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. Agro-ecosystems water requirements for crops

    International Nuclear Information System (INIS)

    Crop water requirements were mainly influenced by meteorological factors like temperature, wind, humidity and radiational balance. In agro-ecosystems, the main water loss was through evapotranspiration. In the present article the water requirements for rice and wheat crops in India are presented. It was observed that there were strong gradients for water requirements in the north-western and south-western parts of the country

  5. 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)

  6. Ecohydrological modeling in agroecosystems: Examples and challenges

    Science.gov (United States)

    Porporato, A.; Feng, X.; Manzoni, S.; Mau, Y.; Parolari, A. J.; Vico, G.

    2015-07-01

    Human societies are increasingly altering the water and biogeochemical cycles to both improve ecosystem productivity and reduce risks associated with the unpredictable variability of climatic drivers. These alterations, however, often cause large negative environmental consequences, raising the question as to how societies can ensure a sustainable use of natural resources for the future. Here we discuss how ecohydrological modeling may address these broad questions with special attention to agroecosystems. The challenges related to modeling the two-way interaction between society and environment are illustrated by means of a dynamical model in which soil and water quality supports the growth of human society but is also degraded by excessive pressure, leading to critical transitions and sustained societal growth-collapse cycles. We then focus on the coupled dynamics of soil water and solutes (nutrients or contaminants), emphasizing the modeling challenges, presented by the strong nonlinearities in the soil and plant system and the unpredictable hydroclimatic forcing, that need to be overcome to quantitatively analyze problems of soil water sustainability in both natural and agricultural ecosystems. We discuss applications of this framework to problems of irrigation, soil salinization, and fertilization and emphasize how optimal solutions for large-scale, long-term planning of soil and water resources in agroecosystems under uncertainty could be provided by methods from stochastic control, informed by physically and mathematically sound descriptions of ecohydrological and biogeochemical interactions.

  7. 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...

  8. 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)

  9. 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…

  10. 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

  11. INCORPORATING BATS IN AGROECOSYSTEM MANAGEMENT AND CROP PROTECTION DECISIONS

    Science.gov (United States)

    By characterizing the diet of bats in agroecosystems, this research likely will document that bats are important consumers of pest species. Additionally, this investigation will document which pest species are consumed and the relative contribution of these species to bat d...

  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. Interactions Among Ecosystem Services Across Land Uses in a Floodplain Agroecosystem

    OpenAIRE

    Bennett, Elena M.

    2014-01-01

    Managing human-dominated landscapes such as agroecosystems is one of the main challenges facing society today. Decisions about land-use management in agroecosystems involve spatial and temporal trade-offs. The key scales at which these trades-offs occur are poorly understood for most systems, and quantitative assessments of the services provided by agroecosystems under different combinations of land uses are rare. To fill these knowledge gaps, we measured 12 ecosystem services (ES), including...

  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. Managing biotic interactions for ecological intensification of agroecosystems

    OpenAIRE

    Gaba, Sabrina; Bretagnolle, François; Rigaud, Thierry; Philippot, Laurent

    2014-01-01

    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, whic...

  16. 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...

  17. 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.

  18. 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

  19. Managing biotic interactions for ecological intensification of agroecosystem

    Directory of Open Access Journals (Sweden)

    SabrinaGaba

    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.

  20. Behavioral diversity of predatory arboreal ants in coffee agroecosystems.

    Science.gov (United States)

    Philpott, Stacy M; Perfecto, Ivette; Vandermeer, John

    2008-02-01

    Aspects of predator assemblages that alter predator effects on prey have received extensive recent attention. Among other mechanisms, differences in behavior or resource use within predator trophic levels may enhance predator effects on prey, especially if effects of each predator species differ with environmental conditions. We address whether three common ant species (Azteca instabilis F. Smith, Camponotus textor Forel, and Crematogaster spp.) are functionally unique in coffee agroecosystems, asking if each species differs in (1) cooperative foraging behavior, (2) responses to experimentally introduced herbivores, and (3) responses to pest outbreaks. Furthermore, we examined the behaviors and effects of each ant species under different conditions by varying herbivore species, herbivore size, and herbivore density and carrying out observations in different seasons. Ant species significantly differed in foraging behaviors, in effects on individual herbivores, and in responses to pest outbreaks in terms of both type and time of response to herbivores. The behaviors and effects of each ant species differed in the dry and wet seasons and for different herbivore species and sizes. Although A. instabilis generally removed more larvae and more quickly removed larvae, this was not the case under all conditions. The data presented thus support that common ant species in coffee agroecosystems are behaviorally diverse in their responses to herbivores under different conditions. We discuss the implications of these differences in ant behaviors for enhancement of predatory function in light of both multipredator effects and in terms of the potential importance of predator diversity. PMID:18348809

  1. The ranging ability of sasso chickens grown under various types of agroecosystems

    OpenAIRE

    Escobin, Jr., Dr Rectorino; Bondoc, Dr. Orville; Lambio, Dr. Angel; Arboleda, Dr. Cecilio; Dagaas, Dr. Claire

    2001-01-01

    The ranging ability of Sasso chicken was estimated using the ranging score as an indicator. The chickens were allowed to range in three agro-ecosystems namely, rice-based, rambutan orchard and grassland. The ranging score was significantly higher in rambutan orchard with 52 m-hr followed by the ranging score in grassland with 48 m-hr. The ranging score was lowest in rice-based agroecosystem. The differences in the ranging score among agroecosystem can be attributed mainly to the presen...

  2. 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

  3. How should we be determining background and baseline antibiotic resistance levels in agroecosystem research?

    Science.gov (United States)

    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 u...

  4. 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.

  5. 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)

  6. 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.

  7. 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 ...

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. Analyzing Groundwater-Vegetation Interactions using a Dynamic Agroecosystem Model

    Science.gov (United States)

    Soylu, M. E.; Kucharik, C. J.; Loheide, S. P.

    2012-12-01

    Groundwater is a crucial source of water for vegetation, especially in arid and semiarid environments in many regions around the world and its availability controls the distribution and the physiology of plant species. However, the impact of groundwater on vegetation is not completely understood mainly due to the limited ability of current models to simulate groundwater and vegetation interactions. Existing land surface models (LSM) simulate water and energy fluxes among soil-vegetation-atmosphere systems in a process-based way, but lack a detailed simulation of soil water movement in the unsaturated zone, particularly when groundwater is present. Furthermore, there are only a few available LSM and/or process based vegetation models that can simulate agroecosystems, which are as important to understand as natural ecosystems considering they occupy approximately 40% of the global land surface. On the other hand, current physically-based, variably-saturated soil water flux models are able to accurately simulate water movement in the unsaturated zone. However, they often lack a detailed plant physiology component making it difficult to understand plant responses to both variations in energy fluxes and upward capillary fluxes in shallow groundwater environments. To connect these two different model types, the objectives of this study are (1) to incorporate an advanced dynamic agroecosystem model (Agro-IBIS) and a variably saturated soil water flow model (Hydrus-1D) into a single framework that is capable of simulating groundwater and plant/crop system interactions in a fully, physically-based fashion, and (2) to apply this model using observed climate records to better understand the responses of managed and natural ecosystems to varied water table depths under inter-annual climate forcing conditions. The model results show that as the water table becomes shallower, (1) soil temperature decreases due to the moisture content driven effects on the thermal diffusivity of

  13. 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.

  14. Rice agroecosystem of the Muda irrigation scheme, Malaysia

    International Nuclear Information System (INIS)

    Pesticides have become one of the major components of modern farming practice. However, their usage needs to be properly carried out and regulated. Farmers need to be aware of the potential hazards arising out of improper use of pesticides, to them as well to the environment. This book presents the results of a comprehensive study on the impact of pesticide usage in the largest rice agroecosystem in Malaysia, the Muda Irrigation Scheme. The study, carried out by a group of local scientists, covers the impact of pesticide usage on biodiversity and bioresources (forest, weed, insect, fish and bird). In addition to farmers education, it shows the potential of crop establishment, irrigation method and double cropping of rice as useful factors that can be employed in minimizing the impact. The book also provides good foundation for future work and points out areas for further studies. It is a valuable reference to policy makers, researchers, regulators, agriculture-related agencies, chemical / fertilizer companies as well as those concerned with sustainable farming. The ecologists, chemists, biochemists, entomologists, zoologists, botanists, microbiologists, agronomists and medical practitioners involved in this study are congratulated for their efforts. (Nahrul Khair Alang Md Rashid)

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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

    Ecosystem Services within an Agro- Ecosystem Agricultural ecosystems produce food, fiber, and nonmarketed ecosystem services (ES). Agriculture also typically involves high negative external costs associated with, for example, fossil fuel use. We estimated, via fieldscale ecological monitoring 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...

  20. Software System Design for Large Scale, Spatially-explicit Agroecosystem Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dali [ORNL; Nichols, Dr Jeff A [ORNL; Kang, Shujiang [ORNL; Post, Wilfred M [ORNL; Liu, Sumang [ORNL

    2012-01-01

    Recently, site-based agroecosystem model has been applied at regional and state level to enable comprehensive analyses of environmental sustainability of food and biofuel production. Those large-scale, spatially-explicit simulations present computational challenges in software systems design. Herein, we describe our software system design for large-scale, spatially-explicit agroecosystem modeling and data analysis. First, we describe the software design principles in three major phases: data preparation, high performance simulation, and data management and analysis. Then, we use a case study at a regional intensive modeling area (RIMA) to demonstrate our system implementation and capability.

  1. 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.

  2. 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

  3. 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.

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

    Science.gov (United States)

    Reganold, John P.; Andrews, Preston K.; Reeve, Jennifer R.; Carpenter-Boggs, Lynne; Schadt, Christopher W.; Alldredge, J. Richard; Ross, Carolyn F.; Davies, Neal M.; Zhou, Jizhong

    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. PMID:20824185

  5. Relative dispersal ability of a key agricultural pest and its predators in an annual agroecosystem

    Science.gov (United States)

    In annual agroecosystems staggered planting dates, pesticide treatments, and harvesting events create a “shifting mosaic” of habitats that leads to frequent recolonization by herbivores and natural enemies. In these systems, an untested assumption is that herbivores have higher rates of dispersal re...

  6. 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

  7. Modeling denitrification in a tile-drained, corn and soybean agroecosystem of Illinois, USA

    Science.gov (United States)

    Denitrification is known as an important pathway for nitrate loss in agroecosystems. It is important to estimate denitrification fluxes to close field and watershed N mass balances, determine greenhouse gas emissions (N2O), and help constrain estimates of other major N fluxes (e.g., nitrate leaching...

  8. 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.

    2015-06-01

    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 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.

  9. 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...

  10. 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

    Experimental field data are used at different levels of complexity to calibrate, validate and improve agro-ecosystem models to enhance their reliability for regional impact assessment. A methodological framework and software are presented to evaluate and classify data sets into four classes regar...... decide on the most effective measurements to improve the usefulness of their data for modelling, statistical analysis and data assimilation....

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Modeling carbon dynamics and social drivers of bioenergy agroecosystems

    Science.gov (United States)

    Hunt, Natalie D.

    Meeting society's energy needs through bioenergy feedstock production presents a significant and urgent challenge, as it can aid in achieving energy independence goals and mitigating climate change. With federal biofuel production standards to be met within the next decade, and with no commercial scale production or markets currently in place, many questions regarding the sustainability and social feasibility of bioenergy still persist. Clarifying these uncertainties requires the incorporation of biogeochemical, biophysical, and socioeconomic modeling tools. Chapter 2 validated the biogeochemical cycling model AGRO-BGC by comparing model estimates with empirical observations from corn and perennial C4 grass systems across Wisconsin and Illinois. AGRO-BGC, in its first application to an annual cropping system, was found to be a robust model for simulating carbon dynamics of an annual cropping system. Chapter 3 investigated the long-term implications of bioenergy feedstock harvest on soil productivity and erosion in annual corn and perennial switchgrass agroecosystems using AGRO-BGC and the soil erosion model RUSLE2. Modeling environments included biophysical landscape characteristics and management practices of bioenergy feedstock production systems. This study found that intensifying aboveground residue harvest reduces soil productivity over time, and the magnitude of these losses is greater in corn than in switchgrass systems. Results of this study will aid in the design of sustainable bioenergy feedstock management practices. Chapter 4 provided evidence that combining biophysical crop canopy characteristics with satellite-derived vegetation indices offers suitable estimates of crop canopy phenology for corn and soybeans in Southwest Wisconsin farms. LANDSAT based vegetation indices, when combined with a light use efficiency model, provide yield estimates in agreement with farmer reports, providing an efficient and accurate means of estimating crop yields from

  17. 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

  18. 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.

  19. 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.

  20. 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)

  1. [Scolitids (Coleoptera: Scolytidae) associated to the cocoa agroecosystem in Tabasco, Mexico].

    Science.gov (United States)

    Pérez-De La Cruz, Manuel; Equihua-Martínez, Armando; Romero-Nápoles, Jesus; Sánchez-Soto, Saúl; García-López, Eustolia; Bravo-Mojica, Hiram

    2009-01-01

    The Scolytidae fauna associated to the cacao agroecosystem in Tabasco, Mexico was studied during 2007. Adult insects were captured by using ethanol and light traps, and by direct collecting in their host plants. 3,192 specimens of 34 species belonging to 18 genera of Scolytidae were collected. Twenty-two species are new records for the State of Tabasco. The genera with more species were Xyleborus (6) and Hypothenemus (6). We conclude that the Scolytidae fauna associated to the cacao agroecosystem captured with the three trap systems are similar through the year of study. We also conclude that although the ethanol traps were more efficient, obtaining the highest species diversity, the use of other methods is important. PMID:19943007

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

    OpenAIRE

    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 an...

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

    OpenAIRE

    Animesh Dey; Chaudhuri, P. S.

    2016-01-01

    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 rarefact...

  4. 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...

  5. 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...

  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. 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 ...

  9. 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.

  10. Spider diversity in coffee agroecosystems: the influence of agricultural intensification and aggressive ants.

    Science.gov (United States)

    Marín, Linda; Perfecto, Ivette

    2013-04-01

    Spiders are a very diverse group of invertebrate predators found in agroecosystems and natural systems. However, spider distribution, abundance, and eventually their ecological function in ecosystems can be influenced by abiotic and biotic factors such as agricultural intensification and dominant ants. Here we explore the influence of both agricultural intensification and the dominant arboreal ant Azteca instabilis on the spider community in coffee agroecosystems in southern Mexico. To measure the influence of the arboreal ant Azteca instabilis (F. Smith) on the spider community inhabiting the coffee layer of coffee agroecosystems, spiders were collected from coffee plants that were and were not patrolled by the ant in sites differing in agricultural intensification. For 2008, generalized linear mixed models showed that spider diversity was affected positively by agricultural intensification but not by the ant. However, results suggested that some spider species were associated with A. instabilis. Therefore, in 2009 we concentrated our research on the effect of A. instabilis on spider diversity and composition. For 2009, generalized linear mixed models show that spider richness and abundance per plant were significantly higher in the presence of A. instabilis. In addition, analyses of visual counts of insects and sticky traps data show that more resources were present in plants patrolled by the ant. The positive effect of A. instabilis on spiders seems to be caused by at least two mechanisms: high abundance of insects and protection against predators. PMID:23575009

  11. 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.

  12. 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.

  13. 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

  14. 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

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

    Science.gov (United States)

    Yang, Jin; Chen, Weichao; Chen, Bin

    2011-09-01

    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 agro-ecosystem 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.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. Simultaneous measurements of CO2 and water exchanges over three agroecosystems in South-West France

    Directory of Open Access Journals (Sweden)

    M. Irvine

    2009-02-01

    Full Text Available During the last few decades, many studies have been performed to determine water and carbon budgets of broadleaf and deciduous forests, crops and grasslands. However, since most measurements have been made in different regions and at different periods, it is difficult to compare the results directly. In order to evaluate accurately the respective contribution of various agroecosystems to global water and carbon exchanges, it is necessary to compare data obtained in similar climatic and weather conditions. To address this question, we present the results from simultaneous measurements carried out from 31 March 2007 to 3 March 2008 over three typical agroecosystems of the Les Landes region in South-West France: an agricultural field with maize from 29 May to 18 October, a young (5 year-old pine forest and a mature (37 year-old pine forest. All measurements were collected as part of the Regional Experiment component of the CarboEurope-IP project. During most of the year, the agricultural field without vegetation is a source of CO2, but from late June to early September the maize crop becomes a stronger carbon sink than the forests. Over the whole measurement period the three agroecosystems behave as CO2 sinks with carbon storage of about 500, 330 and 230 gC m−2 for the young forest, the mature forest and the agricultural field, respectively. Daily Water Use Efficiencies (WUE of the three ecosystems were evaluated and expressed as functions of the mean daily vapour pressure deficit (VPD. Similar trends were observed for the two forests, which suggests that for a given species WUE is independent of stand age. The WUE of the maize crop at maturity was also found to depend upon VPD, but it is about twice as large as for the forests, owing to the physiological advantages of C4 species.

  1. 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

  2. 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

  3. 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

  4. 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)

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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. PMID:26994604

  13. 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)

  14. 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 ...

  15. 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

  16. 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

  17. 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

  18. 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

  19. Simultaneous measurements of CO2 and water exchanges over three agroecosystems in South-West France

    Science.gov (United States)

    Stella, P.; Lamaud, E.; Brunet, Y.; Bonnefond, J.-M.; Loustau, D.; Irvine, M.

    2009-12-01

    During the last few decades, many studies have been performed to determine water and carbon budgets of broadleaf and deciduous forests, crops and grasslands. However, since most measurements have been made in different regions and at different periods, it is difficult to compare the results directly. In order to evaluate accurately the respective contribution of various agroecosystems to global water and carbon exchanges, it is necessary to compare data obtained in similar climatic and weather conditions. To address this question, we present the results from simultaneous measurements carried out during one year over three typical agroecosystems of the Les Landes region in South-West France:~an agricultural field with maize from 29 May to 18 October, a young (5 year-old) pine forest and a mature (37 year-old) pine forest. All measurements were collected as part of the Regional Experiment component of the CarboEurope-IP project. During most of the year, the agricultural field without vegetation is a source of CO2, but from late June to early September the maize crop becomes a stronger carbon sink than the forests. Over the whole measurement period the three agroecosystems behave as CO2 sinks with carbon storage of about 335, 210 and 160 g C m-2 for the young forest, the mature forest and the agricultural field, respectively. We investigated the influence of climatic conditions on Gross Primary Production (GPP) of the three ecosystems and observed a predominant role of vapour pressure deficit (VPD) for forests and of photosynthetic photon flux density (FPP) for maize. Daily Water Use Efficiencies (WUE) of the three ecosystems were evaluated and expressed as functions of the mean daily vapour pressure deficit (VPD). Similar trends were observed for the two forests, which suggests that for a given species WUE is independent of stand age. The WUE of the maize crop at maturity was also found to depend upon VPD, but it is about twice as large as for the forests, owing to

  20. Simultaneous measurements of CO2 and water exchanges over three agroecosystems in South-West France

    Directory of Open Access Journals (Sweden)

    M. Irvine

    2009-12-01

    Full Text Available During the last few decades, many studies have been performed to determine water and carbon budgets of broadleaf and deciduous forests, crops and grasslands. However, since most measurements have been made in different regions and at different periods, it is difficult to compare the results directly. In order to evaluate accurately the respective contribution of various agroecosystems to global water and carbon exchanges, it is necessary to compare data obtained in similar climatic and weather conditions. To address this question, we present the results from simultaneous measurements carried out during one year over three typical agroecosystems of the Les Landes region in South-West France:~an agricultural field with maize from 29 May to 18 October, a young (5 year-old pine forest and a mature (37 year-old pine forest. All measurements were collected as part of the Regional Experiment component of the CarboEurope-IP project. During most of the year, the agricultural field without vegetation is a source of CO2, but from late June to early September the maize crop becomes a stronger carbon sink than the forests. Over the whole measurement period the three agroecosystems behave as CO2 sinks with carbon storage of about 335, 210 and 160 g C m−2 for the young forest, the mature forest and the agricultural field, respectively. We investigated the influence of climatic conditions on Gross Primary Production (GPP of the three ecosystems and observed a predominant role of vapour pressure deficit (VPD for forests and of photosynthetic photon flux density (FPP for maize. Daily Water Use Efficiencies (WUE of the three ecosystems were evaluated and expressed as functions of the mean daily vapour pressure deficit (VPD. Similar trends were observed for the two forests, which suggests that for a given species WUE is independent of stand age. The WUE of the maize crop at maturity was also found to depend upon VPD, but it is about twice as large as for the

  1. 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.

  2. 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

  3. An overview of the sustainability of rice agroecosystem through rice-fish integration

    International Nuclear Information System (INIS)

    Rice-fish integration in the rice agroecosystem has been introduced and is expanding in Malaysia. This type of farm integration has resulted in land optimization, thus enabling farmers to grow both fish and rice in one farming system. Introducing fish into the ricefield has also increased seasonal income as well as reduced pesticide use. Although basic ecological knowledge on rice-fish integration has allowed rice-fish integration to be introduced, further research is required to allow for fine tuning of the methodologies used. Thus research on the ecology, management, production methods and the characterization of rice-fish farming system of Malaysia is needed. Further characterization and description is needed on the ecology of the rice-fish farming system of Malaysia in terms of production, food webs, nutrient flow and system diversity. To increase the sustainability efficiency and productivity of the system, implementation of management techniques formulated through research is required. (Author)

  4. 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.

  5. 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.

  6. 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

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

    DEFF Research Database (Denmark)

    Cortet, J.; Bohanec, M.; Griffiths, B.; Žnidaršič, M.; Debeljak, M.; Caul, S.; Thompson, J.; Krogh, Paul Henning

    2009-01-01

    developing various hierarchical multiattribute models that consist of qualitative attributes and utility (aggregation) functions, represented by decision rules. The assessment of soil quality is based on two main indicators: (1) soil diversity (assessed through microfauna, mesofauna and macrofauna richness...... application to the assessment of crop management on soil quality in the case of using conventional and Bt-maize at three field sites in France and Denmark. Our finding was that soil quality was unaffected even though several input attributes were changed. We also analyse the sensitivity of the model and......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...

  8. Analysis of Cattle Location Data in Complex Agro-Ecosystem of South Florida

    Science.gov (United States)

    Pandey, V.; Kiker, G. A.; Williams, M. J.

    2006-05-01

    Cow-calf operations are a major landuse activity in south Florida, especially in Okeechobee County. These grazing lands have become a matter of concern as Phosphorus (P) loadings in this basin have greatly exceeded the total maximum daily load (TMDL) for the receiving water body, Lake Okeechobee. Our hypothesis is that cattle's position within these complex agro-ecosystems can be potentially degrading the water quality exiting these systems. GPS position data was collected from collars placed on grazing cattle at the research site: MacArthur Agro- ecology Research Center, Lake Placid, Florida. The data was collected across seasons (fall, winter, spring and summer) and in many fields from 2001 to 2003. The data has been analyzed using spatial analysis techniques. Information and spatial relationships from this analysis will be used to develop animal movement sub-models within a spatially-explicit water quality/hydrologic modeling system (ACRU2000).

  9. 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)

  10. 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.

  11. 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

  12. 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.

  13. The biophysical link between climate, water, and vegetation in bioenergy agro-ecosystems

    International Nuclear Information System (INIS)

    Land use change for bioenergy feedstocks is likely to intensify as energy demand rises simultaneously with increased pressure to minimize greenhouse gas emissions. Initial assessments of the impact of adopting bioenergy crops as a significant energy source have largely focused on the potential for bioenergy agroecosystems to provide global-scale climate regulating ecosystem services via biogeochemical processes. Such as those processes associated with carbon uptake, conversion, and storage that have the potential to reduce global greenhouse gas emissions (GHG). However, the expansion of bioenergy crops can also lead to direct biophysical impacts on climate through water regulating services. Perturbations of processes influencing terrestrial energy fluxes can result in impacts on climate and water across a spectrum of spatial and temporal scales. Here, we review the current state of knowledge about biophysical feedbacks between vegetation, water, and climate that would be affected by bioenergy-related land use change. The physical mechanisms involved in biophysical feedbacks are detailed, and interactions at leaf, field, regional, and global spatial scales are described. Locally, impacts on climate of biophysical changes associated with land use change for bioenergy crops can meet or exceed the biogeochemical changes in climate associated with rising GHG's, but these impacts have received far less attention. Realization of the importance of ecosystems in providing services that extend beyond biogeochemical GHG regulation and harvestable yields has led to significant debate regarding the viability of various feedstocks in many locations. The lack of data, and in some cases gaps in knowledge associated with biophysical and biochemical influences on land–atmosphere interactions, can lead to premature policy decisions. - Highlights: • The physical basis for biophysical impacts of expanding bioenergy agroecosystems on climate and water is described. • We

  14. 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...

  15. 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...

  16. 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.

  17. Ecological Recycling Agriculture to Enhance Agro-Ecosystem Services in the Baltic Sea Region: Guidelines for Implementation

    OpenAIRE

    Karin Stein-Bachinger; Moritz Reckling; Johann Bachinger; Johannes Hufnagel; Wijnand Koker; Artur Granstedt

    2015-01-01

    Eutrophication caused by agriculture is an increasing ecological threat to the Baltic Sea. Modern, resource-efficient farming systems based on integrated plant and animal production, effective nutrient recycling and low external inputs can enhance multiple agro-ecosystem services, resulting in reduced pollution. Practical examples of such farming systems are not widespread. Therefore, the Baltic Ecological Recycling Agriculture and Society (BERAS) Implementation project aimed to foster t...

  18. 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

  19. The Long-Term Agro-Ecosystem Research (LTAR) Network: A New In-Situ Data Network For Agriculture

    Science.gov (United States)

    Walbridge, M. R.

    2014-12-01

    Agriculture in the 21st Century faces significant challenges due to increases in the demand for agricultural products from a global population expected to reach 9.5 billion by 2050, changes in land use that are reducing the area of arable land worldwide, and the uncertainties associated with increasing climate variability and change. There is broad agreement that meeting these challenges will require significant changes in agro-ecosystem management at the landscape scale. In 2012, the USDA/ARS announced the reorganization of 10 existing benchmark watersheds, experimental ranges, and research farms into a Long-Term Agro-ecosystem Research (LTAR) network. Earlier this year, the LTAR network expanded to 18 sites, including 3 led by land grant universities and/or private foundations. The central question addressed by the LTAR network is, "How do we sustain or enhance productivity, profitability, and ecosystem services in agro-ecosystems and agricultural landscapes"? All 18 LTAR sites possess rich historical databases that extend up to 100 years into the past. However as LTAR moves forward, the focus is on collecting a core set of common measurements over the next 30-50 years that can be used to draw inferences regarding the nature of agricultural sustainability and how it varies across regional and continental-scale gradients. As such, LTAR is part long-term research network and part observatory network. Rather than focusing on a single site, each LTAR has developed regional partnerships that allow it to address agro-ecosystem function in the large basins and eco-climatic zones that underpin regional food production systems. Partners include other long-term in-situ data networks (e.g., Ameriflux, CZO, GRACEnet, LTER, NEON). 'Next steps' include designing and implementing a cross-site experiment addressing LTAR's central question.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. Using an Agroecosystem Services Approach to Assess Tillage Methods: A Case Study in the Shikma Region

    Directory of Open Access Journals (Sweden)

    Hila Sagie

    2015-10-01

    Full Text Available The use of ecosystem services (ES in agricultural management is expanding; however, its integration in decision making processes is still challenging. This project was formulated to examine the ES approach and its usefulness with regard to management dilemmas. The Shikma region, north of the Negev Desert, was chosen as a case study. The management issue identified was the effect of various alternatives (minimum-tillage, no-tillage, straw-mulch and stubble-grazing on the supply of ES. The expert-based ES assessments’ findings reveal that no-tillage has the potential to increase many agroecosystem services and be more profitable for the farmer and the public. However, trade-offs between different ES and among stakeholder groups make it difficult to reach an unequivocal conclusion. As we have found, the process of the study is as important as the results. Throughout the project, an effort was made to engage stakeholders and policy-makers and to define decision-making processes. The study suggests that the ES approach can be useful in expanding the scope of agricultural management beyond provisioning services and create collaborations among farmers, communities, national institutions and environmental organizations to advance conservation agriculture. The study provides guidelines for conducting a productive ES assessment process that will lead to enhanced awareness and implementation.

  9. 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

  10. 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

  11. 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.

  12. Threats to rainfed and canal irrigated agro-ecosystems of the Punjab, Pakistan by weed infestation

    International Nuclear Information System (INIS)

    To record the weed flora infesting the rainfed and canal irrigated arable fields in the Punjab province, three districts viz. Chakwal, Jhelum and Rawalpindi in rainfed agro-ecosystem, while three districts in canal irrigated wheat fields i.e., Sahiwal, Qasoor and Gujrat were surveyed comprehensively to examine weed spectra. Weeds occurring in various localities largely varied with the variation in the mode of irrigation i.e., Barani areas and Canal irrigated area. In Rainfed (Barani) areas Fumeria parviflora and Asphodelus tenuifolius were noted frequently while their representation was very rare or even absent in canal irrigated areas. Carthamus oxayacantha was also observed at some sites there. The only weeds growing infrequently were hardy grasses like Cynodon dactylon and Cyperus rotundus. None of the weed could cross the limits of occasional frequency level. Nevertheless, in canal irrigated areas Convolvulus arvensis, Anagalus arvensis, Chenopodium sp., Melilotus alba, Lepidium sativum, Lathyrus aphaca, Medicago denticulata, Rumex dentatus and Cynodon dactylon were frequently observed. Phalaris minor and Avena fatua formed very dense stands in many areas. Carthamus oxayacantha, Poa annua, Sonchus asper and Vicia sativa were recorded infrequently. The farmers of Sahiwal and Qasoor districts seem well informed about the importance and use of weedicides as a result the spectrum of weeds growing there was quite low and none of them could establish dense stands. (author)

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

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    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.

  14. Leaching of 14-Carbofuran into sub-surface water in vegetable agroecosystem

    International Nuclear Information System (INIS)

    An experimental setup was constructed to investigate leaching of 14CCarbofuran into sub-surface water through Bungor series sandy loam soil. The indoor lysimeter was constructed using homogenous and packed disturbed soil column. The outdoor lysimeter was constructed using undisturbed soil column. In the field, leachate production was influenced by rainfall intensity but tracer transport was independent of water transport to a certain degree. A high rainfall intensity at 39 DAA has not enhanced tracer leaching into sub-surface water in vegetable agroecosystem whereas a lower rainfall intensity at 21 DAA has enhanced its leaching. Indoor lysimeter behaved incoherently and showed non-parallel relationship between applied water and also volume of leachate produced with tracer transport. In both types of lysimeter, tracer transport and carbofuran transport generally correlated. Carbofuran and tracer were leached at a lower magnitude in outdoor lysimeter compared to the indoor lysimeter. The maximum total radioactivities leached were 1.1% and 0.4% of applied radio activities from indoor lysimeter and outdoor lysimeter at 35 and 21 DAA respectively. The maximum total carbofuran equivalent leached were 193.9 μg/L and 39.3 μg/L at 35 DAA and 21 DAA from indoor lysimeter and outdoor lysimeter respectively. (author)

  15. 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

  16. 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.

  17. Monitoring Antibiotic Residues and Corresponding Antibiotic Resistance Genes in an Agroecosystem

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    Yasser M. Awad

    2015-01-01

    Full Text Available Antibiotic resistance genes (ARGs have been commonly reported due to the overuse worldwide of antibiotics. Antibiotic overuse disturbs the environment and threatens public human health. The objective of this study was to measure the residual concentrations of veterinary antibiotics in the tetracycline group (TCs, including tetracycline (TC and chlortetracycline (CTC, as well as those in the sulfonamide group (SAs, including sulfamethazine (SMT, sulfamethoxazole (SMX, and sulfathiazole (STZ. We also isolated the corresponding ARGs in the agroecosystem. Four sediment samples and two rice paddy soil samples were collected from sites near a swine composting facility along the Naerincheon River in Hongcheon, Korea. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS was employed with a solid-phase extraction method to measure the concentration of each antibiotic. ARGs were identified by the qualitative polymerase chain-reaction using synthetic primers. SAs and their corresponding ARGs were highly detected in sediment samples whereas TCs were not detected except for sediments sample #1. ARGs for TCs and SAs were detected in rice paddy soils, while ARGs for TCs were only found in sediment #2 and #4. Continuous monitoring of antibiotic residue and its comprehensive impact on the environment is needed to ensure environmental health.

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

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    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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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) < "applying trap devices and environment-friendly insecticides 9 times" (0.83) < "applying common insecticides 14 times" (1.08). The treatment "applying frequency vibration lamps and environment-friendly insecticides 8 times" was considered as the best insect pest-controlling strategy in cabbage production in Shanghai, China. PMID:25906199

  4. [Diversity of insects captured by weaver spiders (Arachnida: Araneae) in the cocoa agroecosystem in Tabasco, Mexico].

    Science.gov (United States)

    Pérez-de La Cruz, Manuel; Sánchez-Soto, Saúl; Ortíz-García, Carlos F; Zapata-Mata, Raúl; Cruz-Pérez, Aracely de la

    2007-01-01

    The aim of this work was to know the diversity of insects captured by weaver spiders in a plantation of cocoa (Theobroma cacao L.) of 6 ha in the State of Tabasco, Mexico. The study was carried out from July 2004 to June 2005 by means biweekly samples of the insects captured on the spiders webs. The total of 3,041 webs of 54 species of spiders belonging to seven families (Araneidae, Theridiidae, Tetragnathidae, Uloboridae, Pholcidae, Dyctinidae and Linyphiidae) were revised. We found 1,749 specimens belonging to 10 orders of insects, represented by 93 families, the majority of Coleoptera, Diptera and Hemiptera that constituted 74% of the identified families. The biggest number of specimens of all orders was captured by Araneidae, except of Isoptera, whose specimens were captured mainly by the family Theridiidae. The index of diversity (H'), evenness (J') and similarity (Is), applied to know the diversity of families of insects captured among families of spiders, varied from 0.00 to 3.24, 0.00 to 0.81, and 0.04 to 0.522, respectively. We conclude that there is a wide diversity of insects predated by the weaver spiders in the cocoa agroecosystem, and that there are species that can be promising for the biological control of pests. PMID:17420866

  5. Estimation of the external and internal irradiation doses of agroecosystem objects from regular and emergency emissions of the nuclear power plant

    International Nuclear Information System (INIS)

    The forecast of doses of external and internal irradiation of agroecosystem objects from regular and emergency emissions of the nuclear power plant is carried out . The forecast is constructed with use of the geoinformation model allowing operatively, according to service of external dosimetry of the nuclear power plant and meteorological data, to estimate the degree of radioactive pollution of the ground layer of atmosphere and farmlands in a zone of supervision of the nuclear power plant, to estimate doses of an irradiation of agroecosystem objects and influence of radioactive losses. (authors)

  6. 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

  7. Impact of heavy repeated long term pesticide applications on soil properties in a cotton agroecosystem

    International Nuclear Information System (INIS)

    A study was conducted under field conditions to investigate the effects of heavy repeated long term pesticide applications, at their recommended doses, on some biological properties in relation to the cotton agroecosystem at NIAB, Faisalabad, Pakistan. Control, test and treated soils before (BPA) and after pesticide applications (APA) were collected and analyzed at different stages of pesticide applications. The selective tests were measurements of microbial numbers, basal as well as substrate-induced respiration, nitrification, Fe-III reduction and the activities, of dehydrogenase and arginine deaminase. Endosulfan, profenophos + alphamethrin and methamidophos inhibited while monocrotophos and bifenthrin + acetamiprid enhanced the bacterial population numbers. The fungal population was depressed with endosulfan while monocrotophos, profenophos and methamidophos stimulated it. All other applied pesticides did not cause any appreciable change in total bacterial and fungal populations throughout the study period. Monocrotophos, propargite, endosulfan alone or with dimethoate and profenophos with cypermethrin or with ethion inhibited the respiration and hence affected the biomass. All other pesticides had no effect in test and treated soils compared to control soil. No pronounced inhibition or stimulation was seen in respiration after several weeks following the applications of pesticide. Endosulfan, endosulfan with dimethoate, methamidophos stimulated while profenophos + cypermethrin and bifenthrin + endosulfan inhibited the nitrification. All other pesticide applications showed similar nitrification rates in test and treated soils compared to control soil. Iron reduction capacity was stimulated by dimethoate + endosulfan and propenophos + cypermethrin and profenphos, methamidophos, propargite and diafenthiuron + profenophos reduced it. Soil dehydrogenase activity was inhibited by methamidophos, fenpropathrin, endosulfan + dimethoate and bifenthrin + ethion

  8. The role of ecological models in linking ecological risk assessment to ecosystem services in agroecosystems.

    Science.gov (United States)

    Galic, Nika; Schmolke, Amelie; Forbes, Valery; Baveco, Hans; van den Brink, Paul J

    2012-01-15

    Agricultural practices are essential for sustaining the human population, but at the same time they can directly disrupt ecosystem functioning. Ecological risk assessment (ERA) aims to estimate possible adverse effects of human activities on ecosystems and their parts. Current ERA practices, however, incorporate very little ecology and base the risk estimates on the results of standard tests with several standard species. The main obstacles for a more ecologically relevant ERA are the lack of clear protection goals and the inherent complexity of ecosystems that is hard to approach empirically. In this paper, we argue that the ecosystem services framework offers an opportunity to define clear and ecologically relevant protection goals. At the same time, ecological models provide the tools to address ecological complexity to the degree needed to link measurement endpoints and ecosystem services, and to quantify service provision and possible adverse effects from human activities. We focus on the ecosystem services relevant for agroecosystem functioning, including pollination, biocontrol and eutrophication effects and present modeling studies relevant for quantification of each of the services. The challenges of the ecosystem services approach are discussed as well as the limitations of ecological models in the context of ERA. A broad, multi-stakeholder dialog is necessary to aid the definition of protection goals in terms of services delivered by ecosystems and their parts. The need to capture spatio-temporal dynamics and possible interactions among service providers pose challenges for ecological models as a basis for decision making. However, we argue that both fields are advancing quickly and can prove very valuable in achieving more ecologically relevant ERA. PMID:21802704

  9. 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

  10. 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.

  11. 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)

  12. Relevant magnetic and soil parameters as potential indicators of soil conservation status of Mediterranean agroecosystems

    Science.gov (United States)

    Quijano, Laura; Chaparro, Marcos A. E.; Marié, Débora C.; Gaspar, Leticia; Navas, Ana

    2014-09-01

    The main sources of magnetic minerals in soils unaffected by anthropogenic pollution are iron oxides and hydroxides derived from parent materials through soil formation processes. Soil magnetic minerals can be used as indicators of environmental factors including soil forming processes, degree of pedogenesis, weathering processes and biological activities. In this study measurements of magnetic susceptibility are used to detect the presence and the concentration of soil magnetic minerals in topsoil and bulk samples in a small cultivated field, which forms a hydrological unit that can be considered to be representative of the rainfed agroecosystems of Mediterranean mountain environments. Additional magnetic studies such as isothermal remanent magnetization (IRM), anhysteretic remanent magnetization (ARM) and thermomagnetic measurements are used to identify and characterize the magnetic mineralogy of soil minerals. The objectives were to analyse the spatial variability of the magnetic parameters to assess whether topographic factors, soil redistribution processes, and soil properties such as soil texture, organic matter and carbonate contents analysed in this study, are related to the spatial distribution pattern of magnetic properties. The medians of mass specific magnetic susceptibility at low frequency (χlf) were 36.0 and 31.1 × 10-8 m3 kg-1 in bulk and topsoil samples respectively. High correlation coefficients were found between the χlf in topsoil and bulk core samples (r = 0.951, p SI. High correlation coefficients were found between χlf in topsoil measured in the laboratory and volumetric magnetic susceptibility field measurements (r = 0.894, p physical processes. Runoff redistributes soil components including magnetic minerals and exports fine particles out the field. This research contributed to further knowledge on the application of soil magnetic properties to derive useful information on soil processes in Mediterranean cultivated soils.

  13. Climate determined differences in carbon dioxide fluxes dynamics between two comparable agroecosystems of Central Russia

    Science.gov (United States)

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

    2015-04-01

    Creation of Russian part of Fluxnet - Rusfluxnet, aims to fill the carbon dioxide fluxes data shortage. Because 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. For the first time eddy covariance (EC) GHG study has been conducted at two representative agroecosystems of Central Russia belonging to different climate zones (climate and soils), but both with the same land use: the both fields were under barley. The study was carried out in 2013 and supported by RF Government grant No. 11.G34.31.0079. The first agricultural field located at Precision Farming Experimental Field of the Timiryazev Agricultural University situated in Moscow. It's arable Albeluvisols Umbric have around 1% of SOC, 5.4 pH(KCl) and NPK medium-enhanced contents in sandy loam topsoil. The field was used for barley planting (Hordeum vulgare L., breeding line Mihailovsky). Sowing was in early May 2013 and harvest was in August, 14. The second agricultural field near the Pristen placed at Kursk region of Russia. It's arable Chernozems have around 4% of SOC, 6.5 pH(KCl) and NPK high-enhanced contents in sandy loam topsoil. The field was used for barley planting (Hordeum vulgare L., breeding line Xanadu). Sowing was 25-27 of April and harvest was 14-19 of August. Instrumental equipments (mainly LI-COR) were the same for both stations. Both towers height was 1.4m. Footprints were considered by fields edges, and were about 55m for Moscow and about 150m for Pristen. Canopy growth and snow melting were taking into account in the model. Surface roughness was neglected. Calculations were done using EddyPro software. Since Pristen field is 600 km to the South than the Moscow one, higher PAR values were observed for Pristen field. Modal PAR values were 600 and 400 umol m-2 s-1 for Pristen and Moscow fields respectively. Nevertheless temporal pattern of PAR was similar for both

  14. 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. PMID:25343981

  15. 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.

  16. 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.

  17. 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

  18. Seasonal dynamic of the occurrence of the gregarines infection of Harpalus rufipes (Coleoptera, Carabidae in agroecosystem

    Directory of Open Access Journals (Sweden)

    D. Y. Reshetnyak

    2015-08-01

    Full Text Available Relationships in the “parasite-host” system are closely interrelated and occur at all levels from the molecular to behavioral and population ones. There are two models of realization of these relations. The first case is when the parasites are uniformly distributed in the host population. High extensiveness of invasion is accompanied by its low intensity. The second case is when a part of host population is infected with parasites, but the negative impact is manifested to the maximum extent. Invasion of the ground beetle Harpalus rufipes (De Geer, 1774, dwelling in sweet corn agroecosystems located in the vicinity of Dnipropetrovsk near Doslidnoe village, by several gregarines species is investigated in this study. H. rufipes is an abundant, ubiquitous species, living in extremely wide range of terrestrial ecosystems, with especially high populations inhabiting anthropogenically transformed environments. H. rufipes has a wide range of feeding. This species is distributed in the Central and Eastern Europe, and introduced to North America. Gregarines were found in the intestines of 20 individuals of H. rufipes from 190 (10.5%: Gregarina ovata Dufour, 1828, G. steini Berndt, 1902, G. amarae (Hammerschmidt, 1839 Frantzius, 1848, Clitellocephalus ophoni (Tuzet and Ormieres, 1956 Clopton, 2002, Torogregarina sphinx Clopton, 1998, Gigaductus macrospora Filipponi, 1948 and G. elongatus (Moriggi, 1943 Filipponi, 1948. There is high level of infestation of C. ophoni and G. steini. At the same time, not more than three species of the gregarines were localized in the beetle body. Seasonal dynamic of occurrence of the gregarines is as follows. Maximal indices of occurrence are found at the end of August (22.2% and minimal ones at the end of June (4.8%. The highest total number of gregarines (383 ind. is recorded at the end of August, the lowest one is fixed at the beginning of September (33 ind.. Indices of gregarine species dominance are as follows

  19. 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

  20. A new species of Syphacia (Nematoda: Oxyuridae) from Calomys laucha (Rodentia: Cricetidae) in an agroecosystem of central Argentina.

    Science.gov (United States)

    Herrera, Elba Juliana Rojas; Miño, Mariela Haydée; Notarnicola, Juliana; Robles, María del Rosario

    2011-08-01

    A new oxyurid nematode Syphacia hodarae n. sp. is described from the cecum and rectum of the cricetid rodent Calomys laucha Fischer, 1814 (Sigmodontinae, Phyllotini), captured in an agroecosystem of central Argentina. The new species is distinguished from other members of the genus mainly by the shape of the cephalic plate, presence of cervical alae in females, absence of lateral alae, and absence of deirids. Some characters are shared with Syphacia carlitosi, a parasite of Akodon azarae from the wetlands in Argentina. However, S. hodarae can be differentiated from this species by the absence of ornamentation on the accessory hook of the gubernaculum, length of spicule and gubernaculum, size of the eggs, and distance to the vulva from the anterior end. This is the first record of a Syphacia species from the tribe Phyllotini in Argentina, and the first time a Syphacia species is reported from C. laucha . PMID:21506826

  1. 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.

  2. 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 (Midwest U.S., the management of fields changes the latent heat flux through different crop choices, planting and 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

  3. 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

  4. Carbon fluxes and the carbon budget in agroecosystems on agro-gray soils of the forest-steppe in the Baikal region

    Science.gov (United States)

    Pomazkina, L. V.; Sokolova, L. G.; Zvyagintseva, E. N.

    2013-06-01

    Field studies devoted to the transformation of the carbon cycle in agroecosystems on agro-gray soils (including soils contaminated with fluorides from aluminum smelters) in dependence on the changes in the hydrothermic conditions were performed for the first time within the framework of the long-term (1996-2010) soil monitoring in the forest-steppe zone of the Baikal region. The major attention was paid to the impact of the environmental factors on the synthesis and microbial destruction of organic carbon compounds. Certain differences in the fluxes and budget of carbon were found for the plots with cereal and row crops and for the permanent and annual fallow plots. The adverse effect of fluorides manifested itself in the enhanced C-CO2 emission under unfavorable water and temperature conditions. The long-term average C-CO2 emission from the soils contaminated with fluorides in agroecosystems with wheat after fallow was higher than that from the uncontaminated soil (179 and 198 g of C/m2, respectively) and higher than that in the agroecosystems with a potato monoculture (129 and 141 g of C/m2, respectively). At the same time, no significant variations in the content of the carbon of the microbial biomass (Cmicr) in dependence on the environmental factors were found. The utilization of carbon for respiration and for growth of the soil microorganisms on the contaminated soil were unbalanced in particular years and for the entire period of the observations. The ratio between the fluxes of the net mineralized and re-immobilized carbon was used for the integral assessment of the functioning regime of the agroecosystems and the loads on them. Independently from the soil contamination with fluorides, the loads on the agroecosystems with wheat were close to the maximum permissible value, and the loads on the agroecosystems with potatoes were permissible. It was shown that the carbon deficit in the uncontaminated soils was similar under the wheat and potatoes (-30 and -28 g

  5. 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)

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

    OpenAIRE

    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 descr...

  7. 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...

  8. 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...

  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. Regional tritrophic relationship patterns of five aphid parasitoid species (Hymenoptera: Braconidae: Aphidiinae) in agroecosystem-dominated landscapes of southeastern Europe.

    Science.gov (United States)

    Tomanović, Zeljko; Kavallieratos, Nickolas G; Starý, Petr; Stanisavljević, Ljubisa Z; Cetković, Aleksandar; Stamenković, Srdjan; Jovanović, Slobodan; Athanassiou, Christos G

    2009-06-01

    . Even with these complexities taken into account, the overall trend is that noncrop habitats support more parasitoid-aphid combinations and more so in the continental than in Mediterranean regions, although not always statistically significant. As mentioned, large number of noncrop aphid hosts, especially for Lysiphlebus fabarum (Marshall), Praon volucre (Haliday) and Aphidius colemani Viereck, can significantly enhance the population buildup for these important parasitoids around agroecosystems. These facts can be important in biological aphid pest control in the region. Although not easily quantified, the overall positive effects of larger parasitoid diversity in noncrop habitats are undoubtedly related to the distribution and structure of noncrop habitat patches in agroecosystems at a landscape scale. PMID:19610396

  11. Critical pathways of radionuclides to man from agro-ecosystems. Annual progress report, October 1980-September 1981

    International Nuclear Information System (INIS)

    The research program has as its objectives the description of the fate and behavior of radionuclides released to the environment from nuclear fuel chemical separations facilities. The greenhouse uptake studies designed to examine factors which possibly can alter phytoavailability of radionuclides have shown only slight differences among crop species or soil treatment (lime or lime plus chelate) in Pu or Cm uptake. The temporal effect on Pu and Cm uptake, observed from a partial data set, is inconclusive, with variable effects from different crop species, radionuclides, and soil treatments. Cesium uptake shows variable response with different crop species but generally decreases with time. Broadleaf crops grown in the field hve differing Pu concentrations which appear to be associated with plant morphology, with some species exceeding those concentrations observed for wheat and soybean crops. In crops that tend to trap aerially deposited Pu, washing the leaves removed > 50% of the Pu. Uranium contamination of a wheat crop grown near the F-Area separations facility appears to be strongly affected by root uptake. This is in distinct contrast to the behavior of Pu in agro-ecosystems, where surficial pathways are the dominant modes of contamination, and is probably related to: (1) the ubiquitous presence of naturally occurring U isotopes; and (2) a greater concentration ratio for U than for Pu

  12. Characterization and evaluation of agro-ecosystems on a farm scale a study case: The Paysandu farming center (Medellin. Colombia)

    International Nuclear Information System (INIS)

    The state, condition, and tendencies of the agro-ecosystems (AE) of the Paysandu farming center of the Universidad Nacional de Colombia, sede Medellin 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 Velez and Gasto (1999), in terms of AE diversity and of the uses, management, and technological acceptance, techno-structural and hydro-structural endowment, potential productivity and services to the local, regional, and national society. The results showed that the greater part of the center (72%) has very low RT; which does not permit the establishment of mechanized advanced agro-technological management systems (SMA) however, 69.8% of the area is managed with SMA adequate for the restrictions imposed by the RT sixty-two percent of the area of the center, principally under pasture cover for dairy cattle production, is managed with advanced SMA. As a result of the interaction between RT and the SMA employed, six AE were identified, of which three, that represent 69.8% of the area (100.2 ha.), are managed with technologies adequate for their biophysical conditions or with technological receptivity (adequate IT), and the other three, that represent 28,57% of the are (43.1 ha.) ore managed with technologies that do not correspond to their RT conditions (tradition IT) which leads to a deterioration of their biophysical and ecological conditions

  13. 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

  14. [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) 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. PMID:24015535

  15. The synergistic effects of 2,4-D dimethyl amine and propanil herbicides on weed population in rice agroecosystem

    International Nuclear Information System (INIS)

    Four treatments with the herbicides 2,4-D dimethyl amine and propanil were carried out in two consecutive rice planting seasons, to study the synergistic effect of 2,4-D dimethyl amine and propanil on rice weed populations at Pasir Panjang, the Northwest Selangor Project (PBLS), Projek Barat Laut Selangor) rice granary area. The treatments were control, 1x recommended rate (single dose), 2x recommended rate (double dose) of 2,4-D dimethyl amine and farmer practice. In all plots, propanil herbicide was applied at similar rate. Among the ecological indices measured were Simpson Index of diversity and importance (I.V.). A total number of 19 weed species was identified and the most common important weed was Najas graminae Del. The second most commonly found important weed was Scirpus lateriflorus Gmel. Other important weeds frequently found were Echinochloa crus-galli (L.) Beauv. and Fimbristylis miliacea (L.) Vahl. In the rice agroecosystem, species diversity of weeds was affected but total weed biomass was not affected synergistically by the mixture of 2,4-D dimethyl amine and propanil. The negative synergistic effect of 2,4-D dimethyl amine and propanil was to increase the total biomass of Scirpus lateriflorus, at 2x recommended dose rate of 2,4-D dimethyl amine. (Author)

  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. 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.

  18. 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

    , and future. It comprises of three key stages. Stage 1 quantifies land use change between 1956 and 2008, assesses the impacts on landscape fragmentation, and identifies important drivers of the detected changes. Stage 2 examines the linkage between farmer heterogeneity and the diversity of agricultural...... of their households and of their farm management. Different types of farmers are expected to pursue different land use directions with important impacts on future provision of agro-ecosystem services. Results from the final stage highlight a diverging future. To illustrate, while CA projection...

  19. Functionally ecological assessment of C dominant pools and fluxes in field agroecosystems with sod-podzoluvosols at the Central Region of Russia

    Science.gov (United States)

    Mazirov, Ilya; Vizirskaya, Mariya; Epikhina, Anna; Vasenev, Ivan; Valentini, Riccardo; Meshalkina, Julia

    2014-05-01

    The Global Change problem has obvious interaction with greenhouse gases (GHG) emission. The principal GHG is carbon dioxide. There is a lot of data on its fluxes but the Central Region of Russia is still one of less investigated area especially in case of agroecosystem carbon dioxide fluxes monitoring by chambers and eddy covariance methods combined application. Our research has been at the representative key plots of cultivated sod-podzoluvosols located at the Precision Farming Experimental Field of the Russian Timiryazev State Agricultural University (Moscow) in 2012-2013 in frame of RF Government grant 11.G34.31.0079 and RFBR grant 11-04-01376 activities. The research include the detailed soil cover patterns morphogenetic investigation, soil C pools dynamic analysis, soil CO2 flux decade-based monitoring by method of exposition chambers with IRGA (infra red gas analyzer) and agroecosystem CO2 flux seasonal monitoring by two eddy covariance stations in frame of 4 ha experimental plot. There were two crop versions (barley and grass mixture), and in case of chamber analysis - also two agrotecnology versions (traditional and no-till ones) with soil temperature and moisture analysis too. The results have shown high daily and seasonal dynamic of soil and agroecosystem CO2 emission. The beginning of vegetation period (until plant height of 10-12 cm) is characterized by high average soil CO2 emission and adsorption at the same time. The adsorption is significantly higher. The resulted CO2 absorption during the day is approximately two times higher than emissions at night. After harvesting CO2 emission is becoming essentially higher than adsorption. In 2012 data have shown for barley the small predominance of CO2 emissions over the absorption. The daily dynamics of soil CO2 emissions depends on the air temperature dynamics with the correlation coefficient changes from 0.86 at the beginning of the season to 0.52 and 0.38 at the middle and at the end of one. Soil moisture

  20. 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

  1. 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

  2. Critical pathways of radionuclides to man from agro-ecosystems. Annual progress report, October 1981-September 1982

    International Nuclear Information System (INIS)

    This research program has as its primary objective the description of the fate and behavior of radionuclides released to the environment from nuclear fuel chemical separations facilities. It can be grouped into two general modes of scientific approach: 1) controlled environment greenhouse uptake experiments and 2) field studies. Both modes utilize the uniquely contaminated soils and/or the ongoing operations of the separations facilities at the SRP. The greenhouse experiments seek to determine the long-term availabiltiy of radionuclides to agricultural plants from soils contaminated by a chemical separations facility. In these experiments we are also investigating factors which might modify availability of nuclear contaminants such as different crop species, soil amendments, and soil types. The field research focuses primarily on the environmental behavior in agricultural corps of chronic low-level releases of uranium. From the greenhouse uptake studies, any temporal effect on Pu and Cm uptake is inconclusive, with variable effects from different crop species, radionuclides, and soil treatments. in plant tissues of wheat and soybean crops grown near F-Area separations facility, root uptake is more important in contributing to U concentrations than Pu. This is in distinct contrast to the behavior of Pu in agro-ecosystems, where surficial pathways are the dominant modes of contamination, and is probably related to (1) the ubiquitous presence of naturally occurring U isotopes and (2) a greater phytoavailability of U than did wheat. Completion of corn radionuclide analysis will allow comparisons between Pu and U behavior and among wheat, soybean, and corn crops

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Soil physical conditions as livestock treading effect in tropical Agroecosystem of dryland and strategies to mitigate desertification risk

    Science.gov (United States)

    Florentino, A.; Torres, D.; Ospina, A.; Contreras, J.; Palma, Z.; Silvera, J.

    2012-04-01

    higher quality level than bare soils. Some predictive regression equation had a high R2 value and was a useful tool for to evaluate the risk of extreme climatic changes and to mitigate their detrimental effects. We conclude that the global climatic change (CCG) will have a negative effect on these agroecosystems functions, mainly in soil and water conservation, carbon sequestration, and productivity. Natural recovery of soil physical properties from treading damage of pastoral soils will be possible in the future with the implementation of soil management strategies, mainly through re-vegetation and recuperation of the BSC. Key word: Soil structure; aggregate stability; soil sealing index; hydraulic conductivity of surface sealing.

  10. 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.

  11. 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 homegarden 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. PMID:24790810

  12. 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

  13. 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.

  14. 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.

  15. 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 ...

  16. 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...

  17. 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

  18. 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

  19. 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

  20. Atmospheric deposition, resuspension, and root uptake of Pu 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. Plutonium on vegetation surfaces may be transferred to grain surfaces during mechanical harvesting. Data obtained from corn grown near the U.S. Department of Energy's H-Area nuclear fuel chemical separations facility on the Savannah River Site were used to estimate 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 greater than resuspension of soil to grain surfaces greater than 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 Pu inventory is absorbed and translocated to grains

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Pijika Timsuksai

    Full Text Available 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.

  8. 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.

  9. 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

  10. 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.

  11. Performance of evapotranspiration models for a maize agro-ecosystem: from bare soil to maximum coverage in irrigated and rainfed conditions

    Science.gov (United States)

    Gharsallah, O.; Facchi, A.; Gandolfi, C.

    2012-04-01

    To assure an efficient management and planning of irrigation water resources, an accurate computation of actual evapotranspiration (ET) from cropped surfaces is needed. ET models can be classified in two categories: "direct" methods, based on the original Penman-Monteith (P-M) equation, in which the canopy resistance rc is modelled, and "indirect" methods, based on the calculation of ET for a well-watered reference grass (ET0) with constant rc multiplied by a crop coefficient that represents the relative rate of ET from a specific crop and condition to that of the reference. This last procedure, standardized by FAO-56 bulletin, is the most widely adopted for the estimation of ET. However, in literature there are evidences that direct methods (P-M models with rc modelled) are still the most performing. In fact, for indirect methods, errors introduced by the calculation of ET0considering a constant rc for reference crop and by the estimation of the crop coefficient, which actually integrates several physical and biological factors, can be relevant. This study evaluates the performance of different models for the estimation of ET for a maize agro-ecosystem in the Padana Plain (Northern Italy). The following models have been considered: 1) the "one-step" P-M model using a constant daily canopy resistance following the classical Monteith approach; 2) the "one-step" P-M model using a variable canopy resistance based on the approach of Katerji-Perrier, in which rc is calculated as a function of climate variables, aerodynamic resistance, vegetation type and its water status; 3) the "two-step" Shuttleworth model as updated by Shuttleworth and Gurney (1990), which combines one-dimensional models of crop transpiration and of soil evaporation, where canopy and soil surface resistances regulate the heat and mass transfer at the plant and soil surfaces, and aerodynamic resistances regulate those between these surfaces and the atmospheric boundary layer; 5) the indirect "single

  12. 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

  13. 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

  14. Banco de sementes e estabelecimento de plantas daninhas em agroecossistemas Seed bank in the soil and the establishment of weeds in agro-ecosystems

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    Ricardo Carmona

    1995-01-01

    Full Text Available Em novembro/92 o banco de sementes no solo foi estimado, a 0-10 cm de profundidade, em alguns agroecossistemas: área de rotação de culturas, várzea, pomar de cítrus e pastagem de Brachiaria brizantha, no Distrito Federal, Brasil. Esta estimativa foi realizada através da observação da emergência de plântulas em amostras de solo incubadas, com e sem lavagem através de peneira e presença ou ausência de nitrato de potássio. A lavagem do solo para redução de volume, seguida de utilização de nitrato de potássio, mostrou-se desvantajosa para a determinação dos bancos de sementes viáveis detectadas nas amostras. A quantidade média de sementes por metro quadrado foi de 22313 na várzea, 6768 na área de rotação, 3595 nas coroas do pomar e 529 na pastagem. Verificou-se que as plantas infestantes estabelecidas em maio/93 nos agroecossistemas, representavam, em relação á quantidade inicial de sementes: 0,34% na pastagem, 0,71% na várzea, 1,48% nas coroas do pomar e 1,56% na área de rotação de culturas. Estas plantas seriam aquelas que supostamente mais contribuíram para a manutenção dos bancos de sementes no solo. Houve uma correlação direta do banco de sementes com o número de espécies e indivíduos presentes nos agroecossistemas. As espécies predominantes nas áreas anualmente perturbadas foram Ageratum conyzoides, Bidens pilosa, Cenchrus echinatus, Commelina benghalensis, Emilia sonchifolia, Euphorbia heterophylla e Richardia brasiliensis. Brachiaria spp predominou nas entrelinhas do pomar, enquanto na pastagem as poucas plantas daninhas presentes eram espécies de cerrado. A similaridade entre agroecossistemas, com relação às plantas daninhas foi maior entre as áreas mais perturbadas, como áreas de rotação de culturas, várzea e coroas do pomar.The seed bank in the soil was estimated in November/92 at 0-10 cm depth in some agro-ecosystems: arable land, meadow land, citrus orchard and a Brachiaria brizantha

  15. Atmospheric deposition as an important nitrogen load to a typical agro-ecosystem in the Huang-Huai-Hai Plain. 2. Seasonal and inter-annual variations and their implications (2008-2012)

    Science.gov (United States)

    Huang, Ping; Zhang, Jiabao; Ma, Donghao; Wen, Zhaofei; Wu, Shengjun; Garland, Gina; Pereira, Engil Isadora Pujol; Zhu, Anning; Xin, Xiuli; Zhang, Congzhi

    2016-03-01

    Atmospheric nitrogen (N) deposition, an important N source to agro-ecosystems, has increased intensively in China during recent decades. However, knowledge on temporal variations of total N deposition and their influencing factors is limited due to lack of systematic monitoring data. In this study, total N deposition, including dry and wet components, was monitored using the water surrogate surface method for a typical agro-ecosystem with a winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) rotation system in the Huang-Huai-Hai Plain from May 2008 to April 2012. The results indicated that annual total N deposition ranged from 23.8 kg N ha-1 (2009-2010) to 40.3 kg N ha-1 (2008-2009) and averaged 31.8 kg N ha-1. Great inter-annual variations were observed during the sampling period, due to differences in annual rainfall and gaseous N losses from farmlands. Monthly total N deposition varied greatly, from less than 0.6 kg N ha-1 (January, 2010) to over 8.0 kg N ha-1 (August, 2008), with a mean value of 2.6 kg N ha-1. In contrast to wet deposition, dry portions generally contributed more to the total, except in the precipitation-intensive months, accounting for 65% in average. NH4+ -N was the dominant species in N deposition and its contribution to total deposition varied from 6% (December, 2009) to 79% (July, 2008), averaging 53%. The role of organic N (O-N) in both dry and wet deposition was equal to or even greater than that of NO3- -N. Influencing factors such as precipitation and its seasonal distribution, reactive N sources, vegetation status, field management practices, and weather conditions were responsible for the temporal variations of atmospheric N deposition and its components. These results are helpful for reducing the knowledge gaps in the temporal variations of atmospheric N deposition and their influencing factors in different ecosystems, to improve the understandings on N budget in the typical agro-ecosystem, and to provide references

  16. 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.

  17. THREATS TO BIOTOPES IN AGROECOSYSTEMS

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    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.

  18. 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...

  19. 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

  20. An approach to assess NEE and C-costs associated with an energy-crop production at different erosion-induced transient states in a typical Northeastern Germany landscape using process-based agroecosystem modeling

    Science.gov (United States)

    Chatskikh, D.; Nendel, C.; Hagemann, U.; Specka, X.; Augustin, J.; Sommer, M.; Van Oost, K.

    2012-04-01

    Net Ecosystem Exchange (NEE) and C-costs associated with energy-crop production systems which are outside of NEE must be determined to suggest optimal mitigation options. In theory, NEE can be positive, if SOC is building up, neutral or balanced, with no change in SOC, or negative, if SOC is lost as a result of a soil degradation processes. Unclearness in complex multiscale interactions between different processes in the landscape in combination with a well-known wide range of uncertainties around NEE estimations makes these estimations for landscape scale scarce. In this study we used a process-based modeling to assess C-costs associated with soil erosion, assessing NEE at different erosion-induced transient states in the experiment settled Northeastern Germany (near Dedelow) in a representative section of younger landscape of hummocky ground moraine (CarboZALF-D). We used Monica, a soil-crop-atmosphere model, which is well-validated for various crops and soil in Germany. In the model, NEE (=-NEP) refer to NPP minus C losses in heterotrophic respiration, while NBE (=-NBP) refers to the change in SOC stocks after C losses due to regular (e.g. soil erosion) or occasional (e.g. harvest) disturbances. In this study we applied Monica to analyze relationships between past geomorphic processes, landscape position, crop growth and NEE. In this study we were interested in general trends and associated agroecosystem properties, rather than on magnitude of the fluxes. The results showed that past soil redistribution affected NEE at both positions, while the Monica-based scenarios in combination with data-based interpolations helped to interpret the NEE budgets. The model captured the magnitude of differences in the daily NEE values, but also the differences in an accumulated NEE fluxes between different erosion-induced transient states. Thus for both eroded and deposited positions NEE was negative. However absolute values of NEE were smaller for the deposited site compare to

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. NUEVOS REGISTROS DE PLANTAS HOSPEDERAS Y DISPONIBILIDAD DE RECURSOS PARA MARIPOSAS ITHOMIINI (LEPIDOPTERA: NYMPHALIDAE: DANAINAE, EN AGROECOSISTEMAS DE CAFÉ COLOMBIANOS NEW HOST PLANT RECORDS AND RESOURCE AVAILABILITY TO ITHOMIINI BUTTERFLIES (LEPIDOPTERA: NYMPHALIDAE: DANAINAE, IN COLOMBIAN COFFEE AGROECOSYSTEMS

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    Sandra B. Muriel

    2011-12-01

    Full Text Available En el trópico se dispone de pocos datos de la mayoría de los organismos, incluyendo las mariposas, en aspectos claves de su ciclo de vida, sus plantas hospederas y factores explicativos de su diversidad y abundancia. El objetivo de este trabajo fue identificar las plantas hospederas de larvas Ithomiini (Lepidoptera en agroecosistemas de café y evaluar el efecto de las variables: sistema de producción, área en bosque y diversidad de hospederas sobre la diversidad y abundancia de este grupo. En seis fincas de café de Fredonia (Antioquia, Colombia, se recolectaron plantas de las familias Apocynaceae, Gesneriaceae y Solanaceae, que fueron identificadas en los Herbarios HUA y MEDEL de Medellín. En las fincas se registraron los adultos observados en vuelo y se recolectaron huevos, larvas y pupas de Ithomiini de sus plantas hospederas para su cría en laboratorio, hasta la emergencia de adultos. Se determinó el porcentaje de sobrevivencia y mortalidad debida a parasitoidismo. Los datos de diversidad se analizaron por medio de un Análisis de Regresión de Poisson. En los agroecosistemas de café se registraron 27 especies vegetales y 27 mariposas adultas Ithomiini, en laboratorio, se criaron 326 individuos de ocho especies, recolectados sobre siete plantas de la familia Solanaceae. Dos plantas constituyen registros nuevos como hospederas de las especies de Lepidoptera: Solanum atropurpureum hospedera de Mechanitis menapis y Solanum deflexiflorum hospedera de Pteronymia picta y P. latilla. La diversidad de Ithomiini fue explicada por la diversidad de hospederas y por el sistema de sombrío.In the tropics, few data are available for most organisms, included butterflies, on key aspects of their life cycles, host plants, and explanatory factors of its diversity and abundance. The objective of this study was to identify the larval host plants of Ithomiini (Lepidoptera larvae in coffee agroecosystems and to evaluate the effect of the following

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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

  13. Características edafoclimáticas e informações socioeconômicas no diagnóstico de agroecossistemas da região de São Carlos, SP Soil and climate characteristics and socio-economic data in the diagnostic of agroecosystems of São Carlos region, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Luís Fernando Guedes Pinto

    2001-11-01

    Full Text Available O planejamento regional de agroecossistemas é um componente fundamental para a sustentabilidade da atividade agrícola, devendo considerar a realidade biofísica e socioeconômica. A agropecuária cumpre importante papel na região de São Carlos, SP, porém esta localiza-se em grande parte numa área de preservação ambiental. Este trabalho visou delimitar a Zona Agroecológica dessa região e diagnosticar seus agroecossistemas por meio de informações edafoclimáticas e socioeconômicas. A delimitação foi baseada no clima, geomorfologia e divisão administrativa. Da área delimitada estudou-se o clima, pedologia, uso da terra, estrutura fundiária e o manejo dos agroecossistemas. A Zona delimitada ocupa 286.824,08 ha, e é composta pelos municípios de Analândia, Itirapina, Santa Maria da Serra, São Carlos, São Pedro e Torrinha. Há potencial para a atividade agrícola, ocorrendo principalmente solos arenosos e de baixa fertilidade. Pastagens e cana-de-açúcar são os usos predominantes; a distribuição da posse da terra é desigual, e existe risco de degradação ambiental, pois não se empregam práticas compatíveis com as características naturais. Recomenda-se o uso de práticas que maximizem a conservação do solo, sua correção, e o aproveitamento de seus nutrientes, assim como o cultivo de espécies adaptadas a solos arenosos, que sejam pouco exigentes em fertilidade e resistentes a estresse hídrico.Regional planning of agroecosystems is a key component in the sustainability of agriculture and it should consider the biophysical and socio-economic reality. Agriculture plays an important role in the region of São Carlos, SP, Brazil, but it is located in an area of environmental conservation. This work aimed to delimit the Agroecological Zone of this region and to diagnose agroecosystems through soil, climate and socio-economic data. The delimitation was based on climate, geomorphology and administrative division of the

  14. 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

  15. Risk identification of agricultural drought for sustainable Agroecosystems

    Science.gov (United States)

    Dalezios, N. R.; Blanta, A.; Spyropoulos, N. V.; Tarquis, A. M.

    2014-09-01

    Drought is considered as one of the major natural hazards with a significant impact on agriculture, environment, society and economy. Droughts affect sustainability of agriculture and may result in environmental degradation of a region, which is one of the factors contributing to the vulnerability of agriculture. This paper addresses agrometeorological or agricultural drought within the risk management framework. Risk management consists of risk assessment, as well as a feedback on the adopted risk reduction measures. And risk assessment comprises three distinct steps, namely risk identification, risk estimation and risk evaluation. This paper deals with risk identification of agricultural drought, which involves drought quantification and monitoring, as well as statistical inference. For the quantitative assessment of agricultural drought, as well as the computation of spatiotemporal features, one of the most reliable and widely used indices is applied, namely the vegetation health index (VHI). The computation of VHI is based on satellite data of temperature and the normalized difference vegetation index (NDVI). The spatiotemporal features of drought, which are extracted from VHI, are areal extent, onset and end time, duration and severity. In this paper, a 20-year (1981-2001) time series of the National Oceanic and Atmospheric Administration/advanced very high resolution radiometer (NOAA/AVHRR) satellite data is used, where monthly images of VHI are extracted. Application is implemented in Thessaly, which is the major agricultural drought-prone region of Greece, characterized by vulnerable agriculture. The results show that agricultural drought appears every year during the warm season in the region. The severity of drought is increasing from mild to extreme throughout the warm season, with peaks appearing in the summer. Similarly, the areal extent of drought is also increasing during the warm season, whereas the number of extreme drought pixels is much less than those of mild to moderate drought throughout the warm season. Finally, the areas with diachronic drought persistence can be located. Drought early warning is developed using empirical functional relationships of severity and areal extent. In particular, two second-order polynomials are fitted, one for low and the other for high severity drought classes, respectively. The two fitted curves offer a forecasting tool on a monthly basis from May to October. The results of this drought risk identification effort are considered quite satisfactory offering a prognostic potential. The adopted remote-sensing data and methods have proven very effective in delineating spatial variability and features in drought quantification and monitoring.

  16. CHARACTERIZATION OF SOIL AND LITTER FAUNA IN DIFFERENT COCOA AGROECOSYSTEMS

    Science.gov (United States)

    The objective of this study was to characterize the density and diversity of meso and macro-fauna of soils located under cacao agrosystems of southern Bahia, Brazil. The researched areas studied were: Cacao improved with Erythrina spp. shade tree (CRE); Cacao under an improved cabruca (CRC); Cacao ...

  17. 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.

  18. Nutrient disequilibrium in agro-ecosystems: Concepts and case studies

    International Nuclear Information System (INIS)

    Full text: Amongst the problems that African agriculture faces, soil fertility decline is mentioned as a major pressure. The declining state (lower soil fertility) has led to different responses by researchers, landusers and policy makers. All responses directly or indirectly boil down to some form of 'Integrated Nutrient Management' (INM), which is defined as the 'judicious' manipulation of nutrient stocks and flows. As INM is complex and multi-faceted, it is difficult to derive simple indicators for policy makers from it. The concept of stocks (state) and flows (pressure), however, links well with economic sciences. A continental study revealed that Africa is losing nutrients at a rather alarming rate, i.e., 22 kg N, 2.5 kg P and 15 kg K per ha per year (Stoorvogel and Smaling, 1990). These values represent the sum of the outputs minus the sum of the inputs mentioned below. IN 1 mineral fertilizer OUT 1 nutrients in harvested parts, milk, meat, etc. IN 2 organic fertilizer OUT 2 nutrients in removed crop residues IN 3 atmospheric deposition OUT 3 leaching IN 4 biological N fixation OUT 4 gaseous losses IN 5 sedimentation OUT 5 runoff and erosion This study however, commissioned by FAO, had to deal with a lot of higher-scale problems, i.e., using FAO's production yearbooks, using the 1:5,000,000 FAO Soil Map of the World, generalisation, simplification, and the use of proxies (transfer functions). It triggered many studies at lower spatial scales (field, farm, village, watershed), in which inputs and outputs are accompanied by internal flows within the system. In other words, INM can be geared towards: adding nutrients to the system; saving nutrient from being lost from the system; recycling so as to maximize nutrient use efficiency. Measurement of nutrient flows is complex: a simple fertilizer trial implies adding nutrients, and harvesting part of the extra nutrients, but what happens to the nutrients that were not taken up by the crop? More spatially complex is the ring management system in West Africa where animals spend the night and early morning around the village, fertilizing this area, while they eat and deplete the bushlands during daytime. IFPRI has, for its Vision 2020 study, grouped the tropical world into five 'agricultural landscapes', i.e.: Irrigated lands; High quality rainfed lands; Densely populated marginal lands; Extensive agriculture in marginal lands; (Peri)urban agriculture. The complexity of measuring the nutrient balance for these 'landscapes' will be highlighted. Measurement problems seem to be scientific issues, but they do come back at the policy level. In The Netherlands, a mineral book keeping system is in place (MINAS), which works with farmgate balances. However, a surface balance approach would give other figures and would encompass different incentives for the land user. More accurate compartment approaches are liked by the researcher but generally regarded as too cumbersome to build policies on. It is very difficult to scale up point research to higher spatial and temporal scales. Examples are given of agricultural landscapes in Madagascar and Nigeria that may help in deciding where to focus research efforts. It is crucial that scientific development on INM is closely related to policy and landuse, as all these fields are changing simultaneously. Policies are increasingly developed at decentral levels, opening up avenues for INM approaches that were not applied before. Also, landusers become more vocal, and want to be involved in research for development (e.g., participatory technology development). INM therefore should be a joint effort between researchers, policy makers and land users. Research has a key role to play in development of sound methodologies for measurement, modelling and monitoring. (author)

  19. 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.

  20. 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.

  1. 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.

  2. 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

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

    Institute of Scientific and Technical Information of China (English)

    LIN; Erda; (林而达); LI; Yue'e; (李月娥); GUO; Liping; (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.

  4. 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...

  5. Soil nematodes in cambisol agroecosystems of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    2003-01-01

    Roč. 58, č. 2 (2003), s. 205-216. ISSN 0006-3088 R&D Projects: GA AV ČR KSK6005114 Keywords : Nematoda * community structure * abundance Subject RIV: EH - Ecology, Behaviour Impact factor: 0.183, year: 2003

  6. 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.

  7. Potentials and Prospects of Sorghum Allelopathy in Agroecosystems

    Science.gov (United States)

    The promising allelopathic potential of sorghum [Sorghum bicolor L. (Moench)] opens a fruitful area of research to exploit this phenomenon in weed control and regulation of nutrient cycle. The data suggests that sorghum allelopathy can be exploited in different cropping practices such as cover crop,...

  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. 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.

  10. Aerial contamination agroecosystems following the accident at Chernobyl NPP

    International Nuclear Information System (INIS)

    The regularities of the aerial contamination of agricultural ecosystems are described in the early period after the Chernobyl NPP accident. The aerial contamination is shown to be caused by the development of the above-ground biomass of plants and fallout characteristics. A specific coefficient of primary retention varied between 0.7 and 1.89 for 131In and between 0.46 and 1.2 m2 kg-1 for 137Cs. The first half-life period varies from 9.7 to 13.4 days. The second period varies from 46.2 to 52.2 days. It has been found that parameters of aerial contamination from the Chernobyl accident well correlate with the results of observation in the period of global fallout

  11. 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.

  12. 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...

  13. 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.

  14. 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 ...

  15. 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

  16. 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...

  17. 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.

  18. 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)

  19. 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

  20. 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...

  1. The GPFARM DS for agroecosystem sustainability: the past, future, and lessons learned

    Science.gov (United States)

    The USDA-ARS Agricultural Systems Research Unit (ASRU) developed the Great Plains Framework for Agricultural Resource Management (GPFARM) DSS. GPFARM provides production, economic, and environmental impact analysis from which alternative agricultural management systems can be tested and compared. GP...

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  6. 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

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

    OpenAIRE

    DAMAYANTI BUCHORI; BANDUNG SAHARI; NURINDAH

    2008-01-01

    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 natura...

  8. Tracing individual movements of aphids reveals preferential routes of population transfers in agroecosystems.

    Science.gov (United States)

    Vialatte, Aude; Simon, Jean-Christophe; Dedryver, Charles-Antoine; Fabre, Frederic; Plantegenest, Manuel

    2006-06-01

    Agricultural pests are not restricted to crops, but often simultaneously or successively use different cultivated and uncultivated hosts. Nevertheless, the source-sink role of cultivated and uncultivated habitats in the life cycle of crop pests remains poorly understood. This is largely due to the difficulty of tracking displacements of small organisms in agricultural landscapes. We used stable-isotope ratios in order to infer the natal host plant of individuals of the English grain aphid Sitobion avenae colonizing wheat fields in autumn. We showed that among the numerous plant sources of S. avenae, maize, which has been intensively grown in western France since the 1960s, provided most aphids that attack wheat fields early in autumn. This study illustrates how insect pests respond to land-use changes within a relatively short period of time, rapidly acquiring a new host that in turn affected their population biology considerably by playing a pivotal role on their annual life cycle. PMID:16826984

  9. 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

    to control plot. A negative correlation (r = -0.95) between soil CO2 and O2 concentrations indicated that injected CO2 displaced O2 from soil. Gassing CO2 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...

  10. FREE-FLOWING COMPLEX BACTERIAL PREPARATION FOR CROP AND EFFICIENCY OF ITS USE IN AGROECOSYSTEMS

    Directory of Open Access Journals (Sweden)

    Ivan Кurdish

    2015-06-01

    Full Text Available The present study investigated the influence of different nanomaterials on physiological and biochemical activity of the nitrogen-fixing bacteria Azotobacter vinelandii IMV V-7076 and phosphate mobilizing bacteria Bacillus subtilis IMV V-7023 for the development of high-efficient free-flowing bacterial complex for crop production. Among the studied nanomaterials, vermiculite stimulated the most effectively bacterial growth, synthesis of amino acids and phytohormones, dehydrogenase, catalase and peroxidase activities. Based on vermiculite and highly efficient strains of bacteria Azotobacter vinelandii IMV V-7076 and Bacillus subtilis IMV V-7023, a free-flowing bacterial complex preparation for crop production was created. The preparation was stable during storage, it improved the nitrogenous and phosphorus nutrition of plants stimulated their growth by biologically active substances and protected plants from lesion by phytopathogenic micromicetes and bacteria.

  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. 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.

  14. 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...

  15. 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...

  16. 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.

  17. Changes in Agroecosystem Structure and Function Along a Chronosequence of Taungya System in Chiapas, Mexico

    OpenAIRE

    L. Soto-Pinto; C. Armijo-Florentino

    2014-01-01

    The shifting cultivation system was widely used in the past; however in recent times it is no longer sustainable. In Mexico, a group of Mayan farmers established Taungya system (Ixim’te) as alternative to shifting cultivation. The system consists of the rotational association of crops with cultivated and spontaneous timber trees. The aim was to evaluate the changes in ecological structure and functions, and economic value along a chronosequence of 2 to 13 years. Twenty farmer’s plots were sel...

  18. 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...

  19. 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...

  20. 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

  1. Biodiversity And Livelihoods In Southwestern Ethiopia: Forest Loss And Prospects For Conservation In Shade Coffee Agroecosystems

    OpenAIRE

    Eshete, Getachew Tadesse

    2013-01-01

    The Ethiopian southwest is a global origin for Arabica coffee which is the second most traded global commodity after petroleum; and the most important agricultural commodity for Ethiopia. The region is also a global center of crop domestication and diversification with ancient and diverse social and agricultural systems, languages, and cultural groups. People have been here possibly longer than anywhere on Earth and have longer history of interactions with their natural environment, so they r...

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

    OpenAIRE

    Eugen Skura; Albert Kopali

    2013-01-01

    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-industr...

  3. 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...

  4. 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

    their habitat utilization. The results confirmed that both of these species selected to forage over sugarcane fields instead of over the other habitats available in the area: savanna, riparian forest and urban areas. Foraging ranges were relatively large with C. pumilus travelling on average a maximum of 4.2 km...

  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. 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.

  7. 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...

  8. 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.

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

    OpenAIRE

    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). The study aimed at understanding the long-term effects of (i) ISFM and CA on AMF communities and functioning, and on glomalin concentrations. The study also aimed at understanding the (ii) role of...

  10. 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...

  11. 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.

  12. 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)

  13. 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

  14. 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.

  15. Ecohydrology of agroecosystems: probabilistic description of yield reduction risk under limited water availability

    Science.gov (United States)

    Vico, Giulia; Porporato, Amilcare

    2013-04-01

    Supplemental irrigation represents one of the main strategies to mitigate the effects of climate variability and stabilize yields. Irrigated agriculture currently provides 40% of food production and its relevance is expected to further increase in the near future, in face of the projected alterations of rainfall patterns and increase in food, fiber, and biofuel demand. Because of the significant investments and water requirements involved in irrigation, strategic choices are needed to preserve productivity and profitability, while maintaining a sustainable water management - a nontrivial task given the unpredictability of the rainfall forcing. To facilitate decision making under uncertainty, a widely applicable probabilistic framework is proposed. The occurrence of rainfall events and irrigation applications are linked probabilistically to crop development during the growing season and yields at harvest. Based on these linkages, the probability density function of yields and corresponding probability density function of required irrigation volumes, as well as the probability density function of yields under the most common case of limited water availability are obtained analytically, as a function of irrigation strategy, climate, soil and crop parameters. The full probabilistic description of the frequency of occurrence of yields and water requirements is a crucial tool for decision making under uncertainty, e.g., via expected utility analysis. Furthermore, the knowledge of the probability density function of yield allows us to quantify the yield reduction hydrologic risk. Two risk indices are defined and quantified: the long-term risk index, suitable for long-term irrigation strategy assessment and investment planning, and the real-time risk index, providing a rigorous probabilistic quantification of the emergence of drought conditions during a single growing season in an agricultural setting. Our approach employs relatively few parameters and is thus easily and broadly applicable to different crops and sites, under current and future climate scenarios. Hence, the proposed probabilistic framework provides a quantitative tool to assess the impact of irrigation strategy and water allocation on the risk of not meeting a certain target yield, thus guiding the optimal allocation of water resources for human and environmental needs.

  16. The interaction between soil erosion and soil organisms in temperate agroecosystems: nematode redistribution in tramlines

    Science.gov (United States)

    Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

    2014-05-01

    Arable agriculture presents a unique set of challenges, and one of the most important is soil erosion. Whilst policy and practice look towards sustainable intensification of production to ensure food security, fundamental gaps in our understanding still exist. The physical processes involved in the detachment, transport and deposition of soil are well characterised but further research considering chemical and nutrient transport, fertiliser and pesticide losses, and environmental impacts to downstream environments is still required. Furthermore the interaction between soil erosion and soil organisms have largely been ignored, even though soil organisms serve a myriad of functions essential in the provision of soil ecosystem goods and services. Here we present the findings of a field-scale experiment into soil biotic redistribution undertaken at the James Hutton Institute's Balruddery Farm, Scotland (Link Tramlines Project XDW8001). Farm vehicle-tyre wheelings left in arable fields (tramlines) to enable crop spraying during the crop growth cycle have been identified as key transport pathways for sediment and associated nutrients. We tested the hypothesis that soil organisms were also transported by tramline erosion. During the winter of 2012/13 an experiment was undertaken to measure soil organism export from unbound hillslope plots subject to four different tramline treatments set out in a randomised block design. We used soil nematodes as a model organism as they are ubiquitous and sensitive to disturbance and an established indicator taxa of biological and physico-chemical changes in soil. Tramline treatments included a control tyre (conventional tractor tyre), a control tyre with a sown tramline, a low pressure tyre with sown tramline, and a control tyre with a spiked harrow. Post-event sampling of rainfall events was undertaken, and a range of variables measured in the laboratory. The spiked harrow treatment produced the greatest overall reductions in nematode export with 95% less nematodes exported, compared with the control treatment. We observed wholesale non-selective transport of all nematode trophic groups present in the soil. The findings of this experiment are twofold. Firstly, we demonstrate that soil organisms are transported by erosion processes and confirm that tramlines are key hydrological pathways. Secondly, we highlight practical on-farm solutions that have potential to decrease soil organism losses. These results provide important baseline information to improve our understanding of soil erosion impacts to the wider soil ecosystem. The results help to inform soil and water conservation measures for sustainable agriculture.

  17. 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.

  18. 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...

  19. Elucidating the potential for transfer of antibiotic resistance genes trhough agro-ecosystems

    Science.gov (United States)

    Increases in the occurrence of antibiotic resistance (AR) in clinical pathogens raises concerns about how resistance is spread within and between human, environmental and agricultural eco-systems. Livestock manure applied to soil may increase AR bacterial concentrations as a result of addition of ma...

  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. 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.

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

    OpenAIRE

    Stefano Benvenuti

    2009-01-01

    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 incre...

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

    International Nuclear Information System (INIS)

    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 137Cs 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−1 and 1.5 to 2.1 Mg ha yr−1, respectively. However, in cultivated fields both erosion and deposition were significantly higher (ca. 20 Mg ha yr−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 137Cs peaks in the lake cores and estimates from the sediment budget indicated a net deposition of 671 Mg yr−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. • 137Cs 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

  4. 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

  5. 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.

  6. Current status of bird pest species in agroecosystems of Buenos Aires province, central Argentina

    OpenAIRE

    Codesido, M.; Bilenca, D.

    2011-01-01

    We carried out the first assessment of abundance and distribution of bird pest species (eared dove Zenaida auriculata, monk parakeet Myiopsitta monachus, picazuro pigeon Patagioenas picazuro and spot-winged pigeon P. maculosa) in the pampas of Buenos Aires province, Argentina, and analyzed their association with the presence of crops and/or introduced exotic woodlots in the rural landscape. We surveyed 35 transects located along secondary roads. Bird pest abundance was significantly higher at...

  7. 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

  8. 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.

  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. 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. 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...

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

    Czech Academy of Sciences Publication Activity Database

    Kersebaum, K. C.; Boote, K. J.; Jorgenson, J. S.; Nendel, C.; Bindi, M.; Frühauf, C.; Gaiser, T.; Hoogenboom, G.; Kollas, C.; Olesen, J. E.; Rötter, R. P.; Ruget, F.; Thorburn, P. J.; Trnka, Miroslav; Wegener, M.

    2015-01-01

    Roč. 72, Oct 15 (2015), s. 402-417. ISSN 1364-8152 Institutional support: RVO:67179843 Keywords : field experiments * data quality * crop modeling * data requirement * minimum data * software Subject RIV: EH - Ecology, Behaviour Impact factor: 4.420, year: 2014

  13. 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)

  14. 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

    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 re...

  15. 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.

  16. 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

    sustainability of the agricultural practice. The emergy analysis is an accounting tool which takes into account both the environment and the economic costs of the production system, based on principles of thermodynamics. Here the objective of the study is the evaluation of a novel organically based, food and...

  17. 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%.

  18. Indicators for taxonomic and functional aspects of biodiversity in the vineyard agroecosystem of Southern Switzerland

    OpenAIRE

    Trivellone, Valeria; Schoenenberger, N; Bellosi, B; Jermini, M; F Bello; Mitchell, Edward A. D.; Moretti, M.

    2014-01-01

    It is widely accepted that the concept of biodiversity embraces two essential and complementary components: taxonomic and functional diversity. Our goal is to produce a list of plant species predictive of high taxonomic and functional biodiversity values and discuss their use within biodiversity monitoring programmes. We selected a representative sample of 48 vineyard areas from Southern Switzerland, and vegetation from the ground cover was sampled from within a total of 120 sampling plots. W...

  19. 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...

  20. 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)

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

    Science.gov (United States)

    Barber, Nicholas A; Kiers, E Toby; Hazzard, Ruth V; Adler, Lynn S

    2013-01-01

    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. PMID:24046771

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

    OpenAIRE

    Barber, Nicholas A.; Kiers, E. Toby; Hazzard, Ruth V.; Adler, Lynn S.

    2013-01-01

    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 mutu...

  3. 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...

  4. 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.

  5. 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; Peng, Renkang; Offenberg, Joachim

    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...... solution increased their rate of manure deposition significantly, suggesting that nectaries and/or trophobionts may play a major role in the production of ant manure. This study reveals that O. smaragdina can supply a significant amount of nitrogen to their host plants. In light of their remarkable...... of ant manure may augment the host plants’ acquisition of nitrogen. In this study, we quantified the manure deposited by colonies of the Asian weaver ant Oecophylla smaragdina. We developed a method to estimate the amount of manure deposited in host trees (Mangifera indica) based on the trail...

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

    DEFF Research Database (Denmark)

    Steinwender, Bernhardt Michael

    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...... 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...

  7. 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

  8. Indicators for taxonomic and functional aspects of biodiversity in the vineyard agroecosystem of Southern Switzerland

    Czech Academy of Sciences Publication Activity Database

    Trivellone, V.; Schoenenberger, N.; Bellosi, B.; Jermini, M.; de Bello, Francesco; Mitchell, E.A.D.; Moretti, M.

    2014-01-01

    Roč. 170, Feb 2014 (2014), s. 103-109. ISSN 0006-3207 R&D Projects: GA ČR GAP505/12/1296 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : indicator species * Switzerland * vineyard floor vegetation Subject RIV: EH - Ecology, Behaviour Impact factor: 3.762, year: 2014

  9. 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...

  10. 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

  11. 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

  12. Application of ITS2 metabarcoding to determine the provenance of pollen collected by honey bees in an agroecosystem1

    Science.gov (United States)

    Richardson, Rodney T.; Lin, Chia-Hua; Sponsler, Douglas B.; Quijia, Juan O.; Goodell, Karen; Johnson, Reed M.

    2015-01-01

    • Premise of the study: Melissopalynology, the identification of bee-collected pollen, provides insight into the flowers exploited by foraging bees. Information provided by melissopalynology could guide floral enrichment efforts aimed at supporting pollinators, but it has rarely been used because traditional methods of pollen identification are laborious and require expert knowledge. We approach melissopalynology in a novel way, employing a molecular method to study the pollen foraging of honey bees (Apis mellifera) in a landscape dominated by field crops, and compare these results to those obtained by microscopic melissopalynology. • Methods: Pollen was collected from honey bee colonies in Madison County, Ohio, USA, during a two-week period in midspring and identified using microscopic methods and ITS2 metabarcoding. • Results: Metabarcoding identified 19 plant families and exhibited sensitivity for identifying the taxa present in large and diverse pollen samples relative to microscopy, which identified eight families. The bulk of pollen collected by honey bees was from trees (Sapindaceae, Oleaceae, and Rosaceae), although dandelion (Taraxacum officinale) and mustard (Brassicaceae) pollen were also abundant. • Discussion: For quantitative analysis of pollen, using both metabarcoding and microscopic identification is superior to either individual method. For qualitative analysis, ITS2 metabarcoding is superior, providing heightened sensitivity and genus-level resolution. PMID:25606352

  13. Critical pathways of radionuclides to man from agro-ecosystems. Annual progress report, October 1978-September 1979

    International Nuclear Information System (INIS)

    Progress has been considerable within the past year. Both plutonium and curium analyses were completed on the first year's samples of the greenhouse uptake experiment. Results from this experiment has shown: minimal uptake of plutonium by agricultural crops; greater uptake of curium; immobilization of both radionuclides by lime addition; and partial counteraction of the lime immobilization by chelate addition. Also, dose to man from consumption of edible portions of crops grown in these soils is very small. Initiation of field uranium studies has begun. These studies will allow for an evaluation of the comparative environmental behavior of Pu and U. Winter wheat and rye crops were successfully produced. Additional crops are anticipated for the current year

  14. Quantitative and temporal assessment of 137Cs and 90Sr biofixation by organic wastes in agro-ecosystems

    International Nuclear Information System (INIS)

    Each year considerable quantities of residue from different crops grown on contaminated lands are tilled back into the soil and partly used as forage. Radionuclides in the crop residues are made available to succeeding plants by release thought decomposition. Relative phytoextraction of radionuclides by crops to soil content, quantitative and temporal rate of 137Cs and 90Sr released from plant residues and annual fixation of radionuclides by plant residues tilled into the soil for succeeding crops in rotation were studied. Different crops have shown considerable variation in their ability to uptake the radionuclides from soil. The relative accumulation of 137Cs by the crop residues was lower 0.07% to the total radionuclides content in soil. The maximum quantity of 90Sr extracted from soil can reach up to 4% and it is valuable in respect of the technologies of phytodecontamination. Agricultural crops accumulating the high amounts of 90Sr were rapeseed, clover and Sakhalin buckwheat. The size of 90Sr immobilization by above-mentioned crops can be comparable with 'selfdecay' of radionuclides per year. The release of radionuclides incorporated in the straw is very slow and radionuclides of plant organic wastes tilled in the soil are unavailable to succeeding crops at least during 2 years. (author)

  15. Critical pathways of radionuclides to man from agro-ecosystems. Annual progress report Oct 80-Sep 81

    International Nuclear Information System (INIS)

    The research describes the fate and behavior in the environment of radionuclides from nuclear fuel reprocessing. Greenhouse radionuclide uptake studies which examined factors possibly altering phyto-availability of radionuclides show only slight differences among crop species or soil treatments (lime or lime plus chelate) in Pu or Cm uptake. Field grown broadleaf crops grown have differing Pu concentrations associated with plant morphology, with some species exceeding the concentrations observed in wheat and soybean crops. Uranium contamination of a wheat crop grown near the separations facility appears to be strongly affected by root uptake. This is in contrast to the behavior of Pu where surficial pathways are the dominant modes of contamination, and is probably related to (1) the ubiquitous presence of naturally occurring U isotopes and (2) a greater concentration ratio for U than for Pu

  16. Critical pathways of radionuclides to man from agro-ecosystems. Progress report (annual), 1 October 1979-30 September 1980

    International Nuclear Information System (INIS)

    The studies investigating the environmental behavior of radionuclides released into agricultural systems by a nuclear fuel chemical separations facility have advanced considerably within the past year. Manuscripts reporting uptake of Pu and Cm by agricultural plants have shown that Cm was taken up in greater quantities than Pu. Lime addition to soil depresses uptake of Cm while chelate addition to limed soil increases uptake of Cm. No conclusive effects of soil amendments were observed with regard to Pu uptake. Cesium uptake by agricultural plants differs between species, plant part and year of harvest, with an indication that cesium may be increasingly taken up with the passage of time in some instances. Soil amendments affect 137Cs uptake similarly as that reported for 244Cm. Rice varieties do not differ in their Pu or Cm uptake, nor does uptake by rice in flooded soils differ from those uptake rates reported for dry-land agricultural species. Curium and 239, 240Pu appear to be equally available to rice and more available than 238Pu. Broadleaf crops appear to exhibit Pu concentrations dependent on their shape and form, indicating the importance of physical processes in this field experiment. Because of crop failures caused by drought conditions, there has been little progress on our U-field studies

  17. 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

  18. 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)

  19. 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)

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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...

  7. 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 ...

  8. 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...

  9. 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

  10. 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 ...

  11. 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...

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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...

  19. 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...

  20. 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

  1. 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.

  2. Soil Hydrological Attributes of an Integrated Crop-Livestock Agroecosystem: Increased Adaptation through Resistance to Soil Change

    International Nuclear Information System (INIS)

    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.

  3. 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.

  4. Energy-Landscape Integrated Analysis: A proposal for measuring complexity in internal agroecosystem processes (Barcelona Metropolitan Region)

    OpenAIRE

    Marull López, Joan; Font Moragón, Carme; Padró Caminal, Roc; Tello, Enric; Panazzolo, Andrea

    2016-01-01

    Farm systems are facing a global challenge amidst a socio-metabolic transition that places them in a dilemma between increasing land-use intensity to meet the growing demand of food, feed, fibres and fuels, while avoiding a biodiversity loss at the same time. To solve this dilemma a deeper research on how species richness is kept in different land-use patterns is required, according to the quantity and quality of the ecological disturbance that farmers carry out across the landscape. We propo...

  5. Microfungi Species on the Weeds of Agro-ecosystem (wheat ecosystem) in Adıyaman City

    OpenAIRE

    ÖZASLAN, Cumali; HÜSEYİN, Elşad; ERDOĞDU, Makbule

    2013-01-01

    This study was performed between 2009-2010 to detect the micro fungi on the weed, which create problems on wheat fields of the city Adıyaman and its dependent districts. Within the field of study, 27 different micro fungi were detected on a total of 33 different weed species in the wheat fields. Peronospora aparines (de Bary) Gäum. causing downy mildews of Galium aparine L. is recorded for the first time in Turkey. The morphological characteristics of this newly-recorded species in Turkey wer...

  6. 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 .

  7. 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...

  8. 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...

  9. Multi-scale geospatial agroecosystem modeling: A case study on the influence of soil data resolution on carbon budget estimates

    Science.gov (United States)

    The development of effective measures to stabilize atmospheric 22 CO2 concentration and mitigate negative impacts of climate change requires accurate quantification of the spatial variation and magnitude of the terrestrial carbon (C) flux. However, the spatial pattern and strengt...

  10. 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.

  11. 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.

  12. Use of temporal variations of radon activities in soil gas depth profiles for calibrating trace gas exchange in agro-ecosystems

    International Nuclear Information System (INIS)

    New sensitive radon monitors have been combined with a computer controlled gas sampling system for continuous activity measurements of 222Rn and 220Rn at various altitudes above and below the surface. Air is extracted from semi-permeable membrane tubes of 1.5 m length placed at depths of 10, 25, 50 and 70 cm below the soil surface and from various heights within and above the canopy of a wheat field. The influence of meteorological and soil parameters on the vertical gas exchange between soil, vegetation and atmosphere is investigated. (author)

  13. Intercropping with Shrub Species That Display a ‘Steady-State’ Flowering Phenology as a Strategy for Biodiversity Conservation in Tropical Agroecosystems

    OpenAIRE

    Valerie E. Peters

    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...

  14. Analysis of a village chicken production system and performance of improved dual purpose chickens under a subtropical hill agro-ecosystem in India.

    Science.gov (United States)

    Kumaresan, A; Bujarbaruah, K M; Pathak, K A; Chhetri, Bijoy; Ahmed, S K; Haunshi, Santosh

    2008-08-01

    This study was designed to analyze the low input backyard poultry production system practiced by the tribal farmers, and evaluate the performance of an improved dual-purpose breed, the Vanaraja. Results revealed that a significantly (p poultry houses made of locally available materials, such as bamboo and wood. Most of the farmers (65.9 %) did not provide balanced feed to their poultry and did not vaccinate their birds against any disease. Under standard management conditions, the average body weight of Vanaraja birds at 6 weeks was 625 +/- 10.9 g. Under backyard conditions, the body weight at 18 months was 3.6 +/- 0.8 kg. The age at first egg was 154 +/- 9 days in the backyard system, whereas under the intensive system it was 196 +/- 4 days. Annual production under the backyard and intensive systems of rearing was 176 +/- 9 and 152 +/- 7 eggs, respectively. Mortality of adult birds was 12 % and predation by foxes and wild cats accounted for 1.67 %. This study revealed that village chickens are an important income source for household expenses, and that traditional free-range poultry production in the smallholder sector of developing countries can possibly be improved through the use of improved dual-purpose birds. PMID:18575965

  15. 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

  16. Characterization and evaluation of agro-ecosystems on a farm scale, a case studies: Cotove Farming Center (Santa Fe de Antioquia, Colombia)

    International Nuclear Information System (INIS)

    The state, condition and tendencies of the agro-systems (AS) of the Cotove Farming Center of the Universidad Nacional de Colombia, sede Medellin 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 Velez and Gasto (1999) in terms of the diversity in AE and the uses, management, and technological state, techno-structural and hydro-structural 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 agro-technological 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, l 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

  17. 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.

  18. 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.

  19. Regional tritrophic relationship patterns of five aphid parasitoid species (Hymenoptera: Braconidae: Aphidiinae)in agroecosystem-dominated landscapes of southeastern Europe

    Czech Academy of Sciences Publication Activity Database

    Tomanović, Ž.; Kavallieratos, N. G.; Starý, Petr; Stanisavljević, L. Ž.; Ćetković, A.; Stamenković, S.; Jovanović, S.; Athanassiou, CH. G.

    2009-01-01

    Roč. 102, č. 3 (2009), s. 836-854. ISSN 0022-0493 R&D Projects: GA AV ČR IBS5007102 Grant ostatní: The Ministry of Science and Environmental Protection of the Republic of Serbia(CS) 143006B Institutional research plan: CEZ:AV0Z50070508 Keywords : aphid parasitoids * southeastern Europe * tritropic interactions Subject RIV: EH - Ecology, Behaviour Impact factor: 1.296, year: 2009

  20. 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...

  1. 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.

  2. Ecological relationships between non-cultivated plants and insect predators in agroecosystems: the case of Dittrichia viscosa (Asteraceae) and Macrolophus melanotoma (Hemiptera: Miridae)

    Science.gov (United States)

    Perdikis, Dionyssios; Favas, Charalampos; Lykouressis, Dionyssios; Fantinou, Argyro

    2007-05-01

    Species of the genus Macrolophus (Hemiptera: Miridae) are thought to be effective predators in reducing the numbers of several pests in vegetable crops. These predators are omnivorous as in addition to prey they also utilize plant sap for growth and development. Populations of these predators build in non-crop host plants and provide inoculum that augments natural control of insect pests in adjacent crops. However, to enhance their effectiveness in crops requires knowledge of their trophic relationships with host plants. In this study, the ecological relationships between the predator Macrolophus melanotoma (Costa) ( = M. caliginosus Wagner) and its most important natural host plant Dittrichia viscosa L. (W. Greuter) (Asteraceae) were investigated in the laboratory and in field studies. A 2-year field study of M. melanotoma populations on D. viscosa was made using the percentage of plants infested by C. inulae as a measure of aphid prey abundance. The field studies revealed that M. melanotoma populations were present throughout the year on D. viscosa reaching highest numbers in June and July despite very low levels of aphid infested plants. Laboratory life table studies were used to compare the survival and reproduction of the predator on D. viscosa leaves alone and leaves plus aphid prey ( Capitophorus inulae (Passerini)). Predators reared on D. viscosa leaves plus aphid prey had an average developmental time of 16.73 days, fecundity was 69.55 eggs/female and the intrinsic rate of population increase was 0.0614/day. When fed only leaves, the developmental time was 21.13 days, fecundity was 10.80 eggs/female and the intrinsic rate of population increase was 0.0229/day. The results of the two studies suggest an important role for D. viscosa in conserving and augmenting M. melanotoma in agro ecosystems, and in the development of natural control augmentation strategies in vegetable crops.

  3. 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

  4. 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...

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

    OpenAIRE

    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...

  6. 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 ...

  7. 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

  8. 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.

  9. 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

  10. 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…

  11. 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.

  12. N2O and CH4 emissions from a fallow–wheat rotation with low N input in conservation and conventional tillage under a Mediterranean agroecosystem

    International Nuclear Information System (INIS)

    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 (N2O) and methane (CH4), 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 N2O and CH4 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 N2O and CH4. Total cumulative N2O 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 N2O emissions were significantly higher (P < 0.05) in fallow than in wheat subplots, and NT reduced N2O 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 CH4 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 N2Ofluxes • No tillage reduced N2O fluxes just during spring season • N2O fluxes were only greater in fallow than in wheat during spring season • Denitrification capacity and nirK abundance were similar among tillage systems • Cumulative CH4 fluxes resulted in a low net uptake among tillage systems

  13. [Effects of tillage-cropping systems on methane and nitrous oxide emissions from agro-ecosystems in a purple paddy soil].

    Science.gov (United States)

    Zhang, Jun-Ke; Jiang, Chang-Sheng; Hao, Qing-Ju; Tang, Qi-Wen; Cheng, Bing-Hong; Li, Hui; Chen, Lu-Hao

    2012-06-01

    Using the static opaque chamber method, a field experiment, located in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University (30 degrees 26'N, 106 degrees 26'E) in Chongqing, was conducted in situ for one year to study the effect of different tillage systems on CH4 and N2O emission from ago-ecosystems in a purple paddy soil. In this paper, four tillage treatments including conventional tillage with rice only system (CT), conventional tillage with rotation of rice and rape system (CTR), no-till and plain culture with rotation of rice and rape system (NTP) and no-till and ridge culture with rotation of rice and rape system (NTR) were selected as research objectives. The results showed that the annual CH4 and N2O emissions were mainly occurred in the rice growing period, and were about 77.6% and 55.0% of the total annual of them emitted from this period. The total annual CH4 under CT was higher than that of other treatments. The annual average flux of CH4[CH4, mg x (m2 x h)(-1)] order was CT (2.96 +/- 0.04) >NTR (1.83 +/- 0.21) >NTP (1.42 +/- 0.01) >CTR (0.96 +/- 0.09); the annual average flux of N2O[N2O, microg x (m2 x h)(-1)] order was CTR (123.6 +/- 47.1) > NTR (115.2 +/- 22.1) > NTP (100.5 +/- 25.8) > CT (81.3 +/- 13.5), and the total annual N2O under CTR was higher than that of CT. The global warming potentials (GWPs) of CH4 and N2O emissions under different tillage-cropping systems were assessed in an integrated way. The results showed that the integrated GWPs of CH4 and N2O emission were in the following sequence: CT > NTR > NTP > CTR, and CTR was the best treatment for decrease the integrated GWPs in this area. PMID:22946185

  14. N2O and CH4 emissions from a fallow-wheat rotation with low N input in conservation and conventional tillage under a Mediterranean agroecosystem.

    Science.gov (United States)

    Tellez-Rio, Angela; García-Marco, Sonia; Navas, Mariela; López-Solanilla, Emilia; Tenorio, Jose Luis; Vallejo, Antonio

    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 (N2O) and methane (CH4), 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 N2O and CH4 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 N2O and CH4. Total cumulative N2O 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 N2O emissions were significantly higher (Psoil 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. PMID:25459752

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. Long-Term Effects of Irrigation with Waste Water on Soil AM Fungi Diversity and Microbial Activities: The Implications for Agro-Ecosystem Resilience

    OpenAIRE

    del Mar Alguacil, Maria; Torrecillas, Emma; Torres, Pilar; García-Orenes, Fuensanta; Roldán, Antonio

    2012-01-01

    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 vitali...

  1. 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.

  2. 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

  3. 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...

  4. 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

  5. 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.

  6. 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.

  7. 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...

  8. 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.

    OpenAIRE

    Juan Camilo de los Rios Cardona; Andrés Felipe Gallego Zapata; León Darío Vélez Vargas; José Ignacio Agudelo Otalvaro; Luis Jairo Toro Restrepo; Alvaro de Jesús Lema Tapias; Luis Ignacio Acevedo Agudelo

    2004-01-01

    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 s...

  9. 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.

  10. 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. PMID:23593371

  11. 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.

  12. 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

    Directory of Open Access Journals (Sweden)

    Gary W Luck

    2014-04-01

    Full Text Available 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 bird consumption of almonds. Pre-harvest, the consumption of harvestable almonds by birds cost growers AUD$57.50 ha-1 when averaged across the entire plantation. Post-harvest, the same bird species provide an ecosystem service by removing mummified nuts from trees that growers otherwise need to remove to reduce threats from fungal infection or insect pest infestations. The value of this ecosystem service ranged from AUD$82.50 ha-1–$332.50 ha-1 based on the replacement costs of mechanical or manual removal of mummified nuts, respectively. Hence, bird consumption of almonds yielded a positive net return of AUD$25–$275 ha-1 averaged across the entire plantation. However, bird activity varied spatially resulting in positive net returns occurring primarily at the edges of crops where activity was higher, compared to negative net returns in crop interiors. Moreover, partial mummy nut removal by birds meant that bird activity may only reduce costs to growers rather than replace these costs completely. Similar cost-benefit trade-offs exist across nature, and quantifying net returns can better inform land management decisions such as when to control pests or promote ecosystem service provision.

  13. 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...

  14. 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.

  15. 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...

  16. 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.

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

    OpenAIRE

    Sandra Santana Lima; Adriana Maria de Aquino; Luiz Fernando Carvalho Leite; Elena Velásquez; Patrick Lavelle

    2010-01-01

    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 so...

  18. 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.

  19. 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.

  20. NUEVOS REGISTROS DE PLANTAS HOSPEDERAS Y DISPONIBILIDAD DE RECURSOS PARA MARIPOSAS ITHOMIINI (LEPIDOPTERA: NYMPHALIDAE: DANAINAE), EN AGROECOSISTEMAS DE CAFÉ COLOMBIANOS NEW HOST PLANT RECORDS AND RESOURCE AVAILABILITY TO ITHOMIINI BUTTERFLIES (LEPIDOPTERA: NYMPHALIDAE: DANAINAE), IN COLOMBIAN COFFEE AGROECOSYSTEMS

    OpenAIRE

    Sandra B. Muriel; Jorge Montoya; Alejandra Restrepo; Jonathan Muñoz

    2011-01-01

    En el trópico se dispone de pocos datos de la mayoría de los organismos, incluyendo las mariposas, en aspectos claves de su ciclo de vida, sus plantas hospederas y factores explicativos de su diversidad y abundancia. El objetivo de este trabajo fue identificar las plantas hospederas de larvas Ithomiini (Lepidoptera) en agroecosistemas de café y evaluar el efecto de las variables: sistema de producción, área en bosque y diversidad de hospederas sobre la diversidad y abundancia de este grupo. E...

  1. 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...

  2. 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.

  3. 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...... 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...

  4. Ecology and behavior of Anopheles arabiensis in relation to agricultural practices in central Kenya.

    Science.gov (United States)

    Muturi, Ephantus J; Mwangangi, Joseph M; Beier, John C; Blackshear, Millon; Wauna, James; Sang, Rosemary; Mukabana, Wolfgang R

    2013-09-01

    Ecological changes associated with anthropogenic ecosystem disturbances can influence human risk of exposure to malaria and other vector-borne infectious diseases. This study in Mwea, Kenya, investigated the pattern of insecticide use in irrigated and nonirrigated agroecosystems and association with the density, survival, and blood-feeding behavior of the malaria vector Anopheles arabiensis. The parity rates of adult An. arabiensis from randomly selected houses were determined by examining their ovaries for tracheal distension, and polymerase chain reaction was used to identify the host blood meals. In addition, structured questionnaires were used to generate data on insecticide use. Anopheles arabiensis densities were highest in irrigated rice agroecosystems, intermediate in irrigated French beans agroecosystems, and lowest in the nonirrigated agroecosystem. Anopheles arabiensis adult survivorship was significantly lower in irrigated rice agroecosystems than in irrigated French beans agroecosystems. The human blood index (HBI) was significantly higher in the nonirrigated agroecosystem compared to irrigated agroecosystems. Moreover, there was marked variation in HBI among villages in irrigated agroecosystems with significantly lower HBI in Kangichiri and Mathangauta compared to Kiuria, Karima, and Kangai. The proportion of mosquitoes with mixed blood meals varied among villages ranging from 0.25 in Kangichiri to 0.83 in Kiuria. Sumithion, dimethoate, and alpha cypermethrin were the most commonly used insecticides. The 1st was used mostly in irrigated rice agroecosystems, and the last 2 were used mostly in irrigated French beans agroecosystems. These findings indicate that agricultural practices may influence the ecology and behavior of malaria vectors and ultimately the risk of malaria transmission. PMID:24199496

  5. 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)

  6. 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)

  7. 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

  8. Factors Affecting Soil Microbial Community Structure in Tomato Cropping Systems

    Science.gov (United States)

    Soil and rhizosphere microbial communities in agroecosystems may be affected by soil, climate, plant species, and management. We identified some of the most important factors controlling microbial biomass and community structure in an agroecosystem utilizing tomato plants with the following nine tre...

  9. 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.

  10. Current status and development trends of agritourism within the Ivano-Frankivsk region

    OpenAIRE

    K. Babikova

    2013-01-01

    This paper highlights peculiarities of the rural tourism activities development within the boundaries of rural residential areas. The current state of rural areas has been characterized by the main components of agroecosystems.

  11. 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)

  12. Introduction: Evaluating long-term impacts of harvesting crop residues on soil quality

    Science.gov (United States)

    Utilizing crop residues as biofuel feedstocks will involve trade-offs between bioenergy production and agroecosystem services. Consequently, agricultural production managers and policymakers need to critically evaluate current functions of crop residues in light of increasing demands for agricultura...

  13. 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)

  14. 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...

  15. 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...

  16. POLLUTED IRRIGATION WATERS AS A RISK FACTOR TO PUBLIC HEALTH

    OpenAIRE

    Saghatelyan, A.; L. Sahakyan; O. Belyaeva

    2012-01-01

    Complex investigations of agro-ecosystems adjacent to a huge mining set of plants located within the city of Kapan were performed with a goal to identify risk factors to the health of local populace. A basic factor of pollution of agro-ecosystems is heavy metal enriched ore waters from adits and industrial water streams freely emptying into the irrigation network. Farm crops growing under conditions of pollution accumulate a series of heavy metals and microelements.

  17. POLLUTED IRRIGATION WATERS AS A RISK FACTOR TO PUBLIC HEALTH

    Directory of Open Access Journals (Sweden)

    A. Saghatelyan

    2012-12-01

    Full Text Available Complex investigations of agro-ecosystems adjacent to a huge mining set of plants located within the city of Kapan were performed with a goal to identify risk factors to the health of local populace. A basic factor of pollution of agro-ecosystems is heavy metal enriched ore waters from adits and industrial water streams freely emptying into the irrigation network. Farm crops growing under conditions of pollution accumulate a series of heavy metals and microelements.

  18. 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.)

  19. 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.

  20. 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.

  1. 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.

  2. 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

    OpenAIRE

    Manuel Pérez-De La Cruz; Armando Equihua-Martínez; Jesús Romero-Nápoles; Saúl Sánchez-Soto; Eustolia García-López

    2009-01-01

    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 d...

  3. 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

  4. 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.

  5. Assessment on the vulnerability of different ecosystems to extreme rainfalls in the middle and lower reaches of Yangtze River

    Science.gov (United States)

    Yongxiang, Zhang; Bo, Tao; Li, Yu

    2015-07-01

    The vulnerability of major ecosystems to extreme rainfalls was investigated across the middle and lower reaches of the Yangtze River, China, during 1961-2000, by using an improved process-based model (Carbon Exchange between Vegetation, Soil, and Atmosphere, CEVSA). The simulated Net Primary Productivity (NPP) was selected as the indicator to identify impacts of extreme rainfalls on ecosystem functioning. The changing characteristics of the NPP in the five extreme rainfall years are employed to represent the sensitivity and adaptive capacity of ecosystems to extreme rainfalls events. The vulnerability of major ecosystems to extreme rainfalls was then examined by comparing with the averaged status during 1961-1990. Our results suggest that the relatively lower and higher vulnerable agro-ecosystems were mainly distributed in the central and northwest of the study area. The proportions of high and very high vulnerable agro-ecosystems to rainfall were about 19 and 5 % of the total area. For the forest ecosystem, the lower vulnerability mainly occurred in the south, while the higher vulnerability happened in the north of the study area which had taken about 15 % of the high vulnerable level and about 2 % of the very high vulnerable level. The extreme rainfalls enhanced the vulnerability both of agro-ecosystems and forest ecosystems. The vulnerability of agro-ecosystems to droughts was higher than that of forest ecosystems, while the vulnerability of forest ecosystems to floods was higher than that of agro-ecosystems. Our study demonstrates that both human-dominated (e.g., agro-ecosystem) and natural ecosystems are vulnerable to extreme climatic events. Future warming climate might further worsen the ecosystem sustainability in this area if no mitigation and adaptation measures are adopted.

  6. Reduced greenhouse gas mitigation potential of no-tillage soils through earthworm activity

    OpenAIRE

    Lubbers, Ingrid M.; Kees Jan Van Groenigen; Lijbert Brussaard; Jan Willem van Groenigen

    2015-01-01

    Concerns about rising greenhouse gas (GHG) concentrations have spurred the promotion of no-tillage practices as a means to stimulate carbon storage and reduce CO2 emissions in agro-ecosystems. Recent research has ignited debate about the effect of earthworms on the GHG balance of soil. It is unclear how earthworms interact with soil management practices, making long-term predictions on their effect in agro-ecosystems problematic. Here we show, in a unique two-year experiment, that earthworm p...

  7. 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

  8. Decomposition of 15N-labelled ryegrass in soils from a long-term field experiment with different manuring strategies

    DEFF Research Database (Denmark)

    Jensen, B.K.; Jensen, E.S.; Magid, J.

    The cycling of nitrogen in agroecosystems is influenced by the amount and quality of organic matter applied to soils. The N-mineralization of N-15-labelled ryegrass (Lolium perenne L.) was significantly slightly higher in a soil with long-term application of a high amount of farmyard manure (FYM)...

  9. Genetic diversity and population structure of cacao landraces in Northern and Central coastal Ecuador

    Science.gov (United States)

    Knowledge about genetic diversity among the landraces is essential for developing on-farm conservation strategy in modern agroecosystems. The “arriba” cacao is a group of landraces that are still used today for cacaoa production in the coastal plains and valleys of Ecuador. The strongly rising deman...

  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. 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...

  12. 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 ...

  13. 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 ...

  14. 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.

  15. Long-term rotation history and previous crop effects on corn seedling health

    Science.gov (United States)

    Diverse rotations provide benefits to agroecosystems through changes in the soil environment. A long term experiment was established to study four different four-year rotation sequences in which the crop phase prior to corn was sampled. Soils from rotations ending with soybean, sunflower, corn and p...

  16. 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

  17. 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...

  18. Communities of beetles and spiders in the stands of normal and genetically modified maize

    Czech Academy of Sciences Publication Activity Database

    Habuštová, Oxana; Turanli, Ferit; Spitzer, L.; Růžička, Vlastimil; Doležal, Petr; Sehnal, František

    2005-01-01

    Roč. 3, - (2005), s. 125-131. ISSN 0208-8703 R&D Projects: GA AV ČR(CZ) KJB6007304 Institutional research plan: CEZ:AV0Z50070508 Keywords : GMO * Bt-maize * agroecosystems Subject RIV: EH - Ecology, Behaviour

  19. Expression of the Bacillus thuringiensis toxin from maize does not affect epigeic communities of carabid beetles and spiders

    Czech Academy of Sciences Publication Activity Database

    Spitzer, L.; Růžička, Vlastimil; Hussein, Hany; Habuštová, Oxana; Sehnal, František

    2004-01-01

    Roč. 7, č. 4 (2004), s. 110-112. ISSN 1335-258X R&D Projects: GA AV ČR KJB6007304 Institutional research plan: CEZ:AV0Z5007907 Keywords : GMO * Bt maize * agroecosystems Subject RIV: EH - Ecology, Behaviour

  20. Agro-ecological characterization of inland valleys in West Arica

    NARCIS (Netherlands)

    Andriesse, W.; Windmeijer, P.N.; Duivenbooden, van N.

    1996-01-01

    Conceptual issues related to inland valleys, their morphology, hydrology and agro-ecosystems are discussed, as well as a method for their step-wise characterization at different levels of detail. A definition of inland valleys is given, including the description of the main landscape elements (uplan

  1. Linking a Germplasm Collection of the Cover Crop Hairy Vetch (Vicia villosa Roth) to Traits Related to Improved Nitrogen Fixation

    Science.gov (United States)

    Hairy vetch is used as a leguminous cover crop throughout the United States providing important ecosystem services in agro-ecosystems (Abdul-Baki et al., 2002; Mohler and Teasdale, 1993; Puget and Drinkwater, 2001; Seo et al., 2006; Stute and Posner, 1995). Many traits found in hairy vetch have pro...

  2. 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

  3. ASSESSING POSSIBLE ECOLOGICAL RISKS OF GENETICALLY MODIFIED CROPS: GENE EXPRESSION ASSAYS AND GENETIC MONITORING OF NON-TARGET ORGANISMS

    Science.gov (United States)

    Widespread planting of genetically modified crops with the Bt transgene pesticide has led to concern over non-target effects of Bt compounds in agroecosystems. While some research suggests that non-target organisms exposed to Bt toxin exhibit reduced fecundity and increased morta...

  4. Spatially explicit analysis of land use change: a case study for Ecuador

    NARCIS (Netherlands)

    Koning, de F.

    1999-01-01

    Introduction and objectivesWithin agricultural research increasing attention is paid to the integrated study of agro-ecosystems in order to address issues related to sustainable food production at the eco-regional level. This has been stimulated by the awareness that the world-wide demand for food w

  5. Linking Soil Microbial Ecology to Ecosystem Functioning in Integrated Crop-Livestock Systems

    Science.gov (United States)

    Enhanced soil stability, nutrient cycling and C sequestration potential are important ecosystem functions driven by soil microbial processes and are directly influenced by agricultural management. Integrated crop-livestock agroecosystems (ICL) can enhance these functions via high-residue returning c...

  6. Soil quality indicator responses to row crop, grazed pasture, and agroforestry buffer management

    Science.gov (United States)

    Incorporation of trees and establishment of grass buffers within agroecosystems are management practices shown to enhance soil quality. Soil enzyme activities and water stable aggregates (WSA) have been identified as sensitive soil quality indicators to evaluate early responses to soil management. ...

  7. 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...

  8. NERISK: AN EXPERT SYSTEM TO ENHANCE THE INTEGRATION OF PESTICIDES WITH ARTHROPOD BIOLOGICAL CONTROL

    Science.gov (United States)

    An expert system termed NERISK was developed to evaluate the effects of pesticides on arthropod predators and parasitoids in a variety of agroecosystems. ased on a shell system (RECOG) with minor coding modifications, the system was designed to let even a novice user access the v...

  9. Root isolations of Metarhizium spp. from crops reflect diversity in the soil and indicate no plant specificity

    DEFF Research Database (Denmark)

    Steinwender, Bernhardt M.; Enkerli, Jürg; Widmer, Franco;

    2015-01-01

    revealed a comparable community composition as previously reported from the same agroecosystem when insect baiting of soil samples was used as isolating technique. No specific MLG association with a certain crop was found. This study highlights the diversity of Metarhizium spp. found in the rhizosphere of...

  10. Competition between wild-type and a marked recombinant baculovirus (Spodoptera exigua) nucleopolyhedrovirus) with enhanced speed of action in insect larvae

    NARCIS (Netherlands)

    Georgievska, L.; Velders, R.; Dai, X.; Bianchi, F.J.J.A.; Werf, van der W.; Vlak, J.M.

    2010-01-01

    Competition between virus genotypes in insect hosts is a key element of virus fitness, affecting their long-term persistence in agro-ecosystems. Little information is available on virus competition in insect hosts or during serial passages from one cohort of hosts to the next. Here we report on the

  11. Retrieval of vegetation properties using Top of Atmosphere radiometric data: A multi-sensor approach

    NARCIS (Netherlands)

    Mousivand, A.

    2015-01-01

    Vegetation is the main source of primary production and plays an important role inmodeling the exchanges of energy and mass of carbon, oxygen and water between the earth and the atmosphere. Mapping andmonitoring of vegetation canopies are crucial for various applications including agro-ecosystem mod

  12. 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,...

  13. 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

  14. PHYSIOLOGICAL TRAITS OF WEED GROWTH-SUPPRESSIVE RHIZOBACTERIA

    Science.gov (United States)

    Deleterious rhizobacteria (DRB) may contribute to weed suppression in soils under specific management or as applied biocontrol agents. To understand the mechanisms for growth suppression of weeds, we examined rhizobacteria from several important weeds in seven agroecosystems for a wide array of phys...

  15. Impacts of herbaceous bioenergy crops on atmospheric volatile organic composition and potential consequences for global climate change

    Science.gov (United States)

    The introduction of new crops to agroecosystems can change the chemical composition of the atmosphere by altering the bouquet of plant-derived biogenic volatile organic compounds (BVOCs). BVOCs are low molecular weight secondary metabolites that are generally used by plants for defense, pollination ...

  16. BIOLOGICAL RESOURCES OF AGRICULTURAL ECOLOGICAL BIOTECHNOLOGY

    OpenAIRE

    Gheorghe Jigău; Maria Motelica; Elena Tofan

    2012-01-01

    Alternative agriculture is developing within the conventional agriculture which requires exclusion or minimizing of the negative consequences of the latest practical technologies. Ecological agriculture is an integral part of the conservativeagriculture. This presupposes practice of agricultural biotechnologyproduction based on the principles of landscape adaptationto agroecosystems and their biologization. The practices of agricultural ecological biotechnologies ensure expandedreproduction ...

  17. BIOLOGICAL RESOURCES OF AGRICULTURAL ECOLOGICAL BIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Gheorghe Jigău

    2012-10-01

    Full Text Available Alternative agriculture is developing within the conventional agriculture which requires exclusion or minimizing of the negative consequences of the latest practical technologies. Ecological agriculture is an integral part of the conservativeagriculture. This presupposes practice of agricultural biotechnologyproduction based on the principles of landscape adaptationto agroecosystems and their biologization. The practices of agricultural ecological biotechnologies ensure expandedreproduction of the soil ecosystem

  18. Team-up Crop Diversification and Weed Management: PRODIVA

    DEFF Research Database (Denmark)

    Gerowitt, B.; Melander, B.; Krawczyk, R.;

    2015-01-01

    results. Neither are crop diversification methods restricted to Organic Farming, nor can IWM (Integrated Weed Management) be successfully implemented without respecting the role of weeds in agro-ecosystems. The project “PRODIVA - Crop diversification and weeds“ is supported within the ERA-net CORE Organic...

  19. A HYDRAULIC SOIL CORING SYSTEM FOR SOIL CARBON-ROOT STUDIES

    Science.gov (United States)

    Reliable sampling of belowground components is an essential aspect of agroecosystems research. Factors such as difficult soil conditions (e.g., hardpans, rocky or wet conditions), restricted access, and remote sites can often limit adequate sampling in the field. The objective was to design and cons...

  20. Intercropping frost-sensitive legume crops with winter oilseed rape reduces weed competition, insect damage, and improves nitrogen use efficiency

    OpenAIRE

    Cadoux Stéphane; Sauzet Gilles; Valantin-Morison Muriel; Pontet Célia; Champolivier Luc; Robert Céline; Lieven Jean; Flénet Francis; Mangenot Olivier; Fauvin Pascal; Landé Nathalie

    2015-01-01

    Mixing plant species in agroecosystems is highlighted as an agroecological solution to reduce pesticides and fertilizers while maintaining profitability. In the French context, intercropping frost-sensitive legume crops with winter oilseed rape is potentially interesting and began to be implemented by farmers. In this study we aimed at measuring the services and disservices of this intercrop with three different legume mixtures, in ...

  1. Plus C'est La Meme Chose? Questioning Crop Diversification as a Response to Agricultural Deregulation in Saskatchewan, Canada

    Science.gov (United States)

    Bradshaw, Ben

    2004-01-01

    In the context of declining government subsidization of agriculture, many analysts have predicted reversals in certain characteristic trends of post-1945 Western agriculture with positive implications for agroecosystem well-being. One example, investigated herein, is the suggestion that, in the absence of government safety nets, farmers will seek…

  2. Soil enzyme activities during the 2011 Texas record drought/heat wave and implications to biogeochemical cycling and organic matter dynamics

    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,...

  3. Elevated CO2 and O3 modify N turnover rates, but not N2O emissions

    Science.gov (United States)

    In order to predict and mitigate future climate change, it is essential to understand effects of elevated CO2 (eCO2) and O3 (eO3) on N-cycling, including N2O emissions, due to plant mediated changes. This is of particular interest for agroecosystems, since N-cycling and N2O emissions are responsive ...

  4. The Science behind Ecological Farming Practices

    OpenAIRE

    Lakhani-Goel, Sujata

    2014-01-01

    Summary Traditional farming is based upon ecologically sustainable practices. Recent scientific research is beginning to reveal that these time-tested practices are synergistic with the biological functioning of plants, insects and microbes that constitute the agro-ecosystem. This paper describes the science which underlie traditional farming practices, and renders them truly sustainable for the future.

  5. Temperature determines size and direction of effects of elevated CO2 and nitrogen form on yield quantity and quality of Chinese cabbage

    NARCIS (Netherlands)

    Reich, M.; van den Meerakker, A. N.; Parmar, S.; Hawkesford, M. J.; De Kok, L. J.

    2016-01-01

    Rising atmospheric CO2 concentrations (e[CO2]) are presumed to have a significant impact on plant growth and yield and also on mineral nutrient composition, and therefore, on nutritional quality of crops and vegetables. To assess the relevance of these effects in future agroecosystems it is importan

  6. Nanoscale interactions between engineered nanomaterials and black carbon (Biochar) in soil

    Science.gov (United States)

    Engineered nanomaterials (NMs) enter agricultural soils directly as additives in agrichemical formulations1 and indirectly as contaminants in municipal sewage sludge.2 NIFA has a vested interest in developing predictive models for the fate and nanotoxicity of NMs in agroecosystems. An understanding ...

  7. 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…

  8. 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 ...

  9. Climate change variability and Andean agriculture: The context

    OpenAIRE

    Valdivia, Corinne

    2008-01-01

    A presentation by Valdivia from lessons learned in the SANREM CRSP and past research to frame the two day workshop. First session of the workshop: I. Climate Change Variability and Andean Agriculture: The Context Lessons learned from SANREM CRSP on adapting to climate change. LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  10. Understanding climate variability and change in the Altiplano

    OpenAIRE

    Seth, Anji

    2007-01-01

    This presentation addresses climate variability in the climate change models for 20th and 21st centuries for the Altiplano Region. The models appear to simulate this mechanism in the present, but respond quite differently in 21st century climate. This poses a question: Is this related to LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  11. SANREM CRSP LTR4: Adapting to change in the Andes: Practices and strategies to address market and climate risks in vulnerable ecosystems

    OpenAIRE

    Valdivia, Corinne

    2008-01-01

    This presentation describes the work of the SANREM CRSP Long term research activity 4 (LTRA-4), "Adapting to Change in the Andes: Practices and Strategies to Address Market and Climate Risks in Vulnerable Ecosystems." The objectives of the project are to address: LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  12. Andean highlands: Implications of climate change

    OpenAIRE

    Seth, Anji; Thibeault, J.M.; García, Magali

    2007-01-01

    This presentation provides background on the SANREM CRSP project "Adapting to Change in the Andean Highlands: Practices and Strategies to Address Climate and Market Risks in Vulnerable Agro-Eco Systems" and discusses the means, variability and projections for the Altiplano climate. available in SANREM office, ESIILTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  13. Adapting to Change in Andean Ecosystems: Climate and Strategies

    OpenAIRE

    Valdivia, Corinne; Fernández-Baca, Edith

    2008-01-01

    The presentation summarizes the research activities conducted by SANREM CRSP LTRA4 Adapting to Change in the Andes in the Altiplano region. The objectives were to present the project, emphasizing the research activities revolving around climate, strategies and advocacy coalitions. LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  14. Practices and strategies to address climate and market risks in vulnerable ecosystems: Panel on collective action, participation and agricultural research

    OpenAIRE

    Valdivia, Corinne; Gilles, Jere

    2007-01-01

    A presentation about the results of a panel on collective action, participation and agricultural research within the framework of the SANREM CRSP LTR-4 project "Practices and strategies to address climate and market risks in vulnerable ecosystems". LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  15. Climate change, markets and livelihood strategies for adaptation in vulnerable Altiplano Ecosystems

    OpenAIRE

    Valdivia, Corinne; Jiménez, Elizabeth; Seth, Anji

    2009-01-01

    This presentation discusses a framework of scales and interactions, Altiplano climate trends and change, markets, livelihood strategies and perceptions of risks across the Altiplano ecosystem, uncertainty, and participatory research in adaptive capacities. LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  16. Soils and climate: Consequences and potential adaptation

    OpenAIRE

    Motavalli, Peter P.

    2008-01-01

    This presention outlines results of research about the consequences and potential adaptation of soils to climate change. This includes findings regarding change in soil organic matter and management practices/techniques for adapting to production. LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  17. ECONOMICS-DRIVEN RESEARCH AND INCENTIVES FOR PEARL MILLET PRODUCTION IN THE UNITED STATES

    Science.gov (United States)

    Pearl millet has been grown in the U.S. for livestock forage for over 100 years. Research into grain applications was initially conducted to address environmental constraints of southeastern agro-ecosystems. Early results by growers and diverse industries in the southeastern U.S. have encouraged fur...

  18. Experiential Learnings Inclimate Change Mitigation and Adaptation Through Organic and Sustainable Farming in the Philippines

    OpenAIRE

    Villegas, Pablito; Catedral, Isagani; Custodio, Henry

    2014-01-01

    This paper presents the best practices done by the Sustainable Agriculture and Organic Farmers’ Cooperative to address climate change impacts in agriculture. The issues include food security and access to safe, affordable and health promoting foods; water sufficiency and resilience to drought; environmental and ecological stability of an agro-ecosystem; human health and healthy lifestyle; and climate impacts on agricultural productivity.

  19. Early establishment of the phytoseiid mite Amblyseius swirskii (Acari: Phytoseiidae) on pepper seedlings in a Predator-In-First approach

    Science.gov (United States)

    Establishment of biocontrol agents is critical for success of a biological control strategy. Predator-In-First (PIF) is a novel approach towards establishing predators before the appearance of pests in an agro-ecosystem. PIF utilizes the characteristics of type III generalist phytoseiid mites, which...

  20. Evaluating bee (Hymenoptera: Apoidea) diversity using malaise traps in coffee landscapes of Costa Rica

    Science.gov (United States)

    Even though Arabica coffee (Coffea arabica Linnaeus, Rubiaceae) can self-pollinate, bees are important pollinators, without which there is lower fruit quality and yield. We studied bee diversity in coffee agroecosystems in Costa Rica during two coffee flowering seasons (2005 and 2006). Malaise traps...