher level of soil organic matter and faster growth rate over metal uptake rate in greenhouses compared to open fields. Such mitigation effect was, however, insignificant for leafy vegetables within Dongdagou, when much more severely polluted water for irrigation was applied in greenhouses compared to open fields within Dongdagou. The present study highlights greenhouse cultivation as a potential mitigating approach to providing less-polluted vegetables for residents in the severely polluted area in addition to the source pollution control. PMID:27101456

  10. Surface Water Protection by Productive Buffers:Landscape Impacts of Improved Agro-Ecosystem Service Delivery

    OpenAIRE

    Christen, Benjamin

    2011-01-01

    Vegetated riparian buffer zones are a widely recommended best management practice in agriculture for protecting surface and coastal waters from diffuse nutrient pollution. On the background of the EU funded research project NitroEurope (NEU; www.NitroEurope.eu), this study concentrates on the mitigation of nitrogen pollution in surface and groundwater, using riparian buffer zones for biomass production. The objectives are to map suitable areas for buffer implementation across the six NEU stud...

  11. Soil respiration partition and its components in the total agro-ecosystem respiration

    Science.gov (United States)

    Delogu, Emilie; LeDantec, Valerie; Mordelet, Patrick; Buysse, Pauline; Aubinet, Marc; Pattey, Elizabeth; Mary, Bruno

    2013-04-01

    Close to 15% of the Earth's terrestrial surface is used for cropland. In the context of global warming, and acknowledged by the Kyoto Protocol, agricultural soils could be a significant sink for atmospheric CO2. Understanding the factors influencing carbon fluxes of agricultural soils is essential for implementing efficient mitigation practices. Most of the soil respiration modeling studies was carried out in forest ecosystems, but only a few was carried out in agricultural ecosystems. In the study, we evaluated simple formalisms to model soil respiration using wheat data from four contrasting geographical mi-latitude regions. Soil respiration were measured in three winter wheat fields at Lamasquère (43°49'N, 01°23'E, 2007) and Auradé (43°54'N, 01°10'E, 2008), South-West France and Lonzée (50°33'N, 4°44'E, 2007), Belgium, and in a spring wheat field at Ottawa (45°22'N, 75°43'W, 2007, 2011), Ontario, Canada. Manual closed chambers were used in the French sites. The Belgium and Canadian sites were equipped with automated closed chamber systems, which continuously collected 30-min soil respiration exchanges. All the sites were also equipped with eddy flux towers. When eddy flux data were collected over bare soil, the net ecosystem exchange (NEE) was equal to soil respiration exchange. These NEE data were used to validate the model. Different biotic and abiotic descriptors were used to model daily soil respiration and its heterotrophic and autotrophic components: soil temperature, soil relative humidity, Gross Primary Productivity (GPP), shoot biomass, crop height, with different formalisms. It was interesting to conclude that using biotic descriptors did not improve the performances of the model. In fact, a combination of abiotic descriptors (soil humidity and soil temperature) allowed significant model formalism to model soil respiration. The simple soil respiration model was used to calculate the heterotrophic and autotrophic source contributions to overall soil respiration and to estimate the soil respiration contribution to NEE measured at field scale. These different results have been compared and discussed for the wheat in four different conditions of soil and climate and the results showed that soil respiration consistently represented ~50% of the total ecosystem respiration. A significant portion of the heterotrophic soil respiration was influenced by the location and by the organic carbon content of the soils.

  12. "Tinni" Rice ( Oryza rufipogon Griff.) Production: An Integrated Sociocultural Agroecosystem in Eastern Uttar Pradesh of India

    Science.gov (United States)

    Singh, Ranjay K.; Turner, Nancy J.; Pandey, C. B.

    2012-01-01

    This study reports how Traditional Ecological Knowledge (TEK) and informal cultural institutions have conserved key varieties of the wildgrowing rice, ` tinni' (red rice, or brownbeard rice, Oriza rufipogon Griff.), within the Bhar community of eastern Uttar Pradesh, India. The study was conducted, using conventional and participatory methods, in 10 purposively selected Bhar villages. Two distinct varieties of tinni (` tinni patali' and ` tinni moti') with differing habitats and phenotypic characters were identified. Seven microecosystems (Kari, Badaila, Chammo, Karmol, Bhainsiki, Bhainsala and Khodailia) were found to support these varieties in differing proportions. Tinni rice can withstand more extreme weather conditions (the highest as well as lowest temperatures and rainfall regimes) than the `genetically improved' varieties of rice ( Oriza sativa L.) grown in the region. Both tinni varieties are important bioresources for the Bhar's subsistence livelihoods, and they use distinctive conservation approaches in their maintenance. Bhar women are the main custodians of tinni rice agrobiodiversity, conserving tinni through an institution called Sajha. Democratic decision-making at meetings organized by village elders determines the market price of the tinni varieties. Overall, the indigenous institutions and women's participation seem to have provided safeguards from excessive exploitation of tinni rice varieties. The maintenance of tinni through cultural knowledge and institutions serves as an example of the importance of locally maintained crop varieties in contributing to people's resilience and food security in times of rapid social and environmental change.

  13. Food webs and phenology models: evaluating the efficacy of ecologically based insect pest management in different agroecosystems

    OpenAIRE

    Philips, Christopher Robin

    2013-01-01

    Integrated pest management (IPM) is defined as an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices. Integrated pest management programs use current, comprehensive information on the life cycles of pests and their interactions with host plants and the environment. This information, in combination with available pest control methods, is used to manage pest populations by the most economical means, and with the least possi...

  14. Genetically modified (GM) corn in the Philippines : Ecological impacts on agroecosystems, effects on the economic status and farmers’ experiences

    NARCIS (Netherlands)

    Mabutol-Afidchao, Miladis B.

    2013-01-01

    To seek answers to the issues on GM corn adoption in the Philippines, the thesis focused to find answers on the general question: How can genetically modified (GM) corn and its attributed changes in agricultural practices affect the agro-ecosystem’s biodiversity and the economic status and social li

  15. Comparison greenhouse gas (GHG) emissions and global warming potential (GWP) effect of energy use in different wheat agroecosystems in Iran.

    Science.gov (United States)

    Yousefi, Mohammad; Mahdavi Damghani, Abdolmajid; Khoramivafa, Mahmud

    2016-04-01

    The aims of this study were to determine energy requirement and global warming potential (GWP) in low and high input wheat production systems in western of Iran. For this purpose, data were collected from 120 wheat farms applying questionnaires via face-to-face interviews. Results showed that total energy input and output were 60,000 and 180,000 MJ ha(-1) in high input systems and 14,000 and 56,000 MJ ha(-1) in low input wheat production systems, respectively. The highest share of total input energy in high input systems recorded for electricity power, N fertilizer, and diesel fuel with 36, 18, and 13 %, respectively, while the highest share of input energy in low input systems observed for N fertilizer, diesel fuel, and seed with 32, 31, and 27 %. Energy use efficiency in high input systems (3.03) was lower than of low input systems (3.94). Total CO2, N2O, and CH4 emissions in high input systems were 1981.25, 31.18, and 1.87 kg ha(-1), respectively. These amounts were 699.88, 0.02, and 0.96 kg ha(-1) in low input systems. In high input wheat production systems, total GWP was 11686.63 kg CO2eq ha(-1) wheat. This amount was 725.89 kg CO2eq ha(-1) in low input systems. The results show that 1 ha of high input system will produce greenhouse effect 17 times of low input systems. So, high input production systems need to have an efficient and sustainable management for reducing environmental crises such as change climate. PMID:26690584

  16. Biodiversity, a global threshold - Why preserving biodiversity should go hand-in-hand with climate mitigation in agro-ecosystems

    OpenAIRE

    Richardson, Katherine

    2010-01-01

    This presentation takes as its starting point the relationship between humans and global natural resources. Humans have always been dependent upon them. Only recently, however, has it become obvious that the demand for these natural resources and services is now approaching or exceeding their supply. Sustainability can be defined as using the natural resources we are dependent upon in the most efficient manner possible - also biodiversity. Human activities have dramatically increased over...

  17. Long-term agroecosystem research in the central Mississippi river basin: hyperspectral remote sensing of reservoir water quality.

    Science.gov (United States)

    Sudduth, Kenneth A; Jang, Gab-Sue; Lerch, Robert N; Sadler, E John

    2015-01-01

    In situ methods for estimating water quality parameters would facilitate efforts in spatial and temporal monitoring, and optical reflectance sensing has shown potential in this regard, particularly for chlorophyll, suspended sediment, and turbidity. The objective of this research was to develop and evaluate relationships between hyperspectral remote sensing and lake water quality parameters-chlorophyll, turbidity, and N and P species. Proximal hyperspectral water reflectance data were obtained on seven sampling dates for multiple arms of Mark Twain Lake, a large man-made reservoir in northeastern Missouri. Aerial hyperspectral data were also obtained on two dates. Water samples were collected and analyzed in the laboratory for chlorophyll, nutrients, and turbidity. Previously reported reflectance indices and full-spectrum (i.e., partial least squares regression) methods were used to develop relationships between spectral and water quality data. With the exception of dissolved NH, all measured water quality parameters were strongly related ( ≥ 0.7) to proximal reflectance across all measurement dates. Aerial hyperspectral sensing was somewhat less accurate than proximal sensing for the two measurement dates where both were obtained. Although full-spectrum calibrations were more accurate for chlorophyll and turbidity than results from previously reported models, those previous models performed better for an independent test set. Because extrapolation of estimation models to dates other than those used to calibrate the model greatly increased estimation error for some parameters, collection of calibration samples at each sensing date would be required for the most accurate remote sensing estimates of water quality.

  18. Smallholders' soil fertility management in the Central Highlands of Ethiopia: implications for nutrient stocks, balances and sustainability of agroecosystems

    NARCIS (Netherlands)

    A. Haileslassie; J.A. Priess; E. Veldkamp; J.P. Lesschen

    2006-01-01

    Low agricultural productivity caused by soil degradation is a serious problem in the Ethiopian Highlands. Here, we report how differences in soil fertility management between farming systems, based either on enset (Ensete ventricosum) or on teff (Eragrostis tef) as the major crops, affect the extent

  19. Nutrient and carbon cycling in agro-ecosystems and their interactions with ecosystem services. 27th Francis New Memorial Lecture

    NARCIS (Netherlands)

    Neeteson, J.J.

    2011-01-01

    Ecosystem services are the benefits people obtain from ecosystems. An ecosystem is the interacting system of living organisms and their associated non-living environment. Four types of ecosystem services can be distinguished: provisioning services, regulating services, cultural services, and support

  20. Earth observation based assessment of the water production and water consumption of Nile basin agro-ecosystems

    NARCIS (Netherlands)

    Bastiaanssen, W.G.M.; Karimi, P.; Rebelo, L.M.; Duan, Z.; Senay, G.; Muttuwatte, L.; Smakhtin, V.

    2014-01-01

    The increasing competition for water resources requires a better understanding of flows, fluxes, stocks, and the services and benefits related to water consumption. This paper explains how public domain Earth Observation data based on Moderate Resolution Imaging Spectroradiometer (MODIS), Second Gen

  1. Changes in Actinomycetes community structure under the influence of Bt transgenic brinjal crop in a tropical agroecosystem

    OpenAIRE

    Singh, Amit Kishore; Singh, Major; Dubey, Suresh Kumar

    2013-01-01

    Background The global area under brinjal cultivation is expected to be 1.85 million hectare with total fruit production about 32 million metric tons (MTs). Brinjal cultivars are susceptible to a variety of stresses that significantly limit productivity. The most important biotic stress is caused by the Brinjal fruit and shoot Borer (FSB) forcing farmers to deploy high doses of insecticides; a matter of serious health concern. Therefore, to control the adverse effect of insecticides on the env...

  2. Simulating Soil Organic Carbon Stock Changes in Agro-ecosystems using CQESTR, DayCent, and IPCC Tier 1 Methods

    Science.gov (United States)

    Models are often used to quantify how land use change and management impact soil organic carbon (SOC) stocks because it is often not feasible to use direct measuring methods. Because models are simplifications of reality, it is essential to compare model outputs with measured values to evaluate mode...

  3. Impact of changing land-use and hydrology on soil organic carbon dynamics in beef cattle agroecosystem

    Science.gov (United States)

    Basic information on the ecological understanding and the responses of systems to water regime change is essential for maintaining ecosystems environmental integrity and productivity. Flooding of formerly drained areas is common practice in wetland restoration. Such practice could profoundly affect ...

  4. Uncover the Concealed Link: Gender & Ethnicity-Divided Local Knowledge on the Agro-Ecosystem of a Forest Margin

    OpenAIRE

    Savitri, Laksmi Adriani

    2007-01-01

    This research is a study about knowledge interface that aims to analyse knowledge discontinuities, the dynamic and emergent characters of struggles and interactions within gender system and ethnicity differences. The cacao boom phenomenon in Central Sulawesi is the main context for a changing of social relations of production, especially when the mode of production has shifted or is still underway from subsistence to petty commodity production. This agrarian change is not on...

  5. The effects of organochlorine pesticides on some non-target organisms in maize and cowpea agro-ecosystems in Ghana

    International Nuclear Information System (INIS)

    In order to study the effects of organochlorine pesticides on non-target organisms under tropical conditions, a three-year study was conducted in Ghana applying lindane at 1 kg AI. ha-1 and endosulfan at 0.75 kg AI. ha-1 to maize and cowpeas respectively. The endosulfan treatment was preceded by two consecutive treatments with cypermethrin at 50 g AI ha-1. Lindane significantly reduced the numbers of ants, spiders and springtails trapped though the numbers of ants and spiders generally recovered within the cropping period. Lindane significantly increased the numbers of leafhoppers caught from maize plots probably due to the elimination of a natural enemy. Ant, spider and springtail numbers were also significantly reduced by the endosulfan treatment in cowpea plots 5. Lindane did not significantly increase maize yields in two of the three years. Endosulfan contributed to significant yield increases and reduced seed damage in cowpeas. Neither lindane nor endosulfan seemed to have any significant adverse effects on the activities of soil microfauna and microflora based on the rates of decomposition of leaf discs buried in the experimental plots. (author). 12 refs, 10 figs, 9 tabs

  6. Response of Sunflower Yield and Phytohormonal Changes to Azotobacter,Azospirillum,Pseudomonas and Animal Manure in a Chemical Free Agroecosystem

    OpenAIRE

    Maziyar, Mehran; M. Reza, Ardakani; Hamid, Madani; Mohammad , Zahedi; Mohsen, Amirabadi; Saeed, Mafakheri

    2011-01-01

    There are new trends in agriculture to move toward the low input systems with the lower application of chemical fertilizers. To reach this goal, different methods, such as the application of biofertilizers, may be used. So this experiment was conducted in 2010 at a research farm in Arak, Iran, in factorial in the form of a randomized complete block design with three replications and four factors: animal manure (M), Pseudomonas putida (P), Azotobacter chroococcum (A)and Azospirillum lipoferum ...

  7. Impacts of bioenergy feedstock production on environmental factors in the Central U.S. using an agroecosystem model (Invited)

    Science.gov (United States)

    Twine, T. E.; Vanloocke, A. D.; Williams, M.; Bernacchi, C.

    2010-12-01

    The Renewable Fuel Standard in the Energy Independence and Security Act of 2007 requires annual U.S. production of 36 billion gallons of renewable fuels by 2022, nearly half of this from cellulosic biofuels. We have little guidance as to where to grow bioenergy feedstocks to maximize yield without competing for food resources, and little understanding of the environmental and economic impacts of their production. Furthermore, it is unclear how bioenergy feedstocks might be incorporated into the current landscape to minimize environmental consequences. Numerical models allow us to predict environmental impacts across large spatial domains and long time periods by simulating the response of potential feedstocks to drivers such as soil type and climate. We used the Agro-IBIS (Integrated Biosphere Simulator, agricultural version) model to quantify the impacts on Midwest U.S. water and energy budgets from land use for bioenergy production. We analyzed effects of changes in land cover (e.g., from current crops to perennial grasses) as well as changes in management (e.g., removal of crop residues for fuel). Our analyses indicate that perennial grasses can substantially increase evapotranspiration (water transport to the atmosphere) in locations where fraction cover is greater than 25%. This change in evapotranspiration is lowest in regions where current crops and grasses are highly productive and evapotranspiration is large, and is highest in semi-arid regions where productivity is lower. These results imply that growing bioenergy feedstocks on marginal lands could have substantial effects on water resources.

  8. Distribuição de Carabidae e Staphylinidae em agroecossistemas Distribution of Carabidae and Staphylinidae in agroecosystems

    Directory of Open Access Journals (Sweden)

    Francisco Jorge Cividanes

    2008-02-01

    Full Text Available O objetivo deste trabalho foi determinar a distribuição da riqueza de espécies e a preferência pelo habitat de Carabidae e Staphylinidae (Coleoptera, em áreas com rotação de soja e milho, em plantio direto e convencional, e em áreas adjacentes a estas com fragmento florestal e povoamento de pínus, respectivamente. Os besouros foram amostrados por meio de armadilhas de solo distribuídas em dois transectos de 100 m de comprimento. A distribuição da riqueza de espécies nas culturas, no fragmento florestal e no pínus foi avaliada por meio de análise de regressão linear. A análise de agrupamento foi empregada para identificar as espécies quanto à preferência pelos habitats: fragmento florestal, pínus, cultura e interface. A distribuição da riqueza de espécies de Carabidae e Staphylinidae não variou em relação à posição no transecto, enquanto a riqueza de espécies observada nas interfaces foi elevada em comparação com a encontrada nos demais habitats. A ocorrência de espécies de Carabidae diferiu conforme o tipo de cobertura vegetal: Megacephala sp. e Scarites sp. preferiram áreas cultivadas em sistema de rotação soja-milho; Odontochila nodicornis (Dejean preferiu o fragmento florestal e o povoamento de pínus. A espécie Abaris basistriatus Chaudoir caracterizou-se como generalista quanto à preferência pelo habitat.The objective of this work was to determine the distribution of species richness and habitat preference of Carabidae and Staphylinidae (Coleoptera in two areas cultivated with soybean/corn under no-tillage and conventional tillage systems and in adjacents areas with forest fragment and a Pinus stand, respectively. Beetles were sampled by pitfall traps which were distributed in two transects of 100 m. The distribution of species richness in the crops and forest fragment/Pinus was evaluated by regression analysis. Cluster analysis was used to identify species in relation to preference for the forest fragment, Pinus, crop and interface. The distribution of Carabidae and Staphylinidae species richness did not show variation in relation to the position in transect, while the species richness observed in the interfaces between forest fragment or Pinus stand and crops were higher compared with the ones found in other habitats. The occurrence of Carabidae species differed in relation to the vegetation type: Megacephala sp. and Scarites sp. preferred crop areas under soybean/corn rotation system. The same was observed with Odontochila nodicornis (Dejean in the forest fragment and Pinus stand. The species Abaris basistriatus Chaudoir was characterized as a generalist species in relation to habitat preference.

  9. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: Food consumption and nutrient recycling by waterbirds in Mediterranean rice fields

    NARCIS (Netherlands)

    Navedo, J.G.; Hahn, S.; Parejo, M.; Abad-Gómez, J.; Gutiérrez, J.S.; Villegas, A.; Sánchez-Guzmán, J.M.; Masero, J.A.

    2015-01-01

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food co

  10. Diversity and communities of foliar endophytic fungi from different agroecosystems of Coffea arabica L. in two regions of Veracruz, Mexico.

    Science.gov (United States)

    Saucedo-García, Aurora; Anaya, Ana Luisa; Espinosa-García, Francisco J; González, María C

    2014-01-01

    Over the past 20 years, the biodiversity associated with shaded coffee plantations and the role of diverse agroforestry types in biodiversity conservation and environmental services have been topics of debate. Endophytic fungi, which are microorganisms that inhabit plant tissues in an asymptomatic manner, form a part of the biodiversity associated with coffee plants. Studies on the endophytic fungi communities of cultivable host plants have shown variability among farming regions; however, the variability in fungal endophytic communities of coffee plants among different coffee agroforestry systems is still poorly understood. As such, we analyzed the diversity and communities of foliar endophytic fungi inhabiting Coffea arabica plants growing in the rustic plantations and simple polycultures of two regions in the center of Veracruz, Mexico. The endophytic fungi isolates were identified by their morphological traits, and the majority of identified species correspond to species of fungi previously reported as endophytes of coffee leaves. We analyzed and compared the colonization rates, diversity, and communities of endophytes found in the different agroforestry systems and in the different regions. Although the endophytic diversity was not fully recovered, we found differences in the abundance and diversity of endophytes among the coffee regions and differences in richness between the two different agroforestry systems of each region. No consistent pattern of community similarity was found between the coffee agroforestry systems, but we found that rustic plantations shared the highest number of morphospecies. The results suggest that endophyte abundance, richness, diversity, and communities may be influenced predominantly by coffee region, and to a lesser extent, by the agroforestry system. Our results contribute to the knowledge of the relationships between agroforestry systems and biodiversity conservation and provide information regarding some endophytic fungi and their communities as potential management tools against coffee plant pests and pathogens.

  11. Modeling the effects of saline groundwater and irrigation water on root zone salinity and sodicity dynamics in agro-ecosystems

    NARCIS (Netherlands)

    Shah, S.H.H.

    2013-01-01

    Recent trends and future projections suggest that the need to produce more food and fibre for the world’ s expanding population will lead to an increase in the use of marginal-quality water and land resources (Bouwer, 2000; Gupta and Abrol, 2000; Wild, 2003). This is particularly relevant to l

  12. Gasification biochar has limited effects on functional and structural diversity of soil microbial communities in a temperate agroecosystem

    DEFF Research Database (Denmark)

    Imparato, Valentina; Hansen, Veronika; Santos, Susana;

    2016-01-01

    Biochar may enhance soil fertility and carbon (C) sequestration but there is still a lack of comprehensive understanding of its effects on soil microbial communities and functioning. This study tested the differential effects of two doses (6-8 and 0.8-1.4 t ha-1 for High and Low doses, respectively......) of wheat straw gasification biochar (GBC) and fresh straw incorporated as soil amendments into an agricultural field in Denmark. Soils were analysed three months after the amendments for pH, total organic matter, microbial biomass (ATP), ten enzymatic activities, catabolic potential by substrate...... caused an increase in the relative abundance of the rare members in the microbial communities thus increasing the diversity of soil microorganisms. A comparable effect was observed with the addition of fresh straw. Overall, our results indicated that GBC as soil amendment had a limited effect...

  13. Gasification biochar has limited effects on functional and structural diversity of soil microbial communities in a temperate agroecosystem

    DEFF Research Database (Denmark)

    Imparato, Valentina; Hansen, Veronika; Santos, Susana;

    2016-01-01

    Biochar may enhance soil fertility and carbon (C) sequestration but there is still a lack of comprehensive understanding of its effects on soil microbial communities and functioning. This study tested the differential effects of two doses (6e8 and 0.8e1.4 t ha1 for High and Low doses, respectively......) of wheat straw gasification biochar (GBC) and fresh straw incorporated as soil amendments into an agricultural field in Denmark. Soils were analysed three months after the amendments for pH, total organic matter, microbial biomass (ATP), ten enzymatic activities, catabolic potential by substrate...... caused an increase in the relative abundance of the rare members in the microbial communities thus increasing the diversity of soil microorganisms. A comparable effect was observed with the addition of fresh straw. Overall, our results indicated that GBC as soil amendment had a limited effect...

  14. Current situation and perspective of the multi-use of Arachis pintoi in agro-ecosystems devoted to animal production

    Directory of Open Access Journals (Sweden)

    Verónica Andrade Yucailla

    2016-07-01

    Full Text Available This paper realized an analysis of the scientific literature in which 75 articles were reviewed from indexed Journals in specialized databases and of international recognition about the main aspects reviewed such as the origin, adaptation conditions in areas of the humid tropic, genetic aspects related to the chromosomal markers; demonstrating a big morphologic variability in the germplasms. Inside of the potential uses of major relevancy there was stand out the use as soil coverage and as soil improver, as well as weeds controller, presenting a positive effect in the content of organic matter and nitrogen of soil. The use of Arachis pintoi Frapovickas y Gregory in the animal feeding systems is a resource of high quality; it can be a viable alternative for the animal production systems in the tropic. The impact of some agroecological practices on the agroproductive parameters with the use of A. pintoi is of the important relevancy. It was concludes that A. pintoi presents a potential of multiple use in integrated systems of crops - trees – livestock, constituting an alternative of sustainable management of the tropical animal production.

  15. Overwintering tadpoles and loss of fitness correlates in Polypedates braueri tadpoles that use artificial pools in a lowland agroecosystem

    Science.gov (United States)

    Hsu, Juei-Ling; Kam, Yeong-Choy; Fellers, Gary M.

    2012-01-01

    We studied growth, development, and metamorphic traits of Polypedates braueri tadpoles in Taiwan to elucidate the cause of tadpole overwintering in man-made water containers in lowland orchards on the Bagua Terrace. Polypedates braueri bred from March to August, but tadpoles were present year round. Laboratory experiments demonstrated that tadpole overwintering was facultative; low temperatures and limited food retarded both growth and development, resulting in overwintering in the tadpole stage. Tadpoles at the lowest experimental temperature (15°C) never reached metamorphosis. A field experiment demonstrated that 78, 28, and 4% of tadpoles raised in high, medium, and low food regimes, respectively, metamorphosed before the onset of winter. Tadpoles that did not metamorphose by fall continued to grow slowly and either metamorphosed during the winter or the following spring. These findings indicate that food availability plays a key role in inducing overwintering in tadpoles. Jumping performance of metamorphs was positively correlated with food regimes, but body lipid content was significantly higher in metamorphs raised with either low or high food regimes than in those with medium levels of food. Overwintering by P. braueritadpoles has not been previously reported; however, agricultural activities have created new breeding habitats (i.e., man-made bodies of water), some of which are sufficiently food-limited that tadpoles overwinter to complete development and metamorphosis. An understanding of the survivorship, life history traits, and physiology of these frogs is needed to shed light on how man-made breeding sites affect the population dynamics of native frog populations.

  16. Changes in Soil Microbial Community Structure Influenced by Agricultural Management Practices in a Mediterranean Agro-Ecosystem

    OpenAIRE

    García-Orenes, Fuensanta; Morugán-Coronado, Alicia; Zornoza, Raul; Scow, Kate

    2013-01-01

    Agricultural practices have proven to be unsuitable in many cases, causing considerable reductions in soil quality. Land management practices can provide solutions to this problem and contribute to get a sustainable agriculture model. The main objective of this work was to assess the effect of different agricultural management practices on soil microbial community structure (evaluated as abundance of phospholipid fatty acids, PLFA). Five different treatments were selected, based on the most c...

  17. Soil Hydrological Attributes of an Integrated Crop-Livestock Agroecosystem: Increased Adaptation through Resistance to Soil Change

    Directory of Open Access Journals (Sweden)

    Mark A. Liebig

    2011-01-01

    Full Text Available Integrated crop-livestock systems have been purported to have significant agronomic and environmental benefits compared to specialized, single-enterprise production systems. However, concerns exist regarding the effect of livestock in integrated systems to cause soil compaction, thereby decreasing infiltration of water into soil. Such concerns are compounded by projections of more frequent high-intensity rainfall events from anticipated climate change, which would act to increase surface runoff and soil erosion. A study was conducted to evaluate the effects of residue management, frequency of hoof traffic, season, and production system (e.g., integrated annual cropping versus perennial grass on infiltration rates from 2001 through 2008 in central North Dakota, USA. Imposed treatments had no effect on infiltration rate at three, six, and nine years after study establishment, implying that agricultural producers should not be concerned with inhibited infiltration in integrated annual cropping systems, where winter grazing is used. The use of no-till management, coupled with annual freeze/thaw and wet/dry cycles, likely conferred an inherent resistance to change in near-surface soil properties affecting soil hydrological attributes. Accordingly, caution should be exercised in applying these results to other regions or management systems.

  18. Heavy metal balances: Part I. General aspects of cadmium, copper, zinc and lead balance studies in agro-ecosystems

    NARCIS (Netherlands)

    Moolenaar, S.W.; Lexmond, T.M.

    1999-01-01

    The control of heavy metals in such a way that soil functioning and product quality are not impeded is a prerequisite to sustainable agriculture. The current status of heavy metal accumulation in agricultural soils differs widely by region, by metal, and by agricultural system; levels of concern hav

  19. Arbuscular mycorrhizal fungi diversity influenced by different agricultural management practices in a semi-arid Mediterranean agro-ecosystem

    Science.gov (United States)

    de Mar Alguacil, Maria; Torrecillas, Emma; Garcia-Orenes, Fuensanta; Torres, Maria Pilar; Roldan, Antonio

    2013-04-01

    The arbuscular mycorrhizal fungi (AMF) are a key, integral component of the stability, sustainability and functioning of ecosystems. In this study a field experiment was performed at the El Teularet-Sierra de Enguera Experimental Station (eastern Spain) to assess the influence during a 6-yr period of different agricultural practices on the diversity of arbuscular mycorrhizal fungi (AMF). The management practices included residual herbicide use, ploughing, ploughing + oats, addition of oat straw mulch and a control (land abandonment). Adjacent soil under natural vegetation was used as a reference for local, high-quality soil and as a control for comparison with the agricultural soils under different management practices. The AM fungal small-subunit (SSU) rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses. Thirty-six different phylotypes were identified, which were grouped in four families: Glomeraceae, Paraglomeraceae, Ambisporaceae and Claroideoglomeraceae. The first results showed significant differences in the distribution of the AMF phylotypes as consequence of the difference between agricultural management practices. Thus, the lowest diversity was observed for the plot that was treated with herbicide. The management practices including ploughing and ploughing + oats had similar AMF diversity. Oat straw mulching yielded the highest number of different AMF sequence types and showed the highest diversity index. Thus, this treatment could be more suitable in sustainable soil use and therefore protection of biodiversity.

  20. Changes in soil microbial community structure influenced by agricultural management practices in a mediterranean agro-ecosystem.

    Directory of Open Access Journals (Sweden)

    Fuensanta García-Orenes

    Full Text Available Agricultural practices have proven to be unsuitable in many cases, causing considerable reductions in soil quality. Land management practices can provide solutions to this problem and contribute to get a sustainable agriculture model. The main objective of this work was to assess the effect of different agricultural management practices on soil microbial community structure (evaluated as abundance of phospholipid fatty acids, PLFA. Five different treatments were selected, based on the most common practices used by farmers in the study area (eastern Spain: residual herbicides, tillage, tillage with oats and oats straw mulching; these agricultural practices were evaluated against an abandoned land after farming and an adjacent long term wild forest coverage. The results showed a substantial level of differentiation in the microbial community structure, in terms of management practices, which was highly associated with soil organic matter content. Addition of oats straw led to a microbial community structure closer to wild forest coverage soil, associated with increases in organic carbon, microbial biomass and fungal abundances. The microbial community composition of the abandoned agricultural soil was characterised by increases in both fungal abundances and the metabolic quotient (soil respiration per unit of microbial biomass, suggesting an increase in the stability of organic carbon. The ratio of bacteria:fungi was higher in wild forest coverage and land abandoned systems, as well as in the soil treated with oat straw. The most intensively managed soils showed higher abundances of bacteria and actinobacteria. Thus, the application of organic matter, such as oats straw, appears to be a sustainable management practice that enhances organic carbon, microbial biomass and activity and fungal abundances, thereby changing the microbial community structure to one more similar to those observed in soils under wild forest coverage.

  1. Changes in soil microbial community structure influenced by agricultural management practices in a mediterranean agro-ecosystem.

    Science.gov (United States)

    García-Orenes, Fuensanta; Morugán-Coronado, Alicia; Zornoza, Raul; Cerdà, Artemi; Scow, Kate

    2013-01-01

    Agricultural practices have proven to be unsuitable in many cases, causing considerable reductions in soil quality. Land management practices can provide solutions to this problem and contribute to get a sustainable agriculture model. The main objective of this work was to assess the effect of different agricultural management practices on soil microbial community structure (evaluated as abundance of phospholipid fatty acids, PLFA). Five different treatments were selected, based on the most common practices used by farmers in the study area (eastern Spain): residual herbicides, tillage, tillage with oats and oats straw mulching; these agricultural practices were evaluated against an abandoned land after farming and an adjacent long term wild forest coverage. The results showed a substantial level of differentiation in the microbial community structure, in terms of management practices, which was highly associated with soil organic matter content. Addition of oats straw led to a microbial community structure closer to wild forest coverage soil, associated with increases in organic carbon, microbial biomass and fungal abundances. The microbial community composition of the abandoned agricultural soil was characterised by increases in both fungal abundances and the metabolic quotient (soil respiration per unit of microbial biomass), suggesting an increase in the stability of organic carbon. The ratio of bacteria:fungi was higher in wild forest coverage and land abandoned systems, as well as in the soil treated with oat straw. The most intensively managed soils showed higher abundances of bacteria and actinobacteria. Thus, the application of organic matter, such as oats straw, appears to be a sustainable management practice that enhances organic carbon, microbial biomass and activity and fungal abundances, thereby changing the microbial community structure to one more similar to those observed in soils under wild forest coverage.

  2. Climate Change and Potato Production in Contrasting South African Agro-Ecosystems 2. Assessing Risks and Opportunities of Adaptation Strategies

    NARCIS (Netherlands)

    Franke, A.C.; Haverkort, A.J.; Steyn, J.M.

    2013-01-01

    This study aims to assess the risks and opportunities posed by climate change to potato growers in South Africa and to evaluate adaptation measures in the form of changes in planting time growers could adopt to optimise land and water use efficiencies in potato, using a climate model of past, presen

  3. Soil Erosion and Nutrient Losses control by Plant Covers: Environmental Implications for a Subtropical Agroecosystem (SE Spain)

    International Nuclear Information System (INIS)

    Soil erosion, in addition to causing on-site loss of topsoil and reducing the productivity of the land, brings about major off-site environmental effects such as water body pollution and eutrophication. In the Mediterranean area, this fact is especially relevant where precipitation is characterized by scarcity, torrent storms and extreme variability in space and time. To study the effects of soil erosion runoff potential pollution we installed six erosion plots on the taluses of orchard terraces where an intensive irrigated agriculture based on subtropical crops has been established. (Author)

  4. Soil Erosion and Nutrient Losses control by Plant Covers: Environmental Implications for a Subtropical Agroecosystem (SE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Pleguezuelo, C. R.; Duran-Zuazo, V. H.; Martin-Peinado, F. J.; Franco-Tarifa, D.; Martinez-Raya, A.; Francia-Martinez, J. R.; Carceles-Rodriguez, B.; Arroyo-Panadero, L.; Casado, J. P.

    2009-07-01

    Soil erosion, in addition to causing on-site loss of topsoil and reducing the productivity of the land, brings about major off-site environmental effects such as water body pollution and eutrophication. In the Mediterranean area, this fact is especially relevant where precipitation is characterized by scarcity, torrent storms and extreme variability in space and time. To study the effects of soil erosion runoff potential pollution we installed six erosion plots on the taluses of orchard terraces where an intensive irrigated agriculture based on subtropical crops has been established. (Author)

  5. Combined effects of climatic gradient and domestic livestock grazing on reptile community structure in a heterogeneous agroecosystem.

    Science.gov (United States)

    Rotem, Guy; Gavish, Yoni; Shacham, Boaz; Giladi, Itamar; Bouskila, Amos; Ziv, Yaron

    2016-01-01

    Grazing plays an important role in shaping ecological communities in human-related ecosystems. Although myriad studies have explored the joint effect of grazing and climate on plant communities, this interactive effect has rarely been studied in animals. We hypothesized that the effect of grazing on the reptile community varies along a climatic gradient in relation to the effect of grazing on habitat characteristics, and that grazing differentially affects reptiles of different biogeographic regions. We tested our hypotheses by collecting data on environmental characteristics and by trapping reptiles in four heterogeneous landscapes experiencing differing grazing intensities and distributed along a sharp climatic gradient. We found that while reptile diversity increased with grazing intensity at the mesic end of the gradient, it decreased with grazing intensity at the arid end. Moreover, the proportion of reptile species of differing biogeographic origins varied with the interactive effect of climate and grazing. The representation of species originating in arid biogeographic zones was highest at the arid end of the climatic gradient, and representation increased with grazing intensity within this area. Regardless of the climatic context, increased grazing pressure results in a reduction in vegetation cover and thus in changes in habitat characteristics. By reducing vegetation cover, grazing increased habitat heterogeneity in the dense mesic sites and decreased habitat heterogeneity in the arid sites. Thus, our results suggest that the same direction of habitat alteration caused by grazing may have opposite effects on biodiversity and community composition in different climatic contexts.

  6. Soil Functional Zone Management: A Vehicle for Enhancing Production and Soil Ecosystem Services in Row-Crop Agroecosystems

    Science.gov (United States)

    Williams, Alwyn; Kane, Daniel A.; Ewing, Patrick M.; Atwood, Lesley W.; Jilling, Andrea; Li, Meng; Lou, Yi; Davis, Adam S.; Grandy, A. Stuart; Huerd, Sheri C.; Hunter, Mitchell C.; Koide, Roger T.; Mortensen, David A.; Smith, Richard G.; Snapp, Sieglinde S.; Spokas, Kurt A.; Yannarell, Anthony C.; Jordan, Nicholas R.

    2016-01-01

    There is increasing global demand for food, bioenergy feedstocks and a wide variety of bio-based products. In response, agriculture has advanced production, but is increasingly depleting soil regulating and supporting ecosystem services. New production systems have emerged, such as no-tillage, that can enhance soil services but may limit yields. Moving forward, agricultural systems must reduce trade-offs between production and soil services. Soil functional zone management (SFZM) is a novel strategy for developing sustainable production systems that attempts to integrate the benefits of conventional, intensive agriculture, and no-tillage. SFZM creates distinct functional zones within crop row and inter-row spaces. By incorporating decimeter-scale spatial and temporal heterogeneity, SFZM attempts to foster greater soil biodiversity and integrate complementary soil processes at the sub-field level. Such integration maximizes soil services by creating zones of ‘active turnover’, optimized for crop growth and yield (provisioning services); and adjacent zones of ‘soil building’, that promote soil structure development, carbon storage, and moisture regulation (regulating and supporting services). These zones allow SFZM to secure existing agricultural productivity while avoiding or minimizing trade-offs with soil ecosystem services. Moreover, the specific properties of SFZM may enable sustainable increases in provisioning services via temporal intensification (expanding the portion of the year during which harvestable crops are grown). We present a conceptual model of ‘virtuous cycles’, illustrating how increases in crop yields within SFZM systems could create self-reinforcing feedback processes with desirable effects, including mitigation of trade-offs between yield maximization and soil ecosystem services. Through the creation of functionally distinct but interacting zones, SFZM may provide a vehicle for optimizing the delivery of multiple goods and services in agricultural systems, allowing sustainable temporal intensification while protecting and enhancing soil functioning. PMID:26904043

  7. SUSTAINABLE DEVELOPMENT MANAGEMENT OF THE GRASSLAND AGROECOSYSTEM IN THE CONTEXT OF BIODIVERSITY CONSERVATION AND IMPROVEMENT OF PERMANENT GRASSLAND

    Directory of Open Access Journals (Sweden)

    Pompilica IAGARU

    2015-04-01

    Full Text Available The agricultural enterprise, seen from a sustainable development perspective, operates within an ecosystem, and aims to achieve a harmonious interpenetration and integration with it. The way in which this interpenetration and integration is realized depends on the level achieved by its performances, which requires the adoption of policies and strategies and the economic organization of biotechnical processes. The paper emphasizes an interdisciplinary approach to issues like management and sustainable development of the grassland agro ecosystem and shows that promoting ecological techniques in the grassland agro ecosystem can ensure its versatility. All these supported by obtaining appropriate pastoral values, namely biodiversity conservation and improvement of meadows, and knowing that Romania has a variety of floral structures with high biodiversity indices.

  8. Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem modelecosystem model

    Science.gov (United States)

    Atmospheric ammonia (NH3) is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurement...

  9. Long-term agroecosystem research in the central Mississippi river basin: hyperspectral remote sensing of reservoir water quality.

    Science.gov (United States)

    Sudduth, Kenneth A; Jang, Gab-Sue; Lerch, Robert N; Sadler, E John

    2015-01-01

    In situ methods for estimating water quality parameters would facilitate efforts in spatial and temporal monitoring, and optical reflectance sensing has shown potential in this regard, particularly for chlorophyll, suspended sediment, and turbidity. The objective of this research was to develop and evaluate relationships between hyperspectral remote sensing and lake water quality parameters-chlorophyll, turbidity, and N and P species. Proximal hyperspectral water reflectance data were obtained on seven sampling dates for multiple arms of Mark Twain Lake, a large man-made reservoir in northeastern Missouri. Aerial hyperspectral data were also obtained on two dates. Water samples were collected and analyzed in the laboratory for chlorophyll, nutrients, and turbidity. Previously reported reflectance indices and full-spectrum (i.e., partial least squares regression) methods were used to develop relationships between spectral and water quality data. With the exception of dissolved NH, all measured water quality parameters were strongly related ( ≥ 0.7) to proximal reflectance across all measurement dates. Aerial hyperspectral sensing was somewhat less accurate than proximal sensing for the two measurement dates where both were obtained. Although full-spectrum calibrations were more accurate for chlorophyll and turbidity than results from previously reported models, those previous models performed better for an independent test set. Because extrapolation of estimation models to dates other than those used to calibrate the model greatly increased estimation error for some parameters, collection of calibration samples at each sensing date would be required for the most accurate remote sensing estimates of water quality. PMID:25602322

  10. Effects of earthworms on soil aggregate stability and carbon and nitrogen storage in a legume cover crop agroecosystem.

    NARCIS (Netherlands)

    Ketterings, Q.M.; Blair, J.M.; Marinissen, J.C.Y.

    1997-01-01

    We investigated the effects of earthworms on soil aggregate size-distribution, water-stability, and the distribution of total C and N among aggregates of different sizes. Earthworm populations were experimentally manipulated (reduced, unaltered or increased) in field enclosures cropped to soybean (G

  11. Cassava Mosaic Disease Yield Loss Assessment under Various Altitude Agroecosystems in the Sud Kivu Region, Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    Bisimwa, E.

    2015-01-01

    Full Text Available Cassava mosaic disease (CMD is reported as the most important constraint on cassava production in Sub­Saharan Africa. Yield losses of 25­95% are reported. The use of resistant genotypes is one of the components for its integrated management. However its impact on genotype behavior depends on infection period, age of the infected plants, environment and virus species or strain. This study was carried out to assess its impact in farmers' fields and the behavior of 14 genotypes under high epidemic pressure in the Sud­Kivu province, in the East of Democratic Republic of Congo (DRC. Early infections have induced 77.5% to 97.3% of yield losses whereas 44.9 to 80% were recorded for cassava plants infected during thirteenth to twenty­fourth weeks after planting. The highest yield losses were recorded in low altitude where more EACMV­UG and dual infections were reported. Improved resistant genotypes MM96/002, MM96/0157 and MM96/1920 allowed harvesting more than 30 T/ha and didn't show any symptoms whereas MM96/6967 and Mvuama have developed symptoms at harvest. Local landraces were susceptible to CMD and developed symptoms during the whole season until harvest. However two of them, Pharmakina and Cizinduka yielded more than 50 T/ha of tubers and associated symptoms were moderate. Two improved and two local cassava genotypes are recommended in this area always making sure to use healthy cuttings.

  12. Mosquito species diversity and abundance in relation to riceland agroecosystem and filarial infection in Kafr El-Sheikh Governorate, Egypt

    Directory of Open Access Journals (Sweden)

    TAREK M.Y. EL-SHEIKH , *KOTB M. HAMMAD AND **WALAA A. MOSELHI

    2010-06-01

    Full Text Available The present work studied the mosquitoes abundance, identification, distribution and density in three villages (rural area and one city (urban area in Kafr El-Sheikh Governorate namely; Kebreet, Minyat Al-Ashraaf, El-Salmia and Fowa city, respectively during the rice cultivation season in relation to filaria from June to Oct. 2009. A total of 11381 mosquitoes larvae belonging to four genera and 8 species were collected. Of which 3525 (31.0% in Minyat Al-Ashraaf followed by 3339 (29.3% in Kebreet, 3331 (29.3% in El-Salmia villages compared with 1186 (10.4% in Fowa city. The five most common species collected during this study were Culex pipiens (39.2%, Cx. antennatus (27.3%, Cx. univittatus (15.8%, Anopheles pharoensis (10.4%, and An. coustani (3.8%. The mosquito species diversity (H and evenness (EH in the (rice cultivated areas Minyat Al-Ashraf, Kebreet and El-Salmia villages (H = 1.286, EH = 0.829; H = 1.227, EH = 0.742; H = 1.110, EH = 0.882; respectively were much higher than in the Fowa city (non rice cultivated area (H = 0.718, EH = 0.608. On the other hand, the highest diversity and density of adult mosquitoes species obtained from Minyat Al-Ashraaf were 5 species and (33.8%, followed by Kebreet 5 species and (31.6%, El-Salmia 4 species and (24.5%, respectively compared with 3 species and (10.1% in Fowa city. C. pipiens adults were the predominant species, in all filarial indicator areas (68.1, 53.4, 40.8 and 20.8 mosquitoes/room in Minyat Al-Ashraaf, Kebreet, El-Salmia villages and Fowa city, respectively. Cx. pipiens was the only species to carry infective larvae as well as other stages, while Cx. antennatus carried immature stages only (not infective. Filarial larvae in Cx. pipiens and Cx. antennatus were found only in Minyat Al-Ashraaf and Kebreet villages. It is inferred from the data that different levels of habitat with regard to rice cultivation have different effects on mosquito diversity and abundance. Also, our study revealed that filarial vectors Cx. pipiens and Cx. antennatus had a wide distribution and high relative density especially in irrigated rice regions and hence its role in disease transmission in Kafr El-Sheikh region needs further investigation .

  13. Comparison greenhouse gas (GHG) emissions and global warming potential (GWP) effect of energy use in different wheat agroecosystems in Iran.

    Science.gov (United States)

    Yousefi, Mohammad; Mahdavi Damghani, Abdolmajid; Khoramivafa, Mahmud

    2016-04-01

    The aims of this study were to determine energy requirement and global warming potential (GWP) in low and high input wheat production systems in western of Iran. For this purpose, data were collected from 120 wheat farms applying questionnaires via face-to-face interviews. Results showed that total energy input and output were 60,000 and 180,000 MJ ha(-1) in high input systems and 14,000 and 56,000 MJ ha(-1) in low input wheat production systems, respectively. The highest share of total input energy in high input systems recorded for electricity power, N fertilizer, and diesel fuel with 36, 18, and 13 %, respectively, while the highest share of input energy in low input systems observed for N fertilizer, diesel fuel, and seed with 32, 31, and 27 %. Energy use efficiency in high input systems (3.03) was lower than of low input systems (3.94). Total CO2, N2O, and CH4 emissions in high input systems were 1981.25, 31.18, and 1.87 kg ha(-1), respectively. These amounts were 699.88, 0.02, and 0.96 kg ha(-1) in low input systems. In high input wheat production systems, total GWP was 11686.63 kg CO2eq ha(-1) wheat. This amount was 725.89 kg CO2eq ha(-1) in low input systems. The results show that 1 ha of high input system will produce greenhouse effect 17 times of low input systems. So, high input production systems need to have an efficient and sustainable management for reducing environmental crises such as change climate.

  14. Manipulation of soil microbes using higher biomass cropping systems to sustain soil health in cotton-based agroecosystems

    Science.gov (United States)

    The semiarid Texas High Plains produces ~30% of U.S. cotton (Gossypium hirsutum L.). Agricultural production, however, is experiencing a transition from irrigated to dryland crop production due to reductions in water availability from the Ogallala aquifer. Additional challenges are imposed by extrem...

  15. Long-term agroecosystem research in the Central Mississippi River Basin: Goodwater Creek Experimental Watershed flow data

    Science.gov (United States)

    Flow monitoring in Goodwater Creek Experimental Watershed started in 1971 at three nested watersheds ranging from 12 to 73 km2 in drainage area. Since then, flow has been measured at 14 plots, 3 fields, and 12 additional stream sites ranging from 0.0034 to 6067 km2 in the Central Mississippi River B...

  16. Spatial variability of soil salinity at different scales in the mangrove rice agro-ecosystem in West Africa.

    NARCIS (Netherlands)

    Sylla, M.; Stein, A.; Breemen, van N.; Fresco, L.O.

    1995-01-01

    Spatial variability of soil salinity in coastal low lands results from a complex interaction of climate, river hydrology, topography and tidal flooding. The aim of this study was to determine the significant effects of these causal factors at different scales in the West African mangrove environment

  17. Assessing and monitoring impacts of genetically modefied plants on agro-ecosystems: the approach of AMIGA project.

    NARCIS (Netherlands)

    Arpaia, S.; Messéan, A.; Birch, N.A.; Hokkanen, H.; Härtel, S.; Loon, van J.; Lovei, G.; Park, J.; Spreafico, H.; Squire, G.R.; Steffan-Dewenter, I.; Tebbe, C.; Voet, van der H.

    2014-01-01

    The environmental impacts of genetically modified crops is still a controversial issue in Europe. The overall risk assessment framework has recently been reinforced by the European Food Safety Authority(EFSA) and its implementation requires harmonized and efficient methodologies. The EU-funded resea

  18. Fruit metabolite networks in engineered and non-engineered tomato genotypes reveal fluidity in a hormone and agroecosystem specific manner

    Science.gov (United States)

    Multiple strategies have been explored throughout the world to meet food security. These include molecular breeding, transgenic genotype development, reduced-tillage crop production, modification of the soil environment with cover crops or polyethylene mulches and tunnels, and organic farming. Unde...

  19. REGIONAL EMISSIONS OF NITRIC OXIDE (NO) AND CARBON DIOXIDE (CO2) IN AGROECOSYSTEMS IN CENTRAL WEST REGION, BRAZIL.

    Science.gov (United States)

    The Central West Region in Brazil has been the focus of intense agricultural expansion since the 1970s and, nowadays, a large area of native cerrado has been converted to agricultural use. The expansion was accompanied by intensive use of fertilizer, irrigation and management pra...

  20. Diversity and communities of foliar endophytic fungi from different agroecosystems of Coffea arabica L. in two regions of Veracruz, Mexico.

    Directory of Open Access Journals (Sweden)

    Aurora Saucedo-García

    Full Text Available Over the past 20 years, the biodiversity associated with shaded coffee plantations and the role of diverse agroforestry types in biodiversity conservation and environmental services have been topics of debate. Endophytic fungi, which are microorganisms that inhabit plant tissues in an asymptomatic manner, form a part of the biodiversity associated with coffee plants. Studies on the endophytic fungi communities of cultivable host plants have shown variability among farming regions; however, the variability in fungal endophytic communities of coffee plants among different coffee agroforestry systems is still poorly understood. As such, we analyzed the diversity and communities of foliar endophytic fungi inhabiting Coffea arabica plants growing in the rustic plantations and simple polycultures of two regions in the center of Veracruz, Mexico. The endophytic fungi isolates were identified by their morphological traits, and the majority of identified species correspond to species of fungi previously reported as endophytes of coffee leaves. We analyzed and compared the colonization rates, diversity, and communities of endophytes found in the different agroforestry systems and in the different regions. Although the endophytic diversity was not fully recovered, we found differences in the abundance and diversity of endophytes among the coffee regions and differences in richness between the two different agroforestry systems of each region. No consistent pattern of community similarity was found between the coffee agroforestry systems, but we found that rustic plantations shared the highest number of morphospecies. The results suggest that endophyte abundance, richness, diversity, and communities may be influenced predominantly by coffee region, and to a lesser extent, by the agroforestry system. Our results contribute to the knowledge of the relationships between agroforestry systems and biodiversity conservation and provide information regarding some endophytic fungi and their communities as potential management tools against coffee plant pests and pathogens.

  1. Division S-6-soil and water management and conservation : dynamics of soil physical properties in amazonian agroecosystems inoculated with earthworms

    OpenAIRE

    Alegre, J.C.; Pashanasi, B.; Lavelle, P.

    1996-01-01

    The combined use of earthworm inoculation and organic input is considered an efficient way to improve traditional slash-and-burn agriculture in the humid tropics. This study tests the hypothesis that the resistant macroaggregate structure that results from earthworm activities is likely to promote sustainability by favoring water infiltration and soil aeration. Six successive crops (maize (#Zea mays$ L.) - rice (#Oryza sativa$ L.) - cowpea (#Vigna unguiculata$ (L.) Walp.) - rice - rice - rice...

  2. Climate change and agroecosystems: the effect of elevated atmospheric CO2 and temperature on crop growth, development, and yield

    Directory of Open Access Journals (Sweden)

    Streck Nereu Augusto

    2005-01-01

    Full Text Available The amount of carbon dioxide (CO2 of the Earths atmosphere is increasing, which has the potential of increasing greenhouse effect and air temperature in the future. Plants respond to environment CO2 and temperature. Therefore, climate change may affect agriculture. The purpose of this paper was to review the literature about the impact of a possible increase in atmospheric CO2 concentration and temperature on crop growth, development, and yield. Increasing CO2 concentration increases crop yield once the substrate for photosynthesis and the gradient of CO2 concentration between atmosphere and leaf increase. C3 plants will benefit more than C4 plants at elevated CO2. However, if global warming will take place, an increase in temperature may offset the benefits of increasing CO2 on crop yield.

  3. Water management impacts on arsenic behavior and rhizosphere bacterial communities and activities in a rice agro-ecosystem.

    Science.gov (United States)

    Das, Suvendu; Chou, Mon-Lin; Jean, Jiin-Shuh; Liu, Chia-Chuan; Yang, Huai-Jen

    2016-01-15

    Although rice cultivated under water-saturated conditions as opposed to submerged conditions has received considerable attention with regard to reducing As levels in rice grain, the rhizosphere microbiome potentially influencing As-biotransformation and bioavailability in a rice ecosystem has rarely been studied. In this study, the impacts of flooded, non-flooded and alternate wetting and drying (AWD) practices on rhizosphere bacterial composition and activities that could potentially impact As speciation and accumulation in rhizosphere soil and pore water, As fractions in rhizosphere soil and As speciation and distribution in plant parts were assessed. The results revealed that in addition to pore water As concentration, non-specifically sorbed As fraction, specifically sorbed As fraction and amorphous iron oxide bound As fraction in soil were bio-available to rice plants. In the flooded treatment, As(III) in the pore water was the predominant As species, accounting for 87.3-93.6% of the total As, whereas in the non-flooded and AWD treatments, As(V) was the dominant As species, accounting for 89.6-96.2% and 73.0-83.0%, respectively. The genera Ohtaekwangia, Geobacter, Anaeromyxobacter, Desulfuromonas, Desulfocapsa, Desulfobulbus, and Lacibacter were found in relatively high abundance in the flooded soil, whereas the genera Acinetobacter, Ignavibacterium, Thiobacillus, and Lysobacter were detected in relatively high abundance in the non-flooded soil. Admittedly, the decrease in As level in rice cultivated under the non-flooded and AWD conditions was mostly linked to a relatively high soil redox potential, low As(III) concentration in the soil pore water, a decrease in the relative abundance of As-, Fe- and sulfur-reducing bacteria and an increase in the relative abundance of As-, Fe- and sulfur-oxidizing bacteria in the rhizosphere soil of the rice. This study demonstrated that with substantial reduction in grain As levels and higher water productivity, AWD practice in rice cultivation should be favored over the non-flooded and continuously flooded rice cultivations in As-contaminated sites. PMID:26546760

  4. Technical Report: Impacts of Land Management and Climate on Agroecosystem Greenhouse Gas Exchange in the Upper Midwest United States

    Energy Technology Data Exchange (ETDEWEB)

    Timothy J. Griffis; John M. Baker

    2007-07-01

    Our research is designed to improve the scientific understanding of how carbon is cycled between the land and atmosphere within a heavily managed landscape that is characteristic of the Upper Midwest. The Objectives are: 1) Quantify the seasonal and interannual variation of net ecosystem CO2 exchange of agricultural ecosystems in the Upper Midwest grown under different management strategies; 2) Partition net ecosystem CO2 exchange into photosynthesis and ecosystem respiration by combining micrometeorological and stable isotope techniques; 3) Examine the seasonal variation in canopy-scale photosynthetic discrimination and the isotope ratios of ecosystem respiration and photosynthesis.

  5. A Conceptual Framework for the Assessment of Multiple Functions of Agro-Ecosystems: A Case Study of Tras-os-Montes Olive Groves

    Science.gov (United States)

    Fleskens, Luuk; Duarte, Filomena; Eicher, Irmgard

    2009-01-01

    Multifunctionality in agriculture has received a lot of attention the last decade from researchers and policy-makers alike, perhaps most notably evidenced by the important changes made to the EU's Common Agricultural Policy. While the concept has been embraced by environmentalists envisioning positive impulses for decoupling and a range of local…

  6. 山东省农业生态价值测算及其贡献%Calculation of the Value of Agroecosystems in Shandong Province

    Institute of Scientific and Technical Information of China (English)

    孙能利; 巩前文; 张俊飚

    2011-01-01

    Agriculture not only has economic value, but also with non-economic values, and estimate the economic value of agricultural non-economic values is focused. This article is divided into the value of agricultural production value and ecological value and ecological value by authoritative measure thinking, Accroding to partial global ecosystem services value evaluation results obtained by Costanza et al. Alone with responses of ecological questionnaires from specialists of China, because the study of Costanza et al also received many severe criticism,such as certain data,there are big deviation of arable land estimate is too low,the wetland and partial higher. Therefore,this paper combined with the formation of Shandong Province for the ecological value of the actual calculation method, measured by official statistics, the actual ecological value of Shandong Province. The results showed that in 2008, Shandong Province, agro-ecological value of 7 058.54 billion yuan worth of reality, is an agricultural economy 2.4 times the value of 3002.65 billion yuan.%农业不仅具有经济价值,同时还具有非经济价值,而估算农业的非经济价值成为学术界研究的热点.本文把农业的价值分为生产产品价值和生态价值,并采用具有权威性的生态价值测算思想,即Costanza等于1997年提出的方法作为估算农业生态价值的方法依据,同时,由于该项研究也受到了不少严厉的批评,如某些数据存在着较在偏差,如对耕地的估计过低,对湿地又偏高等.因此,进一步借鉴谢高地等于2003年针对Costanza等的不足,在参考其可靠的部分成果的同时,基于对我国200位生态学者的问卷调查,制定出我国生态系统生态服务价值的当量因子表.以此表为基础,结合山东省实际形成适用的生态价值测算方法,采用官方统计数据实际测算了山东省农业生态价值.结果发现,2008年山东省农业生态价值的现实值为7058.54亿元,是当年农业经济价值3002.65亿元的2.4倍.

  7. Integration of Ground and Multi-Resolution Satellite Data for Predicting the Water Balance of a Mediterranean Two-Layer Agro-Ecosystem

    Directory of Open Access Journals (Sweden)

    Piero Battista

    2016-09-01

    Full Text Available The estimation of site water budget is important in Mediterranean areas, where it represents a crucial factor affecting the quantity and quality of traditional crop production. This is particularly the case for spatially fragmented, multi-layer agricultural ecosystems such as olive groves, which are traditional cultivations of the Mediterranean basin. The current paper aims at demonstrating the effectiveness of spatialized meteorological data and remote sensing techniques to estimate the actual evapotranspiration (ETA and the soil water content (SWC of an olive orchard in Central Italy. The relatively small size of this orchard (about 0.1 ha and its two-layer structure (i.e., olive trees and grasses require the integration of remotely sensed data with different spatial and temporal resolutions (Terra-MODIS, Landsat 8-OLI and Ikonos. These data are used to drive a recently proposed water balance method (NDVI-Cws and predict ETA and then site SWC, which are assessed through comparison with sap flow and soil wetness measurements taken in 2013. The results obtained indicate the importance of integrating satellite imageries having different spatio-temporal properties in order to properly characterize the examined olive orchard. More generally, the experimental evidences support the possibility of using widely available remotely sensed and ancillary datasets for the operational estimation of ETA and SWC in olive tree cultivation systems.

  8. 诱集植物在农业害虫综合治理中的应用%Application of trap crop to IPM of agro-ecosystems

    Institute of Scientific and Technical Information of China (English)

    许向利; 花保祯; 张世泽

    2005-01-01

    诱集植物作为害虫综合治理的重要措施已经越来越引起关注.本文介绍了诱集植物利用的原理和历史,简述了诱集植物的优点,讨论了诱集植物在害虫治理中的应用,并展望了诱集植物的应用前景.

  9. Forecasting the Influence of Climate Change on Agroecosystem Services: Potential Impacts on Honey Yields in a Small-Island Developing State

    Directory of Open Access Journals (Sweden)

    Diana L. Delgado

    2012-01-01

    Full Text Available Global change poses numerous challenges to developing nations and small-island developing states (SIDSs. Among these are the effects of climate change on honeybees’ provisioning services including honey production. Here we ask two questions. First, what is the relationship between honey yield and climate in a tropical environment? Second, how does yield vary spatially under current climate and future scenarios of climate change? Focusing on the island of Puerto Rico, we developed an ensemble of bioclimatic models that were used in a geographical information system to identify suitable areas for honey production under current and future scenarios of climate change. A comparison between contemporary (1998–2005 and historical (1910–1974 honey yield data revealed a reduction in average yield, including variability, over time, with current yields averaging 5.3 L/colony. Three bioclimatic variables were retained by at least three models: temperature seasonality and mean temperature of the wettest quarter were negatively correlated with honey yields whereas precipitation of the wettest month was positively correlated. The four models varied in terms of their predictions but showed that both honey yields and areas suitable for honey production will decrease under scenarios of climate change. These results illustrate the possible impacts of climate change on honey and ultimately honeybees.

  10. Estimating agro-ecosystem carbon balance of northern Japan, and comparing the change in carbon stock by soil inventory and net biome productivity.

    Science.gov (United States)

    Li, Xi; Toma, Yo; Yeluripati, Jagadeesh; Iwasaki, Shinya; Bellingrath-Kimura, Sonoko D; Jones, Edward O; Hatano, Ryusuke

    2016-06-01

    Soil C sequestration in croplands is deemed to be one of the most promising greenhouse gas mitigation options for agriculture. We have used crop-level yields, modeled heterotrophic respiration (Rh) and land use data to estimate spatio-temporal changes in regional scale net primary productivity (NPP), plant C inputs, and net biome productivity (NBP) in northern Japan's arable croplands and grasslands for the period of 1959-2011. We compared the changes in C stocks derived from estimated NBP and using repeated inventory datasets for each individual land use type from 2005 to 2011. For the entire study region of 2193 ha, overall annual plant C inputs to the soil constituted 37% of total region NPP. Plant C inputs in upland areas (excluding bush/fallow) could be predicted by climate variables. Overall NBP for all land use types increased from -1.26MgCha(-1)yr(-1) in 1959-0.26 Mg Cha(-1)yr(-1) in 2011. However, upland and paddy fields showed a decreased in NBP over the period of 1959-2011, under the current C input scenario. From 1988, an increase in agricultural abandonment (bush/fallow) and grassland cover caused a slow increase in the regional C pools. The comparison of carbon budgets using the NBP estimation method and the soil inventory method indicated no significant difference between the two methods. Our results showed C loss in upland crops, paddy fields and sites that underwent land use change from paddy field to upland sites. We also show C gain in grassland from 2005 to 2011. An underestimation of NBP or an overestimation of repeated C inventories cannot be excluded, but either method may be suitable for tracking absolute changes in soil C, considering the uncertainty associated with these methods. PMID:26956176

  11. Differences in carbon density and soil CH4/N2O flux among remnant and agro-ecosystems established since European settlement in the Mornington Peninsula, Australia.

    Science.gov (United States)

    Livesley, Stephen J; Idczak, Daniel; Fest, Benedikt J

    2013-11-01

    National and regional C emissions from historical land use change (LUC) and fossil fuel use are proposed as a basis to ascribe 'burden-sharing' for global emission reduction targets. Changes in non-CO2 greenhouse gas emissions as a result of LUC have not been considered, but may be considerable. We measured soil-atmosphere exchange of methane (CH4) and nitrous oxide (N2O) in remnant forest, pasture and viticulture systems in four seasons, as well as differences in soil C density and the C density of remnant forest vegetation. This approach enabled comparative assessment of likely changes in ecosystem C density and soil non-CO2 greenhouse gas exchange along a LUC continuum since European settlement. Soil CH4 uptake was moderate in forest soil (-27 μg C m(-2) h(-1)), and significantly different to occasionally large CH4 emissions from viticulture and pasture soils. Soil N2O emissions were small and did not significantly differ. Soil C density increased significantly with conversion from forest (5 kg m(-2)) to pasture (9 kg m(-2)), and remained high in viticulture. However, there was a net decrease in ecosystem C density with forest conversion to pasture. Concurrently, net soil non-CO2 emissions (CH4 and N2O combined) increased with conversion from forest to pasture. Since European settlement 170 years ago, it was estimated ~8114 Gg CO2-e has been released from changes in ecosystem C density in the Mornington Peninsula, whereas ~383 Gg CO2-e may have been released from changes in soil non-CO2 exchange processes. Principally, a switch from soil CH4 uptake to soil CH4 emission after forest clearing to agro-pastoral systems provided this further ~5% contribution to the historical landscape CO2-e source strength. Conserving and restoring remnant forests and establishing new tree-based systems will enhance landscape C density. Similarly, minimising anaerobic, wet conditions in pasture/viticulture soils will help reduce non-CO2 greenhouse gas emissions.

  12. Long-term effects of irrigation with waste water on soil AM fungi diversity and microbial activities: the implications for agro-ecosystem resilience.

    Directory of Open Access Journals (Sweden)

    Maria del Mar Alguacil

    Full Text Available The effects of irrigation with treated urban wastewater (WW on the arbuscular mycorrhizal fungi (AMF diversity and soil microbial activities were assayed on a long-term basis in a semiarid orange-tree orchard. After 43 years, the soil irrigated with fresh water (FW had higher AMF diversity than soils irrigated with WW. Microbial activities were significantly higher in the soils irrigated with WW than in those irrigated with FW. Therefore, as no negative effects were observed on crop vitality and productivity, it seems that the ecosystem resilience gave rise to the selection of AMF species better able to thrive in soils with higher microbial activity and, thus, to higher soil fertility.

  13. Carbon Nanotubes Influence the Enzyme Activity of Biogeochemical Cycles of Carbon, Nitrogen, Phosphorus and the Pathogenesis of Plants in Annual Agroecosystems

    Science.gov (United States)

    Vaishlya, O. B.; Osipov, N. N.; Guseva, N. V.

    2015-09-01

    We conducted pre-sowing seed treatment of spring wheat carbon nanotubes modified with thionyl chloride, ethylene diamine, azobenzole, and dodecylamine. CNTs did not disrupt the structure of the crop, but the activity of extracellular enzymes in the rhizosphere of plants in the flowering stage changed: laccase works more poorly in the variant of the CNTs with the amino groups exochitinase and phosphatase activity increased in the case of chlorinated CNTs, OH and COOH groups on the surface of the nanotubes twice accelerate work β-glucosidase. The changes observed in the biogeochemical cycles in the rhizosphere are a possible cause of the effect of nanotubes on the development of epidemic diseases of wheat.

  14. Drinking From the Same Straw: Crop Growth and Evidence of Water Transfer from Native Shrubs to Millet in a Sahelian Agro-Ecosystem

    Science.gov (United States)

    Bogie, N. A.; Bayala, R.; Fogel, M. L.; Diedhiou, I.; Dick, R.; Ghezzehei, T. A.

    2015-12-01

    A changing climate along with human and animal population pressure can have a devastating effect on crop yields and food security in the Sudano-Sahel. Agricultural solutions to address soil degradation and crop water stress are needed to combat this increasingly difficult situation. Significant differences in crop success have been observed in peanut and millet grown in association with two native evergreen shrubs Piliostigma reticulatum, and Guiera senegalensis at the sites of Nioro du Rip and Keur Matar, respectively. We investigate how farmers can increase crop productivity by capitalizing on the evolutionary adaptation of native shrubs to the harsh Sudano-Sahelian environment as well as the physical mechanisms at work in the system that can lead to more robust yields. Soil moisture, transpiration rate, crop growth and soil and leaf water potential data were collected during a dry season millet irrigation experiment where stress was imposed in the intercropped system. Despite lower soil moisture content, crops grown in association with shrubs have increased biomass production and a faster development cycle. An isotopic tracer study investigating hydraulic redistribution was carried out by injecting deuterated water into the roots of three shrubs at one meter depth and sampling shrubs and nearby crops for isotopic analysis of plant water. Deuterium Enriched water was found in the shrubs of two out of three plots. Deuterium enriched water was found in the crops and shrubs in all three plots. These findings build on work that was completed in 2004 at the site, but point to larger differences in crop growth and strong evidence for the sharing of hydraulically redistributed water. Using even the limited resources that farmers possess, this agroforestry technique can be expanded over wide swaths of the Sahel.

  15. Forecasting the Influence of Climate Change on Agroecosystem Services: Potential Impacts on Honey Yields in a Small-Island Developing State

    OpenAIRE

    Delgado, Diana L.; María Eglée Pérez; Alberto Galindo-Cardona; Tugrul Giray; Carla Restrepo

    2012-01-01

    Global change poses numerous challenges to developing nations and small-island developing states (SIDSs). Among these are the effects of climate change on honeybees’ provisioning services including honey production. Here we ask two questions. First, what is the relationship between honey yield and climate in a tropical environment? Second, how does yield vary spatially under current climate and future scenarios of climate change? Focusing on the island of Puerto Rico, we developed an ensemble...

  16. Climate Change and Potato Production in Contrasting South African Agro-Ecosystems 3. Effects on Relative Development Rates of Selected Pathogens and Pests

    OpenAIRE

    Waals, van der, J.H.; K. Krüger; Franke, A. C.; Haverkort, A.J.; Steyn, J.M.

    2013-01-01

    A set of daily weather data simulations for 1961 to 2050 were used to calculate past and future trends in pest and disease pressure in potato cropping systems at three agro-ecologically distinct sites in South Africa: the Sandveld, the Eastern Free State and Limpopo. The diseases and pests modelled were late blight, early blight and brown spot, blackleg and soft rot, root-knot nematodes and the peach-potato aphid Myzus persicae (as indicator of Potato virus Y and Potato leaf roll virus). The ...

  17. Impacts of elevated CO2 concentration on the productivity and surface energy budget of the soybean and maize agroecosystem in the Midwest USA.

    Science.gov (United States)

    Twine, Tracy E; Bryant, Jarod J; T Richter, Katherine; Bernacchi, Carl J; McConnaughay, Kelly D; Morris, Sherri J; Leakey, Andrew D B

    2013-09-01

    The physiological response of vegetation to increasing atmospheric carbon dioxide concentration ([CO2 ]) modifies productivity and surface energy and water fluxes. Quantifying this response is required for assessments of future climate change. Many global climate models account for this response; however, significant uncertainty remains in model simulations of this vegetation response and its impacts. Data from in situ field experiments provide evidence that previous modeling studies may have overestimated the increase in productivity at elevated [CO2 ], and the impact on large-scale water cycling is largely unknown. We parameterized the Agro-IBIS dynamic global vegetation model with observations from the SoyFACE experiment to simulate the response of soybean and maize to an increase in [CO2 ] from 375 ppm to 550 ppm. The two key model parameters that were found to vary with [CO2 ] were the maximum carboxylation rate of photosynthesis and specific leaf area. Tests of the model that used SoyFACE parameter values showed a good fit to site-level data for all variables except latent heat flux over soybean and sensible heat flux over both crops. Simulations driven with historic climate data over the central USA showed that increased [CO2 ] resulted in decreased latent heat flux and increased sensible heat flux from both crops when averaged over 30 years. Thirty-year average soybean yield increased everywhere (ca. 10%); however, there was no increase in maize yield except during dry years. Without accounting for CO2 effects on the maximum carboxylation rate of photosynthesis and specific leaf area, soybean simulations at 550 ppm overestimated leaf area and yield. Our results highlight important model parameter values that, if not modified in other models, could result in biases when projecting future crop-climate-water relationships. PMID:23716193

  18. The Role of Structural, Biochemical and Ecophysiological Plant Acclimation in the Eco-Hydrologic Response of Agro-Ecosystems to Global Change in the Central US

    Science.gov (United States)

    Drewry, D.; Kumar, P.; Long, S.; Sivapalan, M.; Bernacchi, C.; Liang, X.

    2009-12-01

    The acclimation of terrestrial vegetation to changes in ambient growth environment has significant implications for land-atmosphere exchange of carbon dioxide (CO2) and energy, as well as critical ecosystem services such as food production. Recent field campaigns at the SoyFACE Free Air Carbon Enrichment (FACE) facility in central Illinois have provided clear evidence of the modification of structural, biochemical and ecophysiological properties of key agricultural species at CO2 concentrations projected for the middle of this century. While these acclamatory responses have been linked to changes in leaf-level gas exchange and leaf states (ie. leaf temperature and stomatal conductance), determining the implications for these changes at the canopy-scale has remained a challenge. Here we present a simulation analysis that examines the role of observed plant acclimation in two key mid-west agricultural species, soy (C3 photosynthetic pathway) and corn (C4 photosynthetic pathway), in modifying future carbon uptake and surface energy partitioning, crop water use and resilience to water stress. The model canopies are divided into multiple layers, allowing for resolution of the shortwave and longwave radiation regimes that drive photosynthesis, stomatal conductance and leaf energy balance in each layer, along with the canopy microclimate. The canopy component of the model is coupled to a multi-layer soil-root model that computes soil moisture and root water uptake at each time period, accounting for the effects of moisture stress on canopy functioning. Model skill in capturing the sub-diurnal variability in canopy-atmosphere fluxes is demonstrated using multi-year records of eddy covariance CO2, water vapor and heat fluxes collected at the Bondville (Illinois) AmeriFlux site. An evaluation of the ability of the model to simulate observed changes in energy balance components, leaf-level photosynthetic assimilation, leaf temperature and stomatal conductance under elevated CO2 concentrations projected for 2050 (550 ppm) is conducted through observations collected at SoyFACE over several recent growing seasons. With this validated model we quantify the role of structural, biochemical and ecophysiological acclimation on canopy-atmosphere exchange of CO2, water vapor and heat, and examine the within-canopy variability of flux densities and states to elevated CO2 perturbations. The role of meteorological forcing conditions and soil moisture status on mediating the changes in canopy-atmosphere interactions is examined. The model is then used to investigate the magnitude and direction of changes in fluxes and water use efficiency as ambient CO2 is elevated across a range of concentrations expected through the coming century.

  19. AESIS: a support tool for the evaluation of sustainability of agroecosystems. Example of applications to organic and integrated farming systems in Tuscany, Italy

    Directory of Open Access Journals (Sweden)

    Gaio Cesare Pacini

    2011-02-01

    Full Text Available Agricultural researchers widely recognise the importance of sustainable agricultural production systems and the need to develop appropriate methods to measure sustainability on the farm level. Policy makers need accounting and evaluation tools to be able to assess the potential of sustainable production practices and to provide appropriate agro-environmental policy measures. Farmers are in search of sustainable management tools to cope with regulations and enhance efficiency. This paper presents the outcomes of applications to organic and integrated farming of an indicator-based framework to evaluate sustainability of farming systems (Agro-Environmental Sustainability Information System, AESIS. The AESIS was described together with a review of applications dating from 1991 in a previous paper. The objective of the present paper is to present the AESIS application to organic and integrated farming systems in Val d’Elsa (Tuscany and discuss how it is adapted for application to ordinary farms. The AESIS is organised into a number of environmental and production systems. For each system, environmental critical points are identified with corresponding agro-environmental indicators and processing methods. Possible solutions to sustainability issues, and critical points of relevance to the agricultural sector of the local economic and agro-ecological zone, are formulated by including an experimental layout, identifying indicator thresholds and by defining management systems with corresponding policy measures. Alternative solutions are evaluated by calculating and measuring the relevant indicators. The outcomes of the AESIS applications are discussed with specific relevance to the operational adoptability of AESIS to ordinary, agri-touristic farms managed with the organic and the integrated production method, respectively. The AESIS framework proved to be sufficiently flexible to meet the requirements for ordinary farm applications while keeping a holistic perspective and considering pedo-climatic and production factors on different spatial scales.

  20. Use of video surveillance to measure the influences of habitat management and landscape composition on pollinator visitation and pollen deposition in pumpkin (Cucurbita pepo) agroecosystems.

    Science.gov (United States)

    Phillips, Benjamin W; Gardiner, Mary M

    2015-01-01

    Pumpkin (Cucurbita pepo) production relies on insect-mediated pollination, which is provided by managed and wild pollinators. The goals of this study were to measure the visitation frequency, longevity and temporal activity patterns of pumpkin pollinators and to determine if local habitat management and landscape composition affected this pollination service. We used video surveillance to monitor bee acitivty within male and female pumpkin flowers in 2011 and 2012 across a pollination window of 0600-1200 h. We also quantified the amount of pollen deposited in female flowers across this time period. In 2011, A. mellifera made significantly more floral visits than other bees, and in 2012 Bombus spp. was the dominant pumpkin pollinator. We found variation in visitation among male and female pumpkin flowers, with A. mellifera visiting female flowers more often and spending longer per visit within them than male flowers in both 2011 and 2012. The squash bee P. pruinosa visited male flowers more frequently in 2012, but individuals spent equal time in both flower sexes. We did not find variation in the timing of flower visitation among species across the observed pollination window. In both 2011 and 2012 we found that the majority of pollen deposition occurred within the first two hours (0600-0800 h) of observation; there was no difference between the pollen deposited during this two-hour period and full pollination window (0600-1200 h). Local additions of sweet alyssum floral strips or a field buffer strip of native wildflowers did not have an effect on the foraging activity of bees or pollen deposition. However, semi-natural and urban habitats in the surrounding landscape were positively correlated with the frequency of flower visitation by wild pollinators and the amount of pollen deposited within female flowers. PMID:26587337

  1. Diversity and habitat preferences of Carabidae and Staphylinidae (Coleoptera in two agroecosystems Diversidade e preferência de habitat de Carabidae e Staphylinidae (Coleoptera em dois agroecossistemas

    Directory of Open Access Journals (Sweden)

    Ivan Carlos Fernandes Martins

    2012-01-01

    Full Text Available The present study had as objective determine the diversity and abundance of adults Carabidae and Staphylinidae in two areas, constituted by forest fragment and soybean/corn crops under conventional tillage and no-tillage systems and to analyze the distribution and preference of those beetles for the habitat. The beetles were sampled with 48 pitfall traps. In both experimental areas, two parallel transects of pitfall traps were installed. Each transect had 100 m in the crop and 100 m in the forest fragment. Four traps were close to each other (1 m in the edge between the crop and the forest fragment, the other traps were installed each 10 m. The obtained data were submitted to the faunistic analysis and the preference of the species by habitat was obtained by cluster analysis. The results demonstrated that the type of crop system (conventional tillage or no-tillage might have influenced the diversity of species of Carabidae and Staphylinidae. The cluster analysis evidenced that the carabids may prefer a specific habitat. In the present study, the distribution of carabids and staphylinids in the three habitats showed that these beetles have potential to be dispersed at great distances inside the crop.Este estudo teve como objetivo determinar a diversidade e abundância de adultos de Carabidae e Staphylinidae em duas áreas, constituídas por fragmentos florestais e culturas de soja/milho sob sistemas de plantio convencional e direto, e analisar a distribuição e a preferência desses insetos para o habitat. Os besouros foram amostrados com o uso de 48 armadilhas de solo do tipo Pitfall. Em ambas as áreas experimentais, foram instalados dois transectos paralelos de armadilhas; cada transecto teve 100 m na culturas e 100 m no fragmento florestal. Na borda entre a cultura e o fragmento de floresta foram instaladas quatro armadilhas, que ficaram distantes entre si por 1 m e as outras armadilhas, a cada 10 m. Os dados obtidos foram submetidos à análise faunística e a preferência das espécies para o habitat foi obtida pela análise cluster. Pelos resultados, observa-se que o tipo de sistema de cultivo (convencional ou plantio direto pode ter influenciado a diversidade de espécies de Carabidae e Staphylinidae. A análise de cluster evidenciou que os carabídeos tiveram preferência por um habitat específico. Neste estudo, a distribuição de carabídeos e estafilinídeos nos três habitats mostraram que estes besouros têm potencial para se dispersarem em grandes distâncias no interior da cultura.

  2. Diversidade e distribuição espacial de artrópodes associados ao solo em agroecossistemas Diversity and spatial distribution of ground arthropods in agroecosystems

    Directory of Open Access Journals (Sweden)

    Francisco Jorge Cividanes

    2009-01-01

    Full Text Available O conhecimento da diversidade e distribuição de artrópodes associados ao solo contribui para o desenvolvimento de sistemas agrícolas sustentáveis. O presente estudo foi realizado em Jaboticabal (SP, durante o período de fevereiro a abril de 2004. O objetivo foi analisar a comunidade de Carabidae, Staphylinidae, Formicidae e Araneae através de índices faunísticos e determinar a distribuição espacial e a interação interespecífica de espécies predominantes em soja (Glycine max (L. Merr., milho (Zea mays L. e seringueira (Hevea brasiliensis Muell. Arg.. Os artrópodes foram amostrados com armadilhas de solo distribuídas a cada 10 m em dois transectos de 210 m de comprimento, que atravessaram o seringal e avançaram 60 m no interior das culturas. A fauna foi caracterizada pelos índices de diversidade de Shannon-Wiener, de equitabilidade e de similaridade de Morisita. As diferenças entre a ocorrência das espécies predominantes nos hábitats foram determinadas por análise de variância e a interação interespecífica por correlação de Pearson. A soja e o milho cultivados em sistema de plantio direto propiciaram comunidades de carabídeos, formigas e aranhas mais bem estruturadas que o seringal. Entre as 88 espécies capturadas, 20 espécies foram predominantes cuja distribuição espacial mostrou que Odontocheila nodicornis (Dejean, Glenus chrysis Gravenhorst, Castianeira sp. e oito espécies de formigas foram mais abundantes no seringal em comparação às culturas de soja e do milho. A abundância dos carabídeos Calosoma granulatum Perty e O. nodicornis diminuiu conforme aumentou a densidade dos formicídeos Pheidole sp.1 e Odontomachus chelifer Latreille respectivamente.The knowledge of the diversity and distribution of ground arthropods contributes for the development of sustainable agricultural systems. This work was carried out at the Paulista State University, Jaboticabal campus, State of São Paulo, Brazil, during the period from February to April 2004. The objective was to analyse the community of Carabidae, Staphylinidae, Formicidae e Araneae through faunistic indexes, to determine the spatial distribution and interespecific interactions of predominant species in soybean (Glycine max (L. Merr., corn (Zea mays L. and rubber tree (Hevea brasiliensis Muell. Arg.. The arthropods were sampled by pitfall traps distributed each 10 m in two transects of 210 m which crossed the rubber trees and advancing 60 m in the crop lines. The fauna was characterized by Shannon-Wiener diversity index, evenness and Morisita similarity index. The differences among the occurrence of predominant species in the habitats were determined by variance analysis, and the interespecific interaction by Pearson correlation. The soybean and corn under no-tillage system provided better structured carabids, ants and spiders communities than the rubber trees. Among 88 captured species, 20 species were predominant and the spatial distribution of them showed that Odontocheila nodicornis (Dejean, Glenus chrysis Gravenhorst, Castianeira sp. and eight ant species were more abundant in the rubber tree compared to soybean and corn. The abundance of the carabids Calosoma granulatum Perty and O. nodicornis decreased with increased density of the formicids Pheidole sp.1 and Odontomachus chelifer Latreille, respectively.

  3. Dynamics of immature stages of Anopheles arabiensis and other mosquito species (Diptera: Culicidae) in relation to rice cropping in a rice agro-ecosystem in Kenya.

    Science.gov (United States)

    Mwangangi, Joseph; Shililu, Josephat; Muturi, Ephantus; Gu, Weidong; Mbogo, Charles; Kabiru, Ephantus; Jacob, Benjamin; Githure, John; Novak, Robert

    2006-12-01

    We determined changes in species composition and densities of immature stages of Anopheles arabiensis mosquitoes in relation to rice growth cycle in order to generate data for developing larval control strategies in rice ecosystems. Experimental rice paddies (6.3m x 3.15m) exposed to natural colonization of mosquitoes were sampled weekly for two rice growing cycles between February 2004 and March 2005. Overall, 21,325 Anopheles larvae were collected, of which 91.9% were 1st and 2nd instars and 8.1% were 3rd and 4th instars. An. arabiensis was the predominant species (84.1%) with other species, An. pharoensis (13.5%), An. funestus (2.1%), An. coustani (0.3%), and An. maculipalpis (0.1%) accounting for only a small proportion of the anophelines collected. Culex quinquefasciatus (65.7%) was the predominant species among the non-anopheline species. Others species collected included: C. annulioris (9.9%), C. poicilipes (7.3%), C. tigripes (7.2%), C. duttoni (0.6%), Aedes aegypti (5.3%), Ae. cumminsii (3.5%), and Ae. vittatus (0.7%). The densities of the major anopheline species were closely related to rice stage and condition of the rice field. An. arabiensis, the predominant species, was most abundant over a three-week period after transplanting. Low densities of larvae were collected during the late vegetative, reproductive, and ripening phases of rice. An increase in larval density ten days post-transplanting was found to correlate with the application of fertilizer (sulphate of ammonia). Culicine and aedine species densities were significantly higher during the post-harvesting period. Our results suggest that the transplanting stage is favorable for the growth of immature stages of An. arabiensis and provides a narrow window for targeted larval intervention in rice. PMID:17249341

  4. Net Mineralization Response to Fertilizer Application and Site-Specific Setting in a No-Till Dryland Wheat Agroecosystem in the Pacific Northwest (USA)

    Science.gov (United States)

    Bruner, Emily A.; Brown, David J.; Carpenter-Boggs, Lynn

    2015-04-01

    Application of nitrogen (N) fertilizers is pivotal to maintaining agricultural productivity. Nutrient management is typically guided by a combined assessment of crop yield requirements, residual soil inorganic N concentration, and predicted N supply from organic matter. However, laboratory assays employed to forecast mineralization potential do not reflect in situ processes occurring in soils, processes that can vary spatially within a field. Furthermore, fertilizer application alters biogeochemical cycles through a variety of mechanisms including priming effects and microbial community alterations. This study investigates in-situ ammonification/nitrification rates utilizing mineralization cores as part of a five-year Site-Specific Climate-Friendly Farming (SCF) project. In-depth accounting of nitrate and ammonium production and flux was possible via a six bag mixed-bed ion exchange resin system. Soil cores (7.5 cm diameter by 15 cm deep) were isolated from the surrounding soil by three resin bags sealed in the top and bottom of individual plastic cylinders. Fifteen locations were selected across a commercial direct-seed wheat field based on statistical clustering of primary and secondary topographic variables. In each location surface soil-resin cores were installed in fertilized and unfertilized plots immediately after spring planting and removed before harvest. In situ ammonification/nitrification rates will be analyzed as a function of both fertilizer application and site-specific environmental characteristics as determined from soil moisture monitoring, soil characterization, and crop analysis at each measurement location. This site-specific information on N transformations and availability can then be used to guide site-specific crop management.

  5. Intercropping with shrub species that display a 'steady-state' flowering phenology as a strategy for biodiversity conservation in tropical agroecosystems.

    Directory of Open Access Journals (Sweden)

    Valerie E Peters

    Full Text Available Animal species in the Neotropics have evolved under a lower spatiotemporal patchiness of food resources compared to the other tropical regions. Although plant species with a steady-state flowering/fruiting phenology are rare, they provide predictable food resources and therefore may play a pivotal role in animal community structure and diversity. I experimentally planted a supplemental patch of a shrub species with a steady-state flowering/fruiting phenology, Hamelia patens Jacq., into coffee agroforests to evaluate the contribution of this unique phenology to the structure and diversity of the flower-visiting community. After accounting for the higher abundance of captured animals in the coffee agroforests with the supplemental floral resources, species richness was 21% higher overall in the flower-visiting community in these agroforests compared to control agroforests. Coffee agroforests with the steady-state supplemental floral patch also had 31% more butterfly species, 29% more hummingbird species, 65% more wasps and 85% more bees than control coffee agroforests. The experimental treatment, together with elevation, explained 57% of the variation in community structure of the flower-visiting community. The identification of plant species that can support a high number of animal species, including important ecosystem service providers, is becoming increasingly important for restoration and conservation applications. Throughout the Neotropics plant species with a steady-state flowering/fruiting phenology can be found in all aseasonal forests and thus could be widely tested and suitable species used throughout the tropics to manage for biodiversity and potentially ecosystem services involving beneficial arthropods.

  6. Cotton as an entry point for soil fertility maintenance and food crop productivity in savannah agroecosystems - Evidence from a long-term experiment in southern Mali

    NARCIS (Netherlands)

    Ripoche, A.; Crétenet, M.; Corbeels, M.; Affholder, F.; Naudin, K.; Sissoko, F.; Douzet, J.M.; Tittonell, P.A.

    2015-01-01

    Given the scarcity of manure and the limited land available for fallowing, cotton cultivation with its input credit schemes is often the main entry point for nutrients in cropping systems of West Africa. In an experiment carried out during 25 years in southern Mali, the crop and soil responses to or

  7. Biodiversity and integrated pest management in agroecosystems%农田生物多样性与害虫综合治理

    Institute of Scientific and Technical Information of China (English)

    尤民生; 刘雨芳; 侯有明

    2004-01-01

    在现代农田生态系统中,人类为了满足自身的需要,通常把自然界的植物群落改造成大面积种植单种特定的作物,人为地排除其他植物种类的竞争以提高作物的产量.由于单一化的作物不断取代自然植被,降低了农田的物种和生境多样性,结果导致农田生态系统的不稳定和害虫问题的更加恶化.影响农田生物多样性的因素很多,如地理位置、气候类型、环境条件、作物品种、种间关系、人类的栽培活动等.根据现有的生态学原理和研究成果,人类可以通过采用适当的措施来恢复和强化农田生物多样性,提高天敌的控制潜能,减少害虫发生的可能性;这些措施包括合理安排混作的时空格局,通过轮作进行间断性耕种,对多年生作物采用地面覆盖植被,利用不同品种以提高作物的遗传多样性,等等.在设计农田生物多样性的管理策略时,必须同时考虑当地气候、地理,植被,作物,土壤等因素的变化,因为在特定的生境条件下,这些因素可能增加或减少害虫发生的机会.

  8. The Ecological Functions of Weed Biodiversity in Agroecosystem%农业生态系统杂草多样性保持的生态学功能

    Institute of Scientific and Technical Information of China (English)

    陈欣; 王兆骞; 唐建军

    2000-01-01

    @@ 杂草是农业生态系统中的重要生物组成部分,也是影响农林作物生长和导致产量下降的重要因素之一.过去人们一直努力将杂草从农业生态系统地中清除出去,对杂草的研究往往也更多地注重其危害性和防治途径.

  9. Effect of transgenic plants on biodiversity of agroecosystem%转基因植物对农业生物多样性的影响

    Institute of Scientific and Technical Information of China (English)

    聂呈荣; 王建武; 骆世明

    2003-01-01

    论述了近年来转基因植物对农业生态系统生物多样性影响的研究进展.主要在遗传多样性、物种多样性和生态系统多样性3个层次上予以评述,包括转基因植物对作物遗传多样性的影响;转基因植物的外源基因向杂草和近缘野生种转移;转基因抗虫植物对目标害虫的影响,抗除草剂转基因植物对作物和杂草的影响,抗病毒转基因植物对病毒的影响;转基因植物对非目标生物的影响,对土壤生态系统的影响等.

  10. Budgeting of major nutrients and the mitigation options for nutrient mining in semi-arid tropical agro-ecosystem of Tamil Nadu, India using NUTMON model.

    Science.gov (United States)

    Surendran, U; Rama Subramoniam, S; Raja, P; Kumar, V; Murugappan, V

    2016-04-01

    Mining of nutrients from soil is a major problem in developing countries causing soil degradation and threaten long-term food production. The present study attempts to apply NUTrient MONitoring (NUTMON) model for carrying out nutrient budgeting to assess the stocks and flows of nitrogen (N), phosphorus (P), and potassium (K) in defined geographical unit based on the inputs, viz., mineral fertilizers, manures, atmospheric deposition, and sedimentation, and outputs, viz., harvested crop produces, residues, leaching, denitrification, and erosion losses. The study area covers Coimbatore and Erode Districts, which are potential agricultural areas in western agro-ecological zone of Tamil Nadu, India. The calculated nutrient balances for both the districts at district scale, using NUTMON methodology, were negative for nitrogen (N -3.3 and -10.1 kg ha(-1)) and potassium (K -58.6 and -9.8 kg ha(-1)) and positive for phosphorus (P +14.5 and 20.5 kg ha(-1)). Soil nutrient pool has to adjust the negative balance of N and K; there will be an expected mining of nutrient from the soil reserve. A strategy was attempted for deriving the fertilizer recommendation using Decision Support System for Integrated Fertilizer Recommendation (DSSIFER) to offset the mining in selected farms. The results showed that when DSSIFER recommended fertilizers are applied to crops, the nutrient balance was positive. NUTMON-Toolbox with DSSIFER would serve the purpose on enhancing soil fertility, productivity, and sustainability. The management options to mitigate nutrient mining with an integrated system approach are also discussed. PMID:27021693

  11. Seasonal dynamics of CO2 efflux in soils amended with composted and thermally-dried sludge as affected by soil tillage systems in a semi-arid agroecosystem

    Science.gov (United States)

    García-Gil, Juan Carlos; Soler-Rovira, Pedro; López-de-Sa, Esther G.; Polo, Alfredo

    2014-05-01

    In semi-arid agricultural soils, seasonal dynamic of soil CO2 efflux (SCE) is highly variable. Based on soil respiration measurements the effects of different management systems (moldboard plowing, chisel and no-tillage) and the application of composted sludge (CS) and thermally-dried sewage sludge (TSS) was investigated in a long-term field experiment (28 years) conducted on a sandy-loam soil at the experimental station 'La Higueruela' (40o 03'N, 4o 24'W). Both organic amendments were applied at a rate of 30 Mg ha-1 prior to tillage practices. Unamended soils were used as control for each tillage system. SCE was moderate in late spring (2.2-11.8 μmol CO2 m-2 s-1) when amendments were applied and tillage was performed, markedly decreased in summer (0.4-3.2 μmol CO2 m-2 s-1), following a moderate increase in autumn (3.4-14.1 μmol CO2 m-2 s-1), rising sharply in October (5.6-39.8 μmol CO2 m-2 s-1 ). In winter, SCE was low (0.6-6.5 μmol CO2 m-2 s-1). In general, SCE was greater in chisel and moldboard tilled soils, and in CS and particularly TSS-amended soils, due to the addition of labile C with these amendments, meanwhile no-tillage soils exhibited smaller increases in C efflux throughout the seasons. Soil temperature controlled the seasonal variations of SCE. In summer, when drought occurs, a general decrease of SCE was observed due to a deficit in soil water content. After drought period SCE jumped to high values in response to rain events ('Birch effect') that changed soil moisture conditions. Soil drying in summer and rewetting in autumn may promotes some changes on the structure of soil microbial community, affecting associated metabolic processes, and enhancing a rapid mineralization of water-soluble organic C compounds and/or dead microbial biomass that acts as an energy source for soil microorganisms. To assess the effects of tillage and amendments on SCE, Q10 values were calculated. Data were grouped into three groups according to soil moisture (0.03-0.10 m3m-3, 0-11-0.21 m3m-3, 0.22-0.30 m3m-3). In general, Q10 values were lower at elevated temperatures when soil moisture contents decreased, confirming that SCE is less sensitive to soil temperature during drought periods. Q10 values were higher in moldboard and chisel tilled soils, possibly due to the incorporation of residues into soil and the increase of soil C substrate, meanwhile in no-tillage part of the organic C pools are likely protected from microorganisms by physico-chemical mechanisms. TSS-amended soils exhibited higher Q10 values than CS, pointing that the biochemical lability of the organic C added with amendments exerts an influence on SCE. Acknowledgements: this research was supported by the Spanish CICYT, Project no. CTM2011-25557.

  12. Intercropping with shrub species that display a 'steady-state' flowering phenology as a strategy for biodiversity conservation in tropical agroecosystems.

    Science.gov (United States)

    Peters, Valerie E

    2014-01-01

    Animal species in the Neotropics have evolved under a lower spatiotemporal patchiness of food resources compared to the other tropical regions. Although plant species with a steady-state flowering/fruiting phenology are rare, they provide predictable food resources and therefore may play a pivotal role in animal community structure and diversity. I experimentally planted a supplemental patch of a shrub species with a steady-state flowering/fruiting phenology, Hamelia patens Jacq., into coffee agroforests to evaluate the contribution of this unique phenology to the structure and diversity of the flower-visiting community. After accounting for the higher abundance of captured animals in the coffee agroforests with the supplemental floral resources, species richness was 21% higher overall in the flower-visiting community in these agroforests compared to control agroforests. Coffee agroforests with the steady-state supplemental floral patch also had 31% more butterfly species, 29% more hummingbird species, 65% more wasps and 85% more bees than control coffee agroforests. The experimental treatment, together with elevation, explained 57% of the variation in community structure of the flower-visiting community. The identification of plant species that can support a high number of animal species, including important ecosystem service providers, is becoming increasingly important for restoration and conservation applications. Throughout the Neotropics plant species with a steady-state flowering/fruiting phenology can be found in all aseasonal forests and thus could be widely tested and suitable species used throughout the tropics to manage for biodiversity and potentially ecosystem services involving beneficial arthropods.

  13. Intercropping with Shrub Species That Display a ‘Steady-State’ Flowering Phenology as a Strategy for Biodiversity Conservation in Tropical Agroecosystems

    Science.gov (United States)

    Peters, Valerie E.

    2014-01-01

    Animal species in the Neotropics have evolved under a lower spatiotemporal patchiness of food resources compared to the other tropical regions. Although plant species with a steady-state flowering/fruiting phenology are rare, they provide predictable food resources and therefore may play a pivotal role in animal community structure and diversity. I experimentally planted a supplemental patch of a shrub species with a steady-state flowering/fruiting phenology, Hamelia patens Jacq., into coffee agroforests to evaluate the contribution of this unique phenology to the structure and diversity of the flower-visiting community. After accounting for the higher abundance of captured animals in the coffee agroforests with the supplemental floral resources, species richness was 21% higher overall in the flower-visiting community in these agroforests compared to control agroforests. Coffee agroforests with the steady-state supplemental floral patch also had 31% more butterfly species, 29% more hummingbird species, 65% more wasps and 85% more bees than control coffee agroforests. The experimental treatment, together with elevation, explained 57% of the variation in community structure of the flower-visiting community. The identification of plant species that can support a high number of animal species, including important ecosystem service providers, is becoming increasingly important for restoration and conservation applications. Throughout the Neotropics plant species with a steady-state flowering/fruiting phenology can be found in all aseasonal forests and thus could be widely tested and suitable species used throughout the tropics to manage for biodiversity and potentially ecosystem services involving beneficial arthropods. PMID:24598826

  14. The potential of community fish refuges (CFRs) in rice field agro-ecosystems for improving food and nutrition security in the Tonle Sap region

    OpenAIRE

    Brooks, A.; Sieu, C.

    2016-01-01

    The fisheries sector in Cambodia contributes 8%–12% to national GDP and 25% - 30% to agricultural GDP, with an estimated 4.5 million people involved in fishing and associated trades. Fish and other aquatic animals are important food sources, contributing an estimated national average of 60% - 70% of total animal protein intake. Of the 2013 total fish production, 550,000 metric tons were harvested from freshwater habitats, of which rice field fisheries and small-scale family fisheries contribu...

  15. Sustainable land management in dynamic agro-ecosystems: an Integrated, multi-scale socio-ecological analysis in Western Kenya highlands

    NARCIS (Netherlands)

    Mutoko, M.C.

    2013-01-01

    This study was motivated by the puzzlingly localised implementation of available Sustainable Land Management (SLM) practices despite the urgent need to reduce both land degradation and general poverty levels in the western highlands of Kenya. This research aimed to not only unravel reasons for the r

  16. Sustainable land management in dynamic agro-ecosystems: an Integrated, multi-scale socio-ecological analysis in Western Kenya highlands

    OpenAIRE

    Mutoko, M.C.

    2013-01-01

    This study was motivated by the puzzlingly localised implementation of available Sustainable Land Management (SLM) practices despite the urgent need to reduce both land degradation and general poverty levels in the western highlands of Kenya. This research aimed to not only unravel reasons for the restricted geographical diffusion of SLM practices but also make concrete contributions to foster the promotion of SLM practices. Four specific research objectives and questions were formulated, and...

  17. The Role of Vegetation Response to Elevated CO2 in Modifying Land-Atmosphere Feedback Across the Central United States Agro-Ecosystem

    Science.gov (United States)

    Drewry, D.; Kumar, P.; Sivapalan, M.; Long, S.; Liang, X.

    2009-05-01

    Recent local-scale observational studies have demonstrated significant modifications to the partitioning of incident energy by two key mid-west agricultural species, soy and corn, as ambient atmospheric CO2 concentrations are experimentally augmented to projected future levels. The uptake of CO2 by soy, which utilizes the C3 photosynthetic pathway, has likewise been observed to significantly increase under elevated growth CO2 concentrations. Changes to the sensible and latent heat exchanges between the land surface and the atmospheric boundary layer (ABL) across large portions of the mid-western US has the potential to affect ABL growth and composition, and consequently feed-back to the near-surface environment (air temperature and vapor content) experienced by the vegetation. Here we present a simulation analysis that examines the changes in land-atmosphere feedbacks associated with projected increases in ambient CO2 concentrations over extended soy/corn agricultural areas characteristic of the US mid-west. The model canopies are partitioned into several layers, allowing for resolution of the shortwave and longwave radiation regimes that drive photosynthesis, stomatal conductance and leaf energy balance in each layer, along with the canopy microclimate. The canopy component of the model is coupled to a multi-layer soil-root model that computes soil moisture and heat transport and root water uptake. Model skill in capturing the sub-diurnal variability in canopy-atmosphere exchange is evaluated through multi-year records of canopy-top eddy covariance CO2, water vapor and heat fluxes collected at the Bondville (Illinois) FluxNet site. An evaluation of the ability of the model to simulate observed changes in energy balance components (canopy temperature, net radiation and soil heat flux) under elevated CO2 concentrations projected for 2050 (550 ppm) is made using observations collected at the SoyFACE Free Air Carbon Enrichment (FACE) experimental facilities located in central Illinois, by incorporating observed acclimations in leaf biochemsitry and canopy structure. The simulation control volume is then extended by coupling the canopy models to a simple model of daytime mixed-layer (ML) growth and composition, ie. air temperature and vapor content. Through this coupled canopy-ABL model we quantify the impact of elevated CO2 and vegetation acclimation on ML growth, temperature and vapor content and the consequent feedbacks to the land surface by way of the near-surface environment experienced by the vegetation. Particular focus is placed on the role of short-term drought, and possible changes in land cover composition between soy, a C3 crop, and corn, a more water-use efficient C4 crop, on modulating the strength of these CO2-induced feedbacks.

  18. Background antibiotic resistance patterns in antibiotic-free pastured poultry production

    Science.gov (United States)

    Antibiotic resistance (AR) is a significant public health issue, and agroecosystems are often viewed as major environmental sources of antibiotic resistant foodborne pathogens. While the use of antibiotics in agroecosystems can potentially increase AR, appropriate background resistance levels in th...

  19. Multiscale ecology of agroecosystems is an emerging research field that can provide a stronger theoretical background for the integrated pest management. Reply to comments on “Multiscale approach to pest insect monitoring: Random walks, pattern formation, synchronization, and networks”

    Science.gov (United States)

    Petrovskii, Sergei; Petrovskaya, Natalia; Bearup, Daniel

    2014-09-01

    We would like to thank all commentators for their insightful and thought-provoking commentaries [1-4] that also helped to further broaden the scope of our review [5] as well as to extend the list of references. We very much appreciate the positive comments on the relevance, timeliness and comprehensiveness of our work.

  20. Coupling a high resolution soil erosion model with an agro-ecosystem model of SOC dynamics. An approach to assess the potential environmental effect of the new Common Agricultural Policy on soil degradation

    Science.gov (United States)

    Borrelli, Pasqualle; Paustian, Keith; Panagos, Panos; Jones, Arwyn; Schütt, Brigitta; Lugato, Emanuele

    2016-04-01

    At the European Union level, the main mechanisms to promote a more sustainable and environmentally friendly agriculture was introduced by the Common Agricultural Policy (CAP) reform in 2003, through the Cross-compliance. According to this new regulation, the farmer support payments were regulated with respect to environmental, animal welfare and food safety standards. This brought to the Good Agricultural and Environmental Conditions (GAEC), firstly established by Council Regulation No. 1782/2003 and subsequently Council Regulation (EC) No 73/2009. The prevention of soil erosion and maintenance of soil organic matter were two of GAEC requirements, which each Member State was obliged to address through national standards such as: i) minimal soil cover maintenance (GAEC 4); ii) minimum land management reflecting site specific conditions to limit soil loss (GAEC 5) and iii) maintenance of soil organic matter level through appropriate practices including ban on burning arable stubbles (GAEC 6). Although Member States are required to verify whether the farmers are compliant with the regulations (Cross-compliance), the environmental effect of Good Agricultural and Environmental Conditions (GAEC) applications on erosion and carbon budgets are still little known and studied. To investigate the potential impacts of the GAEC, we coupled a high resolution erosion model based on Revised Universal Soil Loss Equation (RUSLE) with the CENTURY biogeochemical model (Land Use Policy, 50, 408-421; 2016). The Italian arable land was selected as a study area, since it is well-known to be highly sensitive to soil erosion. Multi scenario modelling approach was undertaken, i.e., i) a baseline scenario without scenario excluding GAEC (pre 2003 period); ii) a present scenario including the current GAEC standards (post 2003 period), and iii) a technical potential scenario assuming that the GAEC standards were applied to the entire Italian arable land. The results show a 10.8% decrease, from 8.33 Mg ha-1 yr-1 to 7.43 Mg ha-1 yr-1, in soil loss potential due to the adoption of the GAEC conservation practices (with respect to the baseline scenario). The technical potential scenario shows a 50.1% decrease in the soil loss potential (soil loss 4.1 Mg ha-1 yr-1). With regard to the soil organic carbon (SOC), the GAEC application in the current scenario shown an overall soil organic carbon (SOC) gains, with about 17% of the SOC variation related to avoided SOC transport by sediment erosion. The technical potential scenario suggests a potential gain up to 23.3 Mt of C by 2020 with the full GAEC application.

  1. Biological and ecological characterization of two mites (Tetranychus Urticae and Phytoseiulus Persimilis) occurring in some agro-ecosystems; Caratterizzazione biologica ed ecologica di due acari (Tetranichus Urticae e Phytoseiulus Persimilis) interagenti in alcuni ecosistemi agrari

    Energy Technology Data Exchange (ETDEWEB)

    Calvitti, M. [ENEA, Centro Ricerche Casaccia, Roma (Italy). Dip. Innovazione

    1995-12-01

    This work is a brief review of the actual knowledge about biological and ecological characteristics of two species of mites: Tetranychus urticae Koch (Acarina Tetranychidae) (two-spotted spider mite) and the predaceous mite Phytoseiulus persimilis Athias Henriot (Acarina Phytoseiidae). Success obtained in biological control of spider mite, by mass release of P. persimilis, has increased the interest in biological and ecological study of these mites. Particularly, the following biological and ecological aspects of both P. persimilis and T. urticae are hereby discussed: reproductive biology; population dynamics (spider mites outbreaks) and natural regulation of the trophic interaction; feeding behaviour; biological control of two-spotted spider mite by P. persimilis. In this report experimental data obtained in laboratory have been integrated with bibliographic information concerning studies produced in natural conditions.

  2. The effect of nitrogen and glyphosate on survival and colonisation of perennial grass species in an agro-ecosystem: does the relative importance of survival decrease with competitive ability?

    Directory of Open Access Journals (Sweden)

    Christian Damgaard

    Full Text Available The ecological success of a plant species is typically described by the observed change in plant abundance or cover, but in order to more fully understand the fundamental plant ecological processes, it is necessary to inspect the underlying processes of survival and colonization and how they are affected by environmental conditions. A general ecological hypothesis on the effect of environmental gradients on demographic parameters is proposed and tested. The hypothesis is that decreasing fitness or competitive ability along an environmental gradient is associated with an increasing importance of survival for regulating the abundance of the species. The tested hypothesis is related to both the stress gradient hypothesis and whether the importance of competition increases along productivity gradients. The combined effect of nitrogen and glyphosate on the survival and colonization probability of two perennial grass species, Festuca ovina and Agrostis capillaris, which are known to differ in their responses to both glyphosate and nitrogen treatments, is calculated using pin-point cover data in permanent frames. We found that the relative importance of survival increased with the level of glyphosate for the glyphosate sensitive A. capillaris and decreased for the glyphosate tolerant F. ovina. Likewise, increasing levels of nitrogen increased the importance of survival for the relative nitrophobic F. ovina. Consequently, the proposed hypothesis was corroborated in this specific study. The proposed method will enable predictions of the effects of agricultural practices on community dynamics in a relatively simple setup eliminating the need to quantify all the interaction among the species in the plant community. The method will be immediately useful for the regulation of non-cultivated buffer strips between agricultural fields and semi-natural and natural biotopes such as hedgerows and waterways.

  3. N{sub 2}O and CH{sub 4} emissions from a fallow–wheat rotation with low N input in conservation and conventional tillage under a Mediterranean agroecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Tellez-Rio, Angela, E-mail: angela.tellez@upm.es [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); García-Marco, Sonia [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Navas, Mariela; López-Solanilla, Emilia [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Centro de Biotecnología y Genómica de Plantas UPM-INIA. Dpto Biotecnología. E.T.S.I. Agrónomos. Technical University of Madrid. Campus Montegancedo, UPM. Autovía M-40, Salida 38 N, 36S. 28223 Pozuelo de Alarcón. Madrid (Spain); Tenorio, Jose Luis [Dpto. de Medio Ambiente, INIA. Ctra. de La Coruña km. 7.5, 28040 Madrid (Spain); Vallejo, Antonio [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2015-03-01

    Conservation agriculture that includes no tillage (NT) or minimum tillage (MT) and crop rotation is an effective practice to increase soil organic matter in Mediterranean semiarid agrosystems. But the impact of these agricultural practices on greenhouse gases (GHGs), such as nitrous oxide (N{sub 2}O) and methane (CH{sub 4}), is variable depending mainly on soil structure and short/long-term tillage. The main objective of this study was to assess the long-term effect of three tillage systems (NT, MT and conventional tillage (CT)) and land-covers (fallow/wheat) on the emissions of N{sub 2}O and CH{sub 4} in a low N input agricultural system during one year. This was achieved by measuring crop yields, soil mineral N and dissolved organic C contents, and fluxes of N{sub 2}O and CH{sub 4}. Total cumulative N{sub 2}O emissions were not significantly different (P > 0.05) among the tillage systems or between fallow and wheat. The only difference was produced in spring, when N{sub 2}O emissions were significantly higher (P < 0.05) in fallow than in wheat subplots, and NT reduced N{sub 2}O emissions (P < 0.05) compared with MT and CT. Taking into account the water filled pore space (WFPS), both nitrification and denitrification could have occurred during the experimental period. Denitrification capacity in March was similar in all tillage systems, in spite of the higher DOC content maintained in the topsoil of NT. This could be due to the similar denitrifier densities, targeted by nirK copy numbers at that time. Cumulative CH{sub 4} fluxes resulted in small net uptake for all treatments, and no significant differences were found among tillage systems or between fallow and wheat land-covers. These results suggest that under a coarse-textured soil in low N agricultural systems, the impact of tillage on GHG is very low and that the fallow cycle within a crop rotation is not a useful strategy to reduce GHG emissions. - Highlights: • Tillage systems and land-covers with low N input had no effect on total N{sub 2}Ofluxes • No tillage reduced N{sub 2}O fluxes just during spring season • N{sub 2}O fluxes were only greater in fallow than in wheat during spring season • Denitrification capacity and nirK abundance were similar among tillage systems • Cumulative CH{sub 4} fluxes resulted in a low net uptake among tillage systems.

  4. Economic Cost of Human-bird Conflicts in the Lashihai Agroecosystem%拉市海农业生态系统中人鸟冲突的经济代价

    Institute of Scientific and Technical Information of China (English)

    张溪竹; 彭贵鸿; 杨洋; 李学友; 杨士剑

    2008-01-01

    作者2005年5月对由越冬水鸟取食所造成的拉市海农业生态系统的经济损失进行了调查.以由GIS软件所产生的200个随机取样点所获得的资料来推算.拉市海农业生态系统主要的小春作物按所占面积大小排序依次为小麦、蚕豆、油菜、大麦、豌豆、鸡豆和蔬菜.水鸟偏好取食的作物种类主要为小麦(25.9%种植面积受损害).蚕豆(7.8%)和豌豆(6.9%),其他作物相对受害较轻.整个拉市海农业生态系统中的经济损失约144万元.政府对2005年拉市海周边农户提供的水鸟损害的经济补偿为15万元,仅占实际损失量的1/10.研究结果表明.政府应增加经济补偿以促进社会和谐发展.

  5. The effect of nitrogen and glyphosate on survival and colonisation of perennial grass species in an agro-ecosystem: does the relative importance of survival decrease with competitive ability?

    Science.gov (United States)

    Damgaard, Christian; Strandberg, Beate; Mathiassen, Solvejg K; Kudsk, Per

    2013-01-01

    The ecological success of a plant species is typically described by the observed change in plant abundance or cover, but in order to more fully understand the fundamental plant ecological processes, it is necessary to inspect the underlying processes of survival and colonization and how they are affected by environmental conditions. A general ecological hypothesis on the effect of environmental gradients on demographic parameters is proposed and tested. The hypothesis is that decreasing fitness or competitive ability along an environmental gradient is associated with an increasing importance of survival for regulating the abundance of the species. The tested hypothesis is related to both the stress gradient hypothesis and whether the importance of competition increases along productivity gradients. The combined effect of nitrogen and glyphosate on the survival and colonization probability of two perennial grass species, Festuca ovina and Agrostis capillaris, which are known to differ in their responses to both glyphosate and nitrogen treatments, is calculated using pin-point cover data in permanent frames. We found that the relative importance of survival increased with the level of glyphosate for the glyphosate sensitive A. capillaris and decreased for the glyphosate tolerant F. ovina. Likewise, increasing levels of nitrogen increased the importance of survival for the relative nitrophobic F. ovina. Consequently, the proposed hypothesis was corroborated in this specific study. The proposed method will enable predictions of the effects of agricultural practices on community dynamics in a relatively simple setup eliminating the need to quantify all the interaction among the species in the plant community. The method will be immediately useful for the regulation of non-cultivated buffer strips between agricultural fields and semi-natural and natural biotopes such as hedgerows and waterways.

  6. The impact of biological invasion on biodiversity and grassland agroecosystem%生物入侵对生物多样性以及草地农业生态系统的影响

    Institute of Scientific and Technical Information of China (English)

    王海波; 孙娟; 玉永雄

    2007-01-01

    从生物入侵的原理、生物多样性的概念以及草地农业生态系统的健康评价方面对三者的内在生态关系进行了分析和探讨,以期达到合理引入外来物种、保持生物多样性和稳定草地农业生态系统的三重效应.并在此基础之上提出如何保持生态平衡,使草地农业生态系统能够达到经济、社会和生态三盈,做到可持续的发展.

  7. Utilization and conservation of biodiversity in agroecosystem of China after entering WTO%浙江省农业生物多样性的保护、利用与WTO

    Institute of Scientific and Technical Information of China (English)

    薛玉中; 唐建军

    2001-01-01

    本文论述了生物多样性的重要作用及保护现状,分析了浙江省农业生物多样性的特点,并针对我国加入WTO后,面对"农产品市场萎缩"、"绿色壁垒"、"生物入侵"等新问题、新挑战,结合实例,提出了浙江省加强农业生物多样性保护、利用,提高农产品国际市场竞争力,促进效益农业、精品农业发展,维护生态安全的措施、对策.

  8. The Impacts of Agricultural Activities on Biodiversity in Agroecosystems%农业活动对农田生态系统物种多样性的影响

    Institute of Scientific and Technical Information of China (English)

    姜俊红; 金玲; 朱朝荣; 路玉杰

    2005-01-01

    农业活动如化肥、农药、地膜的使用、高产品种的推广、节水灌溉技术的应用等,所导致的生境条件的变化和农田景观结构的不合理是影响农田生态系统物种多样性的重要原因.鉴于此,提出了保护农田生态系统物种多样性的几点建议:①建立可持续的生态农业;②进行合理的农田生态规划;③合理的混合种植不同作物,打破单一的种植结构.

  9. Avaliação do estado nutricional de agroecossistemas de café orgânico no estado de Minas Gerais Nutritional diagnosis of organic coffee agroecosystems in the Minas Gerais state

    OpenAIRE

    Vanessa Cristina de Almeida Theodoro; Janice Guedes de Carvalho; João Batista Corrêa; Rubens José Guimarães

    2003-01-01

    A produção de café orgânico vem se constituindo uma tendência necessária e irreversível do agronegócio brasileiro. Essa atividade tem-se destacado como uma alternativa de renda para alguns cafeicultores, devido à crescente demanda mundial por alimentos mais saudáveis. Entretanto, grande parte das técnicas propostas pela agricultura orgânica está sendo aplicada empiricamente no cultivo de café, principalmente no Estado de Minas Gerais, maior região produtora de café do Brasil. Levando-se em co...

  10. Mechanism of Greenhouse Gas Emission from Agro-ecosystem Soil in Arid Regions%干旱地区农田生态系统土壤温室气体排放机制

    Institute of Scientific and Technical Information of China (English)

    翟洋洋; 程云湘; 常生华; 侯扶江

    2015-01-01

    CO2,CH4 and N2O are main greenhouse gases at present.Agriculture is an important source of greenhouse gases emission which contributes to global warming strongly.In general,the farmland ecosystem is the emission source of atmospheric CO2 and N2O and dry land such as loess plateau is the sink of CH4.CO2 emission includes 2 processes:plant respiration and soil respiration; CH4 emission includes 2 processes:organic restore and oxidation absorption; N2O emission includes 2 processes:nitrification and denitrification.Soil microbes,moisture,temperature,texture and fertilizing all affect greenhouse gas emission and absorption in different ways.In recent years,some conservation tillage technologies,such as no-tillage,straw turnover and mulch have been widely used in farmland ecosystem in arid regions.No-tillage can reduce CO2 and N2O emission,increase soil absorption amount of CH4; straw turnover and mulch have no unified effect on N2O emission,straw turnover can promote CO2 emission and restrain CH4 absorption,while mulch can restrain CO2 emission and promote CH4 absorption.Fortified,deeper and more comprehensive research on greenhouse gas emission in dry land farmland ecosystem should be a key research field in the future,which could provide more accurate theoretical basis for the global climate warming.%CO2、CH4和N2O是目前几种最主要的温室气体,在对全球气候变暖贡献中,农业作为重要的温室气体排放源对其有不可低估的作用.一般而言,旱地农田生态系统是大气CO2和N2O的排放源,黄土高原等旱地是CH4的吸收汇.CO2排放主要包括植物呼吸作用和土壤呼吸作用;CH4排放包括有机物的还原和氧化吸收2个过程;N2O排放包括硝化作用和反硝化作用2个过程.土壤微生物、土壤水分、土壤温度、土壤质地、施肥等均从不同角度影响着温室气体的释放与吸收.近些年,免耕、秸秆还田、地膜等保护性耕作技术在干旱地区农田生态系统中得到广泛应用.其中免耕可以减少CO2和N2O的排放量,增加土壤对CH4的吸收量;秸秆还田和覆膜对N2O排放的影响结果尚未统一,但秸秆还田促进CO2排放抑制CH4吸收,而覆膜促进CH4吸收抑制CO2排放.加强且更深入更全面的研究旱地农田生态系统温室气体排放应该作为今后重点研究领域,为全球气候变暖提供更为准确的理论基础.

  11. The net return from animal activity in agro-ecosystems: trading off benefits from ecosystem services against costs from crop damage [v2; ref status: indexed, http://f1000r.es/3c4

    OpenAIRE

    Luck, Gary W

    2014-01-01

    Animals provide benefits to agriculture through the provision of ecosystem services, but also inflict costs such as damaging crops. These benefits and costs are mostly examined independently, rather than comparing the trade-offs of animal activity in the same system and quantifying the net return from beneficial minus detrimental activities. Here, I examine the net return associated with the activity of seed-eating birds in almond orchards by quantifying the economic costs and benefits of bir...

  12. Microorganismos asociados a la rizosfera de jitomate en un agroecosistema del valle de Guasave, Sinaloa, México Rhizosphere microorganisms associated to tomato in an agroecosystem from Guasave Valley, Sinaloa, Mexico

    OpenAIRE

    Jesús Damián Cordero-Ramírez; Raquel López-Rivera; Carlos Ligne Calderón-Vázquez; Alejandro Miguel Figueroa-López; Juan Carlos Martínez-Álvarez; Karla Yeriana Leyva-Madrigal; Rocío Guadalupe Cervantes-Gámez; Ignacio Eduardo Maldonado-Mendoza

    2012-01-01

    La diversidad de los microorganismos asociados a la rizosfera de diferentes especies vegetales en los suelos, en México se ha estudiado poco y se ha abordado de manera convencional, con técnicas microbiológicas limitadas debido al elevado porcentaje de microorganismos no-cultivables (95-99%). En el presente trabajo se empleó el análisis por secuenciación del ADN ribosomal (ADNr) para evitar esa limitante y explorar mejor la diversidad de los microorganismos cultivables y no-cultivables asocia...

  13. Adapting to change: Changes in community perceptions and management of soil quality and soil organic matter

    OpenAIRE

    Motavalli, Peter P.

    2006-01-01

    This presentation describes the development of the SANREM CRSP project, "Adapting to Change in the Andean Highlands: Practices and Strategies to Address Climate and Market Risks in Vulnerable Agro-Ecosystems", gives an overview of the planned research, and explains the project objectives. LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  14. Vegetation state in the alienation zone after the Chernobyl accident

    International Nuclear Information System (INIS)

    Vegetation state within the alienation zone on the territory of formed state farm 'Savichi' of the Bragin region was studied. 9 agroecosystem associations of the Braun-Blanguet system were selected. Their ecological, biological and economic characteristics are given. The research has shown that the content of Sr 90 in vegetative mass of most agroecosystem associations exceeded normative level. (authors)

  15. Improving rural livelihoods as a 'moving target': trajectories of change in smallholder farming systems of Western Kenya

    NARCIS (Netherlands)

    Valbuena, D.F.; Groot, J.C.J.; Mukalama, J.; Gerard, B.; Tittonell, P.A.

    2015-01-01

    Understanding the diversity of current states, life cycles and past trajectories of households and agroecosystems is essential to contextualise the co-design of more sustainable agroecosystems. The objective of this paper was to document and analyse current states, trajectories of changes and their

  16. Modelling Crop Biocontrol by Wanderer Spiders

    Science.gov (United States)

    Venturino, Ezio; Ghersi, Andrea

    2008-09-01

    We study mathematically the effects some spiders populations have on insects living in and near agroecosystems, where woods and vineyards alternate in the landscape as in the Alta Langa, Piemonte, NW Italy.

  17. The influence of vegetation and landscape structural connectivity on butterflies (Lepidoptera: Papilionoidea and Hesperiidae), Carabids (Coleoptera: Carabidae), Syrphids (Diptera: Syrphidae), and sawflies (Hymenoptera: Symphyta) in Northern Italy farmland

    NARCIS (Netherlands)

    Burgio, G.; Sommaggio, D.; Marini, M.; Chiarucci, A.; Landi, S.; Fabbri, R.; Pesarini, F.; Genghini, M.; Ferrari, R.; Muzzi, E.; Lenteren, van J.C.; Masetti, A.

    2015-01-01

    Landscape structure as well as local vegetation influence biodiversity in agroecosystems. A study was performed to evaluate the effect of floristic diversity, vegetation patterns, and landscape structural connectivity on butterflies (Lepidoptera: Papilionoidea and Hesperiidae), carabids (Coleoptera:

  18. INDIVIDUAL AND POPULATION RESPONSES TO ABIOTIC STRESSES IN ITALIAN RYEGRASS

    Science.gov (United States)

    Expected changes in environmental factors will alter productivity of agroecosystems and influence the distribution of agricultural pests. In addition to the natural factors that cause stress, humans introduce chemical pesticides into the agricultural environment. Weeds persist in...

  19. Summary of work in climate change, pest risk analysis, and biodiversity for Valdivia SANREM project

    OpenAIRE

    Garrett, Karen A.

    2008-01-01

    Metadata only record This presentation summarizes work in climate change, pest risk analysis, and biodiversity for Valdivia SANREM project LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  20. Open software tools for eddy covariance flux partitioning

    Science.gov (United States)

    Agro-ecosystem management and assessment will benefit greatly from the development of reliable techniques for partitioning evapotranspiration (ET) into evaporation (E) and transpiration (T). Among other activities, flux partitioning can aid in evaluating consumptive vs. non-consumptive agricultural...

  1. Organic and chemical fertilizers application effects on potato production soil's fertility (Solanum tuberosum)

    OpenAIRE

    Herrera, E A

    2007-01-01

    Objectives, treatments, activities and preliminary results of the project that evaluates the effects of organic and chemical fertilizers application on potato production soil's fertility (Solanum tuberosum). available in SANREM office, ESIILTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  2. 论全球生态经济系统的不可持续性——基于农业生态系统承载力视角%On unsustainability of global economic ecosystem:based on the capacity of agro-ecosystem

    Institute of Scientific and Technical Information of China (English)

    蔡承智; 梁颖; 廖承红

    2010-01-01

    运用3种方法预测的作物产量潜力分别为:(1)利用作物历年单产回归拟合后进行趋势外推,得出多数作物的未来产量潜力极限大约将是现在单产的2~3倍;(2)运用"国际应用系统研究所"(IIASA)与"联合国粮农组织"(FAO)共同开发的"农业生态区划"(AEZ)模型计算我国主要粮油作物的区域单产最高潜力,得出水稻、小麦、玉米、马铃薯、油菜和大豆的单产潜力分别是它们2005年全国平均单产的1.2、2.2、2.2、2.9、2.0、1.9倍;(3)运用自然界中植物的最大光能利用率计算世界主要粮油作物单产的光合潜力,得出水稻、小麦、玉米、马铃薯、油菜、大豆产量的最大光合生产潜力大约分别是目前高产地区单产的1.4、2.5、1.2、1.8、1.9、2.2倍.据此:从作物产量潜力极限出发,阐述了农业生态系统的承载力;再从"封闭"系统特性出发,论述了全球生态经济系统的不可持续性.人类所能做的是尽力延缓"终点"的出现:行动越早,效果越好.

  3. Faunistic analysis of Carabidae and Staphylinidae (Coleoptera in five agroecosystems in northeastern São Paulo state, Brazil Análise faunística de Carabidae e Staphylinidae (Coleoptera em cinco agroecossistemas da Região Nordeste do Estado de São Paulo

    Directory of Open Access Journals (Sweden)

    Francisco Jorge Cividanes

    2009-08-01

    Full Text Available The objective of this study was to determined species composition and community structure of Carabidae and Staphylinidae in five areas of forest fragment and soybean/corn crops or orange orchard, from December 2004 to May 2007. Beetles were captured in pitfall traps distributed along two parallel transects of 200 m in length, placed across crop land/forest boundary fragment, with 100 m each. The Shannon-Wiener diversity and evenness indexes and Morisita similarity index were calculated. The carabids Abaris basistriatus Chaudoir, Calosoma granulatum Perty, Megacephala brasiliensis Kirby, Odontochila nodicornis (Dejean and Selenophorus seriatoporus Putzeys. are dominant and are widely distributed in northeastern São Paulo state, Brazil. Point-scale species diversity was greatest at the transition between forest fragment and cultivated area. The carabid and staphylinid communities of the forest fragment were more similar to the community of orange orchard than that of soybean/corn crops.O objetivo deste estudo foi determinar a composição de espécies e a estrutura das comunidades de Carabidae e Staphylinidae, em cinco áreas de fragmento florestal e cultura soja/milho ou pomar laranja, de dezembro de 2004 a maio de 2007. Os besouros foram capturados com armadilhas de solo, distribuídas em dois transectos paralelos de 200 m de comprimento, com 100 m no interior da área cultivada e 100 m no interior do fragmento florestal. A fauna foi caracterizada pelos índices de diversidade e equitabilidade de Shannon-Wiener e pelo de similaridade de Morisita. Os carabídeos Abaris basistriatus Chaudoir, Calosoma granulatum Perty, Megacephala brasiliensis Kirby, Odontochila nodicornis (Dejean e Selenophorus seriatoporus Putzeys. são as espécies dominantes com maior distribuição geográfica na região nordeste do Estado de São Paulo. A maior diversidade de espécies de carabídeos e estafilinídeos ocorreu na transição entre fragmento florestal e área cultivada. As comunidades de carabídeos e estafilinídeos de fragmento florestal tiveram maior similaridade com a comunidade do pomar de laranja do que com a de cultura soja/milho.

  4. Population biology of the Grey Francolin (Francolinus pondicerianus) in an agro-ecosystem of the Pothwar Plateau, Pakistan%巴基斯坦波特瓦尔高原农业生态系统中灰鹧鸪(Francolinus pondicerianus)的种群生物学

    Institute of Scientific and Technical Information of China (English)

    Iftikhar HUSSAIN; Asmat-un-NISA; Sungum KHALIL

    2012-01-01

    我们于2009年在巴基斯坦波特瓦尔高原地区对农业生态系统中灰鹧鸪(Francolinus pondicerianus)的种群生物学进行了研究.该地区是灰鹧鸪在巴基斯坦的重要分布区之一.灰鹧鸪在作物区和灌丛林地的密度分别为每公顷1.59±0.39和0.87±0.14只,并且两种生境中的密度在季节间均稍有浮动.灰鹧鸪在由Desmostachia bipinnata、Acacia modesta、Imperata cylindrical、枣树(Zizipus jujuba)及大戟属(Euphorbia)等植物组成的植被地面营巢.产卵期为春夏两季,平均产卵期长约6±0.36天(5-7天),平均窝卵数为7±0.36枚(6-8枚).平均孵卵期为20.6±0.50天(19-22天).所记录的42枚卵中,32枚成功孵化(成功率76.19%),平均孵化率为每窝5.33±1.22枚.离巢雏鸟数约为每窝3.83±0.83只(离巢率63.08%).该鸟种为杂食性,亦食天牛.从该鸟的食物中鉴别出10个种类,包括7种植物:珍珠粟(Pennisetum typhoideum)、高粱(Sorghum bicolor)、假高粱(S.halepense)、牧豆树(Prosopis juliflora)、绿豆(Phaseolus radiates)、尖刺红花(Carthemus axycantha)及金合欢属(Acacia)某种植物,2种昆虫:家白蚁(Coptotermes formosanus)及红褐林蚁(Formica rufa),以及砂砾.

  5. The Health Assessment of Agro-ecosystem in the Typical Agro-pastoral Ecotone:A Case Study in Chifeng City%典型农牧交错区农业生态系统健康测度及其持续利用对策——以赤峰市为例

    Institute of Scientific and Technical Information of China (English)

    谢花林

    2009-01-01

    As a new objective for global management as well as a new method of analyzing ecosystem, ecosystem health is embraced by many researchers with great concerns in the modern ecology. Agricultural ecosystem is an open artificial system and has many output and in put of energy and material. Agricultural ecosystem is different from natural ecosystem. Agricultural ecosystem is an ecosystem controlled and managed by human to satisfy the expectations with regulated system structures and altered industrial scales. The system structure exerts significant influence on the system function. A healthy agricultural ecosystem not only has good ecological environment, reasonable proportions of primary production and secondary production in the agricultural eco-economic system, but also has endurable and stable economic benefit. Agricultural ecosystem health is defined as the capability to avoid "disorder syndrome", withstand stress and meet the requirements of sustainable agricultural production. A healthy agricultural ecosystem can meet human needs without threatening natural resources or even can benefit the natural resources. The aim of healthy agricultural ecosystem is to realize high-yielding, low-input, reasonable farming methods, good stability, resilience and persistence. In this paper, based on the characteristic of agricultural ecosystem in the agricultural and pastoral zone, an index system of agricultural ecosystem assessment is formulated according to the definition of healthy agricultural ecosystem, including the factors of vigor, structure and resilience of agricultural ecosystem. The assessment model is applied to twelve counties in Chifeng region. The evaluation results indicate that the agricultural ecosystem in Hongshan County and Balinyou County is healthy, while that in Keshi-keteng County, Yuanbaoshan County, Aohan County and Songshan County can only be described as critically healthy and the agricultural ecosystems in the other six counties are not healthy. The results generated from the assessment model are basically in accordance with the actual status. Therefore, the index system and model of evaluation are proved to be credible. At last, the suggestions for the sustainable utilization of agricultural ecosystem in the agricultural and pastoral zone are put forward. Adopting the ecosystem health as assessing measure for the agricultural ecosystem can improve the management of agricultural ecosystem.%生态系统健康作为全球管理的新目标,作为分析生态系统的新方法而受到青睐,是现代生态学的研究热点之一.本文根据生态系统健康的内涵和农牧交错带农业生态系统的特点,从活力、组织结构和恢复力3个方面选取18个指标.构建了农牧交错带农业生态系统健康的评价指标体系.在此基础上建立综合评价模型,应用于赤峰12个旗(区、县),得到如下结果:农业生态系统健康状况处在"健康"标准是红山区和巴林右旗;处在"临界健康"标准是克什克腾旗、元宝山区、敖汉旗、松山区;处在"不健康"标准是宁城县、林西县、巴林左旗、喀喇沁旗、阿鲁克尔沁旗、翁牛特旗.评价结果基本上反映了当地农业生态系统的健康状况,说明建立的评价指标体系与模型是可行的.最后提出了农牧交错带农业生态系统持续利用的对策.

  6. Assessment of heavy metal flows in animal husbandry and development of a stategy to reduce heavy metal inputs into agro-ecosystems by animal manures; Erfassung von Schwermetallstroemen in landwirtschaftlichen Tierproduktionsbetrieben und Erarbeitung einer Konzeption zur Verringerung der Schwermetalleintraege durch Wirtschaftsduenger tierischer Herkunft in Agraroekosysteme

    Energy Technology Data Exchange (ETDEWEB)

    Schultheiss, U.; Doehler, H.; Roth, U.; Eckel, H.; Goldbach, H.; Kuehnen, V.; Wilcke, W.; Uihlein, A.; Fruechtenicht, K.; Steffens, G.

    2004-07-01

    The overall objectives of the project were to assess heavy metal flows on livestock farms and to develop a strategy to reduce heavy metal inputs into animal manures. For the experiments 20 farms with animal husbandry in various regions of Germany were selected. On the farms the inputs and outputs of the elements copper and zinc, as well as lead, cadmium, chromium and nickel were balanced at the stable level. The effect of abatement measures was evaluated using a calculation tool for stable balances. It is shown, the main input pathways for heavy metals into animal manures are, apart from copper disinfectants, feeding stuffs and feed supplements. Home grown feeds are the major source of heavy metal input into the stable because they are fed in large quantities. However, the heavy metal content of the home grown feeds in particular of roughages for ruminants is low. Purchased feed stuffs (supplementary feeding stuffs and complete feeding stuffs) were found to have a higher content of heavy metals (due to supplementation with trace elements) compared to home grown feeds. Thus, pig and poultry husbandry rather than ruminant husbandry is susceptible to heavy metal accumulation of manures. Heavy metals are cycling within the farm which is of importance when discussing the environmental impact. The turnover within the farm can hardly be controlled by the farmer. Thus, effective strategies have to be targeted at the inputs, e. g. the purchased feed stuffs. A main option to reduce the heavy metal input is to lower the trace element concentrations in supplementary feed stuffs either by legislation of maximum threshold values (e. g. EG 1334/2003) or by volunteer agreements of the feed industry and agriculture. In addition, the absorption of copper and zinc by the animals should be improved using better absorbable trace element compounds and phytase. (orig.)

  7. Allometria da palmeira babaçu em um agroecossistema de derruba-e-queima na periferia este da Amazônia Allometry of the babassu palm growing on a slash-and-burn agroecosystem of the eastern periphery of Amazonia

    Directory of Open Access Journals (Sweden)

    Christoph Gehring

    2011-03-01

    Full Text Available A palmeira babaçu (Attalea speciosa C.Martius, Arecaceae tem grande importância socioeconômica e ecológica em grande parte da área tropical brasileira, especialmente em áreas degradadas por queimadas freqüentes na Amazônia. No entanto, ainda pouco se sabe sobre as características ecológicas desta espécie-chave. Este estudo investiga a alometria do babaçu com o objetivo de estabelecer uma metodologia eficiente na estimativa da biomassa aérea de palmeiras juvenis e adultas e para um melhor entendimento da sua arquitetura. A biomassa de palmeiras juvenis pode ser estimada facilmente e com precisão com o diâmetro mínimo das ráquis das folhas a 30 cm de extensão. A biomassa de palmeiras adultas pode ser estimada com base na altura do tronco lenhoso, também relativamente de fácil medição em campo. A biomassa foliar das palmeiras adultas foi em media 31,7% da biomassa aérea, porém houve uma alta variação e, portanto, somente pode ser estimada indiretamente através da relação entre a razão madeira:folha e biomassa aérea total. Os teores de carbono no babaçu apresentaram baixa variação, sem diferenças sistemáticas em relação ao tamanho ou estágio de crescimento, o que aponta à aplicabilidade geral dos valores 42.5% C para troncos, 39.8% C para folhas. Em conseqüência do limitado crescimento secundário do diâmetro inerente de palmeiras, não houve relação do diâmetro de tronco com a altura e a biomassa das palmeiras adultas. Observou-se que o afilamento do caule diminui com o aumento da altura das palmeiras, o que é parcialmente compensado pelo incremento da densidade de madeira em troncos quase-cilíndricos. No entanto, a altura máxima do babaçu, de cerca de 30 metros, aparentemente está definida por limitações na estabilidade mecânica. Todas as relações alométricas aqui descritas são independentes da idade da vegetação, indicando a aplicabilidade geral das relações encontradas.Babassu (Attalea speciosa C.Martius, Arecaceae is a palm with extraordinary socioeconomic and ecologic importance in large areas of tropical Brazil, especially in frequently burned and degraded landscapes. Nevertheless, surprisingly little is known about this keystone species. This paper investigates the allometry of babassu, in order to improve understanding on palm architecture and to provide researchers with an efficient tool for aboveground biomass estimation of juvenile and adult palms. Juvenile leaf biomass can be accurately predicted with the easily measurable minimum diameter of rachis at 30 cm extension. Adult palm biomass can be estimated based on woody stem height, a variable fairly easily measurable on-field. Leaf biomass of adult palms was highly variable, averaged 31.7% of aboveground biomass and can be estimated only indirectly through the relationships between wood:leaf-ratio and total aboveground biomass. Carbon contents varied little in the babassu palm, without size- or growth-stage related differences, suggesting the general applicability of values (42.5% C for stems, 39.8% C for leaves. As a consequence of the limited secondary diameter growth inherent to palms, stem diameter of adult palms is unrelated to palm height and biomass. Stem tapering decreases with increasing palm height. This is partially compensated by increasing wood density in near cylindrical stems. Nevertheless, maximum babassu palm height of about 30 meters appears to be dictated by mechanical stability constraints. All allometric relationships of babassu described in this study are not affected by vegetation stand age, indicating the general applicability of these relationships.

  8. 农业生态系统中生物多样性的功能--兼论其保护途径与今后研究方向%Functions of Biodiversity in Agroecosystem-Approaches to Its Conservation and Orientation of Future Research

    Institute of Scientific and Technical Information of China (English)

    陈欣; 王兆骞; 唐建军

    2002-01-01

    重点论述了农业生态系统中生物多样性的功能,其功能主要表现在害虫控制、土壤侵蚀防治、退化环境恢复、消除污染和促进养分循环等方面.探讨了农业生态系统中生物多样性的保护途径及今后应开展的研究重点.

  9. Composition and functional groups of epiedaphic ants (Hymenoptera: Formicidae in irrigated agroecosystem and in nonagricultural areas Composição e grupos funcionais de formigas epiedáficas (Hymenoptera: Formicidae em agroecossistema irrigado e em áreas não agrícolas

    Directory of Open Access Journals (Sweden)

    Patricia Hernández-Ruiz

    2009-08-01

    Full Text Available The objective of this work was to evaluate the species composition and functional groups of ants in nonagricultural (NA and in irrigated areas (S, seasonal irrigation; P, irrigation with well water; W, irrigation with wastewater in an arid agricultural region in central Mexico, throughout 2005 and 2006. A total of 52,358 ants belonging to 6 subfamilies, 21 genera and 39 species was collected using pitfall traps. The species best represented in all plots were: Forelius pruinosus, Pheidole obtusospinosa, Monomorium minimum and Dorymyrmex spp. NA plots recorded the highest density of ants. The highest values for diversity (H' and equitativity (J' were recorded in NA and P plots, while the lowest were recorded in W plots. Cluster analysis showed two different groups regarding species composition: NA-S and W-P. Functional groups recorded were: dominant Dolichoderinae, three species; subordinate Camponotini, five species; hot climate specialists, three species; tropical climate specialists, seven species; cold climate specialists, five species; cryptic species, one species; opportunists, six species; generalized Myrmicinae, nine species. Agricultural activity affects the structure of the ant community with epiedaphic forage, and the constant use of irrigation wastewater in conjunction with intense agricultural practices has negative effect upon species richness of epiedaphic ants.O objetivo deste trabalho foi avaliar a composição de espécies e os grupos funcionais de formigas em áreas não agrícolas (NA e em áreas irrigadas (S, irrigação sazonal; P, irrigação com águas de poço; W, irrigação com água residuária em uma região agrícola de clima árido da região Central do México durante 2005 e 2006. Um total de 52.358 formigas pertencentes a 6 subfamílias, 21 gêneros e 39 espécies foi coletado por meio de armadilhas Pitfall. As espécies mais bem representadas em todas as parcelas foram: Forelius pruinosus, Pheidole obtusospinosa, Monomorium minimum e Dorymyrmex spp. As parcelas NA registraram a maior densidade de formigas. Os maiores valores de diversidade (H' e equitatividade (J' foram observados nas parcelas NA e P, e os menores, nas parcelas W. A análise de cluster mostrou grupos diferentes quanto à composição de espécies: NA-S e W-P. Os grupos funcionais registrados foram: Dolichoderinae dominantes, três espécies; Camponotini subordinadas, cinco espécies; especialistas de clima quente, três espécies; especialistas de clima tropical, sete espécies; especialistas de clima frio, cinco espécies; espécies crípticas, uma espécie; oportunistas, seis espécies; Myrmicinae generalizados, nove espécies. A atividade de agricultura afeta a estrutura das comunidades das formigas epiedáficas e a utilização constante de irrigação com água residuária, em conjunto com práticas agrícolas intensas tem um efeito negativo na riqueza de espécies de formigas epiedáficas.

  10. CARACTERIZACIÓN Y EVALUACIÓN DE AGROECOSISTEMAS A ESCALA PREDIAL UN ESTUDIO DE CASO: CENTRO AGROPECUARIO COTOVE (SANTA FÉ DE ANTIOQUIA, COLOMBIA CHARACTERIZATION AND EVALUATION OF AGROECOSYSTEMS ON A FARM SCALE. A CASE STUDY: COTOVE FARMING CENTER. ( SANTA FE DE ANTIOQUIA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Juan Camilo De los Ríos Cardona

    2004-06-01

    Full Text Available Se caracteriza y evalúa el estado, condición y tendencia, de los Agroecosistemas (AE del Centro Agropecuario Cotové de la Universidad Nacional de Colombia, Sede Medellín, mediante la parametrización y análisis de las variadas Receptividad Tecnológica (RT e Intensidad Tecnológica (IT, con base en la propuesta metodológica de Vélez y Gastó (1999, en cuanto a la diversidad de AE y de usos, manejo y acogida tecnológica, dotación en tecnoestructura e hidroestructura, potencial productivo y servicios a la sociedad local regional y nacional. Los resultados muestran que la mayor parte del área del Centro (60,2% tiene RT Alta, la cual admite el establecimiento de Sistemas de Manejo Agrotecnológico (SMA Mecanizados Avanzados, pero solo el 15,72% del área es manejado con este SMA. El 69.3% del área del Centro, principalmente bajo cobertura de pasto para ganadería de pie de cría, es manejada con SMA tradicional. Como producto de la interacción entre RT y los SMA utilizados, se encontraron nueve AE, de los cuales, cinco, que representan el 27,1% del área ( 33,6 ha, se manejan con tecnologías adecuadas a sus condiciones biofísicas o de receptividad tecnológica (IT Adecuada, y los otros cuatro, que representan el 69,4% del área ( 86,1 ha, son manejados con tecnologías que no se corresponden con sus condiciones de RT (IT extensivas e inadecuadas, lo que conlleva a la subutilización y/o deterioro de sus condiciones biofísicas y ecológicas.The state, condition, and tendencies of the agrosystems (AS of the Cotové Farming Center of the Universidad Nacional de Colombia, Sede Medellín was evaluated by means of a parameterization and analysis of the various Receptivity Technologies (RT and Intensity Technologies (IT, based upon the proposed methodology of Vélez and Gastó (1999, in terms of the diversity in AE and the uses, management, and technological state, technostructural and hydrostructyural endowment, potential productivity and benefits to local, regional, and national society. Results showed that the majority of the area of the center (60% has high RT, that indicates the establishment of Mechanized Advanced Agrotechnological Management Systems (AMS, but only 15,72% of the area is managed with this SMA. Fully 69,3% of the area of the center, mainly under pasture for raising cattle, is managed with traditional SMA. As a product of the interaction between RT and the SMA employed, nine AE were identified, of which five, that represent 27,1% of the area ( 33,6 ha., are managed with technologies adequate for the biophysical conditions and the receptivity technology (adequate IT, and the other four, which represent 69,4% of the area ( 86,1 ha. are managed with technologies that do not correspond to their RT conditions (extensive and inadequate Its, that leads to a sub-utilization and/or deterioration of their biophysical and ecological conditions.

  11. Local, landscape, and diversity drivers of predation services provided by ants in a coffee landscape in Chiapas, Mexico

    OpenAIRE

    de la Mora, A; García-Ballinas, JA; Philpott, SM

    2015-01-01

    © 2014 Elsevier B.V. Agricultural management and the landscape surrounding farms impact biological diversity and ecosystem services, such as predation, in agroecosystems. Diversified coffee agroecosystems harbor biodiversity, and maintain ecosystem services, especially when in complex landscapes, and when diversity of organisms providing services is maintained. But few have examined whether biological diversity, per se, or the local and landscape habitat features are stronger drivers of the s...

  12. First evidence of the effects of agricultural activities on gonadal form and function in Rhinella fernandezae and Dendropsophus sanborni (Amphibia: Anura from Entre Ríos Province, Argentina

    Directory of Open Access Journals (Sweden)

    Laura C. Sanchez

    2014-06-01

    Full Text Available The relationship between male gonadal abnormalities and habitats with different degrees of agricultural activities was quantified in two anuran species, Rhinella fernandezae and Dendropsophus sanborni. The study sites were selected along a gradient of increasing agricultural land use in south-western Entre Ríos province (Argentina: an agroecosystem, a natural wetland (a non-agricultural site adjacent to monoculture zones, and a natural forest (not associated with agriculture. Rhinella fernandezae and D. sanborni were manually captured from each environment during field surveys. A scaled mass index (MI was evaluated for each animal. Specimens of R. fernandezae from the agroecosystem and the natural wetland site presented poorly developed seminiferous tubules, lower testicular volume, and a lower number of seminiferous tubules, primary spermatogonia, and spermatids than specimens from the natural forest site. Additionally, we observed fewer primary spermatocytes in the agroecosystem group than in the natural forest group. Individuals of D. sanborni from the agroecosystem and the natural wetland site presented poorly developed tubules, higher proportions of irregularly shaped testes, and a reduced number of primary and secondary spermatogonia compared with specimens from natural forest sites. Consequently, the affected anurans are likely to have reduced reproductive success. We suggest that agrochemical use may be associated with decreased testicular development and function in both R. fernandezae and D. sanborni occurring in agroecosystems and nearby environments. Buffer zones are needed to prevent contamination, preserve wildlife, and enhance the conservation value of pristine natural forests.

  13. Towards a Better Understanding of Agronomic Efficiency of Nitrogen: Assessment and Improvement Strategies

    Directory of Open Access Journals (Sweden)

    Francesco Montemurro

    2016-05-01

    Full Text Available Agronomic N-use efficiency is the basis for economic and environmental efficiency, and an effective agro-ecosystem management practice, improving nutrient use efficiency, is a crucial challenge for a more sustainable production of horticultural, industrial and cereal crops. However, discrepancy between theory and practice still exists, coming from large gaps in knowledge on net-N immobilization/mineralization rates in agro-ecosystems, as well as on the effects of indigenous and applied N to crop response. A more thorough understanding of these topics is essential to improve N management in agricultural systems. To this end, the present Special Issue collects research findings dealing with different aspects of agronomic efficiency of N in different agro-ecosystems, and environmental impact derived from fertilization management practices. In particular, the Special Issue contains selected papers, which concern a wide range of topics, including analyzing tools, options of management, calculation equation and modeling approaches.

  14. Land use effect on soil meso and macro-organisms in Quindio coffee zone

    International Nuclear Information System (INIS)

    Meso and macro-organisms communities in different agro-ecosystems were evaluated on the Colombian coffee region (Quindio) during the second semester of 1997. Soil samples were taken at 10 cm of deep and the Berlese funnel apparatus was used for evaluations. The agro-ecosystems were Guadual (Guadua angustifolia), traditional and technical coffee, citrus, and cassava crops, cattle ranching (extensive and intensive systems). A total of twenty taxonomic groups were identified. The most abundant and common specimens were ants, acari, collembola and diplura. The greatest diversity and abundance of organisms were registered on the G. angustifolia and coffee agro-ecosystems. The opposite tendency was observed on the cattle ranching due to physical degradation, associated to soil compacting

  15. Facilitative root interactions in intercrops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Jensen, E.S.

    2005-01-01

    Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We discuss examples of facilitative root interactions in intercropped agroecosystems; including...... of root architecture, exudation of growth stimulating substances, and biofumigation. Facilitative root interactions are most likely to be of importance in nutrient poor soils and in low-input agroecosystems due to critical interspecific competition for plant growth factors. However, studies from more...... nitrogen transfer between legumes and non-leguminous plants, exploitation of the soil via mycorrhizal fungi and soil-plant processes which alter the mobilisation of plant growth resources such as through exudation of amino acids, extra-cellular enzymes, acidification, competition-induced modification...

  16. Assessing the risks and benefits of flowering field edges. Strategic use of nectar sources to boost biological control

    NARCIS (Netherlands)

    Winkler, K.

    2005-01-01

    The intensification of agricultural production systems during the last decades hadaenormous impact on the landscape structure in agro-ecosystems. Landscape elements like hedges andvegetationalrichfieldmargins

  17. Integrating stakeholders' goals, research disciplines and levels of scale

    NARCIS (Netherlands)

    Duivenbooden, van N.

    1995-01-01

    This paper describes a methodological framework of a combination of high-tech assessment with participatory methodologies for developing sustainable agro-ecosystems. Basic ingredients are the integration of goals, disciplines, scales, and common methodologies. Quantification is another key issue. Im

  18. Alternate Satellite Models for Estimation of Sugar Beet Residue Nitrogen Credit

    Science.gov (United States)

    Satellite assessment of aboveground plant residue mass and quality is essential for agro-ecosystem management of organic nitrogen (N) because growers credit a portion of residue N towards crop requirements the following spring. Precision agriculture managers are calling for advanced satellite models...

  19. Agricultural Land Use and Conservation Options

    NARCIS (Netherlands)

    Zander, P.

    2003-01-01

    The thesis presents the modeling system MODAM (Multi-Objective Decision support tool for Agroecosystem Management) which was developed at the Centre for Agricultural Landscape and Land Use Research (ZALF) Müncheberg. The aim of the development of MODAM is to foster sustainable development o

  20. The Swiss agri-environment scheme enhances pollinator diversity and plant reproductive succes in nearby intensively managed farmland

    NARCIS (Netherlands)

    Albrecht, M.; Duelli, P.; Müller, C.; Kleijn, D.; Schmid, B.

    2007-01-01

    1. Agri-environment schemes attempt to counteract the loss of biodiversity and associated ecosystem services such as pollination and natural pest control in agro-ecosystems. However, only a few studies have evaluated whether these attempts are successful. 2. We studied the effects of managing meadow

  1. Simulating population recovery of an aquatic isopod: Effects of timing of stress and landscape structure

    NARCIS (Netherlands)

    Galic, N.G.; Baveco, J.M.; Hengeveld, G.M.; Thorbek, P.; Bruns, E.; Brink, van den P.J.

    2012-01-01

    In agroecosystems, organisms may regularly be exposed to anthropogenic stressors, e.g. pesticides. Species' sensitivity to stress depends on toxicity, life-history, and landscape structure. We developed an individual-based model of an isopod, Asellus aquaticus, to explore how timing of stress events

  2. Behavioral Changes Based on a Course in Agroecology: A Mixed Methods Study

    Science.gov (United States)

    Harms, Kristyn; King, James; Francis, Charles

    2009-01-01

    This study evaluated and described student perceptions of a course in agroecology to determine if participants experienced changed perceptions and behaviors resulting from the Agroecosystems Analysis course. A triangulation validating quantitative data mixed methods approach included a written survey comprised of both quantitative and open-ended…

  3. Agroecology: Implications for plant response to climate change

    Science.gov (United States)

    Agricultural ecosystems (agroecosystems) represent the balance between the physiological responses of plants and plant canopies and the energy exchanges. Rising temperature and increasing CO2 coupled with an increase in variability of precipitation will create a complex set of interactions on plant ...

  4. Precision control of soil N cycling via soil functional zone management

    Science.gov (United States)

    Managing the soil nitrogen (N) cycle is a major component of agricultural sustainability. Soil functional zone management (SFZM), a novel framework of agroecosystem management, may improve soil N management compared with conventional and no-tillage approaches by focusing on the timing and location (...

  5. A New GIS-Nitrogen Trading Tool Concept to Minimize Reactive Nitrogen losses to the Environment

    Science.gov (United States)

    Nitrogen (N) is an essential element which is needed to maximize agricultural production and sustainability of worldwide agroecosystems. N losses to the environment are impacting water and air quality that has become an environmental concern for the future generations. It has led to the need for dev...

  6. Development of the Land-use and Agricultural Management Practice web-Service (LAMPS) for generating crop rotations in space and time

    Science.gov (United States)

    Agroecosystem models and conservation planning tools require spatially and temporally explicit input data about agricultural management operations. The Land-use and Agricultural Management Practices web-Service (LAMPS) provides crop rotation and management information for user-specified areas within...

  7. Applying spectral unmixing and support vector machine to airborne hyperspectral imagery for detecting giant reed

    Science.gov (United States)

    This study evaluated linear spectral unmixing (LSU), mixture tuned matched filtering (MTMF) and support vector machine (SVM) techniques for detecting and mapping giant reed (Arundo donax L.), an invasive weed that presents a severe threat to agroecosystems and riparian areas throughout the southern ...

  8. The effects of drought and herbivory on plant–herbivore interactions across 16 soybean genotypes in a field experiment

    Science.gov (United States)

    As the Earth’s climate continues to change, drought and insect population outbreaks are predicted to increase in many parts of the world. It is therefore important to understand how changes in such abiotic and biotic stressors might impact agroecosystems. 16 soybean genotypes were tested in a field ...

  9. Biodiversity and organic farming. Strengthening the interactions between agriculture and ecosystems

    OpenAIRE

    Simon, Sylvaine

    2010-01-01

    The interactions between organic farming and biodiversity show that the organic approach can be proposed as an agricultural system that may best benefit but also provide biodiversity in the agroecosystem, thus minimising the trade-off between production aims and biodiversity preservation and restoration.

  10. Spiders (Araneae) as polyphagous natural enemies in orchards

    NARCIS (Netherlands)

    Bogya, S.

    1999-01-01

    Spiders (Araneae) occur in high abundance in all terrestrial ecosystems including agro-ecosystems. They are a very heterogeneous group of animals with different hunting tactics and therefore they play very different ecological roles. At family level these tactics are rather similar thus properties a

  11. Termites and agricultural production in the Sahel: from enemy to friend?

    NARCIS (Netherlands)

    Mando, A.; Rheenen, van T.

    1998-01-01

    Termites are an important component of agroecosystems, particularly in developing countries where they are an alternative to high priced inputs. Given the major problems in the Sahel of soil crusting and nutrient depletion, this paper shows that termites associated with proper management techniques

  12. Bt Crop Effects on Functional Guilds of Non-target Arthropods: A Meta-Analysis

    Science.gov (United States)

    Uncertainty continues to persist over the potential environmental effects of crops genetically engineered to produce the insecticidal Cry toxins of Bacillus thuringiensis (Bt). Little work has examined broader impacts on ecological function of non-target species within agroecosystems. Here we use me...

  13. Conservation biological control and enemy diversity on a landscape scale

    NARCIS (Netherlands)

    Tscharntke, T.; Bommarco, R.; Clough, Y.; Crist, T.O.; Kleijn, D.; Rand, T.A.; Tylianakis, J.M.; Nouhuys, S.; Vidal, S.

    2007-01-01

    Conservation biological control in agroecosystems requires a landscape management perspective, because most arthropod species experience their habitat at spatial scales beyond the plot level, and there is spillover of natural enemies across the crop–noncrop interface. The species pool in the surroun

  14. Sustainability of pasture-based livestock farming systems in the European Mediterranean context: Synergies and trade-offs

    NARCIS (Netherlands)

    Bernués, A.; Ruiz, R.; Olaizola, A.; Villalba, D.; Casasús, I.

    2011-01-01

    The sustainability of livestock farming systems (LFS) in relation to global concerns about climate change, population dynamics and the quality of the agro-ecosystem services that are provided to society and their trade-offs has become a fundamental issue for public and scientific debate. However, LF

  15. The Future of Food: Scenarios for 2050

    NARCIS (Netherlands)

    Hubert, B.; Rosegrant, M.; Boekel, van M.A.J.S.; Ortiz, R.

    2010-01-01

    This background article addresses key challenges of adequately feeding a population of 9 billion by 2050, while preserving the agro-ecosystems from which other services are also expected. One of the scenario-buildings uses the Agrimonde platform, which considers the following steps: choosing the sce

  16. Exploring socio-ecological niches for legumes in western Kenya smallholder farming systems

    NARCIS (Netherlands)

    Ojiem, J.O.

    2006-01-01

    Keywords: adaptability, agro-ecosystems, biophysical and socio-economic heterogeneity, economic benefits, N2-fixation, productivity.This thesis explores the potential of using herbaceous and grain legume species to improve soil fertility and farm productivity in the heterogeneous s

  17. Soil biodiversity for agricultural sustainability

    NARCIS (Netherlands)

    Brussaard, L.; Ruiter, de P.C.; Brown, G.G.

    2007-01-01

    We critically highlight some evidence for the importance of soil biodiversity to sustaining (agro-)ecosystem functioning and explore directions for future research. We first deal with resistance and resilience against abiotic disturbance and stress. There is evidence that soil biodiversity does conf

  18. Identification of an atrazine-degrading benzoxazinoid in Eastern gamagrass (tripsacum dactyloides)

    Science.gov (United States)

    This study was part of a broader effort to identify and characterize promising atrazine-degrading phytochemicals in Eastern gamagrass (Tripsacum dactyloides; EG) roots for the purpose of mitigating atrazine transport from agroecosystems. The objective of this study was to isolate and identify atrazi...

  19. Enzyme Activity Dynamics in Response to Climate Change: 2011 Drought-Heat Wave

    Science.gov (United States)

    Extreme weather events such as severe droughts and heat waves may have permanent consequences on soil quality and functioning in agroecosystems. The Southern High Plains (SHP) region of Texas, U.S., a large cotton producing area, experienced a historically extreme drought and heat wave during 2011,...

  20. Heavy metals balance in Polish and Dutch agronomy : Actual state and previsions for the future

    NARCIS (Netherlands)

    Dach, J.; Starmans, D.A.J.

    2005-01-01

    This paper presents the state of agro-ecosystem contamination with heavy metals in relation to the level of agricultural development. For this, the Polish and Dutch agricultural situations were compared. The intensive animal and vegetable production observed in the Netherlands over the past 20-30 ye