WorldWideScience

Sample records for sustainable dryland cropping

  1. Sustainable semiarid dryland production in relation to tillage effects on Hydrology: 1983-2013

    Science.gov (United States)

    Semiarid dryland crop yields with no-till, NT, residue management are often greater than stubble-mulch tillage, SM, as a result of improved soil conditions or water conservation, but knowledge of long-term tillage effects on the comprehensive field hydrology and sustained crop production is needed. ...

  2. Long-term conventional and no-tillage effects on field hydrology and yields of a dryland crop rotation

    Science.gov (United States)

    Semiarid dryland crop yields with no-till, NT, residue management are often greater than stubble-mulch, SM, tillage as a result of improved soil conditions and water conservation, but information on long-term tillage effects on field hydrology and sustained crop production are needed. Our objective ...

  3. Effects of crop residue on soil and plant water evaporation in a dryland cotton system

    Science.gov (United States)

    Lascano, R. J.; Baumhardt, R. L.

    1996-03-01

    Dryland agricultural cropping systems emphasize sustaining crop yields with limited use of fertilizer while conserving both rain water and the soil. Conservation of these resources may be achieved with management systems that retain residues at the soil surface simultaneously modifying both its energy and water balance. A conservation practice used with cotton grown on erodible soils of the Texas High Plains is to plant cotton into chemically terminated wheat residues. In this study, the partitioning of daily and seasonal evapotranspiration ( E t) into soil and plant water evaporation was compared for a conventional and a terminated-wheat cotton crop using the numerical model ENWATBAL. The model was configured to account for the effects of residue on the radiative fluxes and by introducing an additional resistance to latent and sensible heat fluxes derived from measurements of wind speed and vapor conductance from a soil covered with wheat-stubble. Our results showed that seasonal E t was similar in both systems and that cumulative soil water evaporation was 50% of E t in conventional cotton and 31% of E t in the wheat-stubble cotton. Calculated values of E t were in agreement with measured values. The main benefit of the wheat residues was to suppress soil water evaporation by intercepting irradiance early in the growing season when the crop leaf area index (LAI) was low. In semiarid regions LAI of dryland cotton seldom exceeds 2 and residues can improve water conservation. Measured soil temperatures showed that early in the season residues reduced temperature at 0.1 m depth by as much as 5°C and that differences between systems diminished with depth and over time. Residues increased lint yield per unit of E t while not modifying seasonal E t and reducing cumulative soil water evaporation.

  4. Life-cycle analysis of dryland greenhouse gases affected by cropping sequence and nitrogen fertilization

    Science.gov (United States)

    Little information is available about management practices effect on net global warming potential (GWP) and greenhouse gas intensity (GHGI) under dryland cropping systems. We evaluated the effects of cropping sequences (conventional till malt barley-fallow [CTB-F], no-till malt barley-pea [NTB-P], a...

  5. Replacing fallow with forage triticale in dryland crop rotations increases profitability

    Science.gov (United States)

    A common dryland rotational cropping system in the semi-arid central Great Plains of the U.S. is wheat (Triticum aestivum L.)-corn (Zea mays L.)-fallow (WCF). However, the 12-month fallow period following corn production has been shown to be relatively inefficient in storing precipitation during the...

  6. Projected dryland cropping system shifts in the Pacific Northwest in response to climate change

    Science.gov (United States)

    Agriculture in the dryland region of the Inland Pacific Northwest (IPNW, including northern Idaho, eastern Washington and northern Oregon) is typically characterized based on annual rainfall and associated distribution of cropping systems that have evolved in response to biophysical and socio-econom...

  7. Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence.

    Science.gov (United States)

    Sainju, Upendra M; Allen, Brett L; Caesar-TonThat, Thecan; Lenssen, Andrew W

    2015-01-01

    Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-year effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and cation exchange capacity (CEC) at the 0-120 cm depth and annualized crop yield in the northern Great Plains, USA. Treatments were no-till continuous spring wheat (Triticum aestivum L.) (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (FSTCW), fall and spring till spring wheat-barley (Hordeum vulgare L., 1984-1999) followed by spring wheat-pea (Pisum sativum L., 2000-2013) (FSTW-B/P), and spring till spring wheat-fallow (STW-F, traditional system). At 0-7.5 cm, P, K, Zn, Na, and CEC were 23-60% were greater, but pH, buffer pH, and Ca were 6-31% lower in NTCW, STCW, and FSTW-B/P than STW-F. At 7.5-15 cm, K was 23-52% greater, but pH, buffer pH, and Mg were 3-21% lower in NTCW, STCW, FSTCW, FSTW-B/P than STW-F. At 60-120 cm, soil chemical properties varied with treatments. Annualized crop yield was 23-30% lower in STW-F than the other treatments. Continuous N fertilization probably reduced soil pH, Ca, and Mg, but greater crop residue returned to the soil increased P, K, Na, Zn, and CEC in NTCW and STCW compared to STW-F. Reduced tillage with continuous cropping may be adopted for maintaining long-term soil fertility and crop yields compared with the traditional system.

  8. Crop model usefulness in drylands of southern Africa: an application ...

    African Journals Online (AJOL)

    Crop models are useful tools for simulating impacts of climate and agricultural practices on crops. Models have to demonstrate the ability to simulate actual crop growth response in particular environments before application. Data limitations in southern Africa frequently hinder adequate assessment of crop models before ...

  9. Projected Dryland Cropping System Shifts in the Pacific Northwest in Response to Climate Change

    Directory of Open Access Journals (Sweden)

    Claudio O. Stöckle

    2017-04-01

    Full Text Available Agriculture in the dryland region of the Inland Pacific Northwest (IPNW, including northern Idaho, eastern Washington and northern Oregon is typically characterized based on annual rainfall and associated distribution of cropping systems that have evolved in response to biophysical and socio-economic factors. Three agro-ecological classes (AEC have been proposed for the region: (a crop/fallow (CF, (b annual crop/fallow transition (CCF, and (c continuous cropping (CC. AECs attempt to associate land use into relatively homogeneous areas that result in common production systems. Although there is an interest in sustainable intensification of cropping systems (e.g., reduction of fallow, the question remains whether climate change will preclude intensification or shift the borders of existing AECs toward greater fallow utilization. A simulation study was conducted to address this question, with the aim of classifying 4 × 4 km pixels throughout the region into one of the three AECs for baseline (1979–2010 and future periods (2030s, 2015–2045; 2050s, 2035–2065; 2070s, 2055–2085. Baseline data were derived from traditional rotations and historical climate records. Data for future projections were derived from atmospheric CO2 concentration considering daily weather downloaded from 12 global circulation models and 2 representative concentration pathways (RCP 4.5 and 8.5. Due to the direct effect of atmospheric CO2 on photosynthesis and stomatal conductance, the transpiration use efficiency of crops (TUE; g above-ground biomass kg water−1 showed an increasing trend, with winter wheat TUE changing from 4.76 in the historical period to 6.17 and 7.08 g kg−1 in 2070s, depending on AEC. Compared to the baseline, total grain yield by the 2070s in the region was projected to increase in the range of 18–48% (RCP 4.5 and 30–65% (RCP 8.5, depending on AEC. As a consequence of these changes, compared to the historical baseline period, the future

  10. Interacting Effects of Heat Stress and Soil Moisture Stress on Crop Yield Losses in Dryland Agriculture

    Science.gov (United States)

    Debats, S. R.; Caylor, K. K.; Estes, L. D.; Chaney, N.; Sheffield, J.

    2012-12-01

    Increased interannual variability and greater frequency of extreme events place new pressures on subsistence farmers as a direct result of climate change. Of particular concern are farmers practicing rainfed agriculture in dryland ecosytems, where food security is closely linked to climate. In these areas, an improved understanding of the occurrence of extreme events as well as their effects on crop yields is essential. The main goals of this research are to identify the relative importance and possible coupling of heat stress and soil moisture stress in determining dryland crop yield losses. In particular, we are interested in determining the extent to which irrigation is an effective buffer against drought and heat stress in dryland regions. While irrigation can protect against soil moisture stress, its ability to mitigate heat stress, or the combined effects of the two stresses, is uncertain. Our study focuses on the Eastern and Southern provinces of Zambia as characteristic regions of dryland agriculture. Sites in the study area are identified based on farming type (irrigated versus rainfed). As irrigation is assumed to negate soil moisture stress, this approach enables separate analysis of heat stress and soil moisture stress, as well as their combined effects. To quantify the effects of heat stress, distributions of daily minimum and maximum temperatures are used to identify the frequency and severity of anomalously warm periods and their correlation with resulting crop yield losses. We also utilize Standardized Precipitation Index (SPI) data and soil moisture data derived from the Variable Infiltration Capacity (VIC) macroscale hydrologic model to examine the effects of meteorological drought and hydrological drought, respectively, on crop yields. To quantify crop yield losses, we employ yield estimates derived from the integration of time series of 250 meter resolution Normalized Difference Vegetation Index (NDVI) images collected by the Moderate Resolution

  11. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia

    Directory of Open Access Journals (Sweden)

    WAHYU ASTIKO

    2016-01-01

    Full Text Available Abstract. Astiko W, Fauzi MT, Sukartono. 2016. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia. Nusantara Bioscience 8: 66-70. Inoculation of arbuscular mycorrhizal fungi (AMF on maize in sandy soil is expected to have positive implications for the improvement of AMF population and nutrient uptake. However, how many increases in the AMF population and nutrient uptake in the second cycle of a certain cropping system commonly cultivated by the farmers after growing their corn crop have not been examined. Since different cropping systems would indicate different increases in the populations of AMF and nutrient uptake. This study aimed to determine the population AMF and nutrient uptake on the second cropping cycle of corn-based cropping systems which utilized indigenous mycorrhizal fungi on sandy soil in dryland area of North Lombok, West Nusa Tenggara, Indonesia. For that purpose, an experiment was conducted at the Akar-Akar Village in Bayan Sub-district of North Lombok, designed according to the Randomized Complete Block Design, with four replications and six treatments of cropping cycles (P0 = corn-soybean as a control, in which the corn plants were not inoculated with AMF; P1 = corn-soybean, P2 = corn-peanut, P3 = corn-upland rice, P4 = corn-sorghum, and P5 = corn-corn, in which the first cycle corn plants were inoculated with AMF. The results indicated that the mycorrhizal populations (spore number and infection percentage were highest in the second cycle sorghum, achieving 335% and 226% respectively, which were significantly higher than those in the control. Increased uptake of N, P, K and Ca the sorghum plants at 60 DAS of the second cropping cycle reached 200%; 550%; 120% and 490% higher than in the control. The soil used in this experiment is rough-textured (sandy loam, so it is relatively low in water holding capacity and high porosity.

  12. The Seed Industry for Dryland Crops in Eastern Kenya

    OpenAIRE

    Muhammad, Lutta; Njoroge, Kiarie; Bett, Charles; Mwangi, Wilfred; Verkuijl, Hugo; De Groote, Hugo

    2003-01-01

    The development and promotion of improved crop varieties as well as efficient seed production, distribution, and marketing systems have contributed significantly to increased agricultural production and food security in Kenya. However, these impacts have not been replicated in the semi-arid midlands due to climatic, soil, and institutional factors. Following the liberalization of agriculture in the late 1980s, there has been greater participation of the private sector, non-governmental organi...

  13. Global warming likely reduces crop yield and water availability of the dryland cropping systems in the U.S. central Great Plains

    Science.gov (United States)

    We investigated impacts of GCM-projected climate change on dryland crop rotations of wheat-fallow and wheat-corn-fallow in the Central Great Plains (Akron in Colorado, USA) using the CERES 4.0 crop modules in RZWQM2. The climate change scenarios for CO2, temperature, and precipitation were produced ...

  14. Nested archetypes of vulnerability in African drylands: where lies potential for sustainable agricultural intensification?

    Science.gov (United States)

    Sietz, D.; Ordoñez, J. C.; Kok, M. T. J.; Janssen, P.; Hilderink, H. B. M.; Tittonell, P.; Van Dijk, H.

    2017-09-01

    Food production is key to achieving food security in the drylands of sub-Saharan Africa. Since agricultural productivity is limited, however, due to inherent agro-ecological constraints and land degradation, sustainable agricultural intensification has been widely discussed as an opportunity for improving food security and reducing vulnerability. Yet vulnerability determinants are distributed heterogeneously in the drylands of sub-Saharan Africa and sustainable intensification cannot be achieved everywhere in cost-effective and efficient ways. To better understand the heterogeneity of farming systems’ vulnerability in order to support decision making at regional scales, we present archetypes, i.e. socio-ecological patterns, of farming systems’ vulnerability in the drylands of sub-Saharan Africa and reveal their nestedness. We quantitatively indicated the most relevant farming systems’ properties at a sub-national resolution. These factors included water availability, agro-ecological potential, erosion sensitivity, population pressure, urbanisation, remoteness, governance, income and undernourishment. Cluster analysis revealed eight broad archetypes of vulnerability across all drylands of sub-Saharan Africa. The broad archetype representing better governance and highest remoteness in extremely dry and resource-constrained regions encompassed the largest area share (19%), mainly indicated in western Africa. Moreover, six nested archetypes were identified within those regions with better agropotential and prevalent agricultural livelihoods. Among these patterns, the nested archetype depicting regions with highest erosion sensitivity, severe undernourishment and lower agropotential represented the largest population (30%) and area (28%) share, mainly found in the Sahel region. The nested archetype indicating medium undernourishment, better governance and lowest erosion sensitivity showed particular potential for sustainable agricultural intensification, mainly in

  15. Comparison of net global warming potential and greenhouse gas intensity affected by management practices in two dryland cropping sites

    Science.gov (United States)

    Little is known about the effect of management practices on net global warming potential (GWP) and greenhouse gas intensity (GHGI) that account for all sources and sinks of greenhouse gas (GHG) emissions in dryland cropping systems. The objective of this study was to compare the effect of a combinat...

  16. Climate change predicted to negatively influence surface soil health of dryland cropping systems in the Inland Pacific Northwest

    Science.gov (United States)

    Soil organic matter (SOM) is a key indicator of agricultural productivity and overall soil health. Currently, dryland cropping systems of the inland Pacific Northwest (iPNW) span a large gradient in mean annual temperature (MAT) and precipitation (MAP). These climatic drivers are major determinants ...

  17. Climate change predicted to negatively influence surface soil organic matter of dryland cropping systems in the Inland Pacific Northwest, USA

    Science.gov (United States)

    Soil organic matter (SOM) is a key indicator of agricultural productivity and overall soil health. Currently, dryland cropping systems of the inland Pacific Northwest (iPNW) span a large gradient in mean annual temperature (MAT) and precipitation (MAP).These climatic drivers are major determinants o...

  18. Challenges and Alternatives to Sustainable Management of Agriculture and Pastoral Ecosystems in Asian Drylands

    Science.gov (United States)

    Qi, J.

    2015-12-01

    There is no question that human must produce additional 70% food to feed the new 2.2 billion of people on the planet by 2050, but the question is where to grow the additional food. The demand for the additional food lies not only in producing the basic resources needed to sustain a healthy lifestyle, but also from a changing diet, especially in rapidly developing countries in the dryland regions around the world. It is forecast that this demand for meat will require an additional 0.2 billion tons per year by 2050, which is almost a doubling of present meat consumption. These new demands create mounting pressures on agriculture and pastoral ecosystems and the reported trajectory of warmer and drier climate in the future increases uncertainties in food security, adding further stresses to the already stressed nations in the Asian dryland belt. Different approaches are being either proposed or practiced in the region but the question is whether or not the current practices are sustainable or optimal in addressing the emerging issues. Given the complexity and interplay among the food, water and energy, what are alternatives to ensure a sustainable trajectory of regional development to meet the new food demand? This presentation reviews existing practices and proposes alternative solutions, by specifically examining the trade-offs between different ecosystem services that drylands in Asian may provide. Preliminary analysis suggested that the current trajectory of meat and milk production is likely not on a sustainable pathway.

  19. 10th anniversary review: addressing land degradation and climate change in dryland agroecosystems through sustainable land management.

    Science.gov (United States)

    Thomas, Richard James

    2008-05-01

    Sustainable land management (SLM) is proposed as a unifying theme for current global efforts on combating desertification, climate change and loss of biodiversity in drylands. A focus on SLM will achieve the multiple goals of the three UN Conventions (UNCCD, UNFCCC and UNCBD) and in particular will address the roots causes of poverty and vulnerability to climate change rather than a current focus on adapting to climate change. The interlinkages between land degradation, climate change and loss of biodiversity are outlined together with a proposed set of interventions to achieve multiple goals. It is argued that improved land productivity is a viable goal to reduce poverty in drylands provided it is linked to payments for environmental services and better crop and weather insurances and coupled with alternative livelihoods that are not primarily dependent on land productivity. Obstacles to the achievement of SLM are discussed and the steps necessary to overcome them are presented. It is suggested that promoting SLM would be a better focus for the UNCCD than combating desertification.

  20. Developing an Agro-Ecological Zoning Model for Tumbleweed (Salsola kali), as Energy Crop in Drylands of Argentina

    Science.gov (United States)

    Falasca, Silvia; Pitta-Alvarez, Sandra; Ulberich, Ana

    2016-12-01

    Salsola kali is considered extremely valuable as an energy crop worldwide because it adapts easily to environments with strong abiotic stresses (hydric, saline and alkaline) and produces large amounts of biomass in drylands. This species is categorized as an important weed in Argentina. The aim of this work was to design an agro-ecological zoning model for tumbleweed in Argentina, employing a Geography Information System. Based on the bioclimatic requirements for the species and the climatic data for Argentina (1981-2010 period), an agro-climatic suitability map was drawn. This map was superimposed on the saline and alkaline soil maps delineated by the Food and Agriculture Organization for dry climates, generating the agro-ecological zoning on a scale of 1 : 500 000. This zoning revealed very suitable and suitable cultivation areas on halomorphic soils. The potential growing areas extend from N of the Salta province (approximately 22° S) to the Santa Cruz province (50° S). The use of tumbleweed on halomorphic soils under semi-arid to arid conditions, for the dual purpose of forage use and source of lignocellulosic material for bioenergy, could improve agricultural productivity in these lands. Furthermore, it could also contribute to their environmental sustainability, since the species can be used to reclaim saline soils over the years. Based on international bibliography, the authors outlined an agro-ecological zoning model. This model may be applied to any part of the world, using the agro-ecological limits presented here.

  1. Sustainable Land Management (SLM) Practices in Drylands: How Do They Address Desertification Threats?

    Science.gov (United States)

    Schwilch, G.; Liniger, H. P.; Hurni, H.

    2014-11-01

    Managing land sustainably is a huge challenge, especially under harsh climatic conditions such as those found in drylands. The socio-economic situation can also pose challenges, as dryland regions are often characterized by remoteness, marginality, low-productive farming, weak institutions, and even conflict. With threats from climate change, disputes over water, competing claims on land, and migration increasing worldwide, the demands for sustainable land management (SLM) measures will only increase in the future. Within the EU-funded DESIRE project, researchers and stakeholders jointly identified existing SLM technologies and approaches in 17 dryland study sites located in the Mediterranean and around the world. In order to evaluate and share this valuable SLM experience, local researchers documented the SLM technologies and approaches in collaboration with land users, utilizing the internationally recognized WOCAT questionnaires. This article provides an analysis of 30 technologies and 8 approaches, enabling an initial evaluation of how SLM addresses prevalent dryland threats, such as water scarcity, soil degradation, vegetation degradation and low production, climate change, resource use conflicts, and migration. Among the impacts attributed to the documented technologies, those mentioned most were diversified and enhanced production and better management of water and soil degradation, whether through water harvesting, improving soil moisture, or reducing runoff. Favorable local-scale cost-benefit relationships were mainly found when considered over the long term. Nevertheless, SLM was found to improve people's livelihoods and prevent further outmigration. More field research is needed to reinforce expert assessments of SLM impacts and provide the necessary evidence-based rationale for investing in SLM.

  2. Sustainable land management (SLM) practices in drylands: how do they address desertification threats?

    Science.gov (United States)

    Schwilch, G; Liniger, H P; Hurni, H

    2014-11-01

    Managing land sustainably is a huge challenge, especially under harsh climatic conditions such as those found in drylands. The socio-economic situation can also pose challenges, as dryland regions are often characterized by remoteness, marginality, low-productive farming, weak institutions, and even conflict. With threats from climate change, disputes over water, competing claims on land, and migration increasing worldwide, the demands for sustainable land management (SLM) measures will only increase in the future. Within the EU-funded DESIRE project, researchers and stakeholders jointly identified existing SLM technologies and approaches in 17 dryland study sites located in the Mediterranean and around the world. In order to evaluate and share this valuable SLM experience, local researchers documented the SLM technologies and approaches in collaboration with land users, utilizing the internationally recognized WOCAT questionnaires. This article provides an analysis of 30 technologies and 8 approaches, enabling an initial evaluation of how SLM addresses prevalent dryland threats, such as water scarcity, soil degradation, vegetation degradation and low production, climate change, resource use conflicts, and migration. Among the impacts attributed to the documented technologies, those mentioned most were diversified and enhanced production and better management of water and soil degradation, whether through water harvesting, improving soil moisture, or reducing runoff. Favorable local-scale cost-benefit relationships were mainly found when considered over the long term. Nevertheless, SLM was found to improve people's livelihoods and prevent further outmigration. More field research is needed to reinforce expert assessments of SLM impacts and provide the necessary evidence-based rationale for investing in SLM.

  3. Multifaceted Impacts of Sustainable Land Management in Drylands: A Review

    Directory of Open Access Journals (Sweden)

    Maria Jose Marques

    2016-02-01

    Full Text Available Biophysical restoration or rehabilitation measures of land have demonstrated to be effective in many scientific projects and small-scale environmental experiments. However circumstances such as poverty, weak policies, or inefficient scientific knowledge transmission can hinder the effective upscaling of land restoration and the long term maintenance of proven sustainable use of soil and water. This may be especially worrisome in lands with harsh environmental conditions. This review covers recent efforts in landscape restoration and rehabilitation with a functional perspective aiming to simultaneously achieve ecosystem sustainability, economic efficiency, and social wellbeing. Water management and rehabilitation of ecosystem services in croplands, rangelands, forests, and coastlands are reviewed. The joint analysis of such diverse ecosystems provides a wide perspective to determine: (i multifaceted impacts on biophysical and socio-economic factors; and (ii elements influencing effective upscaling of sustainable land management practices. One conclusion can be highlighted: voluntary adoption is based on different pillars, i.e. external material and economic support, and spread of success information at the local scale to demonstrate the multidimensional benefits of sustainable land management. For the successful upscaling of land management, more attention must be paid to the social system from the first involvement stage, up to the long term maintenance.

  4. Farming with future: making crop protection sustainable

    NARCIS (Netherlands)

    Wijnands, F.G.

    2011-01-01

    The project Farming with future works with parties with a vested interest to promote sustainable crop protection in practice. Besides developing new knowledge, it spends a good deal of its energy in the embedding of sustainable practices within relevant organisations, businesses and agrarian

  5. Relay cropping as a sustainable approach: problems and opportunities for sustainable crop production.

    Science.gov (United States)

    Tanveer, Mohsin; Anjum, Shakeel Ahmad; Hussain, Saddam; Cerdà, Artemi; Ashraf, Umair

    2017-03-01

    Climate change, soil degradation, and depletion of natural resources are becoming the most prominent challenges for crop productivity and environmental sustainability in modern agriculture. In the scenario of conventional farming system, limited chances are available to cope with these issues. Relay cropping is a method of multiple cropping where one crop is seeded into standing second crop well before harvesting of second crop. Relay cropping may solve a number of conflicts such as inefficient use of available resources, controversies in sowing time, fertilizer application, and soil degradation. Relay cropping is a complex suite of different resource-efficient technologies, which possesses the capability to improve soil quality, to increase net return, to increase land equivalent ratio, and to control the weeds and pest infestation. The current review emphasized relay cropping as a tool for crop diversification and environmental sustainability with special focus on soil. Briefly, benefits, constraints, and opportunities of relay cropping keeping the goals of higher crop productivity and sustainability have also been discussed in this review. The research and knowledge gap in relay cropping was also highlighted in order to guide the further studies in future.

  6. Are the drylands in northern China sustainable? A perspective from ecological footprint dynamics from 1990 to 2010.

    Science.gov (United States)

    Li, Jingwei; Liu, Zhifeng; He, Chunyang; Tu, Wei; Sun, Zexiang

    2016-05-15

    The drylands in northern China (DNC), characterized by water scarcity, high climatic variability, and infertile soil, are crucial for China's sustainable development in the context of rapid urbanization. However, few studies have systematically investigated its sustainability. Our objective was to assess the sustainability of the DNC according to their ecological footprint (EF) dynamics from 1990 to 2010. We analyzed EF in the DNC at multiple scales ranging from the whole, to four dryland subtypes, to the drylands in each province. We found that the total EF in the DNC increased from 3.48 × 10(8) global hectares (gha) in 1990 to 1.26 × 10(9) gha in 2010, with a growth of 2.63 times, resulting in a more than 14 times increase of ecological deficit from 6.26 × 10(7) gha to 9.63 × 10(8)gha. In addition, the water withdrawal increased from 133.29 km(3) to 153.23 km(3) with a growth rate of 14.96%, while the Human Development Index grew from 0.62 to 0.79. We concluded that the DNC has already become unsustainable after the rapid increases of EF and water withdrawal from 1990 to 2010. We argue that effective management is needed to maintain and improve the environmental sustainability of the DNC. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Adoptability of sustainable intensification technologies in dryland smallholder farming systems of West Africa

    NARCIS (Netherlands)

    Woittiez, L.S.; Descheemaeker, K.K.E.; Giller, K.E.

    2015-01-01

    Within the framework of CGIAR Research Program (CRP) 1.1: Dryland Systems, the compilation of a review of options, constraints and potential for agricultural intensification at a number of specific sites in West African dryland areas has been requested, using an integrated systems approach. CRP 1.1

  8. Effects of crop residue on soil and plant water evaporation in a dryland cotton system

    OpenAIRE

    Lascano, R.J.; R. L. Baumhardt

    1996-01-01

    Metadata only record This study is the context of dryland agriculture, which encompasses rainfed systems that require emphases on minimal fertilizer use and conservation of water and soil. Field trials compare cotton planted in terminated wheat stubble with conventional cotton (stubble incorporated with moldboard and disk). The objective is to differentiate between the contributions of soil and plant evaporation to total evapotranspiration on a daily and seasonal basis, using the numerical...

  9. Crop farmers use of environmentally sustainable agricultural ...

    African Journals Online (AJOL)

    The study was carried out to assess crop farmers' use of environmentally sustainable agricultural practices in Ogun State. Multi – Stage-sampling and simple random sampling procedure was employed to select two hundred (200) farmers from villages selected from the four agricultural zones of Ogun State Agricultural ...

  10. Engineering crop nutrient efficiency for sustainable agriculture.

    Science.gov (United States)

    Chen, Liyu; Liao, Hong

    2017-10-01

    Increasing crop yields can provide food, animal feed, bioenergy feedstocks and biomaterials to meet increasing global demand; however, the methods used to increase yield can negatively affect sustainability. For example, application of excess fertilizer can generate and maintain high yields but also increases input costs and contributes to environmental damage through eutrophication, soil acidification and air pollution. Improving crop nutrient efficiency can improve agricultural sustainability by increasing yield while decreasing input costs and harmful environmental effects. Here, we review the mechanisms of nutrient efficiency (primarily for nitrogen, phosphorus, potassium and iron) and breeding strategies for improving this trait, along with the role of regulation of gene expression in enhancing crop nutrient efficiency to increase yields. We focus on the importance of root system architecture to improve nutrient acquisition efficiency, as well as the contributions of mineral translocation, remobilization and metabolic efficiency to nutrient utilization efficiency. © 2017 Institute of Botany, Chinese Academy of Sciences.

  11. Agricultural innovations for sustainable crop production intensification

    Directory of Open Access Journals (Sweden)

    Michele Pisante

    2012-10-01

    Full Text Available Sustainable crop production intensification should be the first strategic objective of innovative agronomic research for the next 40 years. A range of options exist (often very location specific for farming practices, approaches and technologies that ensure sustainability, while at the same time improving crop production. The main challenge is to encourage farmers in the use of appropriate technologies,  and  to  ensure  that  knowledge  about  sound  production  practices  is  increasingly accepted and applied by farmers. There is a huge, but underutilized potential to link farmers’ local knowledge with science-based innovations, through favourable institutional arrangements.  The same  holds  for  the  design,  implementation  and  monitoring  of  improved  natural  resource management  that  links  community  initiatives  to  external  expertise.  It is also suggested that a comprehensive effort be undertaken to measure different stages of the innovation system, including technological adoption and diffusion at the farm level, and to investigate the impact of agricultural policies on technological change and technical efficiency. This paper provides a brief review of agronomic management practices that support sustainable crop production system and evidence on developments  in the selection of crops and cultivars; describes farming systems for crop which take a predominantly ecosystem approach; discusses the scientific application of ecosystem principles for the management of pest and weed populations; reviews the  improvements in fertilizer and nutrient management that explain productivity growth; describes the benefits and constraints of irrigation technologies; and suggests a way forward. Seven changes in the context for agricultural development are proposed that heighten the need to examine how innovation occurs in the agricultural sector.

  12. Root-knot Nematode Management in Dryland Taro with Tropical Cover Crops.

    Science.gov (United States)

    Sipes, B S; Arakaki, A S

    1997-12-01

    Twenty-two cover crops were evaluated for their ability to reduce damage by root-knot nematode, Meloidogyne javanica, to taro, Colocastia esculenta, in a tropical cropping system. Cover crops were grown and incorporated into the soil before taro was planted. Barley, greenpanic, glycine, marigold, sesame, sunn hemp, and sorghum x sudangrass DeKalb ST6E were poor or nonhosts to the nematode as measured by low population changes of nematodes in soil between cover crop planting and taro planting. Alfalfa, buckwheat, cowpea, lablab, Lana vetch, mustard, oat, okra, rhodes grass, ryegrain, ryegrass, siratro, sweet corn, and wheat allowed nematode populations to increase dramatically. Taro yields were greatest in the marigold plots and lowest in the ryegrain plots. Taro corm weight decreased with increasing initial nematode population (Pi) (r = 0.22, P = 0.056). Siratro, ryegrass, and Blizzard wheat plots had higher taro yield than plots with similar Pi's but planted to other cover crops. These cover crops may have antagonism to other soil microorganisms or their decomposition products may be toxic or adversely affect the nematodes. Cover crops can be an effective and valuable nematode management tactic for use in minor tropical cropping systems such as taro.

  13. Conservation tillage for dryland farming in China

    NARCIS (Netherlands)

    Cai, D.X.; Ke, J.; Wang, X.B.; Hoogmoed, W.B.; Oenema, O.; Perdok, U.D.

    2006-01-01

    Dryland regions account for above 70% of total nation's farmland in China. These dryland are vital contributors to the total national production of grains, cash crops and animal products. However, the development of dryland farming is constrained by harsh climate, bad economic situation and poor

  14. Cisgenics - A Sustainable Approach for Crop Improvement

    Science.gov (United States)

    Telem, R.S.; Wani, Shabir. H.; Singh, N.B.; Nandini, R.; Sadhukhan, R.; Bhattacharya, S.; Mandal, N.

    2013-01-01

    The implication of molecular biology in crop improvement is now more than three decades old. Not surprisingly, technology has moved on, and there are a number of new techniques that may or may not come under the genetically modified (GM) banner and, therefore, GM regulations. In cisgenic technology, cisgenes from crossable plants are used and it is a single procedure of gene introduction whereby the problem of linkage drag of other genes is overcome. The gene used in cisgenic approach is similar compared with classical breeding and cisgenic plant should be treated equally as classically bred plant and differently from transgenic plants. Therefore, it offers a sturdy reference to treat cisgenic plants similarly as classically bred plants, by exemption of cisgenesis from the current GMO legislations. This review covers the implications of cisgenesis towards the sustainable development in the genetic improvement of crops and considers the prospects for the technology. PMID:24396278

  15. Long-term no-till: A major driver of fungal communities in dryland wheat cropping systems.

    Directory of Open Access Journals (Sweden)

    Dipak Sharma-Poudyal

    Full Text Available In the dryland Pacific Northwest wheat cropping systems, no-till is becoming more prevalent as a way to reduce soil erosion and fuel inputs. Tillage can have a profound effect on microbial communities and soilborne fungal pathogens, such as Rhizoctonia. We compared the fungal communities in long-term no-till (NT plots adjacent to conventionally tilled (CT plots, over three years at two locations in Washington state and one location in Idaho, US. We used pyrosequencing of the fungal ITS gene and identified 422 OTUs after rarefication. Fungal richness was higher in NT compared to CT, in two of the locations. Humicola nigrescens, Cryptococcus terreus, Cadophora spp. Hydnodontaceae spp., and Exophiala spp. were more abundant in NT, while species of Glarea, Coniochaetales, Mycosphaerella tassiana, Cryptococcus bhutanensis, Chaetomium perlucidum, and Ulocladium chartarum were more abundant in CT in most locations. Other abundant groups that did not show any trends were Fusarium, Mortierella, Penicillium, Aspergillus, and Macroventuria. Plant pathogens such as Rhizoctonia (Ceratobasidiaceae were not abundant enough to see tillage differences, but Microdochium bolleyi, a weak root pathogen, was more abundant in NT. Our results suggest that NT fungi are better adapted at utilizing intact, decaying roots as a food source and may exist as root endophytes. CT fungi can utilize mature plant residues that are turned into the soil with tillage as pioneer colonizers, and then produce large numbers of conidia. But a larger proportion of the fungal community is not affected by tillage and may be niche generalists.

  16. How can we improve Mediterranean cropping systems?

    DEFF Research Database (Denmark)

    Benlhabib, O.; Yazar, A.; Qadir, M.

    2014-01-01

    dryland Mediterranean cropping systems, and to discuss and recommend sustainable cropping technologies that could be used at the small-scale farm level. Four crop management practices were evaluated: crop rotations, reduced tillage, use of organic manure, and supplemental and deficit irrigation. Among......In the Mediterranean region, crop productivity and food security are closely linked to the adaptation of cropping systems to multiple abiotic stresses. Limited and unpredictable rainfall and low soil fertility have reduced agricultural productivity and environmental sustainability. For this reason...... the tested interventions, incorporation of crop residues coupled with supplementary irrigation showed a significantly positive effect on crop productivity, yield stability and environmental sustainability....

  17. Navigating challenges and opportunities of land degradation and sustainable livelihood development in dryland social–ecological systems: a case study from Mexico

    Science.gov (United States)

    Huber-Sannwald, Elisabeth; Ribeiro Palacios, Mónica; Arredondo Moreno, José Tulio; Braasch, Marco; Martínez Peña, Ruth Magnolia; de Alba Verduzco, Javier García; Monzalvo Santos, Karina

    2012-01-01

    Drylands are one of the most diverse yet highly vulnerable social–ecological systems on Earth. Water scarcity has contributed to high levels of heterogeneity, variability and unpredictability, which together have shaped the long coadaptative process of coupling humans and nature. Land degradation and desertification in drylands are some of the largest and most far-reaching global environmental and social change problems, and thus are a daunting challenge for science and society. In this study, we merged the Drylands Development Paradigm, Holling's adaptive cycle metaphor and resilience theory to assess the challenges and opportunities for livelihood development in the Amapola dryland social–ecological system (DSES), a small isolated village in the semi-arid region of Mexico. After 450 years of local social–ecological evolution, external drivers (neoliberal policies, change in land reform legislation) have become the most dominant force in livelihood development, at the cost of loss of natural and cultural capital and an increasingly dysfunctional landscape. Local DSESs have become increasingly coupled to dynamic larger-scale drivers. Hence, cross-scale connectedness feeds back on and transforms local self-sustaining subsistence farming conditions, causing loss of livelihood resilience and diversification in a globally changing world. Effective efforts to combat desertification and improve livelihood security in DSESs need to consider their cyclical rhythms. Hence, we advocate novel dryland stewardship strategies, which foster adaptive capacity, and continuous evaluation and social learning at all levels. Finally, we call for an effective, flexible and viable policy framework that enhances local biotic and cultural diversity of drylands to transform global drylands into a resilient biome in the context of global environmental and social change. PMID:23045713

  18. Navigating challenges and opportunities of land degradation and sustainable livelihood development in dryland social-ecological systems: a case study from Mexico.

    Science.gov (United States)

    Huber-Sannwald, Elisabeth; Palacios, Mónica Ribeiro; Moreno, José Tulio Arredondo; Braasch, Marco; Peña, Ruth Magnolia Martínez; Verduzco, Javier García de Alba; Santos, Karina Monzalvo

    2012-11-19

    Drylands are one of the most diverse yet highly vulnerable social-ecological systems on Earth. Water scarcity has contributed to high levels of heterogeneity, variability and unpredictability, which together have shaped the long coadaptative process of coupling humans and nature. Land degradation and desertification in drylands are some of the largest and most far-reaching global environmental and social change problems, and thus are a daunting challenge for science and society. In this study, we merged the Drylands Development Paradigm, Holling's adaptive cycle metaphor and resilience theory to assess the challenges and opportunities for livelihood development in the Amapola dryland social-ecological system (DSES), a small isolated village in the semi-arid region of Mexico. After 450 years of local social-ecological evolution, external drivers (neoliberal policies, change in land reform legislation) have become the most dominant force in livelihood development, at the cost of loss of natural and cultural capital and an increasingly dysfunctional landscape. Local DSESs have become increasingly coupled to dynamic larger-scale drivers. Hence, cross-scale connectedness feeds back on and transforms local self-sustaining subsistence farming conditions, causing loss of livelihood resilience and diversification in a globally changing world. Effective efforts to combat desertification and improve livelihood security in DSESs need to consider their cyclical rhythms. Hence, we advocate novel dryland stewardship strategies, which foster adaptive capacity, and continuous evaluation and social learning at all levels. Finally, we call for an effective, flexible and viable policy framework that enhances local biotic and cultural diversity of drylands to transform global drylands into a resilient biome in the context of global environmental and social change.

  19. INFLUENCE OF CONSERVATION TILLAGE AND SOIL WATER CONTENT ON CROP YIELD IN DRYLAND COMPACTED ALFISOL OF CENTRAL CHILE

    National Research Council Canada - National Science Library

    Ingrid G Martínez; Carlos Ovalle; Alejandro Del Pozo; Hamil Uribe; Natalia V Valderrama; Christian Prat; Marco Sandoval; Fernando Fernández; Erick Zagal

    2011-01-01

      Chilean dryland areas of the Mediterranean climate region are characterized by highly degraded and compacted soils, which require the use of conservation tillage systems to mitigate water erosion...

  20. Comparison of Greenhouse Gas Offset Quantification Protocols for Nitrogen Management in Dryland Wheat Cropping Systems of the Pacific Northwest

    Directory of Open Access Journals (Sweden)

    Tabitha T. Brown

    2017-11-01

    Full Text Available In the carbon market, greenhouse gas (GHG offset protocols need to ensure that emission reductions are of high quality, quantifiable, and real. Lack of consistency across protocols for quantifying emission reductions compromise the credibility of offsets generated. Thus, protocol quantification methodologies need to be periodically reviewed to ensure emission offsets are credited accurately and updated to support practical climate policy solutions. Current GHG emission offset credits generated by agricultural nitrogen (N management activities are based on reducing the annual N fertilizer application rate for a given crop without reducing yield. We performed a “road test” of agricultural N management protocols to evaluate differences among protocol components and quantify nitrous oxide (N2O emission reductions under sample projects relevant to N management in dryland, wheat-based cropping systems of the inland Pacific Northwest (iPNW. We evaluated five agricultural N management offset protocols applicable to North America: two methodologies of American Carbon Registry (ACR1 and ACR2, Verified Carbon Standard (VCS, Climate Action Reserve (CAR, and Alberta Offset Credit System (Alberta. We found that only two protocols, ACR2 and VCS, were suitable for this study, in which four sample projects were developed representing feasible N fertilizer rate reduction activities. The ACR2 and VCS protocols had identical baseline and project emission quantification methodologies resulting in identical emission reduction values. Reducing N fertilizer application rate by switching to variable rate N (sample projects 1–3 or split N application (sample project 4 management resulted in a N2O emission reduction ranging from 0.07 to 0.16, and 0.26 Mg CO2e ha−1, respectively. Across the range of C prices considered ($5, $10, and $50 per metric ton of CO2 equivalent, we concluded that the N2O emission offset payment alone ($0.35–$13.0 ha−1 was unlikely to

  1. Sustainability of Marketing Food Crops through the Internet in Lagos ...

    African Journals Online (AJOL)

    abdulaphyz

    and communication technological infrastructure to the sustainability (marketing) of food crops. Given these, government ... i. what are the benefits of marketing and purchasing food crops through the Internet in Lagos State? ..... the conventional market and move from one place to the other to buy different food crops, they can ...

  2. Watershed Scale Optimization to Meet Sustainable Cellulosic Energy Crop Demand

    Energy Technology Data Exchange (ETDEWEB)

    Chaubey, Indrajeet [Purdue Univ., West Lafayette, IN (United States); Cibin, Raj [Purdue Univ., West Lafayette, IN (United States); Bowling, Laura [Purdue Univ., West Lafayette, IN (United States); Brouder, Sylvie [Purdue Univ., West Lafayette, IN (United States); Cherkauer, Keith [Purdue Univ., West Lafayette, IN (United States); Engel, Bernard [Purdue Univ., West Lafayette, IN (United States); Frankenberger, Jane [Purdue Univ., West Lafayette, IN (United States); Goforth, Reuben [Purdue Univ., West Lafayette, IN (United States); Gramig, Benjamin [Purdue Univ., West Lafayette, IN (United States); Volenec, Jeffrey [Purdue Univ., West Lafayette, IN (United States)

    2017-03-24

    The overall goal of this project was to conduct a watershed-scale sustainability assessment of multiple species of energy crops and removal of crop residues within two watersheds (Wildcat Creek, and St. Joseph River) representative of conditions in the Upper Midwest. The sustainability assessment included bioenergy feedstock production impacts on environmental quality, economic costs of production, and ecosystem services.

  3. Women's participation in sustainable crop farming activities in Ogun ...

    African Journals Online (AJOL)

    T-test analysis also revealed that, there is no significant difference between the women farmers participation in sustainable crop farming activities in the two different ecological zones of the study area (t = 2.74, P = 0.81). Keywords: crop farming, participation, sustainable, women farmer. Moor Journal of Agricultural Research ...

  4. A NUTRIENT-IN-WATER RESOURCE FOR SUSTAINABLE CROP ...

    African Journals Online (AJOL)

    sys01

    2011-09-03

    Sep 3, 2011 ... SUSTAINABLE CROP PRODUCTION ON 'ACID SANDS' OF SOUTHERN. NIGERIA. Amalu U. C. and Okon P. B. ... sustainable production of arable and vegetable crops. Application of a solution of urea and lime, ... conducted at Teaching and Research Farm,. Faculty of Agriculture, University of Calabar,.

  5. Transgenic Crops: Implications for Biodiversity and Sustainable Agriculture

    Science.gov (United States)

    Garcia, Maria Alice; Altieri, Miguel A.

    2005-01-01

    The potential for genetically modified (GM) crops to threaten biodiversity conservation and sustainable agriculture is substantial. Megadiverse countries and centers of origin and/or diversity of crop species are particularly vulnerable regions. The future of sustainable agriculture may be irreversibly jeopardized by contamination of in situ…

  6. Environmental Sustainability of Some Cropping Systems in the ...

    African Journals Online (AJOL)

    One of the greatest challenges facing agriculture in the tropics is the need to develop viable cropping systems for the rained uplands that are capable of ensuring increased and sustained crop production with minimum degradation of the non- renewable soil resource base. Increased population has reduced the ...

  7. Dryland systems

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2006-01-01

    Full Text Available the aggregated percentages for broad biomes by dryland subtypes. soil formation and organic matter decomposition (Puigdefabregas et al. 1999). These crusts are therefore instrumental in soil devel- opment in and around the clumps and in soil conservation... the breakdown of dead plant parts (thus en- riching the soil with organic matter) and the regeneration of mineral plant nutrients. Unlike non-drylands, where soil micro- organisms are major players in nutrient cycling, invertebrate macro...

  8. Global desertification: building a science for dryland development

    NARCIS (Netherlands)

    Reynolds, J.F.; Smith, D.M.S.; Lambin, E.F.; Turner, B.L.; Mortimore, M.; Batterbury, S.P.J.; Downing, T.E.; Dowlatabadi, H.; Fernandez, R.J.; Herrick, J.E.; Huber-Sannwald, E.; Jiang, H.; Leemans, R.; Lynam, T.; Maestre, T.; Ayarza, M.; Walker, B.

    2007-01-01

    In this millennium, global drylands face a myriad of problems that present tough research, management, and policy challenges. Recent advances in dryland development, however, together with the integrative approaches of global change and sustainability science, suggest that concerns about land

  9. The impact of long-term nitrogen fertilizer applications on soil organic carbon in a dryland cereal cropping system of the Loess Plateau

    Science.gov (United States)

    Guo, S.

    2011-12-01

    Concerns over food security and global climate change require an improved understanding of how to achieve optimal crop yields whilst minimizing net greenhouse gas emissions from agriculture. In the semi-arid Loess Plateau region of China, as elsewhere, fertilizer nitrogen (N) inputs are necessary to increase yields and improve local food security. In a dryland annual cropping system, we evaluated the effects of N fertilizers on crop yield, its long term impact on soil organic carbon (SOC) concentrations and stock sizes, and the distribution of carbon (C) within various aggregate-size fractions. A current version (RothC) of the Rothamsted model for the turnover of organic C in soil was used to simulate SOC measurements. Five N application rates [0 (N0), 45 (N45), 90 (N90), 135 (N135), and 180 (N180) kg N ha-1] were applied to plots for 25 years (1984-2009) on a loam soil (Cumulic Haplustoll) at the Changwu State Key Agro-Ecological Experimental Station, Shaanxi, China. Crop yield varied with year, but increased over time in the fertilized plots. Average annual grain yields were 1.15, 2.46, 3.11, 3.49, and 3.55 Mg ha-1 with the increasing N application rates, respectively. Long-term N fertilizer application significantly (Porganic C) in the continuous wheat cropping system was 26 years. The SOC accumulation rate was estimated to be 40.0, 48.0, 68.0, and 100.0 kg C ha-1 year-1 for the N45, N90, N135 and N180 treatments over 25 years, respectively. As aboveground biomass was removed, the increases in SOC stocks with higher N application are attributed to increased inputs of root biomass and root exudates. Increasing N application rates significantly improved C concentrations in the macroaggregate fractions (>1 mm). The increase in SOC with N fertilizer applications contributed to improved soil quality as well as crop productivity.

  10. Replacing fallow by cover crops: economic sustainability

    Science.gov (United States)

    Gabriel, José Luis; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Replacing fallow by cover crops in intensive fertilized systems has been demonstrated as an efficient tool for reducing nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of this new technology is still limited because they are either unwilling or unable, although adoption reluctance is frequently rooted in low economic profitability, low water se efficiency or poor knowledge. Economic analyses permit a comparison between the profit that farmers obtain from agricultural products and the cost of adopting specific agricultural techniques. The goal of this study was to evaluate the economic impact of replacing the usual winter fallow with cover crops (barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo)) in irrigated maize systems and variable Mediterranean weather conditions using stochastic Monte-Carlo simulations of key farms' financial performance indicators. The three scenarios studied for each cover crop were: i) just leaving the cover crop residue in the ground, ii) leaving the cover crop residue but reduce following maize fertilization according to the N available from the previous cover crop and iii) selling the cover crop residue for animal feeding. All the scenarios were compared with respect to a typical maize-fallow rotation. With observed data from six different years and in various field trials, looking for different weather conditions, probability distribution functions of maize yield, cover crop biomass production and N fertilizer saving was fitted. Based in statistical sources maize grain price, different forage prices and the cost of fertilizer were fitted to probability distribution functions too. As result, introducing a cover crop involved extra costs with respect to fallow as the initial investment, because new seed, herbicide or extra field operations. Additional

  11. Sustainable commercialization of new crops for the agricultural bioeconomy

    Directory of Open Access Journals (Sweden)

    N.R. Jordan

    2016-01-01

    Full Text Available Abstract Diversification of agroecological systems to enhance agrobiodiversity is likely to be critical to advancing environmental, economic, and social sustainability of agriculture. Temperate-zone agroecological systems that are currently organized for production of summer-annual crops can be diversified by integration of fallow-season and perennial crops. Integration of such crops can improve sustainability of these agroecological systems, with minimal interference with current agricultural production. Importantly, these crops can provide feedstocks for a wide range of new bio-products that are forming a new agricultural bioeconomy, potentially providing greatly increased economic incentives for diversification. However, while there are many fallow-season and perennial crops that might be used in such a “bioeconomic” strategy for diversification, most are not yet well adapted and highly-marketable. Efforts are underway to enhance adaptation and marketability of many such crops. Critically, these efforts require a strategic approach that addresses the inherent complexity of these projects. We outline a suitable approach, which we term “sustainable commercialization”: a coordinated innovation process that integrates a new crop into the agriculture of a region, while intentionally addressing economic, environmental and social sustainability challenges via multi-stakeholder governance. This approach centers on a concerted effort to coordinate and govern innovation in three critical areas: germplasm development, multifunctional agroecosystem design and management, and development of end uses, supply chains, and markets. To exemplify the approach, we describe an ongoing effort to commercialize a new fallow-season crop, field pennycress (Thlaspi arvense L..

  12. Pathways to sustainable intensification through crop water management

    Science.gov (United States)

    MacDonald, Graham K.; D'Odorico, Paolo; Seekell, David A.

    2016-09-01

    How much could farm water management interventions increase global crop production? This is the central question posed in a global modelling study by Jägermeyr et al (2016 Environ. Res. Lett. 11 025002). They define the biophysical realm of possibility for future gains in crop production related to agricultural water practices—enhancing water availability to crops and expanding irrigation by reducing non-productive water consumption. The findings of Jägermeyr et al offer crucial insight on the potential for crop water management to sustainably intensify agriculture, but they also provide a benchmark to consider the broader role of sustainable intensification targets in the global food system. Here, we reflect on how the global crop water management simulations of Jägermeyr et al could interact with: (1) farm size at more local scales, (2) downstream water users at the river basin scale, as well as (3) food trade and (4) demand-side food system strategies at the global scale. Incorporating such cross-scale linkages in future research could highlight the diverse pathways needed to harness the potential of farm-level crop water management for a more productive and sustainable global food system.

  13. Dryland forests

    NARCIS (Netherlands)

    Bose, Purabi; Dijk, van Han

    2016-01-01

    This volume provides new insights and conceptual understandings of the human and gender dimension of vulnerability in relation to the dynamics of tenure reforms in the dryland forests of Asia and Africa. The book analyzes the interaction between biophysical factors such as climate variability

  14. Sustainable Biofuel Project: Emergy Analysis of South Florida Energy Crops

    Energy Technology Data Exchange (ETDEWEB)

    Amponsah, Nana Yaw [Intelligentsia International, Inc., LaBelle, FL (United States); Izursa, Jose-Luis [Intelligentsia International, Inc., LaBelle, FL (United States); Hanlon, Edward A. [Univ. of Florida, Gainesville, FL (United States). Soil and Water Sciences Dept.; Capece, John C. [Intelligentsia International, Inc., LaBelle, FL (United States)

    2012-11-15

    This study evaluates the sustainability of various farming systems, namely (1) sugarcane on organic and mineral soils and (2) energycane and sweet sorghum on mineral soils. The primary objective of the study is to compare the relative sustainability matrices of these energy crops and their respective farming systems. These matrices should guide decision and policy makers to determine the overall sustainability of an intended or proposed bioethanol project related to any of these studied crops. Several different methods of energy analysis have been proposed to assess the feasibility or sustainability of projects exploiting natural resources (such as (Life Cycle Analysis, Energy Analysis, Exergy Analysis, Cost Benefit Analysis, Ecological Footprint, etc.). This study primarily focused on the concept of Emergy Analysis, a quantitative analytical technique for determining the values of nonmonied and monied resources, services and commodities in common units of the solar energy it took to make them. With this Emergy Analysis study, the Hendry County Sustainable Biofuels Center intends to provide useful perspective for different stakeholder groups to (1) assess and compare the sustainability levels of above named crops cultivation on mineral soils and organic soils for ethanol production and (2) identify processes within the cultivation that could be targeted for improvements. The results provide as much insight into the assumptions inherent in the investigated approaches as they do into the farming systems in this study.

  15. Sustainability issues on rice–wheat cropping system

    Directory of Open Access Journals (Sweden)

    Rajan Bhatt

    2016-03-01

    In this review, an attempt was made to highlight different issues resulted from the practise of intensive rice–wheat cropping sequence of the region, which must be considered while framing and implementing any integrated approach/project such as conservation agriculture for improving the productions, profits and sustainability of RWCS in the region.

  16. Turning the aquatic weed Azolla into a sustainable crop

    NARCIS (Netherlands)

    Brouwer, P.

    2017-01-01

    Growing worldwide demands for food, energy and chemicals threatens natural ecosystems and global climate. Plants are crucial for food production, but may also be used to produce sustainable energy and materials. Hereto novel crops are sought with high productivity per hectare, whilst requiring

  17. Women's participation in sustainable crop farming activities in ...

    African Journals Online (AJOL)

    A multi-stage random sampling method was used in selecting 150 women farmers from two ADP zones. An interview schedule was designed to obtain data on the respondents' eleven identified sustainable crop-farming activities. Results show that most of the respondents have between 3-10 years of farming experience.

  18. Sustainable Biofuel Crops Project, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Juhn, Daniel [Conservation International, Arlington, VA (United States). Moore Center for Science and Oceans. Integrated Assessment and Planning; Grantham, Hedley [Conservation International, Arlington, VA (United States). Moore Center for Science and Oceans. Integrated Assessment and Planning

    2014-05-28

    Over the last six years, the Food and Agriculture Organization of the United Nations (FAO) has developed the Bioenergy and Food Security (BEFS) Approach to help countries design and implement sustainable bioenergy policies and strategies. The BEFS Approach consists of two sets of multidisciplinary and integrated tools and guidance (the BEFS Rapid Appraisal and the BEFS Detailed Analysis) to facilitate better decision on bioenergy development which should foster both food and energy security, and contribute to agricultural and rural development. The development of the BEFS Approach was for the most part funded by the German Federal Ministry of Food and Agriculture. Recognizing the need to provide support to countries that wanted an initial assessment of their sustainable bioenergy potential, and of the associated opportunities, risks and trade offs, FAO began developing the BEFS-RA (Rapid Appraisal). The BEFS RA is a spreadsheet–based assessment and analysis tool designed to outline the country's basic energy, agriculture and food security context, the natural resources potential, the bioenergy end use options, including initial financial and economic implications, and the identification of issues that might require fuller investigation with the BEFS Detailed Analysis.

  19. Organic versus Conventional Cropping Sustainability: A Comparative System Analysis

    Directory of Open Access Journals (Sweden)

    Tiffany L. Fess

    2018-01-01

    Full Text Available We are at a pivotal time in human history, as the agricultural sector undergoes consolidation coupled with increasing energy costs in the context of declining resource availability. Although organic systems are often thought of as more sustainable than conventional operations, the lack of concise and widely accepted means to measure sustainability makes coming to an agreement on this issue quite challenging. However, an accurate assessment of sustainability can be reached by dissecting the scientific underpinnings of opposing production practices and crop output between cropping systems. The purpose of this review is to provide an in-depth and comprehensive evaluation of modern global production practices and economics of organic cropping systems, as well as assess the sustainability of organic production practices through the clarification of information and analysis of recent research. Additionally, this review addresses areas where improvements can be made to help meet the needs of future organic producers, including organic-focused breeding programs and necessity of coming to a unified global stance on plant breeding technologies. By identifying management strategies that utilize practices with long-term environmental and resource efficiencies, a concerted global effort could guide the adoption of organic agriculture as a sustainable food production system.

  20. GM as a route for delivery of sustainable crop protection.

    Science.gov (United States)

    Bruce, Toby J A

    2012-01-01

    Modern agriculture, with its vast monocultures of lush fertilized crops, provides an ideal environment for adapted pests, weeds, and diseases. This vulnerability has implications for food security: when new pesticide-resistant pest biotypes evolve they can devastate crops. Even with existing crop protection measures, approximately one-third yield losses occur globally. Given the projected increase in demand for food (70% by 2050 according to the UN), sustainable ways of preventing these losses are needed. Development of resistant crop cultivars can make an important contribution. However, traditional crop breeding programmes are limited by the time taken to move resistance traits into elite crop genetic backgrounds and the limited gene pools in which to search for novel resistance. Furthermore, resistance based on single genes does not protect against the full spectrum of pests, weeds, and diseases, and is more likely to break down as pests evolve counter-resistance. Although not necessarily a panacea, GM (genetic modification) techniques greatly facilitate transfer of genes and thus provide a route to overcome these constraints. Effective resistance traits can be precisely and conveniently moved into mainstream crop cultivars. Resistance genes can be stacked to make it harder for pests to evolve counter-resistance and to provide multiple resistances to different attackers. GM-based crop protection could substantially reduce the need for farmers to apply pesticides to their crops and would make agricultural production more efficient in terms of resources used (land, energy, water). These benefits merit consideration by environmentalists willing to keep an open mind on the GM debate.

  1. Ensuring sustainable grain legume-cereal cropping systems

    DEFF Research Database (Denmark)

    Bedoussac, Laurent; Journet, E-P; Hauggaard-Nielsen, Henrik

    2017-01-01

    distribution, the impact of pests and diseases, as well as vulnerability to poor soils, drought and other effects of climate change. This chapter summarises data from over 50 field experiments undertaken since 2001 on cereal-grain legume intercropping in 13 sites in southern and western France as well...... health makes them a key rotation crop in the sustainable intensification and diversification of smallholder farming. This makes grain legumes a key food security crop. However, yields in developing countries are low as a result of such factors as the need for improved varieties of seed, poor seed...

  2. Effect of Integrated Water-Nutrient Management Strategies on Soil Erosion Mediated Nutrient Loss and Crop Productivity in Cabo Verde Drylands.

    Directory of Open Access Journals (Sweden)

    Isaurinda Baptista

    Full Text Available Soil erosion, runoff and related nutrient losses are a big risk for soil fertility in Cabo Verde drylands. In 2012, field trials were conducted in two agro-ecological zones to evaluate the effects of selected techniques of soil-water management combined with organic amendments (T1: compost/manure + soil surfactant; T2: compost/animal or green manure + pigeon-pea hedges + soil surfactant; T3: compost/animal or green manure + mulch + pigeon-pea hedges on nitrogen (N and phosphorus (P losses in eroded soil and runoff and on crop yields. Three treatments and one control (traditional practice were tested in field plots at three sites with a local maize variety and two types of beans. Runoff and eroded soil were collected after each erosive rain, quantified, and analysed for NO3-N and PO4-P concentrations. In all treatments runoff had higher concentrations of NO3-N (2.20-4.83 mg L-1 than of PO4-P (0.02-0.07 mg L-1, and the eroded soil had higher content of PO4-P (5.27-18.8 mg g-1 than of NO3-N (1.30-8.51 mg g-1. The control had significantly higher losses of both NO3-N (5.4, 4.4 and 19 kg ha-1 and PO4-P (0.2, 0.1 and 0.4 kg ha-1 than the other treatments. T3 reduced soil loss, runoff and nutrient losses to nearly a 100% while T1 and T2 reduced those losses from 43 to 88%. The losses of NO3-N and PO4-P were highly correlated with the amounts of runoff and eroded soil. Nutrient losses from the applied amendments were low (5.7% maximum, but the losses in the control could indicate long-term nutrient depletion in the soil (19 and 0.4 kg ha-1 of NO3-N and PO4-P, respectively. T1-T3 did not consistently increase crop yield or biomass in all three sites, but T1 increased both crop yield and biomass. We conclude that T3 (combining crop-residue mulch with organic amendment and runoff hedges is the best treatment for steep slope areas but, the pigeon-pea hedges need to be managed for higher maize yield. T1 (combining organic amendment with soil surfactant could

  3. Effect of Integrated Water-Nutrient Management Strategies on Soil Erosion Mediated Nutrient Loss and Crop Productivity in Cabo Verde Drylands.

    Science.gov (United States)

    Baptista, Isaurinda; Ritsema, Coen; Geissen, Violette

    2015-01-01

    Soil erosion, runoff and related nutrient losses are a big risk for soil fertility in Cabo Verde drylands. In 2012, field trials were conducted in two agro-ecological zones to evaluate the effects of selected techniques of soil-water management combined with organic amendments (T1: compost/manure + soil surfactant; T2: compost/animal or green manure + pigeon-pea hedges + soil surfactant; T3: compost/animal or green manure + mulch + pigeon-pea hedges) on nitrogen (N) and phosphorus (P) losses in eroded soil and runoff and on crop yields. Three treatments and one control (traditional practice) were tested in field plots at three sites with a local maize variety and two types of beans. Runoff and eroded soil were collected after each erosive rain, quantified, and analysed for NO3-N and PO4-P concentrations. In all treatments runoff had higher concentrations of NO3-N (2.20-4.83 mg L-1) than of PO4-P (0.02-0.07 mg L-1), and the eroded soil had higher content of PO4-P (5.27-18.8 mg g-1) than of NO3-N (1.30-8.51 mg g-1). The control had significantly higher losses of both NO3-N (5.4, 4.4 and 19 kg ha-1) and PO4-P (0.2, 0.1 and 0.4 kg ha-1) than the other treatments. T3 reduced soil loss, runoff and nutrient losses to nearly a 100% while T1 and T2 reduced those losses from 43 to 88%. The losses of NO3-N and PO4-P were highly correlated with the amounts of runoff and eroded soil. Nutrient losses from the applied amendments were low (5.7% maximum), but the losses in the control could indicate long-term nutrient depletion in the soil (19 and 0.4 kg ha-1 of NO3-N and PO4-P, respectively). T1-T3 did not consistently increase crop yield or biomass in all three sites, but T1 increased both crop yield and biomass. We conclude that T3 (combining crop-residue mulch with organic amendment and runoff hedges) is the best treatment for steep slope areas but, the pigeon-pea hedges need to be managed for higher maize yield. T1 (combining organic amendment with soil surfactant) could be a

  4. Effect of Integrated Water-Nutrient Management Strategies on Soil Erosion Mediated Nutrient Loss and Crop Productivity in Cabo Verde Drylands

    Science.gov (United States)

    Baptista, Isaurinda; Ritsema, Coen; Geissen, Violette

    2015-01-01

    Soil erosion, runoff and related nutrient losses are a big risk for soil fertility in Cabo Verde drylands. In 2012, field trials were conducted in two agro-ecological zones to evaluate the effects of selected techniques of soil-water management combined with organic amendments (T1: compost/manure + soil surfactant; T2: compost/animal or green manure + pigeon-pea hedges + soil surfactant; T3: compost/animal or green manure + mulch + pigeon-pea hedges) on nitrogen (N) and phosphorus (P) losses in eroded soil and runoff and on crop yields. Three treatments and one control (traditional practice) were tested in field plots at three sites with a local maize variety and two types of beans. Runoff and eroded soil were collected after each erosive rain, quantified, and analysed for NO3-N and PO4-P concentrations. In all treatments runoff had higher concentrations of NO3-N (2.20-4.83 mg L-1) than of PO4-P (0.02-0.07 mg L-1), and the eroded soil had higher content of PO4-P (5.27-18.8 mg g-1) than of NO3-N (1.30-8.51 mg g-1). The control had significantly higher losses of both NO3-N (5.4, 4.4 and 19 kg ha-1) and PO4-P (0.2, 0.1 and 0.4 kg ha-1) than the other treatments. T3 reduced soil loss, runoff and nutrient losses to nearly a 100% while T1 and T2 reduced those losses from 43 to 88%. The losses of NO3-N and PO4-P were highly correlated with the amounts of runoff and eroded soil. Nutrient losses from the applied amendments were low (5.7% maximum), but the losses in the control could indicate long-term nutrient depletion in the soil (19 and 0.4 kg ha-1 of NO3-N and PO4-P, respectively). T1-T3 did not consistently increase crop yield or biomass in all three sites, but T1 increased both crop yield and biomass. We conclude that T3 (combining crop-residue mulch with organic amendment and runoff hedges) is the best treatment for steep slope areas but, the pigeon-pea hedges need to be managed for higher maize yield. T1 (combining organic amendment with soil surfactant) could be a

  5. Using membrane transporters to improve crops for sustainable food production.

    Science.gov (United States)

    Schroeder, Julian I; Delhaize, Emmanuel; Frommer, Wolf B; Guerinot, Mary Lou; Harrison, Maria J; Herrera-Estrella, Luis; Horie, Tomoaki; Kochian, Leon V; Munns, Rana; Nishizawa, Naoko K; Tsay, Yi-Fang; Sanders, Dale

    2013-05-02

    With the global population predicted to grow by at least 25 per cent by 2050, the need for sustainable production of nutritious foods is critical for human and environmental health. Recent advances show that specialized plant membrane transporters can be used to enhance yields of staple crops, increase nutrient content and increase resistance to key stresses, including salinity, pathogens and aluminium toxicity, which in turn could expand available arable land.

  6. Growth and yield of wheat (Triticum aestivum adapted to lowland Lombok Island as an alternative food crop for dryland

    Directory of Open Access Journals (Sweden)

    A. Zubaidi

    2014-10-01

    Full Text Available Wheat is not currently grown as a commercial crop in Indonesia, however since the consumption of wheat in Indonesia is steadily increasing and alternative of dry season crops are required for farming system diversification, wheat becomes an important crop to be adapted in dry land areas of Indonesia, one of them is dry land area of Lombok Island. The aims of this experiment is to adapt and screen wheat varieties including national and introduced Australian varieties in lowland Lombok Island. In future, wheat is expected to be an alternative crop for degraded lands. The experimental method used to evaluate growth and yield of 10 wheat varieties to look at the adaptability on the lowland of 200 m asl (Pringgarata and on higher land of 400 m asl (Aik Bukak. The results showed that at a lower altitude (Pringgarata, wheat growth is slower than in Aik Bukak, which can be caused by the temperature at 200 m asl has exceeded the tolerance limit for grain growth (supra optimal temperature. Wheat can give good yields on 400 m asl, but the yield is decreased at 200 m asl (average 1.68 t/ha vs 0.82 t/ha. This low yield is mainly due to sterility indicated by the low number of grain/spikelet ( 2 t/ha , higher than other varieties

  7. GM Crops, Organic Agriculture and Breeding for Sustainability

    Directory of Open Access Journals (Sweden)

    Salvatore Ceccarelli

    2014-07-01

    Full Text Available The ongoing debate about the use of genetically-modified (GM crops in agriculture has largely focused on food safety and genetic contamination issues. Given that the majority of GM crops have been produced to respond to the problem of crop yield reductions caused by diseases, insects and weeds, the paper argues that in those cases, the currently used GM crops are an unstable solution to the problem, because they represent such a strong selection pressure, that pests rapidly evolve resistance. Organic agriculture practices provide a more sustainable way of producing healthy food; however, the lower yields often associated with those practices, making the resultant healthy food more expensive, open the criticism that such practices will not be able to feed human populations. Evolutionary plant breeding offers the possibility of using the evolutionary potential of crops to our advantage by producing a continuous flow of varieties better adapted to organic systems, to climate change and to the ever changing spectrum of pests, without depending on chemical control.

  8. Dryland Agriculture: Dynamics, Challenges and Priorities

    OpenAIRE

    Bantilan, MCS; Anand Babu, P; Anupama, GV; Deepthi, H; Padmaja, R

    2006-01-01

    The developments in the dryland region reflect the pervasiveness of poverty, which is demonstrated by the growing constraints of water, land degradation, continuing concerns about malnutrition, migration due to frequent droughts, lack of infrastructure, poor dissemination of improved technologies, and effects of government policies and further economic liberalization on the competitiveness of dryland crops. This research bulletin reviews past trends, summarizes the major constraints to income...

  9. SOIL ECOLOGY AS KEY TO SUSTAINABLE CROP PRODUCTION.

    Science.gov (United States)

    De Deyn, G B

    2015-01-01

    Sustainable production of food, feed and fiberwarrants sustainable soil management and crop protection. The tools available to achieve this are both in the realm of the plants and of the soil, with a key role for plant-soil interactions. At the plant level we have vast knowledge of variation within plant species with respect to pests and diseases, based on which we can breed for resistance. However, given that systems evolve this resistance is bound to be temporarily, hence also other strategies are needed. Here I plea for an integrative approach for sustainable production using ecological principles. Ecology, the study of how organisms interact with their environment, teaches us that diversity promotes productivity and yield stability. These effects are thought to be governed through resource use complementarity and reduced build-up of pests and diseases both above- and belowground. In recent years especially the role of soil biotic interactions has revealed new insights in how plant diversity and productivity are related to soil biodiversity and the functions soil biota govern. In our grassland biodiversity studies we found that root feeders can promote plant diversity and succession without reducing plant community productivity, this illustrates the role of diversity to maintain productivity. Also diversity within species offers scope for sustainable production, for example through awareness of differences between plant genotypes in chemical defense compounds that can attract natural enemies of pests aboveground- and belowground thereby providing plant protection. Plant breeding can also benefit from using complementarity between plant species in the selection for new varieties, as our work demonstrated that when growing in species mixtures plant species adapt to each other over time such that their resource acquisition traits become more complementing. Finally, in a recent meta-analysis we show that earthworms can stimulate crop yield with on average 25%, but

  10. Improving water use efficiency in drylands

    NARCIS (Netherlands)

    Stroosnijder, L.; Moore, D.; Alharbi, A.; Argaman, E.; Elsen, van den H.G.M.

    2012-01-01

    Drylands cover 41% of the global terrestrial area and 2 billion people use it for grazing and cropping. Food security is low owing to institutional and technical constraints. Absolute water scarcity and also the inability of crops to use available water are major technical issues. Significant

  11. Total evaporation estimates from a Renosterveld and dryland wheat ...

    African Journals Online (AJOL)

    The study was carried out in the mid-reaches of the Berg River catchment (South Africa), characterised by dryland salinity. ... A change in land use from Renosterveld to dryland annual crops could therefore affect the soil water balance, cause shallow saline groundwater tables and degradation of soil and water resources.

  12. Sustainable crop models for fruit, vegetable and flower quality productions.

    Directory of Open Access Journals (Sweden)

    Inglese Paolo

    2011-02-01

    Full Text Available Sustainable development is a paradigm that has evolved over the time, since the ideas of socially acceptable and compatible development, on which it was originally based, are now supported by the more recent notions of ecological equilibria and production process economy, both of which need to be also preserved. Environmental and health safety, rational use of the natural resources and technological tools, upkeep of high social growth rates and respect of a social equity are the basis of the sustainability for any production process, including the agriculture. The new globalization framework has penalized small farms and, at the same time, has put serious constraints to the development of stronger economic systems (medium/large farms, as well. As consequence, the EU has outlined several strategic programs to support small agricultural systems in marginal areas by: 1 strengthening all the quality- related aspects of agricultural production, including nutritional and cultural traits associated to local, typical and in some cases to neglected crops; 2 improving traditional cultural practices by adapting the cropping cycles and fomenting new partnerships between the different parts of the production chain, as for example; promotion of small horticultural chains. Specific political actions for the horticultural production sector have also been developed. Some of these policies are specifically addressed to preserve the biodiversity and to create quality labels certifying typical and/or organic products. All of these are possible strategies that may counteract and cope with the globalization process and increase the competitiveness of many production systems especially those performed by local and small entrepreneurs. New sustainable development models are required by both the market and the implicit requirements of the production system, inside a context on which Europe must face with new emerging economies with lower production costs, by increasing

  13. Biofuels, bioenergy, and bioproducts from sustainable agricultural and forest crops: proceedings of the short rotation crops international conference

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Rob Mitchell; Jim, eds. Richardson

    2008-01-01

    The goal of this conference was to initiate and provide opportunities for an international forum on the science and application of producing both agricultural and forest crops for biofuels, bioenergy, and bioproducts. There is a substantial global need for development of such systems and technologies that can economically and sustainably produce short rotation crops...

  14. Groundwater Sustainability Through Optimal Crop Choice in the Indian Punjab

    Science.gov (United States)

    Desai, R.; Siegfried, T. U.; B Krishnamurthy, C.; Sobolowski, S.

    2010-12-01

    total discounted crop revenue being the goal function and non-declining revenue as well as groundwater sustainability constraints. Areas set aside for individual crops in individual seasons and districts are decision variables and levels of support prices determine revenue streams. The SP was solved with a Monte Carlo simulation-based approach by sampling the 100 climate realizations where the expected goal function is approximated by the corresponding sample average function. Results indicate that a climate sensitive crop choice can lead to expected net economic gains while ensuring non-declining groundwater tables at the same time if support prices for water intensive crops are sufficiently low as compared to the prices of climate-sensitive crops. This is promising since it shows that wisely chosen support price signals could incentivize farmers to adopt climate-sensitive crop choice while at the same time stabilize the state fiscal burden from subsidized energy for groundwater pumping. It would, however, imply that India should gradually develop other regions of modern mechanized agricultural so as to ensure sufficient caloric supplies at the national scale.

  15. Assessment of future crop yield and agricultural sustainable water use in north china plain using multiple crop models

    Science.gov (United States)

    Huang, G.

    2016-12-01

    Currently, studying crop-water response mechanism has become an important part in the development of new irrigation technology and optimal water allocation in water-scarce regions, which is of great significance to crop growth guidance, sustainable utilization of agricultural water, as well as the sustainable development of regional agriculture. Using multiple crop models(AquaCrop,SWAP,DNDC), this paper presents the results of simulating crop growth and agricultural water consumption of the winter-wheat and maize cropping system in north china plain. These areas are short of water resources, but generates about 23% of grain production for China. By analyzing the crop yields and the water consumption of the traditional flooding irrigation, the paper demonstrates quantitative evaluation of the potential amount of water use that can be reduced by using high-efficient irrigation approaches, such as drip irrigation. To maintain food supply and conserve water resources, the research concludes sustainable irrigation methods for the three provinces for sustainable utilization of agricultural water.

  16. Modelling the biophysical and socio-economic potential of Sustainable Land Management (SLM) in the Cabo Verde drylands: The PESERA-DESMICE approach.

    Science.gov (United States)

    Baptista, Isaurinda; Irvine, Brian; Fleskens, Luuk; Geissen, Violette; Ritsema, Coen

    2015-04-01

    yield and cost-benefit relations. The development of such envelopes help express the agricultural risk associated with climate variability and the potential of the conservation measures to absorb the risk. Thus, highlighting the uncertainty of a given crop yield being achieved in any particular year. Such information that can directly inform or influence the adoption of conservation measures under the climatic variability of the Cabo Verde drylands.

  17. GM Crops, Organic Agriculture and Breeding for Sustainability

    OpenAIRE

    Salvatore Ceccarelli

    2014-01-01

    The ongoing debate about the use of genetically-modified (GM) crops in agriculture has largely focused on food safety and genetic contamination issues. Given that the majority of GM crops have been produced to respond to the problem of crop yield reductions caused by diseases, insects and weeds, the paper argues that in those cases, the currently used GM crops are an unstable solution to the problem, because they represent such a strong selection pressure, that pests rapidly evolve resistance...

  18. GM crops, the environment and sustainable food production.

    Science.gov (United States)

    Raven, Peter H

    2014-12-01

    Today, over 7.1 billion people rely on the earth's resources for sustenance, and nearly a billion people are malnourished, their minds and bodies unable to develop properly. Globally, population is expected to rise to more than 9 billion by 2050. Given the combined pressures of human population growth, the rapidly growing desire for increased levels of consumption, and the continued use of inappropriate technologies, it is not surprising that humans are driving organisms to extinction at an unprecedented rate. Many aspects of the sustainable functioning of the natural world are breaking down in the face of human-induced pressures including our individual and collective levels of consumption and our widespread and stubborn use of destructive technologies. Clearly, agriculture must undergo a redesign and be better and more effectively managed so as to contribute as well as possible to feeding people, while at the same time we strive to lessen the tragic loss of biodiversity and damage to all of its productive systems that the world is experiencing. For GM crops to be part of the solution, biosafety assessments should not be overly politically-driven or a burdensome impedance to delivering this technology broadly. Biosafety scientists and policy makers need to recognize the undeniable truth that inappropriate actions resulting in indecision also have negative consequences. It is no longer acceptable to delay the use of any strategy that is safe and will help us achieve the ability to feed the world's people.

  19. Crop Sequence Influences on Sustainable Spring Wheat Production in the Northern Great Plains

    Directory of Open Access Journals (Sweden)

    Joseph M. Krupinsky

    2010-11-01

    Full Text Available Cropping systems in American agriculture are highly successful since World War II, but have become highly specialized, standardized, and simplified to meet the demands of an industrialized food system. Minimal attention has been given to the efficient exploitation of crop diversity and the synergistic and/or antagonistic relationships of crops in crop sequences. Objectives of our research were to determine if previous crop sequences have long-term benefits and/or drawbacks on spring wheat seed yield, seed N concentration, and seed precipitation-use efficiency in the semiarid northern Great Plains, USA. Research was conducted 6 km southwest of Mandan, ND using a 10 × 10 crop matrix technique as a research tool to evaluate multiple crop sequence effects on spring wheat (triticum aestivum L. production in 2004 and 2005. Spring wheat production risks can be mitigated when second year crop residue was dry pea (Pisium sativum L. averaged over all first year crop residues. When compared to spring wheat as second year crop residue in the dry year of 2004, dry pea as the second year residue crop resulted in a 30% spring wheat seed yield increase. Sustainable cropping systems need to use precipitation efficiently for crop production, especially during below average precipitation years like 2004. Precipitation use efficiency average over all treatments, during the below average precipitation year was 23% greater than the above average precipitation year of 2005. Diversifying crops in cropping systems improves production efficiencies and resilience of agricultural systems.

  20. How does the context and design of participatory decision making processes affect their outcomes? Evidence from sustainable land management in global drylands

    Directory of Open Access Journals (Sweden)

    Joris de Vente

    2016-06-01

    Full Text Available Although the design of participatory processes to manage social-ecological systems needs to be adapted to local contexts, it is unclear which elements of process design might be universal. We use empirical evidence to analyze the extent to which context and process design can enable or impede stakeholder participation and facilitate beneficial environmental and social outcomes. To explore the role of design and minor variations in local context on the outcomes of participatory processes, we interviewed participants and facilitators from 11 case studies in which different process designs were used to select sustainable land management options in Spain and Portugal. We analyzed interview data using quantitative and qualitative approaches. Results showed that although some aspects of local context affected process outcomes, factors associated with process design were more significant. Processes leading to more beneficial environmental and social outcomes included the following: the legitimate representation of stakeholders; professional facilitation including structured methods for aggregating information and balancing power dynamics among participants; and provision of information and decision-making power to all participants. Although processes initiated or facilitated by government bodies led to significantly less trust, information gain, and learning, decisions in these processes were more likely to be accepted and implemented. To further test the role of context in determining the outcomes of participation, we interviewed facilitators from a process that was replicated across 13 dryland study sites around the world, reflecting much greater national variations in context. The similarity of outcomes across these sites suggested that the socio-cultural context in which the process was replicated had little impact on its outcomes, as long as certain design principles were fulfilled. Overall, our findings provide a solid empirical basis for good

  1. Direct and indirect impacts of crop-livestock organization on mixed crop-livestock systems sustainability: a model-based study.

    Science.gov (United States)

    Sneessens, I; Veysset, P; Benoit, M; Lamadon, A; Brunschwig, G

    2016-11-01

    Crop-livestock production is claimed more sustainable than specialized production systems. However, the presence of controversial studies suggests that there must be conditions of mixing crop and livestock productions to allow for higher sustainable performances. Whereas previous studies focused on the impact of crop-livestock interactions on performances, we posit here that crop-livestock organization is a key determinant of farming system sustainability. Crop-livestock organization refers to the percentage of the agricultural area that is dedicated to each production. Our objective is to investigate if crop-livestock organization has both a direct and an indirect impact on mixed crop-livestock (MC-L) sustainability. In that objective, we build a whole-farm model parametrized on representative French sheep and crop farming systems in plain areas (Vienne, France). This model permits simulating contrasted MC-L systems and their subsequent sustainability through the following indicators of performance: farm income, production, N balance, greenhouse gas (GHG) emissions (/kg product) and MJ consumption (/kg product). Two MC-L systems were simulated with contrasted crop-livestock organizations (MC20-L80: 20% of crops; MC80-L20: 80% of crops). A first scenario - constraining no crop-livestock interactions in both MC-L systems - permits highlighting that crop-livestock organization has a significant direct impact on performances that implies trade-offs between objectives of sustainability. Indeed, the MC80-L20 system is showing higher performances for farm income (+44%), livestock production (+18%) and crop GHG emissions (-14%) whereas the MC20-L80 system has a better N balance (-53%) and a lower livestock MJ consumption (-9%). A second scenario - allowing for crop-livestock interactions in both MC20-L80 and MC80-L20 systems - stated that crop-livestock organization has a significant indirect impact on performances. Indeed, even if crop-livestock interactions permit

  2. Transgenic Crops and Sustainable Agriculture in the European Context

    Science.gov (United States)

    Ponti, Luigi

    2005-01-01

    The rapid adoption of transgenic crops in the United States, Argentina, and Canada stands in strong contrast to the situation in the European Union (EU), where a de facto moratorium has been in place since 1998. This article reviews recent scientific literature relevant to the problematic introduction of transgenic crops in the EU to assess if…

  3. Environmental Sustainability of Some Cropping Systems in the ...

    African Journals Online (AJOL)

    Nekky Umera

    This development clearly reduces the vegetative carbon sink, as well as resulting in a loss of biodiversity ... on the length of fallow and cropping cycle, organic inputs, and the inherent fertility of the soil. In regions ... and root crops (cassava, yam, sweet potato and cocoyam) in the humid zone, sorghum, maize and cowpea in ...

  4. Geospatial technologies for conservation planning: An approach to build more sustainable cropping systems

    Science.gov (United States)

    Current agricultural production systems must adapt to meet increasing demands for more economically and environmentally sustainable cropping systems. The application of precision agricultural technologies and geospatial and environmental modeling for conservation planning can aid in this transition....

  5. Assessing the sustainability of wheat-based cropping systems using APSIM: Model parameterisation and evaluation

    NARCIS (Netherlands)

    Moeller, C.; Pala, M.; Manschadi, A.M.; Meinke, H.B.; Sauerborn, J.

    2007-01-01

    Assessing the sustainability of crop and soil management practices in wheat-based rotations requires a well-tested model with the demonstrated ability to sensibly predict crop productivity and changes in the soil resource. The Agricultural Production Systems Simulator (APSIM) suite of models was

  6. Environmental Sustainability of Gm Crops for Food Safety on Risk Society

    Directory of Open Access Journals (Sweden)

    Gil Ramos de Carvalho Neto

    2016-10-01

    Full Text Available GM crops are presented as an alternative to the erradication of hunger. The risk society, however, considering the brazilian environmental law - specially the brazilian legislation on biosafety - the food safety and nutritional law and the economic and social data on the subject, it appears that the environmental sustainability of these crops is not yet complete. Producers should adopt additional safeguards if they wish a sustainable agriculture with effective food security.

  7. Genetically Modified Crops: Towards Agricultural Growth, Agricultural Development, or Agricultural Sustainability?

    OpenAIRE

    Azadi, Hossein; Ghanian, Mansour; Ghuchani, Omid M.; Rafiaani, Parisa; Taning, Clauvis N. T.; Hajivand, Roghaye Y.; Dogot, Thomas

    2015-01-01

    The present debate on how to increase global food production in a sustainable way has focused on arguments over the pros and cons of genetically modified (GM) crops. Scientists in both public and private sectors clearly regard GM technology as a major new set of tools, whereas industry sees it as an opportunity for increased profits. However, it remains questionable whether GM crops can contribute to agricultural growth, agricultural development, and agricultural sustainability. This review p...

  8. Global desertification: building a science for dryland development.

    Science.gov (United States)

    Reynolds, James F; Smith, D Mark Stafford; Lambin, Eric F; Turner, B L; Mortimore, Michael; Batterbury, Simon P J; Downing, Thomas E; Dowlatabadi, Hadi; Fernández, Roberto J; Herrick, Jeffrey E; Huber-Sannwald, Elisabeth; Jiang, Hong; Leemans, Rik; Lynam, Tim; Maestre, Fernando T; Ayarza, Miguel; Walker, Brian

    2007-05-11

    In this millennium, global drylands face a myriad of problems that present tough research, management, and policy challenges. Recent advances in dryland development, however, together with the integrative approaches of global change and sustainability science, suggest that concerns about land degradation, poverty, safeguarding biodiversity, and protecting the culture of 2.5 billion people can be confronted with renewed optimism. We review recent lessons about the functioning of dryland ecosystems and the livelihood systems of their human residents and introduce a new synthetic framework, the Drylands Development Paradigm (DDP). The DDP, supported by a growing and well-documented set of tools for policy and management action, helps navigate the inherent complexity of desertification and dryland development, identifying and synthesizing those factors important to research, management, and policy communities.

  9. Investigation of ethanol productivity of cassava crop as a sustainable ...

    African Journals Online (AJOL)

    GREGORY

    2010-08-30

    Aug 30, 2010 ... a sustainable source of biofuel in tropical countries. B. A. Adelekan. Department of Agricultural ..... supporting sustainable agriculture and sustainable develop- ment, provided the feedstock of biofuels is .... transferred to a mortar where they were mashed using a pestle to attain sufficient size reduction.

  10. Toward Cropping Systems That Enhance Productivity and Sustainability

    National Research Council Canada - National Science Library

    R. James Cook

    2006-01-01

    .... The availability of glyphosate- and insect-resistant varieties of soybeans, corn, cotton, and canola has helped greatly to address weed and insect pest pressures favored by direct seeding these crops...

  11. Sustainable commercialization of new crops for the agricultural bioeconomy

    National Research Council Canada - National Science Library

    Jordan, N.R; Dorn, K; Runck, B; Ewing, P; Williams, A; Anderson, K.A; Felice, L; Haralson, K; Goplen, J; Altendorf, K; Fernandez, A; Phippen, W; Sedbrook, J; Marks, M; Wolf, K; Wyse, D; Johnson, G

    2016-01-01

    .... Importantly, these crops can provide feedstocks for a wide range of new bio-products that are forming a new agricultural bioeconomy, potentially providing greatly increased economic incentives for diversification...

  12. Priority regions for research on dryland cereals and legumes

    Science.gov (United States)

    Hyman, Glenn; Barona, Elizabeth; Biradar, Chandrashekhar; Guevara, Edward; Dixon, John; Beebe, Steve; Castano, Silvia Elena; Alabi, Tunrayo; Gumma, Murali Krishna; Sivasankar, Shoba; Rivera, Ovidio; Espinosa, Herlin; Cardona, Jorge

    2016-01-01

    Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes. PMID:27303632

  13. How does the context and design of participatory decision-making processes affect their outcomes? Evidence from sustainable land management in global drylands.

    Science.gov (United States)

    de Vente, Joris; Reed, Mark; Stringer, Lindsay; Valente, Sandra; Newig, Jens

    2014-05-01

    It is widely accepted that the design of participatory processes in environmental management needs to be adapted to local contexts. Yet, it is not clear which elements of process design are universal, making it difficult to design processes that deliver beneficial outcomes across different contexts. We used empirical evidence to analyse the extent to which context and process design can enable or impede stakeholder participation and facilitate beneficial environmental and social outcomes in a range of decision-making contexts where stakeholders are engaged in environmental management. To explore the role of national-scale context on the outcomes of participatory processes, we interviewed facilitators from a process that was replicated across 13 dryland study sites around the world, which focussed on selecting Sustainable Land Management (SLM) options in close collaboration with stakeholders. To explore the role of process design and local context, we interviewed participants and facilitators in 11 case studies in Spain and Portugal in which different process designs were used. Interview data were analysed using a combination of quantitative and qualitative approaches to characterise relationships between process design, context and process outcomes. The similarity of outcomes across the 13 international study sites suggested that the national socio-cultural context in which a participatory process is conducted has little impact on its outcomes. However, analysis of cases from Spain and Portugal showed that some aspects of local context may affect outcomes. Having said this, factors associated with process design and participant selection played a more significant role in influencing outcomes in both countries. Processes that led to more beneficial outcomes for the environment and/or participants were likely to include: the legitimate representation of stakeholders; professional facilitation including structured methods for eliciting and aggregating information and

  14. Do Smallholder, Mixed Crop-Livestock Livelihoods Encourage Sustainable Agricultural Practices? A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Thomas K. Rudel

    2016-02-01

    Full Text Available As calls for bolstering ecosystem services from croplands have grown more insistent during the past two decades, the search for ways to foster these agriculture-sustaining services has become more urgent. In this context we examine by means of a meta-analysis the argument, proposed by Robert McC. Netting, that small-scale, mixed crop-livestock farming, a common livelihood among poor rural peoples, leads to environmentally sustainable agricultural practices. As predicted, mixed crop-livestock farms exhibit more sustainable practices, but, contrary to predictions, a small scale of operation does not predict sustainability. Many smallholders on mixed crop-livestock farms use sustainable practices, but other smallholders practice a degrading, input-scarce agriculture. Some large farm operators use soil-conserving, minimum-tillage techniques while other large operators ignore soil-conserving techniques and practice an industrialized, high chemical input agriculture. The strength and pervasiveness of the link in the data between mixed crop-livestock farming and sustainable agricultural practices argues for agricultural policies that promote mixed crop-livestock livelihoods.

  15. Plant defense against herbivorous pests: exploiting resistance and tolerance traits for sustainable crop protection

    Directory of Open Access Journals (Sweden)

    Carolyn Mitchell

    2016-07-01

    Full Text Available Interactions between plants and insect herbivores are important determinants of plant productivity in managed and natural vegetation. In response to attack, plants have evolved a range of defenses to reduce the threat of injury and loss of productivity. Crop losses from damage caused by arthropod pests can exceed 15% annually. Crop domestication and selection for improved yield and quality can alter the defensive capability of the crop, increasing reliance on artificial crop protection. Sustainable agriculture, however, depends on reduced chemical inputs. There is an urgent need, therefore, to identify plant defensive traits for crop improvement. Plant defense can be divided into resistance and tolerance strategies. Plant traits that confer herbivore resistance typically prevent or reduce herbivore damage through expression of traits that deter pests from settling, attaching to surfaces, feeding and reproducing, or that reduce palatability. Plant tolerance of herbivory involves expression of traits that limit the negative impact of herbivore damage on productivity and yield. Identifying the defensive traits expressed by plants to deter herbivores or limit herbivore damage, and understanding the underlying defense mechanisms, is crucial for crop scientists to exploit plant defensive traits in crop breeding. In this review, we assess the traits and mechanisms underpinning herbivore resistance and tolerance, and conclude that physical defense traits, plant vigor and herbivore-induced plant volatiles show considerable utility in pest control, along with mixed species crops. We highlight emerging approaches for accelerating the identification of plant defensive traits and facilitating their deployment to improve the future sustainability of crop protection.

  16. Debates on Genetically Modified Crops in the Context of Sustainable Development.

    Science.gov (United States)

    Gerasimova, Ksenia

    2016-04-01

    The paper discusses conflicts in perceptions of GM crops illustrating the complexities of GM debates and applications of the concept of sustainable development. The concept consists of three discourses that both opponents and supporters of GM crops refer to in their analyses: environmentalism, social and economic development and the two sub-issues of sustainable development-biodiversity loss and food security. This creates a unique situation when both proponents and opponents of GM food use the same framework of sustainable development to support their arguments and do not reach a common ground. This will be illustrated by a review of the arguments brought by these two groups.

  17. Gender Analysis of Sustainable Agricultural Practices by Crop ...

    African Journals Online (AJOL)

    Sustainable agricultural practices describe the effort of farmers at protecting and enhancing the environment to preserve it for further exploitation. Therefore both men and women have important roles to play in preserving their environment. This paper analyzed the gender roles in the use of sustainable agricultural practices ...

  18. Cover Crops in West Africa: Contributing to Sustainable Agriculture ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    It documents past experiences withcover cropping in Africa and will hopefully stimulate future research on priority socioeconomic and biophysical aspects of this important topic. The editors Daniel Buckles is Senior ... IDRC evidence and innovation supports India's adaptation to climate change. IDRC is investing in local ...

  19. Investigation of ethanol productivity of cassava crop as a sustainable ...

    African Journals Online (AJOL)

    The ethanol productivity of cassava crop was investigated in a laboratory experiment by correlating volumes and masses of ethanol produced to the masses of samples used. Cassava tubers (variety TMS 30555) were peeled, cut and washed. 5, 15, 25 and 35 kg samples of the tubers were weighed in three replicates, ...

  20. Sustainability of Marketing Food Crops through the Internet in Lagos ...

    African Journals Online (AJOL)

    abdulaphyz

    commerce for marketing and purchasing of agricultural commodities. This study assessed continued success of communicating food crops through the. Internet and by extension e-commerce (virtual retail stores). This becomes imperative .... If sellers and consumers' intention to make use of the Internet for marketing or ...

  1. Improved Crotalaria cover crop fallow system for sustainable maize ...

    African Journals Online (AJOL)

    An on-station trial was carried out at the Research Farm of the Faculty of Agriculture, University for Development Studies, Tamale, in the northern Guinea Savanna agroecological zone of Ghana. The study compared different seeding rates of leguminous cover crops, inorganic fertilization, and a combination of the two in a ...

  2. Boosting innate immunity to sustainably control diseases in crops.

    Science.gov (United States)

    Nicaise, Valerie

    2017-10-01

    Viruses cause epidemics in all major crops, threatening global food security. The development of efficient and durable resistance able to withstand viral attacks represents a major challenge for agronomy, and relies greatly on the understanding of the molecular dialogue between viral pathogens and their hosts. Research over the last decades provided substantial advances in the field of plant-virus interactions. Remarkably, the advent of studies of plant innate immunity has recently offered new strategies exploitable in the field. This review summarizes the recent breakthroughs that define the mechanisms underlying antiviral innate immunity in plants, and emphasizes the importance of integrating that knowledge into crop improvement actions, particularly by exploiting the insights related to immune receptors. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Sustainability, overall and process efficiency of energy crops

    OpenAIRE

    Schäfer, Winfried

    2008-01-01

    A method to calculate efficiency of energy crop production including sun energy, direct and indirect energy for cultivation, processing, and conversion into fuel is demonstrated using rape and derived fuels as an example. Every production and conversion step is a process and calculated separately. The overall efficiency includes energy input and output of all processes. The process efficiency of rape cultivation reaches in Finland up to 1100 %. However, the overall energy effic...

  4. Feed legumes for truly sustainable crop-animal systems

    Directory of Open Access Journals (Sweden)

    Paolo Annicchiarico

    2017-06-01

    Full Text Available Legume cultivation has sharply decreased in Italy during the last 50 years. Lucerne remains widely grown (with about 12% of its area devoted to dehydration, whereas soybean is definitely the most-grown grain legume. Poor legume cropping is mainly due to the gap in yielding ability with major cereals, which has widened up in time according to statistical data. Lucerne displays definitely higher crude protein yield and somewhat lower economic gap with benchmark cereals than feed grain legumes. Pea because of high feed energy production per unit area and rate of genetic progress, and white lupin because of high protein yield per unit area, are particularly interesting for Italian rain-fed environments. Greater legume cultivation in Europe is urged by the need for reducing energy and green-house gas emissions and excessive and unbalanced global N flows through greater symbiotic N fixation and more integrated crop-animal production, as well as to cope with ongoing and perspective raising prices of feed proteins and N fertilisers and insecurity of feed protein supplies. The transition towards greater legume cultivation requires focused research effort, comprehensive stakeholder cooperation and fair economic compensation for legume environmental services, with a key role for genetic improvement dragged by public breeding or pre-breeding. New opportunities for yield improvement arise from the ongoing development of cost-efficient genome-enabled selection procedures, enhanced adaptation to specific cropping conditions via ecophysiological and evolutionary-based approaches, and more thorough exploitation of global genetic resources.

  5. Surge in insect resistance to transgenic crops and prospects for sustainability.

    Science.gov (United States)

    Tabashnik, Bruce E; Carrière, Yves

    2017-10-11

    Transgenic crops have revolutionized insect pest control, but their effectiveness has been reduced by evolution of resistance in pests. We analyzed global monitoring data reported during the first two decades of transgenic crops, with each case representing the responses of one pest species in one country to one insecticidal protein from Bacillus thuringiensis (Bt). The cases of pest resistance to Bt crystalline (Cry) proteins produced by transgenic crops increased from 3 in 2005 to 16 in 2016. By contrast, in 17 other cases there was no decrease in pest susceptibility to Bt crops, including the recently introduced transgenic corn that produces a Bt vegetative insecticidal protein (Vip). Recessive inheritance of pest resistance has favored sustained susceptibility, but even when inheritance is not recessive, abundant refuges of non-Bt host plants have substantially delayed resistance. These insights may inform resistance management strategies to increase the durability of current and future transgenic crops.

  6. A Spanner in the Works: Human–Elephant Conflict Complicates the Food–Water–Energy Nexus in Drylands of Africa

    Directory of Open Access Journals (Sweden)

    Mwangi Githiru

    2017-10-01

    Full Text Available The two major conservation issues for drylands of Africa are habitat loss or degradation and habitat fragmentation, largely from agriculture, charcoal production, and infrastructural development. A key question for management is how these landscapes can retain their critical ecological functions and services, while simultaneously supporting resilient livelihoods. It is a clear nexus question involving food (agriculture, water, and energy (fuelwood, which is complicated by human–wildlife conflicts. While these could appear disparate issues, they are closely connected in dryland forest landscapes of Africa where elephants occur close to areas of human habitation. For instance, crop failure, whether due to weather or wildlife damage, is a key driver for rural farmers seeking alternative livelihoods and incomes, one of the commonest being charcoal production. Similarly, heavy reliance on wood-based energy often leads to degradation of wildlife habitat, which heightens competition with wildlife for food and water, increasing the possibility of crop-raiding. So, for multifunctional landscapes where elephants occur in close proximity with humans, any food–water–energy nexus activities toward achieving sustainability and resilience should consider human–elephant conflicts (HECs. Here, we broach these food–water–energy nexus issues with a focus on dryland areas of Africa and HECs. We highlight an ongoing study attempting to address this nexus holistically by employing a climate-smart agriculture (CSA and agro-forestry based design, augmented by an elephant deterrent study and an eco-charcoal production venture.

  7. Use of human waste in sustainable crop production in Nigeria ...

    African Journals Online (AJOL)

    The plant nutrient in both urine and excreta come from arable fields and thus should be recycled as fertilizers to support sustainability and retain fertility of the soil. Urine acts very fast and is very rich in nitrogen. Policy on the use of the technology must be promoted and awareness created to the farmers to enable them utilize ...

  8. Sustainable soil management practices of crop farmers in Mkpat ...

    African Journals Online (AJOL)

    Sustainability which is the successful management of resources for agriculture to satisfy the changing human needs and the capacity to remain productive and at the same time conserving the resource base, is the focus of this study. Therefore, the various conventional methods of managing soil, which are commonly being ...

  9. Cover crops for sustainable agrosystems in the Americas. Chapter 2

    NARCIS (Netherlands)

    Scholberg, J.M.S.; Dogliotti, S.; Leoni, C.; Zotarelli, L.; Cherr, C.M.; Rossing, W.A.H.

    2010-01-01

    Rapid depletion of global fertilizer and fossil fuel reserves, combined with concerns about global warming, have resulted in increased interest in alternative strategies for sustaining agricultural production. Moreover, many farmers are being caught in a vicious spiral of unsustainability related to

  10. Sustainability assessment of crop protection systems: SustainOS methodology and its application for apple orchards

    NARCIS (Netherlands)

    Mouron, P.; Heijne, B.; Naef, A.; Strassemever, J.; Haver, F.; Avilla, J.

    2012-01-01

    Crop protection in general and apple crop protection in particular often rely on pesticides, although several alternative pest management measures are available. In this context European agricultural policy requires the implementation of Integrated Pest Management (IPM) by 2014. Within IPM, more

  11. Farmers typology and crops sustainability in Alto Urubamba, La Convencion – Cusco

    Directory of Open Access Journals (Sweden)

    Isaías Merma

    2012-06-01

    Full Text Available The research was conducted in the geographical region of Alto Urubamba, province of La Convencion, Cusco - Peru. The objective was to identify types of farmers and evaluate crops sustainability on farms of high forest. Surveys were applied to a sample of 106 farmers in both biophysical and socio-economic terms in order to identify typology; this information was analyzed through descriptive statistics. Multivariate analysis using preselected variables was performed to identify types of farmers. In addition, sustainability of eight tropical crops was evaluated; for this purpose, three farms for each crop were selected from 24 evaluated farms. Practical indicators of soil quality and crop health with a valuation from 0 to 10 were used; farmers participated during this evaluation. The results show that there are three types of farmers according to their efficiency in resources management and their economic logic. The crops of tea (6.65 and mango (6.50 obtained the highest values of sustainability, followed by coffee (6.25, cocoa (6.25, citrus (5.50, banana (5.45 and coca (5.10. Papaya (4.60 shows a value less than five; therefore, is considered as unsustainable according to local conditions.

  12. Traits to ecosystems: The ecological sustainability challenge when developing future energy crops

    Directory of Open Access Journals (Sweden)

    Martin eWeih

    2014-05-01

    Full Text Available Today we are undertaking great efforts to improve biomass production and quality traits of energy crops. Major motivation for developing those crops is based on environmental and ecological sustainability considerations, which however often are de-coupled from the trait-based crop improvement programs. It is now time to develop appropriate methods to link crop traits to production system characteristics set by the plant and the biotic communities influencing it; and to the ecosystem processes affecting ecological sustainability. The relevant ecosystem processes involve the net productivity in terms of biomass and energy yields, the depletion of energy-demanding resources (e.g. nitrogen, N, the carbon dynamics in soil and atmosphere, and the resilience and temporal stability of the production system. In a case study, we compared aspects of N use efficiency in various varieties of an annual (spring wheat and perennial (Salix energy crop grown under two nutrient regimes in Sweden. For example, we found considerable variation among crops, varieties and nutrient regimes in the energy yield per plant-internal N (MJ g-1 yr-1, which would result in different N resource depletion per unit energy produced.

  13. The role of leguminous cover crops in sustainable production of oil ...

    African Journals Online (AJOL)

    They also play an important role in soil erosion control and soil moisture conservation in plantations. The development of sound sustainable and productive cropping systems such as the incorporation of legumes in oil palm plantations is therefore of paramount importance. This paper reviews some research carried out on ...

  14. Developing robust crop plants for sustaining growth and yield under adverse climatic changes

    Science.gov (United States)

    Agricultural production and quality are expected to suffer from adverse changes in climatic conditions, including global warming, and this will affect worldwide human and animal food security. Global warming has been shown to negatively impact crop yield and therefore will affect sustainability of a...

  15. The potential of hemp (Cannabis sativa L.) for sustainable fibre production: a crop physiological appraisal.

    NARCIS (Netherlands)

    Werf, van der H.M.G.; Mathijssen, E.W.J.M.; Haverkort, A.J.

    1996-01-01

    Hemp (Cannabis sativa L.) fibre can be used as a raw material for paper and textile production. A comprehensive research programme in the Netherlands has concluded that fibre hemp is a potentially profitable crop, having the right profile to fit into sustainable farming systems. This paper presents

  16. Changes in soil properties and humic substances after long-term amendments with manure and crop residues in dryland farming systems.

    OpenAIRE

    Dorado, José.; Zancada Fernández, M. Cristina; Almendros Martín, Gonzalo; López-Fando, Cristina

    2003-01-01

    After 16 years of periodical applications of either farmyard manure or crop wastes at two levels of mineral N fertilization to a Calcic Haploxeralf in the semiarid central Spain, we found significant changes in chemical fertility levels and in the concentration, chemical composition, and carbon mineralization rates of soil organic matter (SOM). The changes in SOM quality were related to significant improvements of soil physical properties, mainly aggregate stability and water retention. Such ...

  17. Crop residue recycling for economic and environmental sustainability: The case of India

    Directory of Open Access Journals (Sweden)

    Devi Saroj

    2017-09-01

    Full Text Available India is one of the key producers of food grain, oilseed, sugarcane and other agricultural products. Agricultural crops generate considerable amounts of leftover residues, with increases in food production crop residues also increasing. These leftover residues exhibit not only resource loss but also a missed opportunity to improve a farmer’s income. The use of crop residues in various fields are being explored by researchers across the world in areas such as textile composite non-woven making processes, power generation, biogas production, animal feed, compost and manures, etc. The increasing trend in addition of bio-energy cogeneration plants, increasing demand for animal feedstock and increasing trend for organic agriculture indicates a competitive opportunity forcrop residue in Agriculture. It is to be noted that the use of this left over residue isoften not mutually exclusive which makes measurement of its economic value more difficult.For example, straw can be used as animal bedding and thereafter as a crop fertilizer. In view of this, the main aim of this paper envisaged to know about how much crop residue is left unutilized and how best they can be utilized for alternative purposes for environmental stewardship and sustainability. In this context, an attempt has been made to estimate the total crop residue across the states and its economic value though data available from various government sources and a SWOT analysis performed for possible alternative uses of residue in India. This paper also discusses the successful case studies of India and global level of use of crop residues in economic activities. Over all 516 Mtonnes of crop residue was produced in 2014-15 in India among which cereals were the largest producer of crop residue followed by sugarcane. The energy potential from paddy rice straw crop residue was estimated as 486,955 megawatt for 2014-15 and similarly for coarse cereals it was 226,200megawatt.

  18. Emergy Analysis and Sustainability Efficiency Analysis of Different Crop-Based Biodiesel in Life Cycle Perspective

    DEFF Research Database (Denmark)

    Ren, Jingzheng; Manzardo, Alessandro; Mazzi, Anna

    2013-01-01

    Biodiesel as a promising alternative energy resource has been a hot spot in chemical engineering nowadays, but there is also an argument about the sustainability of biodiesel. In order to analyze the sustainability of biodiesel production systems and select the most sustainable scenario, various...... kinds of crop-based biodiesel including soybean-, rapeseed-, sunflower-, jatropha- and palm-based biodiesel production options are studied by emergy analysis; soybean-based scenario is recognized as the most sustainable scenario that should be chosen for further study in China. DEA method is used...... to evaluate the sustainability efficiencies of these options, and the biodiesel production systems based on soybean, sunflower, and palm are considered as DEA efficient, whereas rapeseed-based and jatropha-based scenarios are needed to be improved, and the improved methods have also been specified....

  19. Emergy Analysis and Sustainability Efficiency Analysis of Different Crop-Based Biodiesel in Life Cycle Perspective

    Science.gov (United States)

    Ren, Jingzheng; Manzardo, Alessandro; Mazzi, Anna; Fedele, Andrea; Scipioni, Antonio

    2013-01-01

    Biodiesel as a promising alternative energy resource has been a hot spot in chemical engineering nowadays, but there is also an argument about the sustainability of biodiesel. In order to analyze the sustainability of biodiesel production systems and select the most sustainable scenario, various kinds of crop-based biodiesel including soybean-, rapeseed-, sunflower-, jatropha- and palm-based biodiesel production options are studied by emergy analysis; soybean-based scenario is recognized as the most sustainable scenario that should be chosen for further study in China. DEA method is used to evaluate the sustainability efficiencies of these options, and the biodiesel production systems based on soybean, sunflower, and palm are considered as DEA efficient, whereas rapeseed-based and jatropha-based scenarios are needed to be improved, and the improved methods have also been specified. PMID:23766723

  20. Syndromes of dryland degradation in southern Africa | Scholes ...

    African Journals Online (AJOL)

    Dryland degradation (in other words, desertification) is defined for the purposes of this paper as a persistent decrease in the capacity of an arid or semiarid ecosystem to supply a range of services, including (but not restricted to) forage, fuel, timber, crops, fresh water, wild-harvested foods, biodiversity habitat and tourism ...

  1. Total evaporation estimates from a Renosterveld and dryland wheat ...

    African Journals Online (AJOL)

    Accurate quantification of the water balance, in particular evapotranspiration, is fundamental in managing water resources, especially in semi-arid areas. The objective of this study was to compare evaporation from endemic vegetation – Renosterveld – and a dryland wheat/fallow cropping system. The study was carried out ...

  2. The role of short-rotation woody crops in sustainable development

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, J.P. [National Council of the Paper Industry for Air and Stream Improvement, Medford, MA (United States); Tolbert, V.R. [Oak Ridge National Lab., TN (United States)

    1996-12-31

    One answer to increase wood production is by increasing management intensity on existing timberland, especially in plantation forests. Another is to convert land currently in agriculture to timberland. Short-rotation woody crops can be used in both cases. But, what are the environmental consequences? Short-rotation woody crops can provide a net improvement in environmental quality at both local and global scales. Conversion of agricultural land to short-rotation woody crops can provide the most environmental quality enhancement by reducing erosion, improving soil quality, decreasing runoff, improving groundwater quality, and providing better wildlife habitat. Forest products companies can use increased production from intensively managed short-rotation woody crop systems to offset decreased yield from the portion of their timberland that is managed less intensively, e.g. streamside management zones and other ecologically sensitive or unique areas. At the global scale, use of short-rotation woody crops for bioenergy is part of the solution to reduce greenhouse gases produced by burning fossil fuels. Incorporating short-rotation woody crops into the agricultural landscape also increases storage of carbon in the soil, thus reducing atmospheric concentrations. In addition, use of wood instead of alternatives such as steel, concrete, and plastics generally consumes less energy and produces less greenhouse gases. Cooperative research can be used to achieve energy, fiber, and environmental goals. This paper will highlight several examples of ongoing cooperative research projects that seek to enhance the environmental aspects of short-rotation woody crop systems. Government, industry, and academia are conducting research to study soil quality, use of mill residuals, nutrients in runoff and groundwater, and wildlife use of short-rotation woody crop systems in order to assure the role of short-rotation crops as a sustainable way of meeting society`s needs.

  3. Optimizing root system architecture in biofuel crops for sustainable energy production and soil carbon sequestration

    Science.gov (United States)

    To, Jennifer PC; Zhu, Jinming; Benfey, Philip N

    2010-01-01

    Root system architecture (RSA) describes the dynamic spatial configuration of different types and ages of roots in a plant, which allows adaptation to different environments. Modifications in RSA enhance agronomic traits in crops and have been implicated in soil organic carbon content. Together, these fundamental properties of RSA contribute to the net carbon balance and overall sustainability of biofuels. In this article, we will review recent data supporting carbon sequestration by biofuel crops, highlight current progress in studying RSA, and discuss future opportunities for optimizing RSA for biofuel production and soil carbon sequestration. PMID:21173868

  4. Optimizing root system architecture in biofuel crops for sustainable energy production and soil carbon sequestration.

    Science.gov (United States)

    To, Jennifer Pc; Zhu, Jinming; Benfey, Philip N; Elich, Tedd

    2010-09-08

    Root system architecture (RSA) describes the dynamic spatial configuration of different types and ages of roots in a plant, which allows adaptation to different environments. Modifications in RSA enhance agronomic traits in crops and have been implicated in soil organic carbon content. Together, these fundamental properties of RSA contribute to the net carbon balance and overall sustainability of biofuels. In this article, we will review recent data supporting carbon sequestration by biofuel crops, highlight current progress in studying RSA, and discuss future opportunities for optimizing RSA for biofuel production and soil carbon sequestration.

  5. ROLE OF ALLELOPATHY IN THE STIMULATORY AND INHIBITORY EFFECTS OF HAIRY VETCH COVER CROP RESIDUE IN NO-TILLAGE SUSTAINABLE PRODUCTION SYSTEMS

    Science.gov (United States)

    Cover crops can provide multiple benefits to sustainable cropping systems including building soil organic matter, controlling soil and nutrient losses from fields, moderating radiation and moisture exchange, releasing nutrients for subsequent crops, and suppressing weed and pest populations. Many o...

  6. Water Resources Assessment and Management in Drylands

    Directory of Open Access Journals (Sweden)

    Magaly Koch

    2016-06-01

    Full Text Available Drylands regions of the world face difficult issues in maintaining water resources to meet current demands which will intensify in the future with population increases, infrastructure development, increased agricultural water demands, and climate change impacts on the hydrologic system. New water resources evaluation and management methods will be needed to assure that water resources in drylands are optimally managed in a sustainable manner. Development of water management and conservation methods is a multi-disciplinary endeavor. Scientists and engineers must collaborate and cooperate with water managers, planners, and politicians to successfully adopt new strategies to manage water not only for humans, but to maintain all aspects of the environment. This particularly applies to drylands regions where resources are already limited and conflicts over water are occurring. Every aspect of the hydrologic cycle needs to be assessed to be able to quantify the available water resources, to monitor natural and anthropogenic changes, and to develop flexible policies and management strategies that can change as conditions dictate. Optimal, sustainable water management is achieved by cooperation and not conflict, thereby necessitating the need for high quality scientific research and input into the process.

  7. Dryland ecohydrology and climate change: critical issues and technical advances

    Directory of Open Access Journals (Sweden)

    L. Wang

    2012-08-01

    Full Text Available Drylands cover about 40% of the terrestrial land surface and account for approximately 40% of global net primary productivity. Water is fundamental to the biophysical processes that sustain ecosystem function and food production, particularly in drylands where a tight coupling exists between ecosystem productivity, surface energy balance, biogeochemical cycles, and water resource availability. Currently, drylands support at least 2 billion people and comprise both natural and managed ecosystems. In this synthesis, we identify some current critical issues in the understanding of dryland systems and discuss how arid and semiarid environments are responding to the changes in climate and land use. The issues range from societal aspects such as rapid population growth, the resulting food and water security, and development issues, to natural aspects such as ecohydrological consequences of bush encroachment and the causes of desertification. To improve current understanding and inform upon the needed research efforts to address these critical issues, we identify some recent technical advances in terms of monitoring dryland water dynamics, water budget and vegetation water use, with a focus on the use of stable isotopes and remote sensing. These technological advances provide new tools that assist in addressing critical issues in dryland ecohydrology under climate change.

  8. Ecology, equity and economics: reframing dryland policy

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, Ced

    2011-11-15

    Drylands are among the world's most variable and unpredictable environments. But people here have long learnt how to live with and harness this variability to support sustainable and productive economies, societies and ecosystems. Policymakers have for too long ignored this wealth of experience and expertise with dire consequences. Attempts to replace traditional land use practices with modern techniques have simply exacerbated poverty, degradation and conflict. In the face of climate change and increasing uncertainty in the drylands, the need to reframe policy and practice has never been greater. The future must be built on sound scientific information, local knowledge, informed participation and the wisdom of customary institutions that emphasise social equity, ecological integrity and economic development.

  9. Effect of crop residue harvest on long-term crop yield, soil erosion, and carbon balance: tradeoffs for a sustainable bioenergy feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Gregg, Jay S.; Izaurralde, Roberto C.

    2010-08-26

    Agricultural residues are a potential feedstock for bioenergy production, if residue harvest can be done sustainably. The relationship between crop residue harvest, soil erosion, crop yield and carbon balance was modeled with the Erosion Productivity Impact Calculator/ Environment Policy Integrated Climate (EPIC) using a factorial design. Four crop rotations (winter wheat [Triticum aestivum (L.)] – sunflower [Helianthus annuus]; spring wheat [Triticum aestivum (L.)] – canola [Brassica napus]; corn [Zea mays L.] – soybean [Glycine max (L.) Merr.]; and cotton [Gossypium hirsutum] – peanut [Arachis hypogaea]) were simulated at four US locations each, under different topographies (0-10% slope), and management practices [crop residue removal rates (0-75%), conservation practices (no till, contour cropping, strip cropping, terracing)].

  10. Drylands and desertification

    OpenAIRE

    Escadafal, Richard

    2016-01-01

    Regions with dry climates cover a large part of the world’s landmass (more than 40%). Collectively known by the English term "drylands", they encompass a wide range of ecosystems, including the American "deserts" of California, Nevada and Mexico ; the vast steppes of Central Asia and North Africa ; the Sahelian savannah and real deserts such as the Sahara in Africa or the Gobi in China.

  11. GIS based evaluation of crop suitability for agricultural sustainability around Kolaghat thermal power plant, India.

    Science.gov (United States)

    Adak, Subhas; Adhikari, Kalyan; Brahmachari, Koushik

    2016-09-01

    Fly ash exhaust from Kolaghat thermal power plant, West Bengal, India,?? affects the areas within the radius of 3 - 4 km. Land information system indicated that surface texture within 4 km was silty loam and clay content increased with increase of distance. Soil pH was alkaline (7.58-8.01) in affected circles, whereas soil was acidic (5.95-6.41) in rest of block. Organic carbon (OC) is roving from 0.36 to 0.64% in the nearer circles which is lesser from others. The present Crop suitability analysis revealed that 96.98 % area was suitable (S1) for maize, sesame, jute, whereas these were cultivated in less than 1% of land. Flowers are the best suitable (S1) in 88.9 % but it was grown in 6.02 % area.? The present rice area within 4 km of KTPP is showing moderately suitable (S2) and S1 for the rest. Wheat is moderately suitable (S2) in the almost all the circles.? Cultivation of vegetable crops is limited in the affected circles while the highly suitable (S1) comprises 67.49 % for the remaining areas though it covered only 6.01 % of the block.? This evaluation precisely improves more than 300% from the earlier cropping intensity of 177.95 %. Suitability based land use allocation serves as stepping stone to promote agricultural sustainability. Geographic information system (GIS) model has been developed to assess site specific crop suitability for sustainable agricultural planning.

  12. Long-Term Cropping Effects on Agricultural Sustainability in Alar Oasis of Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Lu Gong

    2016-01-01

    Full Text Available Agricultural sustainability has become a major concern in arid regions of China. In order to better understand the influence of continuous cropping on soil quality, six experimental fields were established in the Alar Oasis of Xinjiang, including uncultivated land (as a zero year treatment duration and five different continuous cropping years on cotton fields, with different cropping durations (5, 10, 15, 20 and 25 years, respectively. Thirteen soil indicators were selected including soil physicochemical properties, nutrient properties and enzymatic activities. The results show that duration of continuous cropping of cotton fields significantly influences a number of soil properties. Cultivation durations ranked according to soil quality indexes (SQI are as follows: 15 years (0.828 > 20 years (0.816 > 10 years (0.668> 5 years (0.548 > 25 years (0.377 > 0 years (0.205, and sustainable yield index (SYI are as follows: 10 years (0.830 > 15 years (0.777 > 20 years (0.667 > 5 years (0.586 > 25 years (0.159.

  13. Designing a new cropping system for high productivity and sustainable water usage under climate change.

    Science.gov (United States)

    Meng, Qingfeng; Wang, Hongfei; Yan, Peng; Pan, Junxiao; Lu, Dianjun; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

    2017-02-03

    The food supply is being increasingly challenged by climate change and water scarcity. However, incremental changes in traditional cropping systems have achieved only limited success in meeting these multiple challenges. In this study, we applied a systematic approach, using model simulation and data from two groups of field studies conducted in the North China Plain, to develop a new cropping system that improves yield and uses water in a sustainable manner. Due to significant warming, we identified a double-maize (M-M; Zea mays L.) cropping system that replaced the traditional winter wheat (Triticum aestivum L.) -summer maize system. The M-M system improved yield by 14-31% compared with the conventionally managed wheat-maize system, and achieved similar yield compared with the incrementally adapted wheat-maize system with the optimized cultivars, planting dates, planting density and water management. More importantly, water usage was lower in the M-M system than in the wheat-maize system, and the rate of water usage was sustainable (net groundwater usage was ≤150 mm yr-1). Our study indicated that systematic assessment of adaptation and cropping system scale have great potential to address the multiple food supply challenges under changing climatic conditions.

  14. Irrigation treatments, water use efficiency and crop sustainability in cereal-forage rotations in Mediterranean environment

    Directory of Open Access Journals (Sweden)

    Pasquale Martiniello

    2012-10-01

    Full Text Available Agricultural systems based on crop rotation are beneficial to crop sustainability and productivity. Wheat-forage rotations combined with irrigation are the agronomic techniques best able to exploit Mediterranean environmental conditions. This paper describes a long-term field trial to ascertain the effect of combined irrigation and durum wheat-forage rotations on crop yield and soil chemical properties. The two forage crops: annual grass-clover winter binary mixture and perennial lucerne were carried out through 1991-2008 under rainfed and irrigated treatments. The experiments were used to highlight the effect of irrigation and wheat-forage crop rotations on water use efficiency (WUE and sustainability of organic matter (OM in topsoil. Irrigation increased the dry matter (DM of annual binary mixture and lucerne by 49.1% and 66.9%, respectively. Continuous wheat rotation reduced seed yield (SY, stability of production, and crude protein (CP characteristics of kernel and OM in topsoil. The yearly gain in wheat after forage crops was 0.04 t (ha yr-1 under rainfed and 0.07 t (ha yr-1 under irrigation treatments. The CP and soil OM of wheat forage crops rotations, compared with those of continuous wheat under rainfed and irrigated was a 0.8 and 0.5 % increase in CP and 5.1 and 4.4 in OM, respectively. The rotations of annual grass-clover winter binary mixture and lucerne meadow under both irrigated treatments increased the OM over continuous wheat (9.3 % and 8.5 in annual grass-clover winter binary mixture and 12.5 and 9.5 lucerne meadow under rainfed and irrigation, respectively. Irrigation reduced the impact of weather on crop growing, reducing water use efficiency (mean over rotations for DM production (15.5 in meadow and 17.5 in annual grass-clover winter binary mixture [L water (kg DM-1] and wheat SY. However, the agronomic benefits achieved by forage crops in topsoil are exhausted after three years of continuous wheat rotation.

  15. Climate Change and Dryland Wheat Systems in the US Pacific Northwest

    Science.gov (United States)

    Stockle, C.; Karimi, T.; Huggins, D. R.; Nelson, R.

    2015-12-01

    A regional assessment of historical and future yields, and components of the water, nitrogen, and carbon soil balance of dryland wheat-based cropping systems in the US Pacific Northwest is being conducted (Regional Approaches to Climate Change project funded by USDA-NIFA). All these elements intertwines and are important to understand the future of these systems in the region. A computer simulation methodology was used based on the CropSyst model and historic and projected daily weather data downscaled to a 4x4 km grid including 14 general circulation models (GCMs) and two representative concentration pathways of future atmospheric CO2 (RCP 4.5 and RCP 8.5). The study region was divided in 3 agro-ecological zones (AEZ) based on precipitation amount: low (460 mm/year), with a change from crop-fallow, to transition fallow (crop-crop-fallow) to annual cropping, respectively. Typical wheat-based rotations included winter wheat (WW)-Summer fallow (SF) for the low AEZ, WW-spring wheat (SW)-SF for the intermediate AEZ, and WW-SW-spring peas for the high AEZ, all under conventional and no tillage management. Alternative systems incorporating canola were also evaluated. Results suggest that, in most cases, these dryland systems may fare well in the future (31-year periods centered around 2030, 2050, and 2070), with potential gains in productivity. Also, a trend towards increased fallow in the intermediate AEZ appears possible for higher productivity, and the inclusion of less water demanding crops may help sustain cropping intensity. Uncertainties in these projections arise from large discrepancies among climate models regarding the warming rate, compounded by different possible future CO2 emission scenarios, the degree of change in frequency and severity of extreme events and associated potential damages to crop canopies due to cold weather and grain set reduction due to extreme heat events. Furthermore, there is little understanding of the impact of climate change on

  16. Genetic Engineering and Sustainable Crop Disease Management: Opportunities for Case-by-Case Decision-Making

    Directory of Open Access Journals (Sweden)

    Paul Vincelli

    2016-05-01

    Full Text Available Genetic engineering (GE offers an expanding array of strategies for enhancing disease resistance of crop plants in sustainable ways, including the potential for reduced pesticide usage. Certain GE applications involve transgenesis, in some cases creating a metabolic pathway novel to the GE crop. In other cases, only cisgenessis is employed. In yet other cases, engineered genetic changes can be so minimal as to be indistinguishable from natural mutations. Thus, GE crops vary substantially and should be evaluated for risks, benefits, and social considerations on a case-by-case basis. Deployment of GE traits should be with an eye towards long-term sustainability; several options are discussed. Selected risks and concerns of GE are also considered, along with genome editing, a technology that greatly expands the capacity of molecular biologists to make more precise and targeted genetic edits. While GE is merely a suite of tools to supplement other breeding techniques, if wisely used, certain GE tools and applications can contribute to sustainability goals.

  17. Integrated nutrient management (INM) for sustaining crop productivity and reducing environmental impact: A review

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wei, E-mail: weiwu@nwsuaf.edu.cn [College of Agronomy, Northwest A& F University, Yangling, Shaanxi 712100 (China); Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre (ECORC), Ottawa, ON K1A 0C6 (Canada); Ma, Baoluo, E-mail: Baoluo.Ma@AGR.GC.CA [Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre (ECORC), Ottawa, ON K1A 0C6 (Canada)

    2015-04-15

    The increasing food demands of a growing human population and the need for an environmentally friendly strategy for sustainable agricultural development require significant attention when addressing the issue of enhancing crop productivity. Here we discuss the role of integrated nutrient management (INM) in resolving these concerns, which has been proposed as a promising strategy for addressing such challenges. INM has multifaceted potential for the improvement of plant performance and resource efficiency while also enabling the protection of the environment and resource quality. This review examines the concepts, objectives, procedures and principles of INM. A comprehensive literature search revealed that INM enhances crop yields by 8–150% compared with conventional practices, increases water-use efficiency, and the economic returns to farmers, while improving grain quality and soil health and sustainability. Model simulation and fate assessment further reveal that reactive nitrogen (N) losses and GHG (greenhouse gas) emissions are reduced substantially under advanced INM practices. Lower inputs of chemical fertilizer and therefore lower human and environmental costs (such as intensity of land use, N use, reactive N losses and GHG emissions) were achieved under advanced INM practices without compromising crop yields. Various approaches and perspectives for further development of INM in the near future are also proposed and discussed. Strong and convincing evidence indicates that INM practice could be an innovative and environmentally friendly strategy for sustainable agriculture worldwide. - Highlights: • The increasing pressure to meet global cereal demand poses great challenge. • A changing environment further threatens cereal production. • Literature summary shows 8–150% yield advantage from use of INM method. • INM contributions to mitigation of environmental costs are remarkable. • High crop productivity and less environmental impact can be

  18. Farmers' Perception of Integrated Soil Fertility and Nutrient Management for Sustainable Crop Production: A Study of Rural Areas in Bangladesh

    Science.gov (United States)

    Farouque, Md. Golam; Takeya, Hiroyuki

    2007-01-01

    This study aimed to determine farmers' perception of integrated soil fertility and nutrient management for sustainable crop production. Integrated soil fertility (ISF) and nutrient management (NM) is an advanced approach to maintain soil fertility and to enhance crop productivity. A total number of 120 farmers from eight villages in four districts…

  19. On Farm Agronomic and First Environmental Evaluation of Oil Crops for Sustainable Bioenergy Chains

    Directory of Open Access Journals (Sweden)

    Luca Lazzeri

    Full Text Available Energy crops, and in particular oil crops, could be an important occasion for developing new non food production rows for a new multi-functional agriculture in Italy. In this view, the use of local biomass is a fundamental starting point for the development of a virtuous energy chain that should pursue not only agricultural profitability, but also chain sustainability and that is less dependent on the global market, characterized by instability in terms of biomass availability and price. From this perspective, particular attention must be paid to crop choice on the basis of its rusticity and of its adaptability to local growing conditions and to low input cropping systems. In this context, alike woody and herbaceous biomasses, oil crops such as sunflower and rapeseed should be able to support local agricultural bioenergy chain in Italy. In addition, in a local bioenergy chain, the role of the farmers should not be limited just to grain production; but also grain processing should be performed at farm or consortium level in oilseed extraction plants well proportioned to the cropped surface. In this way, by means of a simple power generator, farmer could thus produce its own thermal and electric energy from the oil, maximizing his profit. This objective could also be achieved through the exploitation of the total biomass, including crop residues and defatted seed meals, that may be considered as fundamental additional economic and/or environmental benefits of the chain. This paper reports some results of three-years on-farm experiments on oil crop chain carried out in the framework of “Bioenergie” project, that was focused to enhance farmers awareness of these criteria and to the feasibility at open field scale of low-input cultivation of rapeseed, sunflower and Brassica carinata in seven Italian regions. In several on-farm experiences, these crops produced more than 800 kg ha-1 of oil with good energy properties. Defatted seed meals could be

  20. On Farm Agronomic and First Environmental Evaluation of Oil Crops for Sustainable Bioenergy Chains

    Directory of Open Access Journals (Sweden)

    Paolo Spugnoli

    2011-02-01

    Full Text Available Energy crops, and in particular oil crops, could be an important occasion for developing new non food production rows for a new multi-functional agriculture in Italy. In this view, the use of local biomass is a fundamental starting point for the development of a virtuous energy chain that should pursue not only agricultural profitability, but also chain sustainability and that is less dependent on the global market, characterized by instability in terms of biomass availability and price. From this perspective, particular attention must be paid to crop choice on the basis of its rusticity and of its adaptability to local growing conditions and to low input cropping systems. In this context, alike woody and herbaceous biomasses, oil crops such as sunflower and rapeseed should be able to support local agricultural bioenergy chain in Italy. In addition, in a local bioenergy chain, the role of the farmers should not be limited just to grain production; but also grain processing should be performed at farm or consortium level in oilseed extraction plants well proportioned to the cropped surface. In this way, by means of a simple power generator, farmer could thus produce its own thermal and electric energy from the oil, maximizing his profit. This objective could also be achieved through the exploitation of the total biomass, including crop residues and defatted seed meals, that may be considered as fundamental additional economic and/or environmental benefits of the chain. This paper reports some results of three-years on-farm experiments on oil crop chain carried out in the framework of “Bioenergie” project, that was focused to enhance farmers awareness of these criteria and to the feasibility at open field scale of low-input cultivation of rapeseed, sunflower and Brassica carinata in seven Italian regions. In several on-farm experiences, these crops produced more than 800 kg ha-1 of oil with good energy properties. Defatted seed meals could be

  1. Tree Crops, a Permanent Agriculture: Concepts from the Past for a Sustainable Future

    Directory of Open Access Journals (Sweden)

    C. Reed Funk

    2013-09-01

    Full Text Available J. Russell Smith (1874–1966, a professor of geography at Columbia University, witnessed the devastation of soil erosion during his extensive travels. He first published his landmark text, Tree Crops, A Permanent Agriculture in 1929, in which he described the value of tree crops for producing food and animal feed on sloping, marginal, and rocky soils as a sustainable alternative to annual crop agriculture less suited to these lands. A cornerstone of his thesis was using wide germplasm collection and plant breeding to improve this largely underutilized and genetically unexploited group of plants to develop locally adapted, high-yielding cultivars for the many climatic zones of North America. Smith proposed an establishment of “Institutes of Mountain Agriculture” to undertake this work. For a variety of reasons, though, his ideas were not implemented to any great degree. However, our growing population’s increasing demands on natural resources and the associated environmental degradation necessitate that Smith’s ideas be revisited. In this review, his concepts, supported by modern scientific understanding and advances, are discussed and expanded upon to emphasize their largely overlooked potential to enhance world food and energy security and environmental sustainability. The discussion leads us to propose that his “institutes” be established worldwide and with an expanded scope of work.

  2. Assessment of physical and chemical indicators of sandy soil quality for sustainable crop production

    Science.gov (United States)

    Lipiec, Jerzy; Usowicz, Boguslaw

    2017-04-01

    correspond with low soil organic carbon and cation exchange capacity and high content of sand. These areas are considered as management zones to improve crop productivity and soil properties responsible for soil quality and functions. We conclude that soil organic carbon, cation exchange capacity and pH should be included as indicators of soil quality in sandy soils. The study was funded by HORIZON 2020, European Commission, Programme H2020-SFS-2015-2: Soil Care for profitable and sustainable crop production in Europe, project No. 677407 (SoilCare, 2016-2021).

  3. Sustainability versus yield in agricultural soils under various crop production practices - a microbial perspective

    Science.gov (United States)

    Pereg, Lily; Aldorri, Sind; McMillan, Mary

    2017-04-01

    Wheat and cotton are important food and cash crops often grown in rotation on black, grey and red clay soil, in Australia. The common practice of nitrogen and phosphate fertilizers have been solely in the form of agrochemicals, however, a few growers have incorporated manure or composted plant material into the soil before planting. While the cotton yield in studied farms was comparable, we found that the use of such organic amendments significantly enhanced the pool of nitrogen cycling genes, suggesting increased potential of soil microbial function as well as increased microbial metabolic diversity and abundance. Therefore, the regular use of organic amendments contributed to improved soil sustainability.

  4. Sustainability of current GM crop cultivation : Review of people, planet, profit effects of agricultural production of GM crops, based on the cases of soybean, maize, and cotton

    NARCIS (Netherlands)

    Franke, A.C.; Breukers, M.L.H.; Broer, W.; Bunte, F.H.J.; Dolstra, O.; Engelbronner-Kolff, d' F.M.; Lotz, L.A.P.; Montfort, J.; Nikoloyuk, J.; Rutten, M.M.; Smulders, M.J.M.; Wiel, van de C.C.M.; Zijl, M.

    2011-01-01

    This report adresses the question whether the cultivation of genetically modified (GM) crops abroad for import in the Netherlands, as compared to the cultivation of their conventional (non-GM) counterparts, is in line with Dutch policy and societal aims striving after more sustainable forms of

  5. Natural ecosystem mimicry in traditional dryland agroecosystems: Insights from an empirical and holistic approach.

    Science.gov (United States)

    Blanco, Julien; Michon, Geneviève; Carrière, Stéphanie M

    2017-12-15

    While the aim of Ecological Intensification is to enable the design of more sustainable and productive agricultural systems, it is not suited to dryland agroecosystems that are driven by non-equilibrium dynamics and intrinsic variability. Instead, a model based on mobility and variability management has been proposed for these agroecosystems. However, this model remains under-applied in southern Morocco where there have been few studies on the functioning of traditional agroecosystems. This paper focuses on an agroecosystem in the Moroccan Saharan fringe zone that combines agriculture and pastoralism in an acacia parkland. A grounded theory approach was used over a three-year investigation period (i) to highlight how agro-pastoral activities interface with environmental variability, and (ii) to analyze the formal and informal institutions that support these activities. Results show that farmers interface with rainfall variability through (i) an opportunistic agricultural calendar, (ii) a variation of cultivated areas, and (iii) crop diversification. Herders combine macro-mobility (nomads move over long distances to track rainfall) and micro-mobility (nomadic and sedentary herds are driven on a daily basis around settlements) to optimize the exploitation of ecological heterogeneity. During droughts, they also resort to State-subsidized forage supplies. Both cultivation and pastoral activities tend to interface with ecological dynamics and to mimic nature, resulting in a human-modified parkland that could be considered as a 'green agroecosystem'. The sustainability of natural resource use relies on flexible property rights, backed up by a social and cultural norm-based regulation system, that allow crop-livestock integration and landscape collective management. Despite encouraging results, the agroecosystem appears to be threatened by current agricultural policies, rural exodus and the lack of social recognition of nomadism. Nevertheless, because ecosystem mimicry of

  6. Priority regions for research on dryland cereals and legumes [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Glenn Hyman

    2016-07-01

    Full Text Available Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes.

  7. Priority regions for research on dryland cereals and legumes [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Glenn Hyman

    2016-05-01

    Full Text Available Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes.

  8. Planting geometry and growing season effects on the growth and yield of dryland cotton

    Science.gov (United States)

    The declining Ogallala Aquifer beneath the Southern High Plains may necessitate dryland crop production and cotton (Gossypium hirsutum L.) is a well-adapted and potentially profitable alternative crop. The limited growing season duration of the Texas Panhandle and southwestern Kansas, however, impos...

  9. The hydrometeorological sustainability of Miscanthus x giganteus as a biofuel crop in the US Midwest

    Science.gov (United States)

    Roy, Gavin R.

    Miscanthus x giganteus (M. x giganteus ) is a dense, 3-5 m tall, productive perennial grass that has been suggested to replace corn as the principal source of biofuel for the US transportation industry. However, cultivating a regime of this water-intensive rhizomatous crop across the US Midwest may not be agronomically realistic if it is unable to survive years of low precipitation or extreme cold wintertime soil temperatures, both of which have previously killed experimental crops. The goal of this research was to use a third-generation land surface model (LSM) to provide a new assessment of the hypothetical biogeophysical sustainability of a regime of M. x giganteus across the US Midwest given that, for the first time, a robust and near-complete dataset over a large area of mature M. x giganteus was available for model validation. Modifications to the local hydrology and microclimate would necessarily occur in areas where M. x giganteus is adapted, but a switch to this biofuel crop can only occur where its intense growing season water usage (up to 600 mm) and wintertime soil temperature requirements (no less than -6° C) are feasibly sustainable without irrigation. The first step was to interpret the observed turbulent and ecosystem flux behavior over an extant area of mature M. x giganteus and replicate this behavior within the SiB3 third-generation LSM (Simple Biosphere Model, version 3). A new vegetation parameterization was developed in SiB3 using several previous empirical studies of M. x giganteus as a foundation. The simulation results were validated against a new, robust series of turbulent and ecosystem flux data taken over a four-hectare experimental crop of M. x giganteus in Champaign, IL, USA from 2011-2013. Wintertime mortality of M. x giganteus was subsequently assessed. It was proposed that areas with higher seasonal snowfall in the US Midwest may be favorable for M. x giganteus sustainability and expansion due to the significant insulating effect

  10. From rainfed agriculture to stress-avoidance irrigation: II. Sustainability, crop yield, and profitability

    Science.gov (United States)

    Vico, Giulia; Porporato, Amilcare

    2011-02-01

    The optimality of irrigation strategies may be sought with respect to a number of criteria, including water requirements, crop yield, and profitability. To explore the suitability of different demand-based irrigation strategies, we link the probabilistic description of irrigation requirements under stochastic hydro-climatic conditions, provided in a companion paper [Vico G, Porporato A. From rainfed agriculture to stress-avoidance irrigation: I. A generalized irrigation scheme with stochastic soil moisture. Adv Water Resour 2011;34(2):263-71], to crop-yield and economic analyses. Water requirements, application efficiency, and investment costs of different irrigation methods, such as surface, sprinkler and drip irrigation systems, are described via a unified conceptual and theoretical approach, which includes rainfed agriculture and stress-avoidance irrigation as extreme cases. This allows us to analyze irrigation strategies with respect to sustainability, productivity, and economic return, using the same framework, and quantify them as a function of climate, crop, and soil parameters. We apply our results to corn ( Zea mays), a food staple and biofuel source, which is currently mainly irrigated through surface systems. As our analysis shows, micro-irrigation maximizes water productivity, but more traditional solutions may be more profitable at least in some contexts.

  11. Improvements in crop water productivity increase water sustainability and food security—a global analysis

    Science.gov (United States)

    Brauman, Kate A.; Siebert, Stefan; Foley, Jonathan A.

    2013-06-01

    Irrigation consumes more water than any other human activity, and thus the challenges of water sustainability and food security are closely linked. To evaluate how water resources are used for food production, we examined global patterns of water productivity—food produced (kcal) per unit of water (l) consumed. We document considerable variability in crop water productivity globally, not only across different climatic zones but also within climatic zones. The least water productive systems are disproportionate freshwater consumers. On precipitation-limited croplands, we found that ∼40% of water consumption goes to production of just 20% of food calories. Because in many cases crop water productivity is well below optimal levels, in many cases farmers have substantial opportunities to improve water productivity. To demonstrate the potential impact of management interventions, we calculated that raising crop water productivity in precipitation-limited regions to the 20th percentile of productivity would increase annual production on rainfed cropland by enough to provide food for an estimated 110 million people, and water consumption on irrigated cropland would be reduced enough to meet the annual domestic water demands of nearly 1.4 billion people.

  12. From ozone depletion to agriculture: understanding the role of UV radiation in sustainable crop production.

    Science.gov (United States)

    Wargent, Jason J; Jordan, Brian R

    2013-03-01

    Largely because of concerns regarding global climate change, there is a burgeoning interest in the application of fundamental scientific knowledge in order to better exploit environmental cues in the achievement of desirable endpoints in crop production. Ultraviolet (UV) radiation is an energetic driver of a diverse range of plant responses and, despite historical concerns regarding the damaging consequences of UV-B radiation for global plant productivity as related to stratospheric ozone depletion, current developments representative of a range of organizational scales suggest that key plant responses to UV-B radiation may be exploitable in the context of a sustainable contribution towards the strengthening of global crop production, including alterations in secondary metabolism, enhanced photoprotection, up-regulation of the antioxidative response and modified resistance to pest and disease attack. Here, we discuss the prospect of this paradigm shift in photobiology, and consider the linkages between fundamental plant biology and crop-level outcomes that can be applied to the plant UV-B response, in addition to the consequences for related biota and many other facets of agro-ecosystem processes. © 2013 The Author. New Phytologist © 2012 New Phytologist Trust.

  13. Dedicated Industrial Oilseed Crops as Metabolic Engineering Platforms for Sustainable Industrial Feedstock Production

    Science.gov (United States)

    Zhu, Li-Hua; Krens, Frans; Smith, Mark A.; Li, Xueyuan; Qi, Weicong; van Loo, Eibertus N.; Iven, Tim; Feussner, Ivo; Nazarenus, Tara J.; Huai, Dongxin; Taylor, David C.; Zhou, Xue-Rong; Green, Allan G.; Shockey, Jay; Klasson, K. Thomas; Mullen, Robert T.; Huang, Bangquan; Dyer, John M.; Cahoon, Edgar B.

    2016-01-01

    Feedstocks for industrial applications ranging from polymers to lubricants are largely derived from petroleum, a non-renewable resource. Vegetable oils with fatty acid structures and storage forms tailored for specific industrial uses offer renewable and potentially sustainable sources of petrochemical-type functionalities. A wide array of industrial vegetable oils can be generated through biotechnology, but will likely require non-commodity oilseed platforms dedicated to specialty oil production for commercial acceptance. Here we show the feasibility of three Brassicaceae oilseeds crambe, camelina, and carinata, none of which are widely cultivated for food use, as hosts for complex metabolic engineering of wax esters for lubricant applications. Lines producing wax esters >20% of total seed oil were generated for each crop and further improved for high temperature oxidative stability by down-regulation of fatty acid polyunsaturation. Field cultivation of optimized wax ester-producing crambe demonstrated commercial utility of these engineered crops and a path for sustainable production of other industrial oils in dedicated specialty oilseeds. PMID:26916792

  14. Dedicated Industrial Oilseed Crops as Metabolic Engineering Platforms for Sustainable Industrial Feedstock Production.

    Science.gov (United States)

    Zhu, Li-Hua; Krens, Frans; Smith, Mark A; Li, Xueyuan; Qi, Weicong; van Loo, Eibertus N; Iven, Tim; Feussner, Ivo; Nazarenus, Tara J; Huai, Dongxin; Taylor, David C; Zhou, Xue-Rong; Green, Allan G; Shockey, Jay; Klasson, K Thomas; Mullen, Robert T; Huang, Bangquan; Dyer, John M; Cahoon, Edgar B

    2016-02-26

    Feedstocks for industrial applications ranging from polymers to lubricants are largely derived from petroleum, a non-renewable resource. Vegetable oils with fatty acid structures and storage forms tailored for specific industrial uses offer renewable and potentially sustainable sources of petrochemical-type functionalities. A wide array of industrial vegetable oils can be generated through biotechnology, but will likely require non-commodity oilseed platforms dedicated to specialty oil production for commercial acceptance. Here we show the feasibility of three Brassicaceae oilseeds crambe, camelina, and carinata, none of which are widely cultivated for food use, as hosts for complex metabolic engineering of wax esters for lubricant applications. Lines producing wax esters >20% of total seed oil were generated for each crop and further improved for high temperature oxidative stability by down-regulation of fatty acid polyunsaturation. Field cultivation of optimized wax ester-producing crambe demonstrated commercial utility of these engineered crops and a path for sustainable production of other industrial oils in dedicated specialty oilseeds.

  15. Global temperate drylands climate change vulnerability

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in distribution and...

  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. Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

    Directory of Open Access Journals (Sweden)

    W. A. Timms

    2012-04-01

    Full Text Available The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (<500 mm yr−1 rainfall, potential evapotranspiration >2000 mm yr−1 such as parts of Australia's Murray-Darling Basin (MDB. In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8–1.2 m depth under perennial vegetation and at 2.0–2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91–229 t ha−1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m−1 at 21 to 37 m depth (N = 5, whereas deeper groundwater was less saline (290 mS m−1 with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM software package predicted deep drainage of 3.3–9.5 mm yr−1 (0.7–2.1% rainfall based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total, and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low

  18. Breeding crop plants with deep roots: their role in sustainable carbon, nutrient and water sequestration

    Science.gov (United States)

    Kell, Douglas B.

    2011-01-01

    Background The soil represents a reservoir that contains at least twice as much carbon as does the atmosphere, yet (apart from ‘root crops’) mainly just the above-ground plant biomass is harvested in agriculture, and plant photosynthesis represents the effective origin of the overwhelming bulk of soil carbon. However, present estimates of the carbon sequestration potential of soils are based more on what is happening now than what might be changed by active agricultural intervention, and tend to concentrate only on the first metre of soil depth. Scope Breeding crop plants with deeper and bushy root ecosystems could simultaneously improve both the soil structure and its steady-state carbon, water and nutrient retention, as well as sustainable plant yields. The carbon that can be sequestered in the steady state by increasing the rooting depths of crop plants and grasses from, say, 1 m to 2 m depends significantly on its lifetime(s) in different molecular forms in the soil, but calculations (http://dbkgroup.org/carbonsequestration/rootsystem.html) suggest that this breeding strategy could have a hugely beneficial effect in stabilizing atmospheric CO2. This sets an important research agenda, and the breeding of plants with improved and deep rooting habits and architectures is a goal well worth pursuing. PMID:21813565

  19. Controlled release for crop and wood protection: Recent progress toward sustainable and safe nanostructured biocidal systems.

    Science.gov (United States)

    Mattos, Bruno D; Tardy, Blaise L; Magalhães, Washington L E; Rojas, Orlando J

    2017-09-28

    We review biocide delivery systems (BDS), which are designed to deter or control harmful organisms that damage agricultural crops, forests and forest products. This is a timely topic, given the growing socio-economical concerns that have motivated major developments in sustainable BDS. Associated designs aim at improving or replacing traditional systems, which often consist of biocides with extreme behavior as far as their solubility in water. This includes those that compromise or pollute soil and water (highly soluble or volatile biocides) or those that present low bioavailability (poorly soluble biocides). Major breakthroughs are sought to mitigate or eliminate consequential environmental and health impacts in agriculture and silviculture. Here, we consider the most important BDS vehicles or carriers, their synthesis, the environmental impact of their constituents and interactions with the active components together with the factors that affect their rates of release such as environmental factors and interaction of BDS with the crops or forest products. We put in perspective the state-of-the-art nanostructured carriers for controlled release, which need to address many of the challenges that exist in the application of BDS. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Sustainable management in crop monocultures: the impact of retaining forest on oil palm yield.

    Science.gov (United States)

    Edwards, Felicity A; Edwards, David P; Sloan, Sean; Hamer, Keith C

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture.

  1. Sustainable management in crop monocultures: the impact of retaining forest on oil palm yield.

    Directory of Open Access Journals (Sweden)

    Felicity A Edwards

    Full Text Available Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture.

  2. Soil Tillage Conservation and its Effect on Soil Properties Bioremediation and Sustained Production of Crops

    Science.gov (United States)

    Rusu, Teodor; Ioana Moraru, Paula; Muresan, Liliana; Andriuca, Valentina; Cojocaru, Olesea

    2017-04-01

    soil features resulted in a positive impact on the water permeability of the soil. Availability of soil moisture during the crop growth resulted in better plant water status. Subsequent release of conserved soil water regulated proper plant water status, soil structure, and lowered soil penetrometer resistance. Productions obtained at STC did not have significant differences for the wheat and maize crop but were higher for soybean. The advantages of minimum soil tillage systems for Romanian pedo-climatic conditions can be used to improve methods in low producing soils with reduced structural stability on sloped fields, as well as measures of water and soil conservation on the whole agroecosystem. Presently, it is necessary to make a change concerning the concept of conservation practices and to consider a new approach regarding the good agricultural practice. We need to focus on an upper level concerning conservation by focusing on soil quality. Carbon management is necessary for a complexity of matters including soil, water management, field productivity, biological fuel and climatic change. In conclusion a Sustainable Agriculture includes a range of complementary agricultural practices: (i) minimum soil tillage (through a system of reduced tillage or no-tillage) to preserve the structure, fauna and soil organic matter; (ii) permanent soil cover (cover crops, residues and mulches) to protect the soil and help to remove and control weeds; (iii) various combinations and rotations of the crops which stimulate the micro-organisms in the soil and controls pests, weeds and plant diseases. Acknowledgements: This paper was performed under the frame of the Partnership in priority domains - PNII, developed with the support of MEN-UEFISCDI, project no. PN-II-PT-PCCA-2013-4-0015: Expert System for Risk Monitoring in Agriculture and Adaptation of Conservative Agricultural Technologies to Climate Change, and International Cooperation Program - Sub-3.1. Bilateral AGROCEO c. no. 21BM

  3. Adaptive livelihood strategies for coping with water scarcity in the drylands of central Tanzania

    Science.gov (United States)

    Liwenga, Emma T.

    In this paper, it is argued that local knowledge for adapting to water scarcity is important for integrated resource management by taking into consideration both the natural and social constraints in a particular setting based on accumulated experience. The paper examines the relevance of local knowledge in sustaining agricultural production in the semiarid areas of central Tanzania. The paper specifically focuses on how water scarcity, as the major limiting factor, is addressed in the study area using local knowledge to sustain livelihoods of its people. The study was conducted in four villages; Mzula, Ilolo, Chanhumba and Ngahelezi, situation in Mvumi Division in Dodoma Region. The study mainly employed qualitative data collection techniques. Participatory methods provided a means of exploring perceptions and gaining deeper insights regarding natural resource utilization in terms of problems and opportunities. The main data sources drawn upon in this study were documentation, group interviews and field observations. Group interviews involved discussions with a group of 6-12 people selected on the basis of gender, age and socio-economic groups. Data analysis entailed structural and content analysis within the adaptive livelihood framework in relation to management of water scarcity using local knowledge. The findings confirm that rainfall is the main limiting factor for agricultural activities in the drylands of Central Tanzania. As such, local communities have developed, through time, indigenous knowledge to cope with such environments utilizing seasonality and diversity of landscapes. Use of this local knowledge is therefore effective in managing water scarcity by ensuring a continuous production of crops throughout the year. This practice implies increased food availability and accessibility through sales of such agricultural products. Local innovations for water management, such as cultivation in sandy rivers, appear to be very important means of accessing

  4. Invited review: Sustainable forage and grain crop production for the US dairy industry.

    Science.gov (United States)

    Martin, N P; Russelle, M P; Powell, J M; Sniffen, C J; Smith, S I; Tricarico, J M; Grant, R J

    2017-12-01

    A resilient US dairy industry will be underpinned by forage and crop production systems that are economically, environmentally, and socially sustainable. Land use for production of perennial and annual forages and grains for dairy cattle must evolve in response to multiple food security and environmental sustainability issues. These include increasing global populations; higher incomes and demand for dairy and other animal products; climate change with associated temperature and moisture changes; necessary reductions in carbon and water footprints; maintenance of soil quality and soil nutrient concerns; and competition for land. Likewise, maintaining producer profitability and utilizing practices accepted by consumers and society generally must also be considered. Predicted changes in climate and water availability will likely challenge current feed and dairy production systems and their national spatial distribution, particularly the western migration of dairy production in the late 20th century. To maintain and stabilize profitability while reducing carbon footprint, particularly reductions in methane emission and enhancements in soil carbon sequestration, dairy production will need to capitalize on genetic and management innovations that enhance forage and grain production and nutritive value. Improved regional and on-farm integration of feed production and manure utilization is needed to reduce environmental nitrogen and phosphorus losses and mitigate greenhouse gas emissions. Resilient and flexible feed production strategies are needed to address each of these challenges and opportunities to ensure profitable feeding of dairy cattle and a sustainable dairy industry. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  5. Reducing N2O and NO emissions while sustaining crop productivity in a Chinese vegetable-cereal double cropping system.

    Science.gov (United States)

    Yao, Zhisheng; Yan, Guangxuan; Zheng, Xunhua; Wang, Rui; Liu, Chunyan; Butterbach-Bahl, Klaus

    2017-12-01

    High nitrogen (N) inputs in Chinese vegetable and cereal productions played key roles in increasing crop yields. However, emissions of the potent greenhouse gas nitrous oxide (N2O) and atmospheric pollutant nitric oxide (NO) increased too. For lowering the environmental costs of crop production, it is essential to optimize N strategies to maintain high crop productivity, while reducing the associated N losses. We performed a 2 year-round field study regarding the effect of different combinations of poultry manure and chemical N fertilizers on crop yields, N use efficiency (NUE) and N2O and NO fluxes from a Welsh onion-winter wheat system in the North China Plain. Annual N2O and NO emissions averaged 1.14-3.82 kg N ha-1 yr-1 (or 5.54-13.06 g N kg-1 N uptake) and 0.57-1.87 kg N ha-1 yr-1 (or 2.78-6.38 g N kg-1 N uptake) over all treatments, respectively. Both N2O and NO emissions increased linearly with increasing total N inputs, and the mean annual direct emission factors (EFd) were 0.39% for N2O and 0.19% for NO. Interestingly, the EFd for chemical N fertilizers (N2O: 0.42-0.48%; NO: 0.07-0.11%) was significantly lower than for manure N (N2O: 1.35%; NO: 0.76%). Besides, a negative power relationship between yield-scaled N2O, NO or N2O + NO emissions and NUE was observed, suggesting that improving NUE in crop production is crucial for increasing crop yields while decreasing nitrogenous gas release. Compared to the current farmers' fertilization rate, alternative practices with reduced chemical N fertilizers increased NUE and decreased annual N2O + NO emissions substantially, while crop yields remained unaffected. As a result, annual yield-scaled N2O + NO emissions were reduced by > 20%. Our study shows that a reduction of current application rates of chemical N fertilizers by 30-50% does not affect crop productivity, while at the same time N2O and NO emissions would be reduced significantly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Using internet technology to inform researchers, policy makers and other stakeholders about sustainable land management in drylands: experience from a large interdisciplinary and international project

    Science.gov (United States)

    Geeson, N.; van den Elsen, E.; Brandt, J.; Quaranta, G.; Salvia, R.

    2012-04-01

    In the last twenty years the advent of the internet has made it much easier to share the results of scientific research with a wider range of audiences. Where once there were only scientific journals and books, it is now possible to deliver messages and dissemination products instantly, by email or other media, to huge circulation lists; thereby also addressing non-scientific audiences. Most scientific projects now host a website, but until recently few have exploited the communication possibilities to maximum advantage. DESIRE has been a large interdisciplinary and international project working to mitigate desertification by selecting and trialling sustainable land management practices with stakeholders. Therefore it has been very important to use a general project website, and a separate Harmonised Information System, to ensure that partners and stakeholders are able to understand the sustainable options and learn from one another. The project website has included many useful features, such as general project and partner information, a schedule of future meetings, and repositories of publicly (and project only) downloadable documents. Lessons have been learned about communication preferences between groups with different interests. For example, an on-line forum seemed a good way of allowing project partners to have their say on various topics. However it was not well-used and it was concluded that partners preferred to communicate just by email, a medium that they access most days for many uses. Whereas the project website focuses on the latest news, the Harmonised Information System has been used to document the history of the project, stage by stage, filling in each section as results became available. Information can be accessed from the perspective of both the research aims and each study site. Interactive tools and drop-down menus are among the features that are used to make the information as attractive and as accessible as possible. Although English is the

  7. Impact of Climate Change on Yields and Components of the Water and Nitrogen Budgets of Dryland Wheat Systems in the US Pacific Northwest

    Science.gov (United States)

    Karimi, T.; Stockle, C.; Nelson, R.

    2016-12-01

    As part of the Regional Approaches to Climate Change (REACCH) project (funded by USDA-NIFA), a regional assessment of historical and future yields and greenhouse gas (GHG) emissions of dryland wheat-based cropping systems in the US Pacific Northwest is being conducted. Two issues of interest in the region are changes in the water footprint and nitrogen use of wheat-based systems as a result of climate change. These two are related to the interaction between crop performance and the partitioning of water and nitrogen budget components. They also inform the tradeoff between crop production and environmental services and the sustainability of wheat systems in the future. Computer simulation-based assessment is being done using the CropSyst cropping systems simulation model and daily weather data downscaled to a 4x4 km grid. Future weather is projected using 12 general circulation models (GCMs) and two representative concentration pathways of future atmospheric CO2 (rcp 4.5 and rcp 8.5). The study region is divided in 3 agro-ecological classes (AECs): grain fallow, grain fallow transition and continuous cropping classes. The following rotations were included by AEC: WW - SF, WW - SW - SF and WW - SW - SP, where WW is winter wheat, SW is spring wheat, SP is spring peas, and SF is summer fallow. A typical conventional tillage (CT) cropping system in each AEC is evaluated as a baseline.

  8. Spatial optimization of cropping pattern for sustainable food and biofuel production with minimal downstream pollution.

    Science.gov (United States)

    Femeena, P V; Sudheer, K P; Cibin, R; Chaubey, I

    2018-02-09

    compromising on food and biofuel production. Optimization runs yielded an optimal cropping pattern with 32% of watershed area in stover removal, 15% in switchgrass and 2% in Miscanthus. The optimal scenario resulted in 14% reduction in nitrate and 22% reduction in total phosphorus from the baseline. This framework can be used as an effective tool to take decisions regarding environmentally and economically sustainable strategies to minimize the nutrient delivery at minimal biomass production cost, while simultaneously meeting food and biofuel production targets. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Sustainable energy crop: An analysis of ethanol production from cassava in Thailand

    Science.gov (United States)

    Ubolsook, Aerwadee

    The first essay formulates a dynamic general equilibrium optimal control model of an energy crop as part of a country's planned resource use over a period of time. The model attempts to allocate consumption, production, and factors of production to achieve the country's sustainable development goal. A Cobb-Douglas specification is used for both utility and production functions in the model. We calibrate the model with Thailand data. The selected model is used to generate the stationary state solution and to simulate the optimal policy function and optimal time paths. Two methods are used: a linear approximation method and the Runke-Kutta reverse shooting method. The model provides numerical results that can be used as information for decision makers and stakeholders to devise an economic plan to achieve sustainable development goals. The second essay studies the effect of international trade and changes in labor supply, land supply, and the price of imported energy on energy crop production for bio fuel and food, as well as impacts on social welfare. We develop a dynamic general equilibrium model to describe two baseline scenarios, a closed economy and an open economy. We find that international trade increases welfare and decreases the energy price. Furthermore, resources are allocated to produce more food under the open economy scenario than the quantities produced under a closed economy assumption. An increase in labor supply and land supply result in an increase in social welfare. An increase in imported energy price leads to a welfare loss, higher energy production, and lower food production. The third essay develops a partial equilibrium econometric model to project the impacts of an increase in ethanol production on the Thai agriculture sector over the next ten years. The model is applied to three scenarios for analyzing the effect of government ethanol production targets. The results from the baseline model and scenario analysis indicate that an expansion

  10. Prunus persica crop management as step toward AMF diversity conservation for the sustainable soil management

    Science.gov (United States)

    Alguacil, M. M.; Torrecillas, E.; Lozano, Z.; Garcia-Orenes, F.; Roldan, A.

    2012-04-01

    We investigated the diversity of arbuscular mycorrhizal fungi (AMF) in roots of Prunus persica under two fertilization treatments (CF: consisted of application of chicken manure (1400 kg.ha-1), urea (140 kg.ha-1), complex fertilizer 12-12-17/2 (280 kg.ha-1), and potassium sulfate (40 kg.ha-1) and IF: consisted of application of urea (140 kg.ha-1), complex fertilizer 12-12-17/2 (400 kg.ha-1) and potassium sulfate (70 kg.ha-1)) combined with integrated pest management (IM) or chemical pest management (CM), in a tropical agroecosystem in the north of Venezuela. Our goal was to ascertain how different fertilizers/pest management can modify the AMF diversity colonizing P. persica roots as an important step towards sustainable soil use and therefore protection of biodiversity. The AM fungal small-subunit (SSU) rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses. Twenty-one different phylotypes were identified, which were grouped in five families: Glomeraceae, Paraglomeraceae, Acaulosporaceae, Gigasporaceae and Archaeosporaceae. Sixteen of these sequence groups belonged to the genus Glomus, two to Paraglomus, one to Acaulospora, one to Scutellospora and one to Archaeospora. A different distribution of the AMF phylotypes as consequence of the difference between treatments was observed. Thus, the AMF communities of tree roots in the (IF+CM) treatment had the lowest diversity (H'=1.78) with the lowest total number of AMF sequence types (9). The trees from both (CF+IM) and (IF+IM) treatments had similar AMF diversity (H'?2.00); while the treatment (CF+CM) yielded the highest number of different AMF sequence types (17) and showed the highest diversity index (H'=2.69). In conclusion, the crop management including combination of organic and inorganic fertilization and chemical pest control appears to be the most suitable strategy with respect to reactivate the AMF diversity in the roots of this crop and thus, the agricultural and environmental

  11. MY SIRR: Minimalist agro-hYdrological model for Sustainable IRRigation management-Soil moisture and crop dynamics

    Science.gov (United States)

    Albano, Raffaele; Manfreda, Salvatore; Celano, Giuseppe

    The paper introduces a minimalist water-driven crop model for sustainable irrigation management using an eco-hydrological approach. Such model, called MY SIRR, uses a relatively small number of parameters and attempts to balance simplicity, accuracy, and robustness. MY SIRR is a quantitative tool to assess water requirements and agricultural production across different climates, soil types, crops, and irrigation strategies. The MY SIRR source code is published under copyleft license. The FOSS approach could lower the financial barriers of smallholders, especially in developing countries, in the utilization of tools for better decision-making on the strategies for short- and long-term water resource management.

  12. Sustainable domestic effluent reuse via Subsurface Drip Irrigation (SDI): alfalfa as a perennial model crop.

    Science.gov (United States)

    Kazumba, Shija; Gillerman, Leonid; DeMalach, Yoel; Oron, Gideon

    2010-01-01

    Scarcity of fresh high-quality water has heightened the importance of wastewater reuse primarily in dry regions together with improving its efficient use by implementing the Subsurface Drip Irrigation (SDI) method. Sustainable effluent reuse combines soil and plant aspects, along with the maintainability of the application system. In this study, field experiments were conducted for two years on the commercial farm of Revivim and Mashabay-Sade farm (RMF) southeast of the City of Beer-Sheva, Israel. The purpose was to examine the response of alfalfa (Medicago sativa) as a perennial model crop to secondary domestic effluent application by means of a SDI system as compared with conventional overhead sprinkler irrigation. Emitters were installed at different depths and spacing. Similar amounts of effluent were applied to all plots during the experimental period. The results indicated that in all SDI treatments, the alfalfa yields were 11% to 25% higher than the ones obtained under sprinkler irrigated plots, besides the one in which the drip laterals were 200 cm apart. The average Water Use Efficiency (WUE) was better in all SDI treatments in comparison with the sprinkler irrigated plots. An economic assessment reveals the dependence of the net profit on the emitters' installation geometry, combined with the return for alfalfa in the market.

  13. Influence of time scale wind speed data on sustainability analysis for irrigating greenhouse crops

    Science.gov (United States)

    Díaz Méndez, Rodrigo; García Llaneza, Joaquín; Peillón, Manuel; Perdigones, Alicia; Sanchez, Raul; Tarquis, Ana M.; Garcia, Jose Luis

    2014-05-01

    Appropriate water supply at crop/farm level, with suitable costs, is becoming more and more important. Energy management is closely related to water supply in this context, being wind energy one of the options to be considered, using wind pumps for irrigation water supply. Therefore, it is important to characterize the wind speed frequency distribution to study the technical feasibility to use its energy for irrigation management purpose. The general objective of this present research is to analyze the impact of time scale recorded wind speed data in the sustainability for tomato (Solanum lycopersicum L.) grown under greenhouse at Cuban conditions using drip irrigation system. For this porpoise, a daily estimation balance between water needs and water availability was used to evaluate the feasibility of the most economic windmill irrigation system. Several factors were included: wind velocity (W, m/s) in function of the time scale averaged, flow supplied by the wind pump as a function of the elevation height (H, m) and daily greenhouse evapotranspiration. Monthly volumes of water required for irrigation (Dr, m3/ha) and in the water tank (Vd, m3), as well as the monthly irrigable area (Ar, ha), were estimated by cumulative deficit water budgeting taking in account these factors. Three-hourly wind velocity (W3h, m/s) data from 1992 till 2008 was available for this study. The original data was grouped in six and twelve hourly data (W6h and W12h respectively) as well as daily data (W24h). For each time scale the daily estimation balance was applied. A comparison of the results points out a need for at least three-hourly data to be used mainly in the months in which mean wind speed are close or below the pumps threshold speed to start-up functioning. References Manuel Esteban Peillon Mesa, Ana Maria Tarquis Alfonso, José Luis García Fernández, and Raúl Sánchez Calvo. The use of wind pumps for irrigating greenhouse tomato crops: a case study in Cuba. Geophysical

  14. Fisheries in the drylands of Sub-Saharan Africa “Fish come with the Rains”

    NARCIS (Netherlands)

    Kolding, Jeppe; Zwieten, van P.A.M.; Marttin, Felix; Poulain, Florence

    2016-01-01

    Dryland areas cover more than half of sub-Saharan Africa and are home to nearly 50 percent of
    its populations, who depend on agriculture (including livestock, crops and fisheries) as their main
    livelihood strategy. Sporadic and irregular rainfall patterns are the most important

  15. Drought preparedness and drought mitigation in the developing world׳s drylands

    Directory of Open Access Journals (Sweden)

    Mahmoud Solh

    2014-06-01

    Drought is a climatic event that cannot be prevented, but interventions and preparedness to drought can help to: (i be better prepared to cope with drought; (ii develop more resilient ecosystems (iii improve resilience to recover from drought; and (iv mitigate the impacts of droughts. Preparedness strategies to drought include: (a geographical shifts of agricultural systems; (b climate-proofing rainfall-based systems; (c making irrigated systems more efficient; (d expanding the intermediate rainfed–irrigated systems. The paper presents successful research results and case studies applying some innovative techniques where clear impact is demonstrated to cope with drought and contribute to food security in dry areas. The CGIAR Consortium Research Program (CRP on “Integrated and Sustainable Agricultural Production Systems for Improved Food Security and Livelihoods in Dry Areas” (in short, “Dryland Systems”, led by ICARDA, was launched in May 2013 with many partners and stakeholders from 40 countries. It addresses farming systems in dry areas, at a global level, involving 80 partner institutions. The Dryland Systems Program aims at coping with drought and water scarcity to enhance food security and reduce poverty in dry areas through an integrated agro-ecosystem approach. It will also deliver science-based solutions that can be adopted in regions that are not yet experiencing extreme shocks, but will be affected in the medium to long-term. The approach entails shifting the thinking away from the traditional focus on a small number of research components to take an integrated approach aiming to address agro-ecosystems challenges. Such an approach involves crops, livestock, rangeland, trees, soils, water and policies. It is one of the first global research for development efforts that brings “systems thinking” to farming innovations leading to improved livelihoods in the developing world. The new technique uses modern innovation platforms to involve all

  16. Sustainability of European winter wheat- and maize-based cropping systems: Economic, environmental and social ex-post assessment of conventional and IPM-based systems

    NARCIS (Netherlands)

    Vasileiadis, V.P.; Dachbrodt-saaydeh, S.; Kudsk, P.; Colnenne-David, C.; Leprince, F.; Holb, I.J.; Kierzek, R.; Furlan, L.; Loddo, D.; Melander, B.; Jørgensen, L.N.; Newton, A.C.; Toque, C.; Dijk, van W.; Lefebvre, M.; Benezit, M.; Sattin, M.

    2017-01-01

    In order to ensure higher sustainability of winter wheat and maize production in Europe, cropping systems featuring different levels of Integrated Pest Management (IPM) need to be tested in the field and validated for their sustainability before being adopted by farmers. However, the sustainability

  17. Arid waste? Reassessing the value of dryland pastoralism

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, Ced; MacGregor, James

    2009-06-15

    East Africa has a huge hidden asset – but risks throwing it away in the quest for economic development. This is its millions-strong herds of dryland livestock managed by pastoralists. New findings show that pastoralism has immense potential value for reducing poverty, managing the environment, promoting sustainable development and building climate resilience. In Kenya alone, the sector is worth an estimated three-quarters of a billion dollars a year. Yet pastoralism is seen by many as archaic, economically inefficient, chaotic and environmentally destructive – perceptions that are not evidence-based, yet drive much regional policy. Inadequate, inaccurate national statistics on pastoralism do little to alter this view. Persistent undervaluation has effectively trapped up to 20 million dryland pastoralists in a cycle of poverty, conflict and environmental degradation. Now, with climate change biting, the time is ripe for a conceptual framework that captures the total economic benefits of this livelihood.

  18. Biofertilizers function as key player in sustainable agriculture by improving soil fertility, plant tolerance and crop productivity

    OpenAIRE

    Bhardwaj, Deepak; Ansari, Mohammad Wahid; Sahoo, Ranjan Kumar; Tuteja, Narendra

    2014-01-01

    Current soil management strategies are mainly dependent on inorganic chemical-based fertilizers, which caused a serious threat to human health and environment. The exploitation of beneficial microbes as a biofertilizer has become paramount importance in agriculture sector for their potential role in food safety and sustainable crop production. The eco-friendly approaches inspire a wide range of application of plant growth promoting rhizobacteria (PGPRs), endo- and ectomycorrhizal fungi, cyano...

  19. Re-spacing African drylands

    DEFF Research Database (Denmark)

    Korf, Benedikt; Hagmann, Tobias; Emmenegger, Rony

    2015-01-01

    This paper traces the re-spacing of pastoral drylands in Africa. We argue that rendering pastoral resources legible and profitable occurs both within and beyond the state. Through a multi-sited case study from Ethiopia's Somali region, we excavate different mechanisms of sedentarization, whereby ...... has failed to consolidate sedentarization through planned interventions. Instead, capital investment by local and transnational Somali merchants has opened up a neoliberal frontier that re-spaces drylands towards increasing sedentarization....... claims to territory, capital investment and new technopolitics through which indigenous (pastoral, Somali) merchants and politicians become complicit with the state's project of territorialization and sedentarization in a self-governing fashion. The irony of this situation is that the (Ethiopian) state...

  20. Mixed crop-livestock farming systems: a sustainable way to produce beef? Commercial farms results, questions and perspectives.

    Science.gov (United States)

    Veysset, P; Lherm, M; Bébin, D; Roulenc, M

    2014-08-01

    Mixed crop-livestock (MC-L) farming has gained broad consensus as an economically and environmentally sustainable farming system. Working on a Charolais-area suckler cattle farms network, we subdivided the 66 farms of a constant sample, for 2 years (2010 and 2011), into four groups: (i) 'specialized conventional livestock farms' (100% grassland-based farms (GF), n=7); (ii) 'integrated conventional crop-livestock farms' (specialized farms that only market animal products but that grow cereal crops on-farm for animal feed, n=31); (iii) 'mixed conventional crop-livestock farms' (farms that sell beef and cereal crops to market, n=21); and (iv) organic farms (n=7). We analyse the differences in structure and in drivers of technical, economic and environmental performances. The figures for all the farms over 2 years (2010 and 2011) were pooled into a single sample for each group. The farms that sell crops alongside beef miss out on potential economies of scale. These farms are bigger than specialized beef farms (with or without on-farm feed crops) and all types of farms show comparable economic performances. The big MC-L farms make heavier and consequently less efficient use of inputs. This use of less efficient inputs also weakens their environmental performances. This subpopulation of suckler cattle farms appears unable to translate a MC-L strategy into economies of scope. Organic farms most efficiently exploit the diversity of herd feed resources, thus positioning organic agriculture as a prototype MC-L system meeting the core principles of agroecology.

  1. Greenhouse gas emissions from cultivation of energy crops may affect the sustainability of biofuels

    DEFF Research Database (Denmark)

    Carter, Mette Sustmann; Hauggaard-Nielsen, Henrik; Heiske, Stefan

    2011-01-01

    Agro‐biofuels are expected to reduce the emissions of greenhouse gases because CO2 emitted during the combustion of the biofuels has recently been taken from the atmosphere by the energy crop. Thus, when replacing fossil fuels with biofuels we reduce the emission of fossil fuel‐derived CO2...... or incorporation of crop residues. In this study we relate measured field emissions of N2O to the reduction in fossil fuel‐derived CO2, which is obtained when energy crops are used for biofuel production. The analysis includes five organically managed crops (viz. maize, rye, rye‐vetch, vetch and grass......‐clover) and three scenarios for conversion of biomass to biofuel. The scenarios are 1) bioethanol production, 2) biogas production and 3) co‐production of bioethanol and biogas, where the energy crops are first used for bioethanol fermentation and subsequently the residues from this process are utilized for biogas...

  2. Greenhouse gas emissions from cultivation of energy crops may affect the sustainability of biofuels

    DEFF Research Database (Denmark)

    Carter, Mette Sustmann; Hauggaard-Nielsen, Henrik; Heiske, Stefan

    2011-01-01

    Agro-biofuels are expected to reduce the emissions of greenhouse gases because CO2 emitted during the combustion of the biofuels has recently been taken from the atmosphere by the energy crop. Thus, when replacing fossil fuels with biofuels we reduce the emission of fossil fuel-derived CO2...... or incorporation of crop residues. In this study we relate measured field emissions of N2O to the reduction in fossil fuel-derived CO2, which is obtained when energy crops are used for biofuel production. The analysis includes five organically managed crops (viz. maize, rye, rye-vetch, vetch and grass......-clover) and three scenarios for conversion of biomass to biofuel. The scenarios are 1) bioethanol production, 2) biogas production and 3) co-production of bioethanol and biogas, where the energy crops are first used for bioethanol fermentation and subsequently the residues from this process are utilized for biogas...

  3. Biofuels as a sustainable energy source: an update of the applications of proteomics in bioenergy crops and algae.

    Science.gov (United States)

    Ndimba, Bongani Kaiser; Ndimba, Roya Janeen; Johnson, T Sudhakar; Waditee-Sirisattha, Rungaroon; Baba, Masato; Sirisattha, Sophon; Shiraiwa, Yoshihiro; Agrawal, Ganesh Kumar; Rakwal, Randeep

    2013-11-20

    Sustainable energy is the need of the 21st century, not because of the numerous environmental and political reasons but because it is necessary to human civilization's energy future. Sustainable energy is loosely grouped into renewable energy, energy conservation, and sustainable transport disciplines. In this review, we deal with the renewable energy aspect focusing on the biomass from bioenergy crops to microalgae to produce biofuels to the utilization of high-throughput omics technologies, in particular proteomics in advancing our understanding and increasing biofuel production. We look at biofuel production by plant- and algal-based sources, and the role proteomics has played therein. This article is part of a Special Issue entitled: Translational Plant Proteomics. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Sustainable conversion of coffee and other crop wastes to biofuels and bioproducts using combined biochemical and thermochemical processes in a multi-stage biorefinery concept

    Science.gov (United States)

    The environmental impact of agricultural waste from processing of food and feed crops is an increasing concern worldwide. Concerted efforts are underway to develop sustainable practices for the disposal of residues from processing of such crops as coffee, sugarcane, or corn. Coffee is crucial to the...

  5. [Effects of different tillage and fertilization modes on the soil physical and chemical properties and crop yield under winter wheat/spring corn rotation on dryland of east Gansu, Northwest China].

    Science.gov (United States)

    Zhang, Jian-jun; Wang, Yong; Fan, Ting-lu; Guo, Tian-wen; Zhao, Gang; Dang, Yi; Wang, Lei; Li, Shang-zhong

    2013-04-01

    Based on the 7-year field experiment on the dryland of east Gansu of Northwest China in 2005-2011, this paper analyzed the variations of soil moisture content, bulk density, and nutrients content at harvest time of winter wheat and of the grain yield under no-tillage and conventional tillage and five fertilization modes, and approached the effects of different tillage and fertilization modes on the soil water storage and conservation, soil fertility, and grain yield under winter wheat/ spring corn rotation. In 2011, the soil moisture content in 0-200 cm layer and the soil bulk density and soil organic matter and available nitrogen and phosphorus contents in 0-20 cm and 20-40 cm layers under different fertilization modes were higher under no-tillage than under conventional tillage. Under the same tillage modes, the contents of soil organic matter and available nitrogen and available phosphorus were higher under the combined application of organic and inorganic fertilizers, as compared with other fertilization modes. The soil available potassium content under different tillage and fertilization modes decreased with years. The grain yield under conventional tillage was higher than that under no-tillage. Under the same tillage modes, the grain yield was the highest under the combined application of organic and inorganic fertilizers, and the lowest under no fertilization. In sum, no-tillage had the superiority than conventional tillage in improving the soil water storage and conservation and soil fertility, and the combined application of organic and inorganic fertilizers under conventional tillage could obtain the best grain yield.

  6. Biofertilizers function as key player in sustainable agriculture by improving soil fertility, plant tolerance and crop productivity

    Science.gov (United States)

    2014-01-01

    Current soil management strategies are mainly dependent on inorganic chemical-based fertilizers, which caused a serious threat to human health and environment. The exploitation of beneficial microbes as a biofertilizer has become paramount importance in agriculture sector for their potential role in food safety and sustainable crop production. The eco-friendly approaches inspire a wide range of application of plant growth promoting rhizobacteria (PGPRs), endo- and ectomycorrhizal fungi, cyanobacteria and many other useful microscopic organisms led to improved nutrient uptake, plant growth and plant tolerance to abiotic and biotic stress. The present review highlighted biofertilizers mediated crops functional traits such as plant growth and productivity, nutrient profile, plant defense and protection with special emphasis to its function to trigger various growth- and defense-related genes in signaling network of cellular pathways to cause cellular response and thereby crop improvement. The knowledge gained from the literature appraised herein will help us to understand the physiological bases of biofertlizers towards sustainable agriculture in reducing problems associated with the use of chemicals fertilizers. PMID:24885352

  7. Biofertilizers function as key player in sustainable agriculture by improving soil fertility, plant tolerance and crop productivity.

    Science.gov (United States)

    Bhardwaj, Deepak; Ansari, Mohammad Wahid; Sahoo, Ranjan Kumar; Tuteja, Narendra

    2014-05-08

    Current soil management strategies are mainly dependent on inorganic chemical-based fertilizers, which caused a serious threat to human health and environment. The exploitation of beneficial microbes as a biofertilizer has become paramount importance in agriculture sector for their potential role in food safety and sustainable crop production. The eco-friendly approaches inspire a wide range of application of plant growth promoting rhizobacteria (PGPRs), endo- and ectomycorrhizal fungi, cyanobacteria and many other useful microscopic organisms led to improved nutrient uptake, plant growth and plant tolerance to abiotic and biotic stress. The present review highlighted biofertilizers mediated crops functional traits such as plant growth and productivity, nutrient profile, plant defense and protection with special emphasis to its function to trigger various growth- and defense-related genes in signaling network of cellular pathways to cause cellular response and thereby crop improvement. The knowledge gained from the literature appraised herein will help us to understand the physiological bases of biofertlizers towards sustainable agriculture in reducing problems associated with the use of chemicals fertilizers.

  8. Promoting Cassava as an Industrial Crop in Ghana: Effects on Soil Fertility and Farming System Sustainability

    OpenAIRE

    Adjei-Nsiah, S.; Owuraku Sakyi-Dawson

    2012-01-01

    Cassava is an important starchy staple crop in Ghana with per capita consumption of 152.9 kg/year. Besides being a staple food crop, cassava can be used as raw material for the production of industrial starch and ethanol. The potential of cassava as an industrial commercial crop has not been exploited to a large extent because of perceptions that cassava depletes soils. Recent finding from field studies in the forest/savannah transitional agroecological zone of Ghana indicates that when integ...

  9. Ecohydrologic Modeling of Hillslope Scale Processes in Dryland Ecosystems

    Science.gov (United States)

    Franz, T. E.; King, E. G.; Lester, A.; Caylor, K. K.; Nordbotten, J.; Celia, M. A.; Rodriguez-Iturbe, I.

    2008-12-01

    Dryland ecosystem processes are governed by complex interactions between the atmosphere, soil, and vegetation that are tightly coupled through the mass balance of water. At the scale of individual hillslopes, mass balance of water is dominated by mechanisms of water redistribution which require spatially explicit representation. Fully-resolved physical models of surface and subsurface processes require numerical routines that are not trivial to solve for the spatial (hillslope) and temporal (many plant generations) scales of ecohydrologic interest. In order to reduce model complexity, we have used small-scale field data to derive empirical surface flux terms for representative patches (bare soil, grass, and tree) in a dryland ecosystem of central Kenya. The model is coupled spatially in the subsurface by an analytical solution to the Boussinesq equation for a sloping slab. The semi-analytical model is spatially explicit driven by pulses of precipitation over a simulation period that represents many plant generations. By examining long-term model dynamics, we are able to investigate the principles of self-organization and optimization (maximization of plant water use and minimization of water lost to the system) of dryland ecosystems for various initial conditions and climatic variability. Precipitation records in central Kenya reveal a shift to more intense infrequent rain events with a constant annual total. The range of stable solutions of initial conditions and climatic variability are important to land management agencies for addressing current grazing practices and future policies. The model is a quantitative tool for addressing perturbations to the system and the overall sustainability of pastoralist activities in dryland ecosystems.

  10. Ants and termites increase crop yield in a dry climate.

    Science.gov (United States)

    Evans, Theodore A; Dawes, Tracy Z; Ward, Philip R; Lo, Nathan

    2011-03-29

    Agricultural intensification has increased crop yields, but at high economic and environmental cost. Harnessing ecosystem services of naturally occurring organisms is a cheaper but under-appreciated approach, because the functional roles of organisms are not linked to crop yields, especially outside the northern temperate zone. Ecosystem services in soil come from earthworms in these cooler and wetter latitudes; what may fulfill their functional role in agriculture in warmer and drier habitats, where they are absent, is unproven. Here we show in a field experiment that ants and termites increase wheat yield by 36% from increased soil water infiltration due to their tunnels and improved soil nitrogen. Our results suggest that ants and termites have similar functional roles to earthworms, and that they may provide valuable ecosystem services in dryland agriculture, which may become increasingly important for agricultural sustainability in arid climates.

  11. Optimizing soil and water management in dryland farming systems in Cabo Verde

    NARCIS (Netherlands)

    Santos Baptista Costa, Dos I.

    2016-01-01

     “Optimizing Soil and Water Management in Dryland Farming Systems in Cabo Verde” Isaurinda Baptista Summary Soil and land degradation poses a great challenge for sustainable development worldwide and, in Cabo Verde, has strongly affected both

  12. Climate Variability and Change in Bihar, India: Challenges and Opportunities for Sustainable Crop Production

    Directory of Open Access Journals (Sweden)

    Kindie Tesfaye

    2017-11-01

    Full Text Available Climate change and associated uncertainties have serious direct and indirect consequences for crop production and food security in agriculture-based developing regions. Long-term climate data analysis can identify climate risks and anticipate new ones for planning appropriate adaptation and mitigation options. The aim of this study was to identify near-term (2030 and mid-term (2050 climate risks and/or opportunities in the state of Bihar, one of India’s most populous and poorest states, using weather data for 30 years (1980–2009 as a baseline. Rainfall, maximum and minimum temperatures, and evapotranspiration will all increase in the near- and mid-term periods relative to the baseline period, with the magnitude of the change varying with time, season and location within the state. Bihar’s major climate risks for crop production will be heat stress due to increasing minimum temperatures in the rabi (winter season and high minimum and maximum temperatures in the spring season; and intense rainfall and longer dry spells in the kharif (monsoon season. The increase in annual and seasonal rainfall amounts, and extended crop growing period in the kharif season generally provide opportunities; but increasing temperature across the state will have considerable negative consequences on (staple crops by affecting crop phenology, physiology and plant-water relations. The study helps develop site-specific adaptation and mitigation options that minimize the negative effects of climate change while maximizing the opportunities.

  13. Smart investments in sustainable food production: revisiting mixed crop-livestock systems.

    Science.gov (United States)

    Herrero, M; Thornton, P K; Notenbaert, A M; Wood, S; Msangi, S; Freeman, H A; Bossio, D; Dixon, J; Peters, M; van de Steeg, J; Lynam, J; Parthasarathy Rao, P; Macmillan, S; Gerard, B; McDermott, J; Seré, C; Rosegrant, M

    2010-02-12

    Farmers in mixed crop-livestock systems produce about half of the world's food. In small holdings around the world, livestock are reared mostly on grass, browse, and nonfood biomass from maize, millet, rice, and sorghum crops and in their turn supply manure and traction for future crops. Animals act as insurance against hard times and supply farmers with a source of regular income from sales of milk, eggs, and other products. Thus, faced with population growth and climate change, small-holder farmers should be the first target for policies to intensify production by carefully managed inputs of fertilizer, water, and feed to minimize waste and environmental impact, supported by improved access to markets, new varieties, and technologies.

  14. Sustainability of maize-based cropping systems in rural areas of ...

    African Journals Online (AJOL)

    The residual soil fertility benefits of the preceding legumes to the following maize crop were demonstrated in the study. Incorporating stover of Bambara nut, cowpea, groundnut dry bean and soyabean gave higher maize yields compared to plots where the stover was removed. Total maize dry matter yield increases of 1.30 ...

  15. Nematode Interactions in Nature: Models for Sustainable Control of Nematode Pests of Crop Plants?

    NARCIS (Netherlands)

    Putten, van der W.H.; Cook, R.; Costa, S.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; Peña, de la E.; Piskiewicz, A.M.; Raeymaekers, A.D.W.; Rodriquez-Echeverria, S.; Wurff, van der A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  16. Nematode interactions in nature: models for sustainable control of nematode pests of crop plants?

    NARCIS (Netherlands)

    Van der Putten, W.H.; Cook, R.; Costa, S.R.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; De la Peña, E.; Piskiewicz, A.; Raeymaekers, A.; Rodríguez-Echeverría, S.; Van der Wurff, A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  17. Sustainable agriculture for a dynamic world: Forage-Crop-Livestock systems research

    Science.gov (United States)

    Research at the USDA-Agricultural Research Service, Grazinglands Research Laboratory is focused on development and delivery of improved technologies, strategies, and planning tools for integrated crop-forage-livestock systems under variable climate, energy, and market conditions. The GRL research p...

  18. Fibre crops as sustainable source of biobased material for industrial products in Europe and China

    NARCIS (Netherlands)

    Dam, van J.E.G.

    2014-01-01

    Bast fibre industries have a long standing tradition, both in China and Europe. In the past decades significant changes have taken place in the sector and strong competition is faced on the market with manmade fibres on the one hand, and on the other hand at the farm level with other crops that

  19. Sustainable introduction of GM crops into european agriculture: a summary report of the FP6 SIGMEA research project*

    Directory of Open Access Journals (Sweden)

    Messéan Antoine

    2009-01-01

    Full Text Available In 2003, the European Commission established the principle of coexistence which refers to “the ability of farmers to make a practical choice between conventional, organic and GM-crop production, in compliance with the legal obligations for labelling and/or purity standards” and laid down guidelines defining the context of this coexistence1. In order to determine what is needed for the sustainable introduction of GM crops in Europe, the cross-disciplinary SIGMEA Research Project was set up to create a science-based framework to inform decision-makers. SIGMEA has (i collated and analysed European data on gene flow and the environmental impacts of the major crop species which are likely to be transgenic in the future (maize, rapeseed, sugar beet, rice, and wheat, (ii designed predictive models of gene flow at the landscape level, (iii analysed the technical feasibility and economic impacts of coexistence in the principal farming regions of Europe, (iv developed novel GMO detection methods, (v addressed legal issues related to coexistence, and (vi proposed public and farm scale decisionmaking tools, as well as guidelines regarding management and governance. This publishable version of the final activity report of the FP6 SIGMEA research project, covers the fourteen major issues under investigation.

  20. A transgenic approach to enhance phosphorus use efficiency in crops as part of a comprehensive strategy for sustainable agriculture.

    Science.gov (United States)

    Gaxiola, Roberto A; Edwards, Mark; Elser, James J

    2011-08-01

    Concerns about phosphorus (P) sustainability in agriculture arise not only from the potential of P scarcity but also from the known effects of agricultural P use beyond the field, i.e., eutrophication leading to dead zones in lakes, rivers and coastal oceans due to runoffs from fertilized fields. Plants possess a large number of adaptive responses to P(i) (orthophosphate) limitation that provide potential raw materials to enhance P(i) scavenging abilities of crop plants. Understanding and engineering these adaptive responses to increase the efficiency of crop capture of natural and fertilizer P(i) in soils is one way to optimize P(i) use efficiency (PUE) and, together with other approaches, help to meet the P sustainability challenge in agriculture. Research on the molecular and physiological basis of P(i) uptake is facilitating the generation of plants with enhanced P(i) use efficiency by genetic engineering. Here we describe work done in this direction with emphasis on the up-regulation of plant proton-translocating pyrophosphatases (H(+)-PPases). Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. THE NUTRIENTS BALANCE OF CROP ROTATION AS AN INDICATOR OF SUSTAINABLE FARMING ON ARABLE LAND

    Directory of Open Access Journals (Sweden)

    Eva Hanáčková

    2009-03-01

    Full Text Available The nutrient balance of five crop rotation systems under conventional and minimal tillage with interaction of different fertilization treatments was investigated at the experimental station of Slovak Agricultural University in Nitra Dolná Malanta, during 2004-2005. The five-field crop rotation of maize (Zea mays L. - winter wheat (Triticum aestivum L. - spring barley (Hordeum vulgare L. underseeded with red clover - red clover (Trifolium pratense - common pea (Pisum sativum L. and mustard as catch crop was used. The most serious deficit of nitrogen (- 62.2 kg.ha-1.yr-1, phosphorus (- 24.0 kg.ha-1.yr-1 and potassium (- 89.2 kg.ha-1.yr-1 was on control treatments. Deficit of nitrogen was also found-out in treatments with mineral fertilizers application. However higher deficit of nitrogen (- 25.4 kg.ha-1.yr- 1 was registered under conventional tillage. In treatment fertilized with mineral fertilizers together with by - product of pre - crop incorporation into soil (PZ, small balance surplus of nitrogen (8 kg.ha-1.yr-1 - B1, 11.5 kg. ha-1.yr-1 - B2, respectively was calculated. The positive balance of phosphorus achieved in treatments with into soil incorporated by - products of pre - crops (in both systems of soil cultivation amounting value of 3.9 kg.ha-1.yr-1 can contribute to good supply of phosphorous in soil. The negative balance of potassium fluctuating from - 89.2 kg.ha-1.yr-1 (control treatment to - 22 kg.ha-1.yr-1 (PZ is acceptable owing to high content of available potassium in soil of experimental stand.

  2. Sustainable crop intensification through surface water irrigation in Bangladesh? A geospatial assessment of landscape-scale production potential.

    Science.gov (United States)

    Krupnik, Timothy J; Schulthess, Urs; Ahmed, Zia Uddin; McDonald, Andrew J

    2017-01-01

    Changing dietary preferences and population growth in South Asia have resulted in increasing demand for wheat and maize, along side high and sustained demand for rice. In the highly productive northwestern Indo-Gangetic Plains of South Asia, farmers utilize groundwater irrigation to assure that at least two of these crops are sequenced on the same field within the same year. Such double cropping has had a significant and positive influence on regional agricultural productivity. But in the risk-prone and food insecure lower Eastern Indo-Gangetic Plains (EIGP), cropping is less intensive. During the dryer winter months, arable land is frequently fallowed or devoted to lower yielding rainfed legumes. Seeing opportunity to boost cereals production, particularly for rice, donors and land use policy makers have consequently reprioritized agricultural development investments in this impoverished region. Tapping groundwater for irrigation and intensified double cropping, however, is unlikely to be economically viable or environmentally sound in the EIGP. Constraints include saline shallow water tables and the prohibitively high installation and energetic extraction costs from deeper freshwater aquifers. The network of largely underutilized rivers and natural canals in the EIGP could conversely be tapped to provide less energetically and economically costly surface water irrigation (SWI). This approach is now championed by the Government of Bangladesh, which has requested USD 500 million from donors to implement land and water use policies to facilitate SWI and double cropping. Precise geospatial assessment of where freshwater flows are most prominent, or where viable fallow or low production intensity cropland is most common, however remains lacking. In response, we used remotely sensed data to identify agricultural land, detect the temporal availability of freshwater in rivers and canals, and assess crop production intensity over a three-year study period in a 33,750 km2

  3. Dryland maize yields and water use efficiency in response to tillage and nutrient management practices in China

    NARCIS (Netherlands)

    Wang, X.B.; Dai, K.; Zhao, Q.; Cai, D.X.; Hoogmoed, W.B.; Oenema, O.

    2009-01-01

    Rainfed crop production in northern China is constrained by low and variable rainfall. This study explored the effects of tillage and nutrient management practices on maize (Zea mays L.) yield and water use efficiency (WUE), at Shouyang Dryland Farming Experimental Station in northern China during

  4. Beyond desertification: New paradigms for dryland landscapes

    Science.gov (United States)

    The dryland desertification paradigm focuses on losses of ecosystem services accompanying transitions from grasslands to systems dominated by bare ground or woody plants unpalatable for domestic livestock. However, recent studies reveal complex transitions across a range of environmental conditions ...

  5. Sustaining global agriculture through rapid detection and deployment of genetic resistance to deadly crop diseases.

    Science.gov (United States)

    Periyannan, Sambasivam

    2017-12-04

    Contents I. II. III. IV. V. VI. VII. VIII. References SUMMARY: Genetically encoded resistance is a major component of crop disease management. Historically, gene loci conferring resistance to pathogens have been identified through classical genetic methods. In recent years, accelerated gene cloning strategies have become available through advances in sequencing, gene capture and strategies for reducing genome complexity. Here, I describe these approaches with key emphasis on the isolation of resistance genes to the cereal crop diseases that are an ongoing threat to global food security. Rapid gene isolation enables their efficient deployment through marker-assisted selection and transgenic technology. Together with innovations in genome editing and progress in pathogen virulence studies, this creates further opportunities to engineer long-lasting resistance. These approaches will speed progress towards a future of farming using fewer pesticides. © 2017 Commonwealth of Australia. New Phytologist © 2017 New Phytologist Trust.

  6. Crop and irrigation management strategies for saline-sodic soils and waters aimed at environmentally sustainable agriculture.

    Science.gov (United States)

    Qadir, M; Oster, J D

    2004-05-05

    Irrigation has long played a key role in feeding the expanding world population and is expected to play a still greater role in the future. As supplies of good-quality irrigation water are expected to decrease in several regions due to increased municipal-industrial-agricultural competition, available freshwater supplies need to be used more efficiently. In addition, reliance on the use and reuse of saline and/or sodic drainage waters, generated by irrigated agriculture, seems inevitable for irrigation. The same applies to salt-affected soils, which occupy more than 20% of the irrigated lands, and warrant attention for efficient, inexpensive and environmentally acceptable management. Technologically and from a management perspective, a couple of strategies have shown the potential to improve crop production under irrigated agriculture while minimizing the adverse environmental impacts. The first strategy, vegetative bioremediation--a plant-assisted reclamation approach--relies on growing appropriate plant species that can tolerate ambient soil salinity and sodicity levels during reclamation of salt-affected soils. A variety of plant species of agricultural significance have been found to be effective in sustainable reclamation of calcareous and moderately sodic and saline-sodic soils. The second strategy fosters dedicating soils to crop production systems where saline and/or sodic waters predominate and their disposal options are limited. Production systems based on salt-tolerant plant species using drainage waters may be sustainable with the potential of transforming such waters from an environmental burden into an economic asset. Such a strategy would encourage the disposal of drainage waters within the irrigated regions where they are generated rather than exporting these waters to other regions via discharge into main irrigation canals, local streams, or rivers. Being economically and environmentally sustainable, these strategies could be the key to future

  7. The extent of forest in dryland biomes

    Science.gov (United States)

    Jean-Francois Bastin; Nora Berrahmouni; Alan Grainger; Danae Maniatis; Danilo Mollicone; Rebecca Moore; Chiara Patriarca; Nicolas Picard; Ben Sparrow; Elena Maria Abraham; Kamel Aloui; Ayhan Atesoglu; Fabio Attore; Caglar Bassullu; Adia Bey; Monica Garzuglia; Luis G. GarcÌa-Montero; Nikee Groot; Greg Guerin; Lars Laestadius; Andrew J. Lowe; Bako Mamane; Giulio Marchi; Paul Patterson; Marcelo Rezende; Stefano Ricci; Ignacio Salcedo; Alfonso Sanchez-Paus Diaz; Fred Stolle; Venera Surappaeva; Rene Castro

    2017-01-01

    Dryland biomes cover two-fifths of Earth’s land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high...

  8. Dryland climate change: Recent progress and challenges

    Science.gov (United States)

    Huang, J.; Li, Y.; Fu, C.; Chen, F.; Fu, Q.; Dai, A.; Shinoda, M.; Ma, Z.; Guo, W.; Li, Z.; Zhang, L.; Liu, Y.; Yu, H.; He, Y.; Xie, Y.; Guan, X.; Ji, M.; Lin, L.; Wang, S.; Yan, H.; Wang, G.

    2017-09-01

    Drylands are home to more than 38% of the world's population and are one of the most sensitive areas to climate change and human activities. This review describes recent progress in dryland climate change research. Recent findings indicate that the long-term trend of the aridity index (AI) is mainly attributable to increased greenhouse gas emissions, while anthropogenic aerosols exert small effects but alter its attributions. Atmosphere-land interactions determine the intensity of regional response. The largest warming during the last 100 years was observed over drylands and accounted for more than half of the continental warming. The global pattern and interdecadal variability of aridity changes are modulated by oceanic oscillations. The different phases of those oceanic oscillations induce significant changes in land-sea and north-south thermal contrasts, which affect the intensity of the westerlies and planetary waves and the blocking frequency, thereby altering global changes in temperature and precipitation. During 1948-2008, the drylands in the Americas became wetter due to enhanced westerlies, whereas the drylands in the Eastern Hemisphere became drier because of the weakened East Asian summer monsoon. Drylands as defined by the AI have expanded over the last 60 years and are projected to expand in the 21st century. The largest expansion of drylands has occurred in semiarid regions since the early 1960s. Dryland expansion will lead to reduced carbon sequestration and enhanced regional warming. The increasing aridity, enhanced warming, and rapidly growing population will exacerbate the risk of land degradation and desertification in the near future in developing countries.

  9. A New Dryland Development Paradigm Grounded in Empirical Analysis of Dryland Systems Science

    NARCIS (Netherlands)

    Stringer, Lindsay C.; Reed, Mark S.; Fleskens, Luuk; Thomas, Richard J.; Le, Quang Bao; Lala-Pritchard, Tana

    2017-01-01

    Global drylands face a host of urgent human and environmental challenges with far-reaching impacts. Improving smallholder agriculture remains a key development pathway to tackle these challenges. The dryland development paradigm (DDP), introduced in 2007, presented a highly influential framework

  10. Do Smallholder, Mixed Crop-Livestock Livelihoods Encourage Sustainable Agricultural Practices? A Meta-Analysis

    NARCIS (Netherlands)

    Rudel, Thomas K.; Kwon, Oh-Jung; Paul, B.K.

    2016-01-01

    As calls for bolstering ecosystem services from croplands have grown more insistent during the past two decades, the search for ways to foster these agriculture-sustaining services has become more urgent. In this context we examine by means of a meta-analysis the argument, proposed by Robert McC.

  11. Sustainability aspects of biobased products : comparison of different crops and products from the vegetable oil platform

    NARCIS (Netherlands)

    Meesters, K.P.H.; Corré, W.J.; Conijn, J.G.; Patel, M.K.; Bos, H.L.

    2012-01-01

    This study focusses on the production of vegetable oil based products. A limited number of aspacts of the sustainability of the full chain (from agriculture to product at the factory gate) was evaluated. Three different vegetable oils were taken into account: palm oil, soy oil and rapeseed oil. Also

  12. Dedicated Industrial Oilseed Crops as Metabolic Engineering Platforms for Sustainable Industrial Feedstock Production

    NARCIS (Netherlands)

    Zhu, Li Hua; Krens, Frans; Smith, Mark A.; Li, Xueyuan; Qi, Weicong; Loo, Van Eibertus N.; Iven, Tim; Feussner, Ivo; Nazarenus, Tara J.; Huai, Dongxin; Taylor, David C.; Zhou, Xue Rong; Green, Allan G.; Shockey, Jay; Klasson, Thomas K.; Mullen, Robert T.; Huang, Bangquan; Dyer, John M.; Cahoon, Edgar B.

    2016-01-01

    Feedstocks for industrial applications ranging from polymers to lubricants are largely derived from petroleum, a non-renewable resource. Vegetable oils with fatty acid structures and storage forms tailored for specific industrial uses offer renewable and potentially sustainable sources of

  13. Soil biota enhance agricultural sustainability by improving crop yield, nutrient uptake and reducing nitrogen leaching losses

    NARCIS (Netherlands)

    Bender, S.F.; van der Heijden, M.G.A.

    2015-01-01

    Efficient resource use is a key factor for sustainable production and a necessity for meeting future global food demands. However, the factors that control resource use efficiency in agro-ecosystems are only partly understood. We investigated the influence of soil biota on nutrient leaching,

  14. Fertiliser use: one of the keys to attaining and sustaining higher crop ...

    African Journals Online (AJOL)

    exhausted. The decline in native fertility is worsened by other factors such as soil erosion and deforestation on top of low input continuous cultivation that characterises much of subsistence fanning in Sub-Saharan Africa . Improving the productivity of such soils to a nigh sustainable level in light of increasing population ...

  15. Food security as a function of Sustainable Intensification of Crop Production

    Directory of Open Access Journals (Sweden)

    Theodor Friedrich

    2016-05-01

    Full Text Available The challenge to eradicate hunger and establish food security across all its four pillars (availability, accessibility, health and safety, and continuity is ongoing. The actual situation in global food production leads most of the attention to improving accessibility and safety of food, particularly to vulnerable populations. However, in view of the growth in demand, which includes changes in preferences for example towards food of animal origin, availability and continuity will play larger roles in future. Food production needs to increase over the coming decades at challenging rates, while facing problems of degradation and reduced availability of natural resources for production such as soil and water, and facing increasing challenges from climate change. The actual trends in yield development suggest that a simple gradual improvement of production within the existing concepts will not provide a sustainable or feasible solution, and that more fundamental changes in the agricultural production paradigm are required to face these future challenges. The Sustainable Intensification represents such a change in paradigm in which high production levels are combined with sustainability. The concept of sustainable intensification, the rationale for it and its functional elements, represented by Conservation Agriculture, are presented in this paper.

  16. Expansion of World Drylands Under Global Warming

    Science.gov (United States)

    Feng, S.; Fu, Q.; Hu, Q. S.

    2012-12-01

    The world drylands including both semi-arid and arid regions comprise of one-third of the global land surfaces, which support 14% of the world's inhabitants and a significant share of the world agriculture. Because of meager annual precipitation and large potential evaporative water loss, the ecosystems over drylands are fragile and sensitive to the global change. By analyzing the observations during 1948-2008 and 20 fully coupled climate model simulations from CMIP5 for the period 1900-2100, this study evaluated the changes of the world drylands that are defined with a modified form of the Thornthwaite's moisture index. The results based on observational data showed that the world drylands are steadily expanding during the past 60 years. The areas occupied by drylands in 1994-2008 is about 2.0×10^6km^2 (or 4%) larger than the average during the 1950s. Such an expansion is also a robust feature in the simulations of the 20 global climate models, though the rate is much smaller in the models. A stronger expanding rate is projected during the first half of this century than the simulations in the last century, followed by accelerating expansion after 2050s under the high greenhouse gas emission scenario (RCP8.5). By the end of this century, the world drylands are projected to be over 58×10^6km^2 (or 11% increase compared to the 1961-1990 climatology). The projected expansion of drylands, however, is not homogeneous over the world drylands, with major expansion of arid regions over the southwest North America, the northern fringe of Africa, southern Africa and Australia. Major expansions of semi-arid regions are projected over the north side of the Mediterranean, southern Africa, North and South America. The global warming is the main factor causing the increase of potential evapotranspiration estimated by Penman-Monteith algorithm, which in turn dominants the expansion of drylands. The widening of Hadley cell, which has impact on both temperature and precipitation

  17. Is current irrigation sustainable in the United States? An integrated assessment of climate change impact on water resources and irrigated crop yields.

    Science.gov (United States)

    Blanc, Elodie; Caron, Justin; Fant, Charles; Monier, Erwan

    2017-08-01

    While climate change impacts on crop yields has been extensively studied, estimating the impact of water shortages on irrigated crop yields is challenging because the water resources management system is complex. To investigate this issue, we integrate a crop yield reduction module and a water resources model into the MIT Integrated Global System Modeling framework, an integrated assessment model linking a global economic model to an Earth system model. We assess the effects of climate and socioeconomic changes on water availability for irrigation in the U.S. as well as subsequent impacts on crop yields by 2050, while accounting for climate change projection uncertainty. We find that climate and socioeconomic changes will increase water shortages and strongly reduce irrigated yields for specific crops (i.e., cotton and forage), or in specific regions (i.e., the Southwest) where irrigation is not sustainable. Crop modeling studies that do not represent changes in irrigation availability can thus be misleading. Yet, since the most water-stressed basins represent a relatively small share of U.S. irrigated areas, the overall reduction in U.S. crop yields is small. The response of crop yields to climate change and water stress also suggests that some level of adaptation will be feasible, like relocating croplands to regions with sustainable irrigation or switching to less irrigation intensive crops. Finally, additional simulations show that greenhouse gas (GHG) mitigation can alleviate the effect of water stress on irrigated crop yields, enough to offset the reduced CO 2 fertilization effect compared to an unconstrained GHG emission scenario.

  18. Transport and homeostasis of potassium and phosphate: limiting factors for sustainable crop production.

    Science.gov (United States)

    Luan, Mingda; Tang, Ren-Jie; Tang, Yumei; Tian, Wang; Hou, Congong; Zhao, Fugeng; Lan, Wenzhi; Luan, Sheng

    2017-06-01

    Potassium (K) and phosphate (Pi) are both macronutrients essential for plant growth and crop production, but the unrenewable resources of phosphorus rock and potash have become limiting factors for food security. One critical measure to help solve this problem is to improve nutrient use efficiency (NUE) in plants by understanding and engineering genetic networks for ion uptake, translocation, and storage. Plants have evolved multiple systems to adapt to various nutrient conditions for growth and production. Within the NUE networks, transport proteins and their regulators are the primary players for maintaining nutrient homeostasis and could be utilized to engineer high NUE traits in crop plants. A large number of publications have detailed K+ and Pi transport proteins in plants over the past three decades. Meanwhile, the discovery and validation of their regulatory mechanisms are fast-track topics for research. Here, we provide an overview of K+ and Pi transport proteins and their regulatory mechanisms, which participate in the uptake, translocation, storage, and recycling of these nutrients in plants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. Evaluating the environmental sustainability of energy crops: A life cycle assessment of Spanish rapeseed and Argentinean soybean cultivation

    Directory of Open Access Journals (Sweden)

    Francisca Fernández-Tirado

    2017-04-01

    Full Text Available Rapeseed oil is expected to be increasingly used in Spain as raw material to produce biodiesel to the detriment of extra-EU imports of biodiesel mainly based on soybean oil from Argentina. Therefore, the environmental impacts produced throughout the life cycle of energy crops used to produce biodiesel which is consumed in Spain could be radically affected. In this context, the environmental impacts of rapeseed cultivation in Spain and soybean cultivation in Argentina, were compared under certain growing conditions using Life Cycle Assessment (LCA. Two methods of calculation for Life Cycle Impact Assessment (LCIA and two functional units (FUs were used to test potential biases. The results showed that the cultivation of soybean in Argentina had, in general, fewer environmental impacts than rapeseed cultivation in Spain when the FU was the area of cultivation, but these findings are inverted when the analysis is conducted according to the energy content of the biodiesel obtained from these crops. Soybean in fact has very low oil content, meaning that larger areas of land are required to obtain the same amount of biodiesel and that consequently it has a higher environmental impact by energy content. Fertilization was, in general, the process that generated the greatest environmental burdens, and is an area in which improvement is necessary in order to increase sustainability, particularly with regard to Spanish rapeseed.

  20. Evaluating the environmental sustainability of energy crops: A life cycle assessment of Spanish rapeseed and Argentinean soybean cultivation

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Tirado, F.; Parra-López, C.; Romero-Gámez, M.

    2017-09-01

    Rapeseed oil is expected to be increasingly used in Spain as raw material to produce biodiesel to the detriment of extra-EU imports of biodiesel mainly based on soybean oil from Argentina. Therefore, the environmental impacts produced throughout the life cycle of energy crops used to produce biodiesel which is consumed in Spain could be radically affected. In this context, the environmental impacts of rapeseed cultivation in Spain and soybean cultivation in Argentina, were compared under certain growing conditions using Life Cycle Assessment (LCA). Two methods of calculation for Life Cycle Impact Assessment (LCIA) and two functional units (FUs) were used to test potential biases. The results showed that the cultivation of soybean in Argentina had, in general, fewer environmental impacts than rapeseed cultivation in Spain when the FU was the area of cultivation, but these findings are inverted when the analysis is conducted according to the energy content of the biodiesel obtained from these crops. Soybean in fact has very low oil content, meaning that larger areas of land are required to obtain the same amount of biodiesel and that consequently it has a higher environmental impact by energy content. Fertilization was, in general, the process that generated the greatest environmental burdens, and is an area in which improvement is necessary in order to increase sustainability, particularly with regard to Spanish rapeseed.

  1. Agricultural sustainable intensification improved nitrogen use efficiency and maintained high crop yield during 1980-2014 in Northern China.

    Science.gov (United States)

    Zhang, Xin; Bol, Roland; Rahn, Clive; Xiao, Guangmin; Meng, Fanqiao; Wu, Wenliang

    2017-10-15

    Global population increase will require rapid increase of food production from existing agricultural land by 2050, which will inevitably mean the increase of agricultural productivity. Due to agricultural sustainable intensification since the 1990s, crop production in Huantai County of northern China has risen to 15tha-1yr-1 for the annual wheat-maize rotation system. We examined the temporal dynamics of nitrogen (N) budget, N losses, and N use efficiency (NUE) during the 35years (1980-2014) in Huantai. The results revealed that atmospheric N deposition increased 220% while reactive N losses decreased by 21.5% from 1980s to 2010s. During 1980-2002, annual N partial factor productivity (PFPN), apparent NUE and N recovery efficiency (REN) increased from 20.3 to 40.7kggrainkg-1Nfert, from 36.5% to 71.0%, and from 32.4% to 57.7%, respectively; meanwhile, reactive N losses intensity, land use intensity and N use intensity decreased by 69.8%, 53.4%, 50.0%, respectively, but without further significant changes after 2002. Overall increases in NUE and decreases in N losses were largely due to the introduction of optimized fertilization practice, mechanization and increased incorporation of crop straw in Huantai. Straw incorporation was also significant in soil N stock accrual and fertility improvement. By 2030, northern China may reach the lowest end of PFPN values in developed countries (>45kggrainkg-1Nfert). These agricultural sustainable intensification practices will be critical in maintaining high grain yields and associated decreases in environmental pollution, although water use efficiency in the region still needs to be improved. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Carabid assemblages (Coleoptera: Carabidae) in a rotation of three different crops in southern Alberta, Canada: a comparison of sustainable and conventional farming.

    Science.gov (United States)

    Bourassa, S; Cárcamo, H A; Larney, F J; Spence, J R

    2008-10-01

    Carabids were sampled in 2000 (pretreatment year) and 2003-2005 in experimental plots in southern Alberta, Canada, after a rotation of beans, wheat, and potato under sustainable and conventional farming practices. Each phase of the rotation was present in every year. Crop type had a stronger effect than sustainable treatment on carabid-expected species richness, diversity, and species composition. However, carabid activity density was consistently higher in plots under sustainable treatments than those maintained conventionally. Potato plots, which were sprayed with insecticide for pest control, showed a significantly lower carabid activity density than the other crops. These results support other studies showing the beneficial effect of sustainable farming on activity density of carabid beetles.

  3. Performance and sustainability of short-rotation energy crops treated with municipal and industrial residues

    OpenAIRE

    Dimitriou, Ioannis

    2005-01-01

    The sustainability of short-rotation willow coppice (SRWC) as a multifunctional system for phytoremediation—the use of plants for treatment of contaminated air, soil or water—and for producing energy biomass, was studied. SRWC is grown commercially in Sweden to produce energy biomass, nutrient-rich residues being applied as cost-efficient fertiliser to increase production. The principal residues used are municipal wastewater, landfill leachate, industrial wastewater (e.g. log-yard runoff), se...

  4. Optimal Cropping Pattern Based on Multiple Economic, Regional, and Agricultural Sustainability Criteria in Sari, Iran: Application of a Consolidated Model of AHP and Linear Programming

    Directory of Open Access Journals (Sweden)

    E. Fallahi

    2016-10-01

    Full Text Available Introduction: Determining a suitable cropping pattern is an important task for planners and requires an exact and realistic decision-making process based on several goals and criteria corresponding to secure the interest of agricultural beneficiaries in long-term. Accordingly, this study reviews the current pattern operated by farmers in Sari, Iran, and intends to provide a cropping pattern that considers the multifold regional and agricultural sustainability criteria along with economic considerations. Materials and Methods: In order to achieve the study goals, a consolidated model of AHP and Linear Programming was applied. For this purpose, we constructed a three-level AHP, including a goal (determining the weight of each crop, seven criteria, and seven alternatives. Profitability, compatibility with regional and geographical conditions, water consumption, environmental effects of cropping, job creation opportunities, skill and proficiency required for producing a crop, and risk taken to cultivate a crop were considered as the criteria in the model. Seven alternative crops including rice, wheat, rapeseed, barley, soybean, clover, and vegetables were considered too. The next step is determining the weight of each criterion with regard to the goal and the weight of each alternative with regard to each criteria. By multiplying these weights, final weights for various crops were obtained from the model. Derived weights for each crop were then applied as objective function coefficients in the Linear Programming model and the model was solved subject to the constraints. Results and Discussion: Optimal cropping pattern determined based on the consolidated model of AHP and Linear Programming and the results compared to a scenario that only looks forward to maximizing the economic interests. Due to the low profitability of rapeseed and barley, these crops eliminated from the pattern in the profit-maximizing scenario. According to the results, the

  5. Dryland degradation: Measurement and effects on ecosystems

    Science.gov (United States)

    Noojipady, P.; Prince, S. D.; Rishmawi, K.

    2012-12-01

    Land degradation is frequently described as a global crisis, affecting large areas globally and large numbers of people. Nevertheless, the location and severity of degradation globally with a resolution relevant to human activities is unknown. Beyond the direct stress of degradation on human livelihoods, there are important effects on the physical and biological environment. Examples include loss of potential primary production, changes in the surface water and energy balances, erosion, sediment transport and lofting of dust aerosols. Globally , degradation is mainly associated with drylands, such as the US dustbowl of the 1930s and, supposedly, ongoing loss of crop and livestock production in desert margins on all continents. The alarm over loss of land to deserts, particularly early 1980s in the African Sahel, led to the adoption of the term "desertification". Such degradation is said to have two components; a physical environment that reduces productivity; and human land use that exceeds the resilience of the land. Ecological theory suggests that land can exist in multiple stable states with transitions between them. Some experimental evidence suggests that one such state is degradation from which there can be no recovery. Clearly the occurrence of such stable degradation, where land is unable to recover when the physical conditions such as rainfall and human land use are ameliorated, is of theoretical and practical importance. The aim of this work is to contribute to the resolution of two issues: (i) are there significant areas in which land has been degraded by human actions and, (ii), have any of these areas entered a stable degraded state? Detection of the human component necessarily requires control of the physical component of degradation. We have developed a technique to detect areas that are at their potential production and to assess other areas relative to these. Satellite measurements of vegetation indices are used as a surrogate for Net Primary

  6. Unravelling the causes of variability in crop yields and treatment responses for better tailoring of options for sustainable intensification in southern Mali

    NARCIS (Netherlands)

    Falconnier, G.N.; Descheemaeker, Katrien; Mourik, Van T.A.; Giller, K.E.

    2016-01-01

    Options that contribute to sustainable intensification offer an avenue to improve crop yields and farmers' livelihoods. However, insufficient knowledge on the performance of various options in the context of smallholder farm systems impedes local adaptation and adoption. Therefore, together with

  7. Assessment of driving factors for yield and productivity developments in crop and cattle production as key to increasing sustainable biomass potentials

    NARCIS (Netherlands)

    Gerssen-Gondelach, Sarah|info:eu-repo/dai/nl/355262436; Wicke, Birka|info:eu-repo/dai/nl/306645955; Faaij, Andre

    The sustainable production potential of biomass for energy and material purposes largely depends on the future availability of surplus agricultural lands made available through yield improvements in crop and livestock production. However, the rates at which yields may develop, and the influence of

  8. Sustainable deployment of QTLs conferring quantitative resistance to crops: first lessons from a stochastic model.

    Science.gov (United States)

    Bourget, Romain; Chaumont, Loïc; Durel, Charles-Eric; Sapoukhina, Natalia

    2015-05-01

    Quantitative plant disease resistance is believed to be more durable than qualitative resistance, since it exerts less selective pressure on the pathogens. However, the process of progressive pathogen adaptation to quantitative resistance is poorly understood, which makes it difficult to predict its durability or to derive principles for its sustainable deployment. Here, we study the dynamics of pathogen adaptation in response to quantitative plant resistance affecting pathogen reproduction rate and its colonizing capacity. We developed a stochastic model for the continuous evolution of a pathogen population within a quantitatively resistant host. We assumed that pathogen can adapt to a host by the progressive restoration of reproduction rate or of colonizing capacity, or of both. Our model suggests that a combination of quantitative trait loci (QTLs) affecting distinct pathogen traits was more durable if the evolution of repressed traits was antagonistic. Otherwise, quantitative resistance that depressed only pathogen reproduction was more durable. In order to decelerate the progressive pathogen adaptation, QTLs that decrease the pathogen's maximum capacity to colonize must be combined with QTLs that decrease the spore production per lesion or the infection efficiency or that increase the latent period. Our theoretical framework can help breeders to develop principles for sustainable deployment of QTLs. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  9. Camelina as a sustainable oilseed crop: contributions of plant breeding and genetic engineering.

    Science.gov (United States)

    Vollmann, Johann; Eynck, Christina

    2015-04-01

    Camelina is an underutilized Brassicaceae oilseed plant with a considerable agronomic potential for biofuel and vegetable oil production in temperate regions. In contrast to most Brassicaceae, camelina is resistant to alternaria black spot and other diseases and pests. Sequencing of the camelina genome revealed an undifferentiated allohexaploid genome with a comparatively large number of genes and low percentage of repetitive DNA. As there is a close relationship between camelina and the genetic model plant Arabidopsis, this review aims at exploring the potential of translating basic Arabidopsis results into a camelina oilseed crop for food and non-food applications. Recently, Arabidopsis genes for drought resistance or increased photosynthesis and overall productivity have successfully been expressed in camelina. In addition, gene constructs affecting lipid metabolism pathways have been engineered into camelina for synthesizing either long-chain polyunsaturated fatty acids, hydroxy fatty acids or high-oleic oils in particular camelina strains, which is of great interest in human food, industrial or biofuel applications, respectively. These results confirm the potential of camelina to serve as a biotechnology platform in biorefinery applications thus justifying further investment in breeding and genetic research for combining agronomic potential, unique oil quality features and biosafety into an agricultural production system. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Potential effects of climate change on Oregon crops

    Science.gov (United States)

    This talk will discuss: 1) potential changes in the Pacific Northwest climate with global climate change, 2) how climate change can affect crops, 3) the diversity of Oregon agriculture, 4) examples of potential response of Oregon crops – especially dryland winter wheat, and 5) br...

  11. Realities, Perceptions, Challenges and Aspirations of Rural Youth in Dryland Agriculture in the Midelt Province, Morocco

    OpenAIRE

    Alessandra Giuliani; Sebastian Mengel; Courtney Paisley; Nicole Perkins; Ingrid Flink; Oliver Oliveros; Mariana Wongtschowski

    2017-01-01

    Active involvement of youth in agriculture is necessary for sustainable agricultural systems but is currently a challenge in many areas. Using a combination of qualitative and quantitative participatory research methods, this study analyses rural youth’s realities, perspectives and aspirations in dryland Agricultural Livelihood Systems (ALSs) in the Midelt Province, Morocco, with a particular focus on gender. The data collected are an important first step in understanding the target group and...

  12. Rice Cultivation Methods and Their Sustainability Aspects: Organic and Conventional Rice Production in Industrialized Tropical Monsoon Asia with a Dual Cropping System

    Directory of Open Access Journals (Sweden)

    Hung-Chun Lin

    2016-06-01

    Full Text Available Options to tackle the sustainability challenges faced in the production of rice, including global and local environmental perspectives, need to be discussed. Here, the global warming potential, water consumption and cumulative energy demand were analyzed using a life-cycle assessment to highlight the sustainability aspects of rice production in Taiwan, where a mixed organic and conventional rice production with a dual cropping system is practiced. The results show that the conventional farming method practiced in Houbi district contributes less to global warming and annual water consumption and consumes less energy than the organic method practiced in Luoshan village on a grain weight basis. It is also more lucrative for farmers because of the higher rice yield. Considering the yield ratio based on the data from two districts, the regional characteristics are more responsible for these differences. Giving up dual cropping to avail water to other sectors by fallowing during the second cropping season is preferable from the GHG emission and productivity perspectives. However, because water shortages usually occur in the first cropping season, it is more realistic to fallow during the first cropping season when domestic and other industrial users have the higher priority. The results presented here can serve as the foundation for exploring the possibilities of options, such as new biorefinery technologies and water allocation policies, in relation to influences on GHG emissions and the national self-sufficiency of rice.

  13. Influence of Conservation Tillage and Soil Water Content on Crop Yield in Dryland Compacted Alfisol of Central Chile Influencia de la Labranza de Conservación y el Contenido de Agua sobre el Rendimiento del Cultivo en un Alfisol compactado del Secano Central de Chile

    Directory of Open Access Journals (Sweden)

    Ingrid Martinez G

    2011-12-01

    Full Text Available Chilean dryland areas of the Mediterranean climate region are characterized by highly degraded and compacted soils, which require the use of conservation tillage systems to mitigate water erosion as well as to improve soil water storage. An oat (Avena sativa L. cv. Supernova-INIA - wheat (Triticum aestivum L. cv. Pandora-INIA crop rotation was established under the following conservation systems: no tillage (Nt, Nt + contour plowing (Nt+Cp, Nt + barrier hedge (Nt+Bh, and Nt + subsoiling (Nt+Sb, compared to conventional tillage (Ct to evaluate their influence on soil water content (SWC in the profile (10 to 110 cm depth, the soil compaction and their interaction with the crop yield. Experimental plots were established in 2007 and lasted 3 yr till 2009 in a compacted Alfisol. At the end of the growing seasons, SWC was reduced by 44 to 51% in conservation tillage systems and 60% in Ct. Soil water content had a significant (p En Chile, las zonas de clima mediterráneo se caracterizan por suelos altamente degradados y compactados por erosión, lo que requiere el uso de sistemas de labranza conservacionista para mitigar la erosión hídrica, así como incrementar el contenido de agua en el suelo. Se evaluó una rotación avena (Avena sativa L. cv. Supernova-INIA - trigo (Triticum aestivum L. cv. Pandora-INIA establecida bajo los siguientes sistemas conservacionistas: cero labranza (Nt, Nt + curvas de nivel (Nt+Cp, Nt + franjas vivas (Nt+Bh y Nt + subsolado (Nt+Sb, las que fueron comparadas al sistema de labranza convencional (Ct, para evaluar su influencia en el contenido de agua en el suelo (SWC en el perfil (10 a 110 cm profundidad, la compactación del suelo y su interacción con el rendimiento del cultivo. Las parcelas experimentales fueron establecidas 3 años seguidos (2007 al 2009 en un Alfisol compactado. Al final de la temporada, el SWC disminuyó 44 a 51% en los sistemas conservacionistas y 60% en el sistema convencional. El sistema de

  14. Improving evapotranspiration estimates in Mediterranean drylands

    DEFF Research Database (Denmark)

    Morillas, Laura; Leuning, Ray; Villagarcia, Luis

    2013-01-01

    measurements from eddy covariance systems located in two functionally different sparsely vegetated drylands sites: a littoral Mediterranean semiarid steppe and a dry-subhumid Mediterranean montane site. The method providing the best results in both areas was fdrying (mean absolute error of 0.17 mm day−1) which...

  15. ALMOST IDEAL AREA YIELD CROP INSURANCE CONTRACTS

    OpenAIRE

    Smith, Vincent H.; Chouinard, Hayley H.; Baquet, Alan E.

    1994-01-01

    Using yield data for a sample of 123 dryland wheat producers in Montana, the effects of three area yield contracts, including the contract currently offered by the United States Federal Crop Insurance Corporation and two individual yield contracts on individual farm yield variability, are examined. The results indicate that while the Federal Crop Insurance Corporation area yield contract provides all farmers in the sample with some protection against yield variability, a simpler, actuarially ...

  16. Water use in a winter camelina – soybean double crop system

    Science.gov (United States)

    Double-cropping winter camelina (Camelina sativa) followed by soybean (Glycine max) may increase land-use efficiency by producing food and biofuel in a single season and is a viable cropping system for the northern Corn Belt. However, regional success of double-cropping, especially under dryland con...

  17. Modeling ecohydrological dynamics of smallholder strategies for food production in dryland agricultural systems

    Science.gov (United States)

    Gower, Drew B.; Dell'Angelo, Jampel; McCord, Paul F.; Caylor, Kelly K.; Evans, Tom P.

    2016-11-01

    In dryland environments, characterized by low and frequently variable rainfall, smallholder farmers must take crop water sensitivity into account along with other characteristics like seed availability and market price when deciding what to plant. In this paper we use the results of surveys conducted among smallholders located near Mount Kenya to identify clusters of farmers devoting different fractions of their land to subsistence and market crops. Additionally, we explore the tradeoffs between water-insensitive but low-value subsistence crops and a water-sensitive but high-value market crop using a numerical model that simulates soil moisture dynamics and crop production over multiple growing seasons. The cluster analysis shows that most farmers prefer to plant either only subsistence crops or only market crops, with a minority choosing to plant substantial fractions of both. The model output suggests that the value a farmer places on a successful growing season, a measure of risk aversion, plays a large role in whether the farmer chooses a subsistence or market crop strategy. Furthermore, access to irrigation, makes market crops more appealing, even to very risk-averse farmers. We then conclude that the observed clustering may result from different levels of risk aversion and access to irrigation.

  18. Application of municipal biosolids to dry-land wheat fields - A monitoring program near Deer Trail, Colorado (USA). A presentation for an international conference: "The Future of Agriculture: Science, Stewardship, and Sustainability", August 7-9, 2006, Sacramento, CA

    Science.gov (United States)

    Crock, James G.; Smith, David B.; Yager, Tracy J.B.

    2006-01-01

    Since late 1993, Metro Wastewater Reclamation District of Denver (Metro District), a large wastewater treatment plant in Denver, Colorado, has applied Grade I, Class B biosolids to about 52,000 acres of non-irrigated farmland and rangeland near Deer Trail, Colorado. In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring ground water at part of this site. In 1999, the USGS began a more comprehensive study of the entire site to address stakeholder concerns about the chemical effects of biosolids applications. This more comprehensive monitoring program has recently been extended through 2010. Monitoring components of the more comprehensive study included biosolids collected at the wastewater treatment plant, soil, crops, dust, alluvial and bedrock ground water, and stream bed sediment. Streams at the site are dry most of the year, so samples of stream bed sediment deposited after rain were used to indicate surface-water effects. This presentation will only address biosolids, soil, and crops. More information about these and the other monitoring components are presented in the literature (e.g., Yager and others, 2004a, b, c, d) and at the USGS Web site for the Deer Trail area studies at http://co.water.usgs.gov/projects/CO406/CO406.html. Priority parameters identified by the stakeholders for all monitoring components, included the total concentrations of nine trace elements (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc), plutonium isotopes, and gross alpha and beta activity, regulated by Colorado for biosolids to be used as an agricultural soil amendment. Nitrogen and chromium also were priority parameters for ground water and sediment components. In general, the objective of each component of the study was to determine whether concentrations of priority parameters (1) were higher than regulatory limits, (2) were increasing with time, or (3) were significantly higher in biosolids

  19. On-farm research in Western Siberia: Potential of adapted management practices for sustainable intensification of crop production systems

    Science.gov (United States)

    Kühling, Insa; Trautz, Dieter

    2015-04-01

    Western Siberia is of global significance in terms of agricultural production, carbon sequestration and biodiversity preservation. Abandonment of arable land and changes in the use of permanent grasslands were triggered by the dissolution of the Soviet Union in and the following collapse of the state farm system. The peatlands, forests and steppe soils of Western Siberia are one of the most important carbon sinks worldwide. These carbon stocks are, if deteriorated, an important source of radiative forcing even in comparison to anthropogenic emissions. This situation is aggravated by recent and future developments in agricultural land use in the southern part of Western Siberia, in particular in Tyumen province. The increase of drought risk caused by climate change will led to more challenges in these water-limited agricultural production systems. The German-Russian interdisciplinary research project "SASCHA" aims to provide sustainable land management practices to cope with these far-reaching changes for Tyumen province. In particular, on farm scale agricultural strategies are being developed for increased efficiencies in crop production systems. Therefore a 3-factorial field trial with different tillage and seeding operations was installed with spring wheat on 10 ha under practical conditions in 2013. Within all combinations of tillage (no-till/conventional), seed rate (usual/reduced) and seed depth (usual/shallower) various soil parameters as well as plant development and yield components were intensively monitored during the growing seasons. Results after 2-years show significant impacts of the tillage operation on soil moisture and soil temperature. Also a higher trend in nitrogen mineralization could be observed without tillage. Plant development in terms of phenological growth stages took place simultaneously in all variants. Under no-till regime we measured slightly higher grain yields and significant advantages in protein yields. In conjunction with

  20. Microbial colonization and controls in dryland systems

    Science.gov (United States)

    Pointing, Stephen B.; Belnap, Jayne

    2012-01-01

    Drylands constitute the most extensive terrestrial biome, covering more than one-third of the Earth's continental surface. In these environments, stress limits animal and plant life, so life forms that can survive desiccation and then resume growth following subsequent wetting assume the foremost role in ecosystem processes. In this Review, we describe how these organisms assemble in unique soil- and rock-surface communities to form a thin veneer of mostly microbial biomass across hot and cold deserts. These communities mediate inputs and outputs of gases, nutrients and water from desert surfaces, as well as regulating weathering, soil stability, and hydrological and nutrient cycles. The magnitude of regional and global desert-related environmental impacts is affected by these surface communities; here, we also discuss the challenges for incorporating the consideration of these communities and their effects into the management of dryland resources.

  1. Linyphiid spider populations in sustainable wheat‐clover bi‐cropping compared to conventional wheat‐growing practice

    DEFF Research Database (Denmark)

    Gravesen, Eigil Vestergaard

    2008-01-01

    Linyphiid web densities in wheat-clover bi-crop systems where winter wheat was grown in an under-storey of white clover were compared with web densities estimated in conventional wheat-growing systems. The web densities in the wheat-clover bi-crop systems were on average between 200 and 250 webs ...

  2. Biotech crops: imperative for achieving the millenium development goals and sustainability of agriculture in the climate change era.

    Science.gov (United States)

    Husaini, Amjad M; Tuteja, Narendra

    2013-01-01

    Biotechnological intervention in the development of crops has opened new vistas in agriculture. Central to the accomplishment of the Millennium Development Goals (MDGs), biotech-agriculture is essential in meeting these targets. Biotech crops have already made modest contributions toward ensuring food and nutrition security by reducing losses and increasing productivity, with less pesticide input. These crops could help address some of the major challenges in agriculture-based economies created by climate change. Projections of global climate change expect the concentration of greenhouse gases to increase, aridization of the environment to increase, temperature fluctuations to occur sharply and frequently, and spatial and temporal distribution of rainfall to be disturbed-all of which will increase abiotic stress-related challenges to crops. Countering these challenges and to meet the food requirement of the ever-increasing world population (expected to reach 9 billion by 2030) we need to (1) develop and use biotech crops for mitigating adverse climatic changes; (2) develop biotech crops resilient to adverse environmental conditions; and (3) address the issues/non-issues raised by NGO's and educate the masses about the benefits of biotech crops.

  3. First or second generation biofuel crops in Brandenburg, Germany? A model-based comparison of their production-ecological sustainability

    NARCIS (Netherlands)

    Vries, de S.C.; Ven, van de G.W.J.; Ittersum, van M.K.

    2014-01-01

    We assessed and compared the production-ecological sustainability of first and second generation biofuel production systems in the state of Brandenburg, Germany. Production ecological sustainability was defined by a limited set of sustainability indicators including net energy yield per hectare, GHG

  4. Evaluating a core germplasm collection of the cover crop hairy vetch for use in sustainable farming systems

    Science.gov (United States)

    Understanding linkage between genotype and agronomically important phenotypes (early flowering, hard seed and winter hardiness) will facilitate cultivar selection and inform breeding programs concerned with the cover crop hairy vetch (Vicia villosa). . We used molecular and biochemical techniques to...

  5. Woody plants in drylands: plastic responses to environmental stress

    NARCIS (Netherlands)

    Xu, L.|info:eu-repo/dai/nl/345500822

    2012-01-01

    Plants in drylands are exposed to a suite of stress factors. The most obvious stress factor is drought stress induced by a strongly negative balance between precipitation and potential evapotranspiration. Drylands are increasingly being used for grazing livestock and with increasing human

  6. Development of sorghum varieties and hybrids for dryland areas of ...

    African Journals Online (AJOL)

    Mo

    A study was conducted to scrutinize the development of sorghum (Sorghum bicolar) varieties and hybrids that have been carried out for the dryland areas of Ethiopia in the past 35 years (1969-2003). The experiments were conducted at the three major research centers and sub-centers representing the dryland areas of the ...

  7. Dryland Degradation by wind erosion and its control

    NARCIS (Netherlands)

    Sterk, G.; Riksen, M.; Goossens, D.

    2001-01-01

    Global population growth, is expected to impose an increasing pressure on agricultural production in the world's drylands, which cover approximately 41␘f the continental area. The land resources in drylands are severely threatened by soil degradation, with wind erosion being, one of the major

  8. Future soil moisture and temperature extremes imply expanding suitability for rainfed agriculture in temperate drylands.

    Science.gov (United States)

    Bradford, John B; Schlaepfer, Daniel R; Lauenroth, William K; Yackulic, Charles B; Duniway, Michael; Hall, Sonia; Jia, Gensuo; Jamiyansharav, Khishigbayar; Munson, Seth M; Wilson, Scott D; Tietjen, Britta

    2017-10-10

    The distribution of rainfed agriculture, which accounts for approximately ¾ of global croplands, is expected to respond to climate change and human population growth and these responses may be especially pronounced in water limited areas. Because the environmental conditions that support rainfed agriculture are determined by climate, weather, and soil conditions that affect overall and transient water availability, predicting this response has proven difficult, especially in temperate regions that support much of the world's agriculture. Here, we show that suitability to support rainfed agriculture in temperate dryland climates can be effectively represented by just two daily environmental variables: moist soils with warm conditions increase suitability while extreme high temperatures decrease suitability. 21 st century projections based on daily ecohydrological modeling of downscaled climate forecasts indicate overall increases in the area suitable for rainfed agriculture in temperate dryland regions, especially at high latitudes. The regional exception to this trend was Europe, where suitability in temperate dryland portions will decline substantially. These results clarify how rising temperatures interact with other key drivers of moisture availability to determine the sustainability of rainfed agriculture and help policymakers, resource managers, and the agriculture industry anticipate shifts in areas suitable for rainfed cultivation.

  9. Elevated CO2 as a driver of global dryland greening

    KAUST Repository

    Lu, Xuefei

    2016-02-12

    While recent findings based on satellite records indicate a positive trend in vegetation greenness over global drylands, the reasons remain elusive. We hypothesize that enhanced levels of atmospheric CO2 play an important role in the observed greening through the CO2 effect on plant water savings and consequent available soil water increases. Meta-analytic techniques were used to compare soil water content under ambient and elevated CO2 treatments across a range of climate regimes, vegetation types, soil textures and land management practices. Based on 1705 field measurements from 21 distinct sites, a consistent and statistically significant increase in the availability of soil water (11%) was observed under elevated CO2 treatments in both drylands and non-drylands, with a statistically stronger response over drylands (17% vs. 9%). Given the inherent water limitation in drylands, it is suggested that the additional soil water availability is a likely driver of observed increases in vegetation greenness.

  10. Water Efficient Alternative Crops for Sustainable Agriculture along the Tarim Basin: A Comparison of the Economic Potentials of Apocynum pictum, Chinese Red Date and Cotton in Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Aihemaitijiang Rouzi

    2017-12-01

    Full Text Available This study explores a paradigm of sustainable land use in the oases along the Tarim River of northwest China, where a fragile, semi-arid riparian ecosystem is being damaged by excessive land and water use for agriculture, especially for the growing of cotton. The reliance of agriculture on water-demanding cash crops in this region poses a grave threat to survival of the natural Tugai vegetation in the area and to the long-term sustainability of the region. We explored the hypothesis that the species Apocynum pictum (A. pictum, known as Lop-Kendir by locals, and the Chinese red date (Zyzyphus jujube may act as sustainable crop substitutes for the region, thereby replacing the widely distributed cash crop of cotton that has high water demands. Therefore, we investigated current utilization and cost-revenue structure of these two alternative plants and compared the results to cotton. Three natural resource management types of A. pictum were both identified in the wild and cultivation, with cost-revenue analysis carried out for each. The results show that all three types of institutional arrangements of natural resources, which are namely open access, ranching and farming, were present in our study and at various levels for A. pictum. A. pictum farming costs 16,250.25 yuan/ha, generates 49,014.45 yuan/ha of revenue from raw materials and brings a profit of 32,764.2 yuan/ha, which is the highest of all three cash crops compared. The Chinese government encourages Chinese red date plantations with a “Grain for green” campaign in the Tarim Basin with this plant being more profitable than cotton, which could serve to diversify the region’s agriculture. We conclude that A. pictum offers opportunities for the restoration of vegetation in riparian ecosystems on salinized sites under the arid conditions of the Tarim Basin. Furthermore, it can serve as a viable land-use alternative to cotton for cash crop agriculture, as it may generate a certain income

  11. Modeling Soil Sodicity Problems under Dryland and Irrigated Conditions: Case Studies in Argentina and Colombia

    Science.gov (United States)

    Pla-Sentís, Ildefonso

    2014-05-01

    Salt-affected soils, both saline and sodic, my develop both under dryland and irrigated conditions, affecting negatively the physical and chemical soil properties, the crop production and the animal and human health.Among the development processes of salt-affected soils, the processes of sodification have been generally received less attention and is less understood than the development of saline soils. Although in both of them, hydrological processes are involved in their development, in the case of sodic soils we have to consider some additional chemical and physicochemical reactions, making more difficult their modeling and prediction. In this contribution we present two case studies: one related to the development of sodic soils in the lowlands of the Argentina Pampas, under dryland conditions and sub-humid temperate climate, with pastures for cattle production; the other deals with the development of sodic soils in the Colombia Cauca Valley, under irrigated conditions and tropical sub-humid climate, in lands used for sugarcane cropping dedicated to sugar and ethanol production. In both cases the development of sodicity in the surface soil is mainly related to the effects of the composition and level of groundwater, affected in the case of Argentina Pampas by the off-site changes in dryland use and management in the upper zones and by the drainage conditions in the lowlands, and in the case of the Cauca Valley, by the on-site irrigation and drainage management in lands with sugarcane. There is shown how the model SALSODIMAR, developed by the main author, based on the balance of water and soluble componentes of both the irrigation water and groundwater under different water and land management conditions, may be adapted for the diagnosis and prediction of both problems, and for the selection of alternatives for their management and amelioration.

  12. The Impacts of Agricultural Land Use on Dissolved Organic Matter in a Dryland River System

    Science.gov (United States)

    Wise, J. L.; Bergamaschi, B. A.; Van Horn, D. J.; Diefendorf, A. F.

    2015-12-01

    Globally, expanding agriculture is significantly impacting aquatic nutrient cycles. In mesic systems, agriculture is a source of nitrogen and phosphorus and increases concentrations of structurally simple dissolved organic carbon (DOC). In contrast, recent studies suggest in dryland systems, where wastewater effluent is a primary nutrient source, agriculture is a nutrient sink—retaining nitrogen and phosphorous. Importantly, very little, is known about the influence of agriculture on DOC dynamics in dryland systems. To address this gap we used synoptic sampling, UV-absorbance, and fluorescence spectroscopy to elucidate source, character, and concentration of riverine and runoff DOC in a dryland agricultural system. Samples were collected along a 25 km stretch of the Rio Grande River in New Mexico (USA). The Rio Grande is an impoundment/irrigation-withdrawal controlled river that receives water from snowmelt, monsoonal storms, and wastewater effluent. During irrigation approximately 80% of the river's water is diverted into a manmade network where it waters crops and percolates through the soil before it enters a series of drains that return water to the river. Our preliminary characterization of the DOC reentering the river (DOCmean=3.23 mg/L, sd=0.81; SUVAmean=4.05, sd=1.37) indicates the agricultural pool is similar in concentration and aromaticity to riverine DOC (DOCmean= 3.10 mg/L, sd=1.17; SUVAmean= 4.64, sd=1.12). However, riverine organic matter is more terrestrially derived (FImean=1.68, sd=0.17) than organic matter in the drains (FImean=1.9, sd=0.24). Additionally, drains directly adjacent to actively irrigated fields show high concentrations (DOCmean=58.35; sd=0.91) of low aromaticity organic matter (SUVAmean=0.33; sd=0.11). We are continuing analysis throughout the irrigation season to further explore organic matter quality (traits such as bioavailability and freshness) and identify locations and processes of DOC transformation within the system

  13. VIC-CropSyst-v2: A regional-scale modeling platform to simulate the nexus of climate, hydrology, cropping systems, and human decisions

    Science.gov (United States)

    Malek, Keyvan; Stöckle, Claudio; Chinnayakanahalli, Kiran; Nelson, Roger; Liu, Mingliang; Rajagopalan, Kirti; Barik, Muhammad; Adam, Jennifer C.

    2017-08-01

    Food supply is affected by a complex nexus of land, atmosphere, and human processes, including short- and long-term stressors (e.g., drought and climate change, respectively). A simulation platform that captures these complex elements can be used to inform policy and best management practices to promote sustainable agriculture. We have developed a tightly coupled framework using the macroscale variable infiltration capacity (VIC) hydrologic model and the CropSyst agricultural model. A mechanistic irrigation module was also developed for inclusion in this framework. Because VIC-CropSyst combines two widely used and mechanistic models (for crop phenology, growth, management, and macroscale hydrology), it can provide realistic and hydrologically consistent simulations of water availability, crop water requirements for irrigation, and agricultural productivity for both irrigated and dryland systems. This allows VIC-CropSyst to provide managers and decision makers with reliable information on regional water stresses and their impacts on food production. Additionally, VIC-CropSyst is being used in conjunction with socioeconomic models, river system models, and atmospheric models to simulate feedback processes between regional water availability, agricultural water management decisions, and land-atmosphere interactions. The performance of VIC-CropSyst was evaluated on both regional (over the US Pacific Northwest) and point scales. Point-scale evaluation involved using two flux tower sites located in agricultural fields in the US (Nebraska and Illinois). The agreement between recorded and simulated evapotranspiration (ET), applied irrigation water, soil moisture, leaf area index (LAI), and yield indicated that, although the model is intended to work on regional scales, it also captures field-scale processes in agricultural areas.

  14. Sediment and PM10 flux from no-tillage cropping systems in the Pacific Northwest

    Science.gov (United States)

    Wind erosion is a concern in the Inland Pacific Northwest (PNW) United States where the emission of fine particulates from winter wheat – summer fallow (WW/SF) dryland cropping systems during high winds degrade air quality. Although no-tillage cropping systems are not yet economically viable, these ...

  15. Pathways for sustainable development of mixed crop livestock systems: Taking a livestock and pro-poor approach

    NARCIS (Netherlands)

    Tarawali, S.A.; Herrero, M.; Descheemaeker, K.K.E.; Grings, E.; Blmmel, M.

    2011-01-01

    Mixed crop livestock systems provide the majority of the cereal and livestock domestic products for households in developing countries. We explore the question of whether such systems can respond to increasing demands for livestock products without compromising future livelihoods of the poor or the

  16. Using NIRS to predict fiber and nutrient content of dryland cereal cultivars.

    Science.gov (United States)

    Stubbs, Tami L; Kennedy, Ann C; Fortuna, Ann-Marie

    2010-01-13

    Residue from cultivars of spring wheat (Triticum aestivum L.), winter wheat, and spring barley (Hordeum vulgare L.) was characterized for fiber and nutrient traits using reference methods and near-infrared spectroscopy (NIRS). Calibration models were developed for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), carbon (C), sulfur (S), nitrogen (N), and C:N. When calibrations were tested against validation sets for each crop year, NIRS was an acceptable method for predicting NDF (standard error of prediction (SEP)0.90) and ADF (SEP0.92) and moderately successful for ADL in 1 year of the study (SEP=0.44; R2=0.81) but less successful for C, S, N, and C:N (R2 all<0.57). These results indicate that NIRS can predict the NDF and ADF of cereal residue from dryland cropping systems and is a useful tool to estimate residue decomposition potential.

  17. Determinants and the perceived effects of adoption of sustainable improved food crop technologies by smallholder farmers along the value chain in Nigeria

    Directory of Open Access Journals (Sweden)

    Abiodun Elijah Obayelu

    2016-06-01

    Full Text Available Adoption of improved agricultural technologies is fundamental to transformation of sustainable farming system, and a driving force for increasing agricultural productivity. This study provides empirical evidence on the determinants, and the perceived effects of adoption of improved food crop technologies in Nigeria. It is a cross-sectional survey of available technologies and 1,663 farm households in Nigeria. Data were analyzed with both descriptive and inferential statistics. The findings revealed very low technology adoption index. Available food crop production technologies used by sampled respondents were assessed as effective, appropriate, readily available, affordable, durable, user and gender friendly, with requisite skill to use them. However, processing technologies such as cabinet dryer were observed as unaffordable, not durable, not gender or users friendly. Packaging machines are also not users or gender friendly; washing machine not affordable, durable and gender friendly. Grain processing technologies like De-stoner, grading, and packaging machines are still not locally available and affordable. While parboilers have a negative impact on product quality, farmers’ health and the environment, tomato grinding machines have positive impact on the quality of the product, health of the users, yield and negatively affect the environment. The main determinants of adoption are the crop types, farm size and locations. Adoption of herbicide and inorganic fertilizer were influenced by travel cost to nearest place of acquisition, while the age of farmer has a positive and significant influence on the adoption of pesticide, water management and cassava harvester. Interestingly, male farmers only exhibit greater likelihood of adopting land preparation, inorganic and organic fertilizer technologies compared to their female counterpart. Therefore, policy options that consider all users at the development stages, favour reduction of travel cost

  18. Future Rangeland Ecosystems in the Dryland Belt of Asia

    Science.gov (United States)

    Qi, Jiaguo

    2015-04-01

    One of the greatest challenges humans are facing is sustainably managing water and land resources under changing global environment. This issue is especially pertinent in dryland belt in Asia where freshwater is scarce and shared among many nations. The region is heavily dependent on the diminishing Himalayan glaciers and limited and changing precipitation patterns. With increasing climate variability and a regional warming trend water security issues are acute and if not properly addressed could affect regional stability and lead to international conflicts. Solutions to these urgent regional issues are lacking and further research efforts are needed. Adaptive strategies addressing the complex and multifaceted water resource issues in the region will require a co-design and co-delivery of knowledge specific to the region and must consider exogenous factors such as policies of neighbouring countries and changing precipitation patterns due to climate change. There is a need to determine and fund scientific research priorities and practical approaches co-developed by local stakeholders and scientists to change the region's paradigm to "science for society". This presentation will summarize the collective outcome from a focused group discussion at the international workshop on "Future Earth and Science for Society" to be held from February 25-27, 2015 at Michigan State University, including knowledge gaps, research priorities, a general framework and international collaborations to move forward to addressing the future of the dyrland belt of Asia.

  19. Earth Observation of Vegetation Dynamics in Global Drylands

    DEFF Research Database (Denmark)

    Tian, Feng

    and exploring the widely used long-term datasets and 2) mapping trends in woody vegetation. A highlight of the thesis is the mapping of trends in the non-green woody vegetation component in global tropical drylands, which is obtained for the first time from combing satellite optical and passive microwave......Land degradation in global drylands has been a concern related to both the local livelihoods and the changes in terrestrial biosphere, especially in the context of substantial global environmental changes. Earth Observation (EO) provides a unique way to assess the vegetation dynamics over the past...... decades, which are keys to understanding the changes in global drylands. However, there are still large uncertainties and unknowns in the quality and capabilities of remote sensing data. This thesis contributes to an improved EO based assessment of dryland vegetation dynamics by 1) evaluating...

  20. Expansion of global drylands under a warming climate

    National Research Council Canada - National Science Library

    Feng, S; Fu, Q

    2013-01-01

    Global drylands encompassing hyper-arid, arid, semiarid, and dry subhumid areas cover about 41 percent of the earth's terrestrial surface and are home to more than a third of the world's population...

  1. Strengthening dryland women's land rights: local contexts, global change

    OpenAIRE

    Forsythe, Lora; Morton, John; Nelson, Valerie; Quan, Julian; Martin, Adrienne; Hartog, Maaike

    2015-01-01

    Thematic study 1: Strengthening dryland women's land rights: local contexts, global change found that significant opportunities exist for facilitating dryland women's empowerment with respect to land, in international research, policy, dialogue and practical action. There is increased international attention on women’s land rights amongst global institutions and in international development debates. There is growing pressure for progressive legislation on women’s land rights, with increasing ...

  2. Agricultural biology in the 3rd millennium: nutritional food security & specialty crops through sustainable agriculture and biotechnology

    Science.gov (United States)

    Food security and agricultural sustainability are of prime concern in the world today in light of the increasing trends in population growth in most parts of the globe excepting Europe. The need to develop capacity to produce more to feed more people is complicated since the arable land is decreasin...

  3. Remote sensing of vegetation dynamics in drylands

    DEFF Research Database (Denmark)

    Tian, Feng; Brandt, Martin Stefan; Liu, Yi Y.

    2016-01-01

    greenness. The vegetation optical depth (VOD) derived from satellite passive microwave observations is mainly sensitive to the water content in total aboveground vegetation layer. VOD therefore provides a complementary data source to NDVI for monitoring biomass dynamics in drylands, yet further evaluations...... mass) in the semi-arid Senegalese Sahel. Results show that the magnitude and peak time of VOD are sensitive to the woody plant foliage whereas NDVI seasonality is primarily governed by the green herbaceous vegetation stratum in the study area. Moreover, VOD is found to be more robust against typical...... NDVI drawbacks of saturation effect and dependence on plant structure (herbaceous and woody compositions) across the study area when used as a proxy for vegetation productivity. Finally, both VOD and NDVI well reflect the spatial and inter-annual dynamics of the in situ green biomass data; however...

  4. Increase globe artichoke cropping sustainability using sub-surface drip-irrigation systems in a Mediterranean coastal area for reducing groundwater withdrawal

    Science.gov (United States)

    Mantino, Alberto; Marchina, Chiara; Bonari, Enrico; Fabbrizzi, Alessandro; Rossetto, Rudy

    2017-04-01

    During the last decades in coastal areas of the Mediterranean basin, human growth posed severe stresses on freshwater resources due to increasing demand by agricultural, industrial and civil activities, in particular on groundwater. This in turn led to worsening of water quality, loss/reduction of wetlands, up to soil salinization and abandonment of agricultural areas. Within the EU LIFE REWAT project a number of demonstration measures will take place in the lower Cornia valley (Livorno, Italy), both structural (pilot) and non-structural (education, dissemination and capacity building), aiming at achieving sustainable and participated water management. In particular, the five demonstration actions are related to: (1) set up of a managed aquifer recharge facility, (2) restoration of a Cornia river reach, (3) water saving in the civil water supply sector, (4) water saving in agriculture, (5) reuse of treated wastewater for irrigation purposes. Thus, the REWAT project general objective is to develop a new model of governance for sustainable development of the lower Cornia valley based on the water asset at its core. As per water use in agriculture, the lower Cornia valley is well known for the horticultural production. In this regard, globe artichoke (Cynara cardunculus L. var. scolymus L. (Fiori)) crops, a perennial cool-season vegetable, cover a surface of about 600 ha. In order to increase stability and productivity of the crop, about 2000 - 4000 m3 ha-1 yr-1 of irrigation water is required. Recent studies demonstrated that yield of different crops increases using Sub-surface Drip-Irrigation (SDI) system under high frequency irrigation management enhancing water use efficiency. In the SDI systems, the irrigation water is delivered to the plant root zone, below the soil surface by buried plastic tubes containing embedded emitters located at regular spacing. Within the LIFE REWAT, the specific objectives of the pilot on irrigation efficiency is to (i) demonstrate the

  5. Mobility and uptake of zinc, cadmium, nickel, and lead in sludge-amended soils planted to dryland maize and irrigated maize-oat rotation.

    Science.gov (United States)

    Ogbazghi, Zekarias M; Tesfamariam, Eyob H; Annandale, John G; De Jager, Petrus C

    2015-03-01

    Sludge application to agricultural lands is often limited mainly because of concerns about metal accumulation in soils and uptake by crops. The objective of the study was to test the following hypotheses: (i) in the short to medium term (5-10 yr), the application of good-quality sludge according to crop N requirements will not lead to significant accumulation of water-soluble metal fractions in soil, (ii) mobility and uptake of metals is higher under irrigated than dryland systems, and (iii) metal concentrations in plant tissue could reach phytotoxic levels before the soil reaches environmental threshold levels. Field plots were arranged in a randomized complete block design comprising four replications of three treatments (0, 8, and 16 Mg ha yr anaerobically digested municipal sludge) planted to dryland maize and irrigated maize-oat rotation. Soil and plant samples were collected after 7 yr of treatment application for selected metal analyses. A large fraction of the Zn, Ni, and Pb in the soil profile was ethylenediaminetetraacetic acid extractable (46-79%). Saturated paste-extractable fractions of Cd and Pb were <1 mg kg. Plant uptake of Cd, Pb, and Ni under irrigation was double that for dryland systems. Concentrations of the metals considered in plant tissue of both cropping systems remained well below phytotoxic levels, except for Zn under dryland maize, which received 16 Mg sludge ha yr. Metal concentrations in the soil remained far below total maximum threshold levels. Therefore, hypotheses 1 and 3 were accepted for the metals considered, and hypothesis 2 was rejected for Zn. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Tapping the Potential of Neglected and Underutilized Food Crops for Sustainable Nutrition Security in the Mountains of Pakistan and Nepal

    Directory of Open Access Journals (Sweden)

    Lipy Adhikari

    2017-02-01

    Full Text Available Neglected and underutilized food crops (NUFCs have high nutritional value, but their role in achieving nutrition security is not adequately understood, and they do not feature in food and nutrition policies and programs of the countries of the Hindu-Kush Himalayan (HKH region. Drawing examples from Pakistan and Nepal, this study investigates the importance of NUFCs in achieving nutrition security in the mountains and identifies key underlying reasons for the decline in their cultivation and use. The study found that the prevalence of malnutrition is significantly higher in the mountains than nationally in both Pakistan and Nepal and identifies the decline in the cultivation and use of micronutrient-rich NUFCs as one of the key reasons for this. The deterioration of local food systems, changing food habits, lack of knowledge about the cultivation, use and nutritional value of NUFCs and lack of attention to NUFCs in programs and policies are the key reasons for the abandoning of NUFCs by mountain communities. There is an urgent need to mainstream these crops into national programs and policies and to integrate them into local food systems. This will not only improve the nutrition security of mountain areas, but also biodiversity and local mountain economies.

  7. State of the art and perspectives of the cultivation of energy crops in Hesse. Significance, procedure of cultivation, sustainability; Stand und Perspektiven des Energiepflanzenanbaus in Hessen. Bedeutung, Anbauverfahren, Nachhaltigkeit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-15

    In line with the further increase in the use of renewable energy sources, the expansion of biomass utilization in Hesse increasingly becomes important. In light of the increasing criticism of the cultivation of energy crops, it is important to learn about the situation in the Federal State Hessen (Federal Republic of Germany). Under this aspect, the booklet under consideration contributes to proper information and creating acceptance in the current discussion on the development of bioenergy in Hessen. In particular, the brochure reports on the following topics: (1) What is the advantage of the bioenergy in Hessen?; (2) Scope of the cultivation of energy crops in the Hessian agriculture?; (3) Economic aspects of the cultivation of energy crops for biogas plants; (4) Cultivation of oil crops for the production of biodiesel oil and vegetable oil; (5) Cultivation of cereals and sugar beet for bioethanol production; (6) One-year-old energy crops; (7) Perennial energy crops; (8) Aspects of sustainability in the cultivation of energy crops; (9) Areas of conflict in the cultivation of energy crops.

  8. Climate Science, Development Practice, and Policy Interactions in Dryland Agroecological Systems

    NARCIS (Netherlands)

    Twyman, C.; Fraser, E.D.G.; Stringer, L.C.; Quinn, C.; Dougill, A.J.; Crane, T.A.; Sallu, S.M.

    2011-01-01

    The literature on drought, livelihoods, and poverty suggests that dryland residents are especially vulnerable to climate change. However, assessing this vulnerability and sharing lessons between dryland communities on how to reduce vulnerability has proven difficult because of multiple definitions

  9. Climate change reduces extent of temperate drylands and intensifies drought in deep soils

    Science.gov (United States)

    Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, William K.; Munson, Seth M.; Tietjen, Britta; Hall, Sonia A.; Wilson, Scott D.; Duniway, Michael C.; Jia, Gensuo; Pyke, David A.; Lkhagva, Ariuntsetseg; Jamiyansharav, Khishigbayar

    2017-01-01

    Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in extent and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the twenty first century, temperate drylands may contract by a third, primarily converting to subtropical drylands, and that deep soil layers could be increasingly dry during the growing season. These changes imply major shifts in vegetation and ecosystem service delivery. Our results illustrate the importance of appropriate drought measures and, as a global study that focuses on temperate drylands, highlight a distinct fate for these highly populated areas.

  10. Modelling sediment export, retention and reservoir sedimentation in drylands with the WASA-SED model

    Directory of Open Access Journals (Sweden)

    E. N. Mueller

    2010-04-01

    Full Text Available Current soil erosion and reservoir sedimentation modelling at the meso-scale is still faced with intrinsic problems with regard to open scaling questions, data demand, computational efficiency and deficient implementations of retention and re-mobilisation processes for the river and reservoir networks. To overcome some limitations of current modelling approaches, the semi-process-based, spatially semi-distributed modelling framework WASA-SED (Vers. 1 was developed for water and sediment transport in large dryland catchments. The WASA-SED model simulates the runoff and erosion processes at the hillslope scale, the transport and retention processes of suspended and bedload fluxes in the river reaches and the retention and remobilisation processes of sediments in reservoirs. The modelling tool enables the evaluation of management options both for sustainable land-use change scenarios to reduce erosion in the headwater catchments as well as adequate reservoir management options to lessen sedimentation in large reservoirs and reservoir networks. The model concept, its spatial discretisation scheme and the numerical components of the hillslope, river and reservoir processes are described and a model application for the meso-scale dryland catchment Isábena in the Spanish Pre-Pyrenees (445 km2 is presented to demonstrate the capabilities, strengths and limits of the model framework. The example application showed that the model was able to reproduce runoff and sediment transport dynamics of highly erodible headwater badlands, the transient storage of sediments in the dryland river system, the bed elevation changes of the 93 hm3 Barasona reservoir due to sedimentation as well as the life expectancy of the reservoir under different management options.

  11. Efficiency and environmental indexes to evaluate the sustainability of mineral and organic fertilization in an irrigated melon crop

    Science.gov (United States)

    Requejo Mariscal, María Isabel; Villena Gordo, Raquel; Cartagena Causapé, María Carmen; Arce Martínez, Augusto; Ribas Elcorobarrutia, Francisco; Jesús Cabello Cabello, María; María Tarquis Alfonso, Ana; Castellanos Serrano, María Teresa

    2014-05-01

    Melon is traditionally cultivated in fertigated farmlands in the center of Spain with high inputs of water and N fertilizer. Excess N can have a negative impact, from the economic point of view, since it can diminish the production and quality of the fruit, from the environmental point of view, since it is a very mobile element in the soil and can contaminate groundwater. From health point of view, nitrate can be accumulated in fruit pulp, and, in addition, groundwater is the fundamental supply source of human populations. Best management practices are particularly necessary in this region as many zones have been declared vulnerable to NO3- pollution (Directive 91/676/CEE) During successive years, a melon crop (Cucumis melo L.) was grown under field conditions applying mineral and organic fertilizers under drip irrigation. Different doses of ammonium nitrate were used as well as compost derived from the wine-distillery industry which is relevant in this area. The present study reviews the most common N efficiency indexes [1] under the different management options with a view to maximizing yield and minimizing N loss. Acknowledgements: This project has been supported by INIA-RTA04-111-C3 and INIA-RTA2010-00110-C03-01. [1] Castellanos, M., Tarquis, A., Ribas, F., Cabello, M., Arce, A., & Cartagena, M. (2013). Nitrogen fertigation: An integrated agronomic and environmental study. Agricultural Water Management, 120, 46-55.

  12. Dryland Landscapes: Forest Management, Gender and Social Diversity in Asia and Africa’

    NARCIS (Netherlands)

    Bose, P.; Dijk, van J.W.M.

    2016-01-01

    Drylands cover 40 % of the earth’s surface and provide the basis for the livelihoods of 2 billion people, many of whom belong to the poorest of the world. Dryland forests provide these people with woods, fruits, fibre and pasture. Drylands are among the poorest and most problem-ridden areas of the

  13. Vegetation and erosion: comments on the linking mechanisms from the perspective of the Australian drylands.

    Science.gov (United States)

    Dunkerley, D.

    2009-04-01

    of overland flow behaviour. In such analyses, the role of vascular plants has to be seen as one component of the system that also includes organic litter and non-vascular plants. A gap in understanding here relates to splash dislodgement of soil materials. This is known to depend on the depth of water lying above the mineral soil, being reduced for both shallow and deep water layers, and maximised at depths of a few incident drop diameters. Resolving how vegetation modifies surface water depths, and how splash dislodgement responds, across the spectrum of event sizes, remains a significant research challenge. Australian dryland streams exhibit abundant channel-associated vegetation. This exhibits diverse roles, again depending on context. Trees growing in the channel, together with associated barriers formed from floating woody debris, reduce flow speeds. On the other hand, deflector jams can result in locally intensified erosion of the banks. But the mechanisms linking vegetation and erosion are again complex. For instance, by reducing flow speeds and creating backwater effects, debris barriers promote mud deposition over channel margin sediments. This in turn reduces transmission losses, and sustains peak flow and associated sediment transport capacity further downstream than would otherwise be the case. As for hillslope processes, much remains to be learned about how these various processes play out across the spectrum of event magnitudes. Clearly, therefore, in a time of ongoing environmental change, the informed management of the global drylands requires continued research effort of the kind so well championed by John Thornes.

  14. Integrating knowledge exchange and the assessment of dryland management alternatives - A learning-centered participatory approach.

    Science.gov (United States)

    Bautista, Susana; Llovet, Joan; Ocampo-Melgar, Anahí; Vilagrosa, Alberto; Mayor, Ángeles G; Murias, Cristina; Vallejo, V Ramón; Orr, Barron J

    2017-06-15

    The adoption of sustainable land management strategies and practices that respond to current climate and human pressures requires both assessment tools that can lead to better informed decision-making and effective knowledge-exchange mechanisms that facilitate new learning and behavior change. We propose a learning-centered participatory approach that links land management assessment and knowledge exchange and integrates science-based data and stakeholder perspectives on both biophysical and socio-economic attributes. We outline a structured procedure for a transparent assessment of land management alternatives, tailored to dryland management, that is based on (1) principles of constructivism and social learning, (2) the participation of stakeholders throughout the whole assessment process, from design to implementation, and (3) the combination of site-specific indicators, identified by local stakeholders as relevant to their particular objectives and context conditions, and science-based indicators that represent ecosystem services of drylands worldwide. The proposed procedure follows a pattern of eliciting, challenging, and self-reviewing stakeholder perspectives that aims to facilitate learning. The difference between the initial baseline perspectives and the final self-reviewed stakeholder perspectives is used as a proxy of learning. We illustrate the potential of this methodology by its application to the assessment of land uses in a Mediterranean fire-prone area in East Spain. The approach may be applied to a variety of socio-ecological systems and decision-making and governance scales. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The charcoal-degradation nexus: contested 'fuelscapes' in the sub-Saharan drylands of northern Kenya

    Science.gov (United States)

    Bergmann, Christoph; Petersen, Maike; Roden, Paul; Nüsser, Marcus

    2017-04-01

    Charcoal ranks amongst the most commercialized but least regulated commodities in sub-Saharan Africa. Despite its prevalence as an energy source for cooking and heating, localized environmental and livelihood impacts of charcoal production are poorly understood so far. The identified research deficit is amplified by widespread negative views of this activity as a poverty-driven cause of deforestation and land degradation. However, the charcoal-degradation nexus is apparently more complicated, not least because the extraction of biomass from already degraded woodlands can also be interpreted as an appropriate option under given management regimes. In order to better calibrate existing research agendas to site-specific geographies of charcoal production, we propose a re-conceptualization of such energy landscapes as 'fuelscapes' with complex material and social dimensions. The concept is tested with reference to a case study in Central Pokot, northern Kenya, where charcoal production only began in the early 1990's. Based on the assumption that the fine line between sustainable land management and degradation in dryland energy landscapes is not only highly variable but also increasingly contested, our study combines the knowledge input of different stakeholders with longitudinal time series of remote sensing data. Based on the results of our interdisciplinary analyses, we outline an integrated tool for the co-operative monitoring and management of prevailing degradation processes against the background of diversified livelihood activities in sub-Saharan drylands.

  16. Biocide plants as a sustainable tool for the control of pests and pathogens in vegetable cropping systems

    Directory of Open Access Journals (Sweden)

    Trifone D'Addabbo

    2014-11-01

    Full Text Available Synthetic pesticides have played a major role in crop protection related to the intensification of agricultural systems. In the recent years, environmental side effects and health concerns raised by an indiscriminate use have led the EU to the ban of many synthetic pesticides. As a result of this drastic revision, currently there is a strong need for new and alternative pest control methods. An interesting source of biorational pesticides may be represented by the biocidal compounds naturally occurring in plants as products of the secondary metabolism. Groups of plant secondary metabolites most promising for the development of pesticidal formulations are glucosinolates, saponins, and more generally terpenoid phytoconstituents, such as essential oil and their constituents. Glucosinolates are thioglucosidic secondary metabolites occurring mainly in the Brassicaceae and, at a less extent, in Capparidaceae families. The incorporation of glucosinolate- containing plant material into the soil results in degradation products highly toxic to soilborne pest, pathogens and weeds. This practice, known as biofumigation, may be considered as an ecological alternative to soil toxic fumigants. Plant-derived saponins are triterpene glycosides present in top and root tissues of plant species of the families Leguminosae, Alliaceae, Asteraceae, Polygalaceae and Agavaceae. Saponins and saponin-rich plant materials have been also reported for a biocidal activity on phytoparasites and soilborne plant pathogens. Essential oils are volatile, natural, heterogeneous mixtures of single substances, mainly terpenes and phenolics, formed as secondary metabolites by aromatic plants belonging to several botanical families. Among terpenes, limonoid triterpenes have been demonstrated to possess interesting insecticidal, nematicidal and antifungal properties. Occurrence of these compounds is mainly limited to Meliaceae and Rutaceae. Alkaloids, phenolics, cyanogenic glucosides

  17. [Ecological effects of cover crops].

    Science.gov (United States)

    Liu, Xiaobing; Song, Chunyu; Herbert, Stephen J; Xing, Baoshan

    2002-03-01

    This paper reviewed the effects of cover crops in reducing soil loss, surface runoff, NO3- leaching and water pollution, and elucidated roles of cover crops in controlling pest insects, weeds and diseases, and increasing soil nutrients. The potential roles and appropriate application of cover crops in sustainable development of agriculture were also discussed.

  18. Sustainability of current agriculture practices, community perception, and implications for ecosystem health: an Indian study.

    Science.gov (United States)

    Sarkar, Atanu; Patil, Shantagouda; Hugar, Lingappa B; vanLoon, Gary

    2011-12-01

    In order to support agribusiness and to attain food security for ever-increasing populations, most countries in the world have embraced modern agricultural technologies. Ecological consequences of the technocentric approaches, and their sustainability and impacts on human health have, however, not received adequate attention particularly in developing countries. India is one country that has undergone a rapid transformation in the field of agriculture by adopting strategies of the Green Revolution. This article provides a comparative analysis of the effects of older and newer paradigms of agricultural practices on ecosystem and human health within the larger context of sustainability. The study was conducted in three closely situated areas where different agricultural practices were followed: (a) the head-end of a modern canal-irrigated area, (b) an adjacent dryland, and (c) an area (the ancient area) that has been provided with irrigation for some 800 years. Data were collected by in-depth interviews of individual farmers, focus-group discussions, participatory observations, and from secondary sources. The dryland, receiving limited rainfall, continues to practice diverse cropping centered to a large extent on traditional coarse cereals and uses only small amounts of chemical inputs. On the other hand, modern agriculture in the head-end emphasizes continuous cropping of rice supported by extensive and indiscriminate use of agrochemicals. Market forces have, to a significant degree, influenced the ancient area to abandon much of its early practices of organic farming and to take up aspects of modern agricultural practice. Rice cultivation in the irrigated parts has changed the local landscape and vegetation and has augmented the mosquito population, which is a potential vector for malaria, Japanese encephalitis and other diseases. Nevertheless, despite these problems, perceptions of adverse environmental effects are lowest in the heavily irrigated area.

  19. Do earthworms help to sustain the slug predator Pterostichus melanarius (Coleoptera: carabidae) within crops? Investigations using monoclonal antibodies.

    Science.gov (United States)

    Symondson, W O; Glen, D M; Erickson, M L; Liddell, J E; Langdon, C J

    2000-09-01

    Earthworms provide a major potential source of alternative food for polyphagous predators, such as carabid beetles, that are natural enemies of slugs, aphids and other agricultural pests. Non-pest prey may foster larger numbers of natural enemies, which then help to control pests, or alternatively may help to divert the predators away from pest control. An earthworm-specific monoclonal antibody was developed to study carabid-earthworm interactions in the field and assess the role of earthworms as alternative prey. The antibody could identify as little at 7 ng of earthworm protein in an ELISA, and could detect earthworm remains in the foregut of the carabid beetle Pterostichus melanarius for 64 h after consumption. Thirty-six per cent of field-collected beetles contained earthworm remains. Quantities of earthworm proteins in the beetle foreguts were negatively related to total foregut biomass, suggesting that earthworm consumption increased as total prey availability declined. There was also a negative relationship between foregut biomass and beetle numbers, but both quantities and concentrations of earthworm proteins in beetle foreguts were positively related to beetle numbers. This suggests that as beetle activity-density increased, total prey availability declined, or, as prey availability declined, beetles spent more time searching. In these circumstances, beetles fed to a greater extent on earthworms, an acceptable but nonpreferred food item. Earthworms may, therefore, provide an ideal alternative prey for P. melanarius, helping to sustain it when pest numbers are low but allowing it to perform a 'lying-in-wait' strategy, ready to switch back to feeding on pests when they become available.

  20. From Theory to Rural Farms: Testing the Efficacy of the Dryland Development Paradigm of Desertification

    Science.gov (United States)

    Reynolds, J. F.; Herrick, J.; Huber-Sannwald, E.; Ayarza, M.

    2011-12-01

    The social and economic systems of humans (H) are inextricably linked with environmental (E) systems. This tight coupling is especially relevant in drylands, where ecosystem goods and services vital to sustaining the livelihoods of human populations are constantly changing over time. The Dryland Development Paradigm (DDP; Reynolds et al. 2007, Science 316, 847-851) was proposed as an integrated framework for dealing with the enormous complexity associated with coupled H-E systems. The DDP consists of five principles: (1) the structure, function and interrelationships that characterize H-E systems are always changing so both H and E factors must always be considered simultaneously; (2) a limited suite of "slow" variables are critical determinants of H-E dynamics; (3) thresholds in both H and E systems are vital: if a key slow variable crosses a threshold this can lead to a different state or condition (a switch in culture resistance to the introduction of new technology such as tractors to plow fields); (4) H-E systems are hierarchical in nature and because of the many cross-scale linkages and feedbacks, adaptation, surprises and self-organization are the norm; and (5) lastly, "solving" land degradation problems cannot be accomplished without drawing upon the firsthand experience and insights (local knowledge) of local stakeholders. For the past 7 years, ARIDnet-AMERICAS, an NSF-supported coordination research network, has applied these five principles via 11 case studies at diverse locations in Argentina, Bolivia, Chile, Columbia, Honduras, Mexico and the United States with the goal to compare and contrast the causes and processes of land degradation and their effects on the balance between the demand for, and supply of, ecosystem services. We present a summary of our initial synthesis. The causal human-environmental processes driving land degradation (e.g., overgrazing, government policies, international markets) are often similar but with differing levels of

  1. Is current irrigation sustainable in the United States? An integrated assessment of climate change impact on water resources and irrigated crop yields

    National Research Council Canada - National Science Library

    Blanc, Elodie; Caron, Justin; Fant, Charles; Monier, Erwan

    2017-01-01

    Climate and socioeconomic changes will increase water shortages and strongly reduce irrigated crop yields in specific regions or crops GHG mitigation has the potential to alleviate the effect of water...

  2. Cowpea (Vigna unguiculata L. Walp), a renewed multipurpose crop for a more sustainable agri-food system: nutritional advantages and constraints.

    Science.gov (United States)

    Gonçalves, Alexandre; Goufo, Piebiep; Barros, Ana; Domínguez-Perles, Raúl; Trindade, Henrique; Rosa, Eduardo A S; Ferreira, Luis; Rodrigues, Miguel

    2016-07-01

    The growing awareness of the relevance of food composition for human health has increased the interest of the inclusion of high proportions of fruits and vegetables in diets. To reach the objective of more balanced diets, an increased consumption of legumes, which constitutes a sustainable source of essential nutrients, particularly low-cost protein, is of special relevance. However, the consumption of legumes also entails some constraints that need to be addressed to avoid a deleterious impact on consumers' wellbeing and health. The value of legumes as a source of nutrients depends on a plethora of factors, including genetic characteristics, agro-climatic conditions, and postharvest management that modulate the dietary effect of edible seeds and vegetative material. Thus, more comprehensive information regarding composition, especially their nutritional and anti-nutritional compounds, digestibility, and alternative processing procedures is essential. These were the challenges to write this review, which focusses on the nutritional and anti-nutritional composition of Vigna unguiculata L. Walp, an emerging crop all over the world intended to provide a rational support for the development of valuable foods and feeds of increased commercial value. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. An evaluation of four crop:weed competition models using a common data set

    NARCIS (Netherlands)

    Deen, W.; Cousens, R.; Warringa, J.; Bastiaans, L.; Carberry, P.; Rebel, K.; Riha, S.; Murphy, C.; Benjamin, L.R.; Cloughley, C.; Cussans, J.; Forcella, F.

    2003-01-01

    To date, several crop : weed competition models have been developed. Developers of the various models were invited to compare model performance using a common data set. The data set consisted of wheat and Lolium rigidum grown in monoculture and mixtures under dryland and irrigated conditions.

  4. Modeling the yield potential of dryland canola under current and future climates in California

    Science.gov (United States)

    George, N.; Kaffka, S.; Beeck, C.; Bucaram, S.; Zhang, J.

    2012-12-01

    Models predict that the climate of California will become hotter, drier and more variable under future climate change scenarios. This will lead to both increased irrigation demand and reduced irrigation water availability. In addition, it is predicted that most common Californian crops will suffer a concomitant decline in productivity. To remain productive and economically viable, future agricultural systems will need to have greater water use efficiency, tolerance of high temperatures, and tolerance of more erratic temperature and rainfall patterns. Canola (Brassica napus) is the third most important oilseed globally, supporting large and well-established agricultural industries in Canada, Europe and Australia. It is an agronomically useful and economically valuable crop, with multiple end markets, that can be grown in California as a dryland winter rotation with little to no irrigation demand. This gives canola great potential as a new crop for Californian farmers both now and as the climate changes. Given practical and financial limitations it is not always possible to immediately or widely evaluate a crop in a new region. Crop production models are therefore valuable tools for assessing the potential of new crops, better targeting further field research, and refining research questions. APSIM is a modular modeling framework developed by the Agricultural Production Systems Research Unit in Australia, it combines biophysical and management modules to simulate cropping systems. This study was undertaken to examine the yield potential of Australian canola varieties having different water requirements and maturity classes in California using APSIM. The objective of the work was to identify the agricultural regions of California most ideally suited to the production of Australian cultivars of canola and to simulate the production of canola in these regions to estimate yield-potential. This will establish whether the introduction and in-field evaluation of better

  5. Linking Regional Satellite Observations with Coupled Human-Ecological Systems in Global Drylands

    Science.gov (United States)

    Hutchinson, C.; Reynolds, J. F.

    2009-12-01

    The African Sahel has attracted consistent attention since a series of droughts in the 1970s and 1980s caused widespread famine and land degradation (desertification). These events spawned international conventions and sustained development efforts to increase food security and reverse poverty for the local populations, and to arrest environmental degradation. Since 1985, several studies using satellite data have described a general “greening” in response to increased rainfall trends. However, some areas show more greening while others less greening than can be explained by precipitation alone (Glob. Env. Change 15- 2005). The debated question is how to explain the residual changes: management, policy, human adaptation, or something else? Placing results in an human-ecological framework could help answer this question. Providing a meaningful assessment will allow national and international agencies to evaluate the effectiveness of alternative approaches to poverty alleviation and environmental restoration in drylands at regional and global scales.

  6. Specific leaf area predicts dryland litter decomposition via two mechanisms

    NARCIS (Netherlands)

    Liu, Guofang; Wang, Lei; Jiang, Li; Pan, Xu; Huang, Zhenying; Dong, Ming; Cornelissen, Johannes H.C.

    2018-01-01

    Litter decomposition plays important roles in carbon and nutrient cycling. In dryland, both microbial decomposition and abiotic degradation (by UV light or other forces) drive variation in decomposition rates, but whether and how litter traits and position determine the balance between these

  7. Expansion of global drylands under a warming climate

    Directory of Open Access Journals (Sweden)

    S. Feng

    2013-10-01

    Full Text Available Global drylands encompassing hyper-arid, arid, semiarid, and dry subhumid areas cover about 41 percent of the earth's terrestrial surface and are home to more than a third of the world's population. By analyzing observations for 1948–2008 and climate model simulations for 1948–2100, we show that global drylands have expanded in the last sixty years and will continue to expand in the 21st~century. By the end of this century, the world's drylands (under a high greenhouse gas emission scenario are projected to be 5.8 × 106 km2 (or 10% larger than in the 1961–1990 climatology. The major expansion of arid regions will occur over southwest North America, the northern fringe of Africa, southern Africa, and Australia, while major expansions of semiarid regions will occur over the north side of the Mediterranean, southern Africa, and North and South America. The global dryland expansions will increase the population affected by water scarcity and land degradations.

  8. Response of a dryland fluvial system to climate–tectonic ...

    Indian Academy of Sciences (India)

    2Department of Earth and Environmental Science, K.S.K.V. Kachchh University, Bhuj, Kachchh 370 001, India. ∗. Corresponding ... Temporal changes in the hydrological condition are manifested in the ... Response of a dryland fluvial system to climate–tectonic perturbations during Late Quaternary 1121 during the Late ...

  9. The development of reforestation options for dryland farmland in ...

    African Journals Online (AJOL)

    Current forest industries in south-western Australia are based on regrowth natural eucalypt forests and Pinus and Eucalyptus spp. plantations, and restricted to areas with >600 mm y−1 annual rainfall. Dryland farming systems have been developed across 20 million ha in a zone with 300–600 mm y−1 annual rainfall and a ...

  10. Rainfall probability and EONR for dryland corn in Colorado

    Science.gov (United States)

    Nitrogen fertilizer costs have increased 70% in the last 6 yrs in the Central Great Plains Region (CGPR). This cost increase coincides with a decrease in dryland grain yields due to drought. How does the economic optimum N rate (EONR) change with grain price and fertilizer cost? Here we evaluated 11...

  11. Insistent Dryland Narratives: Portraits of Knowledge about Human ...

    African Journals Online (AJOL)

    The drylands in the West African Sahel region have, since the catastrophic drought event in the 1970s, been a focal point of interest in the cross field between environmental research, knowledge systems and policy intervention strategies. Major international institutions, agencies and conventions have played an important ...

  12. Organic Waste Nitrogen and Phosphorus Dynamics Under Dryland Agroecosystems

    Science.gov (United States)

    Organic waste beneficial-use programs effectively recycle plant nutrients when applied at agronomic rates. Plant-nutrient availability, transport, and fate questions have arisen when organic wastes such as biosolids have been applied to dryland agroecosystems. What is the N-fertilizer equivalency ...

  13. Desertification, land use, and the transformation of global drylands

    Science.gov (United States)

    Desertification is an escalating concern in global drylands, yet assessments to guide management and policy responses are limited by ambiguity concerning what this term means and what processes are involved. In order to provide greater clarity, we propose that desertification assessments be placed w...

  14. Restoration of Native Hawaiian Dryland Forest at Auwahi, Maui

    Science.gov (United States)

    Medieros, Arthur C.; vonAllmen, Erica

    2006-01-01

    BACKGROUND The powerful volcanoes that formed the high islands of the Hawaiian archipelago block northeasterly tradewinds, creating wet, windward rain forests and much drier, leeward forests. Dryland forests in Hawai'i receive only about 20 inches of rain a year. However, the trees in these forests intercept fog and increase ground moisture levels, thereby enabling these seemingly inhospitable habitats to support a diverse assemblage of plants and animals. Dryland forests of the Hawaiian Islands, like those worldwide, have been heavily impacted by humans both directly and indirectly. Less than 10% of Hawai'i's original dryland forest habitat remains. These forests have been severely impacted by urban development, ranching and agriculture, and invasive species. In particular, browsing animals and alien grasses have caused significant damage. Feral ungulates, including goats, sheep, cattle, and pigs, consume sensitive plants. Alien grasses have become dominant in the understory in many dryland habitats. In addition, these introduced grasses are fire-adapted and have increased the incidence of wildfire in these ecosystems. Native Hawaiian plants did not evolve with frequent fires or mammalian herbivores and typically do not survive well under these pressures.

  15. Response of a dryland fluvial system to climate–tectonic ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 6. Response of a dryland fluvial system to climate–tectonic perturbations during the Late Quaternary: Evidence from Rukmawati River basin, Kachchh, western India. Archana Das Falguni Bhattacharya B K Rastogi Gaurav Chauhan Mamata Ngangom ...

  16. Performance of Medicago sativa under dryland conditions on the ...

    African Journals Online (AJOL)

    Reports the results of research conducted into pasture establishment using legumes. Examines possible strategies for integrating dryland lucerne into livestock production systems on the eastern Highveld. Focuses on livestock production from pure and mixed lucerne pastures; Increased livestock numbers and improved ...

  17. Salvadora persica agro-ecological suitability for oil production in Argentine dryland salinity.

    Science.gov (United States)

    Falasca, Silvia; Pitta-Alvarez, Sandra; del Fresno, Carolina Miranda

    2015-12-15

    One of the major causes of crop stress is soil or water salinity. Thus, selection of the best species for cultivation in semiarid and arid climates is fundamental. Salvadora persica is an evergreen perennial halophyte that can grow under extreme conditions, from very dry environments to highly saline soils. Based on international bibliography, the authors outlined an agro-ecological zoning model to determine the potential cultivation zones for S. persica in Argentina. This model may be applied to any part of the world, using the agro-ecological limits presented in this work. All the maps were developed by the implementation of a geographic information system (GIS) that can be updated by the further incorporation of complementary information, with the consequent improvement of the original database. The overlap of the agroclimatic suitability map on the drylands' saline soils and the drylands' alkaline soils maps, determined the agro-ecological zoning. Since some areas in the agro-ecological zoning can overlap with land that is already assigned for other uses, protected areas, current land use/cover of the different zones, and urban areas maps were incorporated into the GIS and subtracted by a mask. This resulted in the delimitation of "potential cultivation zoning", thus avoiding possible conflicts surrounding the use of land and making the agro-ecological zonation more efficient. There is a broad agro-ecological zone for cultivation of S. persica that extends from Northern Argentina to approximately 41° South latitude, under dry-subhumid to semiarid climates. Lands classified with different degrees of suitability in the potential cultivation zoning could be used for production of this species for energy purposes on lands that are either unsuitable for food production or currently assigned for other purposes. This paper represents pioneering work since there are no previous studies concerning the introduction of S. persica in Argentina. Copyright © 2015 Elsevier

  18. Understanding Land System Change Through Scenario-Based Simulations: A Case Study from the Drylands in Northern China.

    Science.gov (United States)

    Liu, Zhifeng; Verburg, Peter H; Wu, Jianguo; He, Chunyang

    2017-03-01

    The drylands in northern China are expected to face dramatic land system change in the context of socioeconomic development and environmental conservation. Recent studies have addressed changes of land cover with socioeconomic development in the drylands in northern China. However, the changes in land use intensity and the potential role of environmental conservation measures have yet to be adequately examined. Given the importance of land management intensity to the ecological conditions and regional sustainability, our study projected land system change in Hohhot city in the drylands in northern China from 2013 to 2030. Here, land systems are defined as combinations of land cover and land use intensity. Using the CLUMondo model, we simulated land system change in Hohhot under three scenarios: a scenario following historical trends, a scenario with strong socioeconomic and land use planning, and a scenario focused on achieving environmental conservation targets. Our results showed that Hohhot is likely to experience agricultural intensification and urban growth under all three scenarios. The agricultural intensity and the urban growth rate were much higher under the historical trend scenario compared to those with more planning interventions. The dynamics of grasslands depend strongly on projections of livestock and other claims on land resources. In the historical trend scenario, intensively grazed grasslands increase whereas a large amount of the current area of grasslands with livestock converts to forest under the scenario with strong planning. Strong conversion from grasslands with livestock and extensive cropland to semi-natural grasslands was estimated under the conservation scenario. The findings provide an input into discussions about environmental management, planning and sustainable land system design for Hohhot.

  19. Understanding Land System Change Through Scenario-Based Simulations: A Case Study from the Drylands in Northern China

    Science.gov (United States)

    Liu, Zhifeng; Verburg, Peter H.; Wu, Jianguo; He, Chunyang

    2017-03-01

    The drylands in northern China are expected to face dramatic land system change in the context of socioeconomic development and environmental conservation. Recent studies have addressed changes of land cover with socioeconomic development in the drylands in northern China. However, the changes in land use intensity and the potential role of environmental conservation measures have yet to be adequately examined. Given the importance of land management intensity to the ecological conditions and regional sustainability, our study projected land system change in Hohhot city in the drylands in northern China from 2013 to 2030. Here, land systems are defined as combinations of land cover and land use intensity. Using the CLUMondo model, we simulated land system change in Hohhot under three scenarios: a scenario following historical trends, a scenario with strong socioeconomic and land use planning, and a scenario focused on achieving environmental conservation targets. Our results showed that Hohhot is likely to experience agricultural intensification and urban growth under all three scenarios. The agricultural intensity and the urban growth rate were much higher under the historical trend scenario compared to those with more planning interventions. The dynamics of grasslands depend strongly on projections of livestock and other claims on land resources. In the historical trend scenario, intensively grazed grasslands increase whereas a large amount of the current area of grasslands with livestock converts to forest under the scenario with strong planning. Strong conversion from grasslands with livestock and extensive cropland to semi-natural grasslands was estimated under the conservation scenario. The findings provide an input into discussions about environmental management, planning and sustainable land system design for Hohhot.

  20. Is current irrigation sustainable in the United States? An integrated assessment of climate change impact on water resources and irrigated crop yields

    OpenAIRE

    Blanc, Elodie; Caron, Justin; Fant, Charles; Monier, Erwan

    2017-01-01

    Abstract While climate change impacts on crop yields has been extensively studied, estimating the impact of water shortages on irrigated crop yields is challenging because the water resources management system is complex. To investigate this issue, we integrate a crop yield reduction module and a water resources model into the MIT Integrated Global System Modeling framework, an integrated assessment model linking a global economic model to an Earth system model. We assess the effects of clima...

  1. Advances in the prognosis of soil sodicity under dryland irrigated conditions

    Directory of Open Access Journals (Sweden)

    Ildefonso Pla Sentís

    2014-12-01

    Full Text Available Salt-affected soils, both saline and sodic, may develop under both dryland and irrigated conditions, affecting the physical and chemical soil properties, with negative consequences in the environment, in crop production and in animal and human health. Among the development processes of salt-affected soils, the processes of sodification have generally received less attention and are less understood than the development of saline soils. Although in both, hydrological processes are involved in their development, in the case of sodic soils we have to consider some additional chemical and physicochemical reactions, making more difficult their modeling and prediction. This is especially true where we have to consider the effects of the groundwater level and composition. In this contribution there are presented three case studies: one related to the development of sodic soils in the lowlands of the Argentina Pampas, under dry-land conditions with sub-humid temperate climate and pastures for cattle production; the second deals with the development of sodic soils in the Colombia Cauca Valley, under irrigated conditions and tropical sub-humid climate, in lands used for sugarcane cropping dedicated to sugar and ethanol production; and the last one related to the sodification of soils in the Western Plains of Venezuela, under irrigated conditions, sub-humid tropical climate and continuous cropping of rice under flooding. The development of sodicity in the surface soil is partially related to the composition and level of the ground-water, mainly affected in the Argentina case by drainage conditions, in the case of Colombia to the inefficient irrigation and inadequate drainage, and in the case of Venezuela to the soil management and irrigation system. There is shown how the model SALSODIMAR, developed by the author, based on the balance of water and soluble components of both irrigation water and ground-water, under different water and land management

  2. Enhancing agricultural productivity and rural incomes through sustainable use of natural resources in the semi arid tropics.

    Science.gov (United States)

    Wani, Suhas P; Dixin, Yin; Li, Zhong; Dar, William D; Chander, Girish

    2012-03-30

    A participatory watershed management approach is one of the tested, sustainable and eco-friendly options to upgrade rain-fed agriculture to meet growing food demand along with additional multiple benefits in terms of improving livelihoods, addressing equity issues and biodiversity concerns. Watershed interventions at study sites in Thailand (Tad Fa and Wang Chai) and India (Kothapally) effectively reduced runoff and the associated soil loss. Such interventions at Xiaoxincun (China) and Wang Chai improved groundwater recharging and availability. Enhanced productive transpiration increased rainwater use efficiency for crop production by 13-29% at Xiaoxincun; 13-160% at Lucheba (China), 32-37% at Tad Fa and 23-46% at Wang Chai and by two to five times at Kothapally. Watershed interventions increased significantly the additional net returns from crop production as compared with the pre-watershed intervention period. Increased water availability opened up options for crop diversification with high-value crops, including increased forage production and boosted livestock-based livelihoods. In dryland tropics, integrated watershed management approach enabled farmers to diversify the systems along with increasing agricultural productivity through increased water availability, while conserving the natural resource base. Household incomes increased substantially, leading to improved living and building the resilience of the community and natural resources. Copyright © 2011 Society of Chemical Industry.

  3. Incorporating soil health management practices into viable potato cropping systems

    Science.gov (United States)

    Soil health is critical to agricultural sustainability, environmental quality, and ecosystem function, but is generally degraded through intensive potato production. Soil and crop management practices beneficial to soil health, such as crop rotations, cover crops and green manures, organic amendment...

  4. Making rainfed agriculture sustainable through environmental friendly technologies in Pakistan: A review

    Directory of Open Access Journals (Sweden)

    Mirza B. Baig

    2013-09-01

    Full Text Available Pakistan is an agricultural country spreading over an area of about 79. 6 million hectares (Mha with an arid and semi arid climate. Of 79. 6 Mha, about 23 Mha is suitable for crop production and nearly 25 percent of the total cultivated area is designated for rainfed agriculture. Unfortunately, rain-fed agriculture is constrained with multifarious problems such as moisture stress, soil erosion and crusting, nutrient deficiency, depletion and poor nutrient use efficiency, and weed infestation limiting the yield potential of these lands. In addition, deforestation and poor crop husbandry techniques are commonly noticed features. To meet the food requirements, farmers bring all the available pieces of lands under plough including steep slopes. Farming on steep slopes if not managed on scientific lines, results in severe erosion. The problems faced by the farmers are due to the unsustainable practices they adopt to practice dryland agriculture, limiting the productive potential of these important ecosystems. However, their potential can be improved by adopting suitable rainwater harvesting techniques; employing scientific soil and water conservation methods and using sustainable agricultural practices. This paper highlights some important issues associated with the rainfed agriculture of Pakistan. Working strategies for realizing optimum and sustainable yields have been outlined while conserving both land and water resources.

  5. Agroecology of Novel Annual and Perennial Crops for Biomass Production

    DEFF Research Database (Denmark)

    Manevski, Kiril; Jørgensen, Uffe; Lærke, Poul Erik

    The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production.......The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production....

  6. Climatic and Socioeconomic Determinants of the Supply and Demand of Net Primary Production in sub-Saharan Drylands

    Science.gov (United States)

    Abdi, A.

    2015-12-01

    Around two-thirds of Africa's inhabitants live in drylands and rely on multifaceted livelihoods involving rain-fed agriculture, cash crops, pastoralism, and livestock production. A large portion of dryland sub-Saharan Africa is under the influence of global climatic teleconnections that produces variability in the Earth's climate. Areas where the vegetation has a strong response to climatic variability clearly exhibit the relationship between human well-being and the climate system. We define NPP supply as the annual amount of carbon that plants remove from the atmosphere through photosynthesis and store as biomass, and NPP demand is the annual amount of carbon required for food, feed and fuel and it drives land use changes such as the expansion of cropland, wood fuel extraction and pasture creation. In this poster, we present preliminary evidence to show that global climatic teleconnections regulate the NPP supply in Africa, while NPP demand increase as a function of demographic growth. Our results point to a scenario whereby the demand for NPP could outpace available supply. Increased climatic variability and extreme events could potentialy tilt this balance further by reducing NPP supply through intense droughts and floods.

  7. Agricultural Investments and Farmer-Fulani Pastoralist Conflict in West African Drylands: A Northern Ghanaian Case Study

    Directory of Open Access Journals (Sweden)

    Sebastiaan Soeters

    2017-11-01

    Full Text Available In the Global South, there is a push to drive agricultural modernisation processes through private sector investments. In West African drylands, land concessions are required for such agri-businesses are often negotiated through customary authorities, and inject large amounts of money into localised rural systems with low cash bases. The article argues that such transactions serve to increase area under crop cultivation on an inter-seasonal basis, as financial spill-overs allow for farmers to purchase larger quantities of agricultural inputs and prepare larger tracts of land. Simultaneously, such direct and indirect cash flows also result in larger local herd sizes and an increase in the number of locally-owned cattle, as cash is exchanged for cattle, largely regarded as an interest-accruing, savings buffer. Larger herd sizes, in turn, attract Fulani pastoralists in search of employment as contracted herders for local cattle owners. Taking Integrated Water and Agricultural Development (IWAD, a private sector, large-scale irrigation initiative in northern Ghana as a case study, the article argues that there is an inevitability of the pathway, which leads from large-scale land acquisitions in West-African drylands, to an increase in conflict (and/or the risk thereof between sedentary and Fulani pastoralists.

  8. Desertification, land use, and the transformation of global drylands

    Science.gov (United States)

    Bestelmeyer, Brandon T.; Okin, Gregory S.; Duniway, Michael C.; Archer, Steven R.; Sayre, Nathan F.; Williamson, Jebediah C.; Herrick, Jeffrey E.

    2015-01-01

    Desertification is an escalating concern in global drylands, yet assessments to guide management and policy responses are limited by ambiguity concerning the definition of “desertification” and what processes are involved. To improve clarity, we propose that assessments of desertification and land transformation be placed within a state change–land-use change (SC–LUC) framework. This framework considers desertification as state changes occurring within the context of particular land uses (eg rangeland, cropland) that interact with land-use change. State changes that can be readily reversed are distinguished from regime shifts, which are state changes involving persistent alterations to vegetation or soil properties. Pressures driving the transformation of rangelands to other types of land uses may be low, fluctuating, or high, and may influence and be influenced by state change. We discuss how the SC–LUC perspective can guide more effective assessment of desertification and management of drylands.

  9. Resilience of small-scale societies: a view from drylands

    Directory of Open Access Journals (Sweden)

    Andrea L. Balbo

    2016-06-01

    Full Text Available To gain insights on long-term social-ecological resilience, we examined adaptive responses of small-scale societies to dryland-related hazards in different regions and chronological periods, spanning from the mid-Holocene to the present. Based on evidence from Africa (Sahara and Sahel, Asia (south margin of the Thar desert, and Europe (South Spain, we discuss key traits and coping practices of small-scale societies that are potentially relevant for building resilience. The selected case studies illustrate four main coping mechanisms: mobility and migration, storage, commoning, and collective action driven by religious beliefs. Ultimately, the study of resilience in the context of drylands emphasizes the importance of adaptive traits and practices that are distinctive of small-scale societies: a strong social-ecological coupling, a solid body of traditional ecological knowledge, and a high degree of internal cohesion and self-organization.

  10. Plant species richness and ecosystem multifunctionality in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Quero, José L.; Gotelli, Nicholas J.; Escudero, Adriá; Ochoa, Victoria; Delgado-Baquerizo, Manuel; García-Gómez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; García-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceição, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitán, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gómez-González, Susana; Gutiérrez, Julio R.; Hernández, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Aníbal; Pucheta, Eduardo; Ramírez-Collantes, David A.; Romão, Roberto; Tighe, Matthew; Torres-Díaz, Cristian; Val, James; Veiga, José P.; Wang, Deli; Zaady, Eli

    2013-01-01

    Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report on the first global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality, and always included species richness as a predictor variable. Our results suggest that preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands. PMID:22246775

  11. Plant species richness and ecosystem multifunctionality in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Quero, Jose L.; Gotelli, Nicholas J.; Escudero, Adrian; Ochoa, Victoria; Delgado-Baquerizo, Manuel; Garcia-Gomez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; Garcia-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceicao, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitan, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gomez-Gonzalez, Susana; Gutie, Julio R.; Hernandez, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Anibal; Pucheta, Eduardo; Ramirez-Collantes, David A.; Romao, Roberto; Tighe, Matthew; Torres-Diaz, Cristian; Val, James; Veiga, Jose P.; Wang, Deli; Zaady, Eli

    2012-01-01

    Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

  12. Climate and soil factors influencing seedling recruitment of plant species used for dryland restoration

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Erickson, Todd E.; Martini, Dylan C.; Dixon, Kingsley W.; Merritt, David J.

    2016-06-01

    Land degradation affects 10-20 % of drylands globally. Intensive land use and management, large-scale disturbances such as extractive operations, and global climate change, have contributed to degradation of these systems worldwide. Restoring these damaged environments is critical to improving ecosystem services and functions, conserve biodiversity, and contribute to climate resilience, food security, and landscape sustainability. Here, we present a case study on plant species of the mining intensive semi-arid Pilbara region in Western Australia that examines the effects of climate and soil factors on the restoration of drylands. We analysed the effects of a range of rainfall and temperature scenarios and the use of alternative soil materials on seedling recruitment of key native plant species from this area. Experimental studies were conducted in controlled environment facilities where conditions simulated those found in the Pilbara. Soil from topsoil (T) stockpiles and waste materials (W) from an active mine site were mixed at different proportions (100 % T, 100 % W, and two mixes of topsoil and waste at 50 : 50 and 25 : 75 ratios) and used as growth media. Our results showed that seedling recruitment was highly dependent on soil moisture and emergence was generally higher in the topsoil, which had the highest available water content. In general, responses to the climate scenarios differed significantly among the native species which suggest that future climate scenarios of increasing drought might affect not only seedling recruitment but also diversity and structure of native plant communities. The use of waste materials from mining operations as growth media could be an alternative to the limited topsoil. However, in the early stages of plant establishment successful seedling recruitment can be challenging in the absence of water. These limitations could be overcome by using soil amendments but the cost associated to these solutions at large landscape scales

  13. Improving rice-based rainfed production systems in Southeast Asia for contributing towards food security and rural development through sustainable crop production intensification

    Directory of Open Access Journals (Sweden)

    Abha Mishra

    2016-04-01

    Full Text Available Continuing degradation of the environment and the cumulating food, energy, water and financial crises have led to a situation where many people’s access to sufficient, nutritious food is affected as well as their livelihoods, income, and ultimate food and nutrition security. In the wake of these stresses and crises, there is an emerging interest to find efficient, easily accessible and sustainable approaches that can address these crises. One candidate for this is the System of Rice Intensification (SRI with its “less can produce more” prescription. A regional collaborative project currently underway is being implemented in rainfed areas of the Lower Mekong River Basin (LMB countries. This involves smallholder rice farmers, researchers, extension personnel, and development professionals, together with staff of relevant government ministries (http://www.sri-lmb.ait.asia/. The project objective is to produce healthier and profitable rice crops under rainfed conditions using SRI methods, evaluated and refined through farmers’ participatory action research (FPAR. As part of the action-research, more than 120 sets of field experiments have been carried out at 60 FPAR sites in Cambodia and Thailand, directly involving 3600 farmers. The experiments have ranged from the integration of many SRI principles with farmers’ current local practices or improved practices which was termed as “SRI-transition” to full demonstrations and assessments of SRI methodology, i.e., SRI demonstration. The initial calculation of yields has showed an average paddy yield of 5.03 t/ha with SRI-transition, whereas with SRI-demonstration the average yield was 6.41 t/ha. These yields were 60 and 100% higher than the average baseline yield in the region, 3.14 t/ha, for the same farmers and same locales. Productivity gains (dollars gained/dollars spent per ha were calculated for both rainfed and irrigated production areas. In comparative terms, the economic gains for

  14. Establishment of a constructed wetland in extreme dryland.

    Science.gov (United States)

    Tencer, Yoram; Idan, Gil; Strom, Marjorie; Nusinow, Uri; Banet, Dorit; Cohen, Eli; Schröder, Peter; Shelef, Oren; Rachmilevitch, Shimon; Soares, Ines; Gross, Amit; Golan-Goldhirsh, Avi

    2009-11-01

    The project was set to construct an extensive wetland in the southernmost region of Israel at Kibbutz Neot Smadar (30 degree 02'45" N and 35 degree 01'19" E). The results of the first period of monitoring, summary, and perspectives are presented. The constructed wetland (CW) was built and the subsequent monitoring performed in the framework of the Southern Arava Sustainable Waste Management Plan, funded by the EU LIFE Fund. The specific aims were: (1) To end current sewage disposal and pollution of the ground, the aquifer, and the dry river bed (wadi) paths by biologically treating the sewage as part of the creation of a sustainable wetland ecosystem. (2) Serve as an example of CW in the Negev highlands and the Arava Valley climates for neighboring communities and as a test ground for plants and building methods appropriate to hyper arid climate. (3) Serve as an educational resource and tourist attraction for groups to learn about water reuse, recycling, local wildlife and migrating birds, including serving the heart of a planned Ecological-Educational Bird Park. This report is intended to allow others who are planning similar systems in hyper arid climates to learn from our experience. The project is located in an extreme arid desert with less than 40 mm of rain annually and temperature ranges of -5 degree C to +42 degree C. The site receives 165-185 m3 of municipal and agricultural wastes daily, including cowshed and goat wastes and winery outflow. The CW establishment at Neot Smadar was completed in October 2006. For 8 months, clean water flowed through the system while the plants were taking root. In June 2007, the wetland was connected to the oxidation pond and full operation began. Because of seepage and evaporation, during the first several months, the water level was not high enough to allow free flow from one bed to the next. To bed A, the water was pumped periodically from the oxidation pond (Fig. 1) and from there flowed by gravitation through the rest

  15. Stable Food Crops Turning Into Commercial Crops: Case studies of ...

    African Journals Online (AJOL)

    RahelYilma

    Sustainable food security and welfare cannot be achieved through subsistence agriculture (Pingali, 1997). ... Hence, in this study,. 3 Teff is a grass-like fine seeded staple food crop grown in Ethiopia. 4 APA is the .... the suitability of the agro-ecology for the crop, while distance to milling service affects cost of consumption.

  16. A coupled vegetation/sediment transport model for dryland environments

    Science.gov (United States)

    Mayaud, Jerome R.; Bailey, Richard M.; Wiggs, Giles F. S.

    2017-04-01

    Dryland regions are characterized by patchy vegetation, erodible surfaces, and erosive aeolian processes. Understanding how these constituent factors interact and shape landscape evolution is critical for managing potential environmental and anthropogenic impacts in drylands. However, modeling wind erosion on partially vegetated surfaces is a complex problem that has remained challenging for researchers. We present the new, coupled cellular automaton Vegetation and Sediment TrAnsport (ViSTA) model, which is designed to address fundamental questions about the development of arid and semiarid landscapes in a spatially explicit way. The technical aspects of the ViSTA model are described, including a new method for directly imposing oblique wind and transport directions onto a cell-based domain. Verification tests for the model are reported, including stable state solutions, the impact of drought and fire stress, wake flow dynamics, temporal scaling issues, and the impact of feedbacks between sediment movement and vegetation growth on landscape morphology. The model is then used to simulate an equilibrium nebkha dune field, and the resultant bed forms are shown to have very similar size and spacing characteristics to nebkhas observed in the Skeleton Coast, Namibia. The ViSTA model is a versatile geomorphological tool that could be used to predict threshold-related transitions in a range of dryland ecogeomorphic systems.

  17. Evaluating sustainable and profitable cropping sequences with cassave and four legume crops: Effects on soil fertility and maize yields in the forest/savannah transitional agro-ecological zone of Ghana

    NARCIS (Netherlands)

    Adjei-Nsiah, S.; Kuyper, T.W.; Leeuwis, C.; Abekoe, M.K.; Giller, K.E.

    2007-01-01

    Rotations are important practices for managing soil fertility on smallholder farms. Six cropping sequences (cassava, pigeonpea, mucuna-maize-mucuna, cowpea-maize-cowpea, maize-maize-maize, and speargrass fallow) were evaluated during 2003-2004 in Wenchi district of Ghana for their effects on the

  18. The effect of conservation tillage on crop yield in China

    Directory of Open Access Journals (Sweden)

    Hongwen LI,Jin HE,Huanwen GAO,Ying CHEN,Zhiqiang ZHANG

    2015-06-01

    Full Text Available Traditional agricultural practices have resulted in decreased soil fertility, shortage of water resources and deterioration of agricultural ecological environment, which are seriously affecting grain production. Conservation tillage (CT research has been developed and applied in China since the 1960s and 1970s, and a series of development policies have been issued by the Chinese government. Recent research and application have shown that CT has positive effects on crop yields in China. According to the data from the Conservation Tillage Research Center (CTRC, Chinese Ministry of Agriculture (MOA, the mean crop yield increase can be at least 4% in double cropping systems in the North China Plain and 6% in single cropping systems in the dryland areas of North-east and North-west China. Crop yield increase was particularly significant in dryland areas and drought years. The mechanism for the yield increase in CT system can be attributed to enhanced soil water content and improved soil properties. Development strategies have been implemented to accelerate the adoption of CT in China.

  19. Coupled Human-Ecological Dynamics and Land Degradation in Global Drylands-A modelling approach (Invited)

    Science.gov (United States)

    Helldén, U.

    2009-12-01

    Drylands comprise one-third of the Earth’s land area. They pose research, management, and policy challenges impacting the livelihoods of 2.5 billion people. Desertification is said to affect some 10-20% of the drylands and is assumed to expand with climate change and population growth. Recent paradigms stress the importance of understanding linkages between human-ecological (H-E) systems in order to achieve sustainable management policies. Understanding coupled H-E systems is difficult at local levels. It represents an even greater challenge at regional scales to guide priorities and policy decisions at national and international levels. System dynamic modelling may help facilitating the probblem. Desertification and land degradation are often modelled and mathematically defined in terms of soil erosion. The soil erosion process is usually described as a function of vegetation ground cover, rainfall characteristics, topography, soil characteristics and land management. On-going research based on system dynamic modelling, focussing on elucidating the inherent complexity of H-E systems across multiple scales, enables an assessment of the relative roles that climate, policy, management, land condition, vulnerability and human adaptation may play in desertification and dryland development. An early approach (1995) to study desertification through an H-E coupled model considered desertification to be stress beyond resilience, i.e. irreversible, using a predator-prey system approach. As most predator-prey models, it was based on two linked differential equations describing the evolution of both a human population (predator) and natural resources (prey) in terms of gains, losses and interaction. A recent effort used a model approach to assess desertification risk through system stability condition analysis. It is based on the assumption that soil erosion and the soil sub-system play an overriding final role in the desertification processes. It is stressing the role and

  20. Visualizing and quantifying microtopographic change of dryland landscapes from an unmanned aircraft system

    Science.gov (United States)

    Background/Question/Methods: Soil and site stability are key attributes of assessing the health of dryland landscapes because these lands are susceptible to high rates of wind- and water-caused erosion. Field techniques for measuring and monitoring soil erosion in drylands are often labor intensive...

  1. Rainwater harvesting for dryland agriculture in the Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.

    2012-01-01

    The Ethiopian drylands occupy about 65% of the total land mass (close to 700,000km2) of the country. The predominantly rainfed agriculture in these drylands is highly constrained due to erratic rainfall, long dry-spells and excessive loss of rainwater through non-productive pathways

  2. Estimation of livestock appropriation of net primary productivity in Texas Drylands

    Science.gov (United States)

    Robert Washington-Allen; Jody Fitzgerald; Stephanie Grounds; Faisar Jihadi; John Kretzschmar; Kathryn Ramirez; John Mitchell

    2009-01-01

    The ecological state of US Drylands is unknown. This research is developing procedures to determine the impact of the ecological footprint of grazing livestock on the productive capacity of US Drylands. A pilot geodatabase was developed for the state of Texas that includes 2002 data for county boundaries, net primary productivity (NPP) derived from the Moderate...

  3. Planting geometry and plant population affect dryland maize grain yield and harvest index

    Science.gov (United States)

    Water for dryland grain production in the Texas panhandle is limited. Agronomic practices such as reduction in plant population or change in sowing time may help increase maize (Zea mays L.) yield potential. Tiller formation under dryland conditions leads to more vegetative growth and reduced yield....

  4. Genomic footprints of dryland stress adaptation in Egyptian fat-tail sheep and their divergence from East African and western Asia cohorts.

    Science.gov (United States)

    Mwacharo, Joram M; Kim, Eui-Soo; Elbeltagy, Ahmed R; Aboul-Naga, Adel M; Rischkowsky, Barbara A; Rothschild, Max F

    2017-12-15

    African indigenous sheep are classified as fat-tail, thin-tail and fat-rump hair sheep. The fat-tail are well adapted to dryland environments, but little is known on their genome profiles. We analyzed patterns of genomic variation by genotyping, with the Ovine SNP50K microarray, 394 individuals from five populations of fat-tail sheep from a desert environment in Egypt. Comparative inferences with other East African and western Asia fat-tail and European sheep, reveal at least two phylogeographically distinct genepools of fat-tail sheep in Africa that differ from the European genepool, suggesting separate evolutionary and breeding history. We identified 24 candidate selection sweep regions, spanning 172 potentially novel and known genes, which are enriched with genes underpinning dryland adaptation physiology. In particular, we found selection sweeps spanning genes and/or pathways associated with metabolism; response to stress, ultraviolet radiation, oxidative stress and DNA damage repair; activation of immune response; regulation of reproduction, organ function and development, body size and morphology, skin and hair pigmentation, and keratinization. Our findings provide insights on the complexity of genome architecture regarding dryland stress adaptation in the fat-tail sheep and showcase the indigenous stocks as appropriate genotypes for adaptation planning to sustain livestock production and human livelihoods, under future climates.

  5. Nurse crop

    Science.gov (United States)

    Wayne D. Shepperd; John R. Jones

    1985-01-01

    In forestry, a nurse crop generally is a crop of trees or shrubs that fosters the development of another tree species, usually by protecting the second species, during its youth, from frost, insolation, or wind (Ford-Robertson 1971). Aspen may be a nurse crop for shade-tolerant tree species that do not become established in full sunlight (e.g., Engelmann spruce)....

  6. Realities, Perceptions, Challenges and Aspirations of Rural Youth in Dryland Agriculture in the Midelt Province, Morocco

    Directory of Open Access Journals (Sweden)

    Alessandra Giuliani

    2017-05-01

    Full Text Available Active involvement of youth in agriculture is necessary for sustainable agricultural systems but is currently a challenge in many areas. Using a combination of qualitative and quantitative participatory research methods, this study analyses rural youth’s realities, perspectives and aspirations in dryland Agricultural Livelihood Systems (ALSs in the Midelt Province, Morocco, with a particular focus on gender. The data collected are an important first step in understanding the target group and working with youth to identify and develop appropriate programmatic interventions to improve their livelihoods and rural futures. Prior to expressing their aspirations for their rural life and career, the youth first raised the issue of unfulfilled primary needs: access to education, potable water, heath care, and lack of infrastructure in their villages. The issue of outmigration from rural areas is controversial and not so widespread. The youth’s dream village is envisioned as a rural place where people have a more comfortable life with their own families, farming better and more sustainably rather than seeking a job in urban areas. To support the youth’s aspirations and their willingness to stay in agriculture, there is a need for infrastructural and regulatory interventions and specific training in agricultural practices targeting and engaging youth.

  7. Effects of planting pattern on pea (Pissum sativum L. production in dryland situation of Lorestan province

    Directory of Open Access Journals (Sweden)

    karim moosavi

    2009-06-01

    Full Text Available In order to select optimum spatial arrangement (row and plant space and its effects on grain and biological yield of pea (Pissum sativum L., Spring Pea-2 line, a 2-years (2002-3, and 2003-4 growing season field experiment were conducted in Agricultural Research Station of Kohdasht in Lorestan Province. The experimental design was a split-plot with 4 replications. The experiment had 2 factors: row spacing at 2 levels (30 and 50 cm as main plot, and plant space at 4 levels (5, 10, 15, and 20 cm as subplot. Increase in row space from 30 to 50 cm, and plant space from 5 to 20 cm, reduced pea pod number per unit area by 30, and 67 % , respectively. Pea biomass and seed production showed an asymptotic respopnse to crop density. On the basis of hyperbolic function, maximum grain yield for 2002 and 2003 years were estimated as 2738 and 1067 kg/ha, respectively. On the basis of 2 years results, the maximum grain yield (1050 kg/ha and biomass (3001 kg/ha was belonged to the 30×5 cm spatial arrangement with density of 67 plants/m2. Therefore, this spatial arrangement is recommended for grain or forage production in dryland situation of Lorestan Province and other similar climates.

  8. Water satisfaction analysis for dryland maize production in Frankfort

    CSIR Research Space (South Africa)

    Moeletsi, ME

    2010-09-01

    Full Text Available Water deficiency during the growing period of summer crops is the main limiting factor for optimum crop production in most semi-arid areas of South Africa. Water requirements of the crop depend mainly on the nature and stage of the crop...

  9. Sustainability aspects of biobased applications : comparison of different crops and products from the sugar platform BO-12.05-002-008

    NARCIS (Netherlands)

    Bos, H.L.; Meesters, K.P.H.; Conijn, J.G.; Corre, W.J.; Patel, M.

    2011-01-01

    In this study different uses of biomass are compared. In order to allow for a systematic comparison the study focuses on three different chemicals that can be produced from sugar. In this way it is also, in principle, possible to compare different crops for the production of the same product. The

  10. Biological soil crusts: a fundamental organizing agent in global drylands

    Science.gov (United States)

    Belnap, J.; Zhang, Y.

    2013-12-01

    Ecosystem function is profoundly affected by plant community composition, which is ultimately determined by factors that govern seed retention. Dryland ecosystems constitute ~35% of terrestrial surfaces, with most soils in these regions covered by biological soil crusts (biocrusts), a community whose autotrophs are dominated by cyanobacteria, lichens, and mosses. Studies at 550 sites revealed that plant community composition was controlled by the interaction among biocrust type, disturbance regime, and external morphology of seeds. In bare soils (due to disturbance), all seed types were present in the seedbank and plant community. As biocrusts became better developed (i.e., the cover of lichens and mosses increased), they more strongly filtered out seeds with appendages. Thus, soils under late successional biocrusts contained seedbanks dominated by smooth seeds and vascular plants growing in late successional biocrusts were dominated by those with smooth seeds. Therefore, the tension between the removal of biocrusts by soil surface disturbance and their recovery creates a shifting mosaic of plant patch types in both space and time. Because changes in vascular plant communities reverberate throughout both below ground and above ground food webs and thus affect multiple trophic levels, we propose that biocrusts are a fundamental organizing agent in drylands worldwide. Future increased demand for resources will intensify land use both temporally and spatially, resulting in an increased rate of biocrust loss across larger areas. As a result, we can expect shifts in the composition and distribution of plant communities, accompanied by concomitant changes in many aspects of dryland ecosystems. Conceptual model of shifting dryland plant mosaics through space and time. Within the large circles, soil surface type changes with time in the same space, going from bare uncrusted soil (B) to cyanobacterial biocrust (C) to lichen/moss (L/M) biocrust. Disturbance (D) drives the

  11. The impact of dry-land sprint start training on the short track speed skating start.

    Science.gov (United States)

    Haug, William B; Drinkwater, Eric J; Cicero, Nicholas J; Barthell, J Anthony; Chapman, Dale W

    2017-05-05

    This investigation sought to determine the effects of dry-land sprint start training on short track speed skating (STSS) start performance. Nine highly trained short track athletes completed a control period of normal STSS training followed by a four-week training intervention. Before and after the control and intervention periods, athletes performed three electronically timed dry-land and on-ice 14.43 m maximal sprint start efforts. The intervention consisted of two sprint sessions per week consisting of nine electronically timed 14.43 m dry-land sprint starts in addition to normal STSS training. The control period resulted in no substantial change in on-ice start performance (Mean Δ: -0.01 s, 95% Confidence Limits (CL): -0.08 to 0.05 s; Effect Size (ES): -0.05; Trivial) however, a small change was observed in dry-land start performance (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.02 s; ES: -0.49). Following brief specific dry-land sprint start training a small improvement was observed in both on-ice (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.01 s; ES: -0.33) and dry-land (Mean Δ: -0.04 s, 95% CL: -0.09 to 0.00 s; ES: -0.29) start performance. This investigation suggests STSS start performance can be improved through a brief dry-land sprint start training program.

  12. Drylands face potential threat under 2 °C global warming target

    Science.gov (United States)

    Huang, Jianping; Yu, Haipeng; Dai, Aiguo; Wei, Yun; Kang, Litai

    2017-06-01

    The Paris Agreement aims to limit global mean surface warming to less than 2 °C relative to pre-industrial levels. However, we show this target is acceptable only for humid lands, whereas drylands will bear greater warming risks. Over the past century, surface warming over global drylands (1.2-1.3 °C) has been 20-40% higher than that over humid lands (0.8-1.0 °C), while anthropogenic CO2 emissions generated from drylands (~230 Gt) have been only ~30% of those generated from humid lands (~750 Gt). For the twenty-first century, warming of 3.2-4.0 °C (2.4-2.6 °C) over drylands (humid lands) could occur when global warming reaches 2.0 °C, indicating ~44% more warming over drylands than humid lands. Decreased maize yields and runoff, increased long-lasting drought and more favourable conditions for malaria transmission are greatest over drylands if global warming were to rise from 1.5 °C to 2.0 °C. Our analyses indicate that ~38% of the world's population living in drylands would suffer the effects of climate change due to emissions primarily from humid lands. If the 1.5 °C warming limit were attained, the mean warming over drylands could be within 3.0 °C therefore it is necessary to keep global warming within 1.5 °C to prevent disastrous effects over drylands.

  13. The land productivity dynamics trend as a tool for land degradation assessment in a dryland ecosystem.

    Science.gov (United States)

    Baskan, Oguz; Dengiz, Orhan; Demirag, İnci Turan

    2017-05-01

    The aim of this study was to produce a land productivity dynamic map of a degraded catchment located in dryland ecosystem via a land degradation assessment using three indicators, namely land use, land productivity, and soil organic carbon density. The study was conducted in the Mogan Catchment, Turkey, between 2000 and 2010. The study embraced the current trend for assessing ecosystem services over wide areas. For this purpose, satellite images were used to determine changes in land use and vegetation density. In addition, a total of 834 soil samples were collected from the surface soil in 2000 and 2010 to assess the soil organic carbon density. In more than 37% of the catchment area of approx. 37,100 ha, land productivity had declined, while about 43% of the catchment showed early signs of decline. Analysis of long-term changes and the conversion of levels of vegetative or standing biomass into land productivity dynamics (LPD) is only the first step. Current land management practices are contributing to serious, widespread land degradation, with only a very small area of the catchment showing a stable or increasing LPD for the period from 2000 to 2010. The implementation of land management policies and practices in order to achieve sustainable land management are urgently required.

  14. [Effects of different cropping system and fertilization on functional diversity in soil microbial community of Chrysanthemum morifolium].

    Science.gov (United States)

    Shao, Qingsong; Guo, Qiaosheng; Gu, Guangtong; Cao, Shenli

    2011-12-01

    To study the effects of Chrysanthemum morifolium based on functional diversity in soil microbial community with different cropping system and fertilization and offer scientific basis for the establishment of the reasonable planting patterns. Combined yield and quality of Ch. morifolium, 8 treatments of different cropping system and fertilization on functional diversity in soil microbial community of Ch. morifolium were investigated by the Biolog. The AWCD of Ch. morifolium paddy-dryland rotation was higher than that of the continuous cropping, the AWCD of organic fertilizer and compound NPK > single organic fertilizer > single compound NPK > no fertilizer. The principal component analysis about Ch. morifolium soil microbial carbon source use showed that the contribution rate of principal component 1 was 45.5% and principal component 2 was 12.1%, which could explain most information about the variation. Different cropping system of Ch. morfolium differentiated in principal component 1 axis, different fertilization differentiated in principal component 2 axis. The yield of Ch. morifolium and volatile oil content paddy-dryland rotation was significantly higher than that of continuous cropping. The Ch. morifolium should be cultivated with organic fertilizer and compound NPK by paddy-dryland rotation patters.

  15. Biotechnology Towards Energy Crops.

    Science.gov (United States)

    Margaritopoulou, Theoni; Roka, Loukia; Alexopoulou, Efi; Christou, Myrsini; Rigas, Stamatis; Haralampidis, Kosmas; Milioni, Dimitra

    2016-03-01

    New crops are gradually establishing along with cultivation systems to reduce reliance on depleting fossil fuel reserves and sustain better adaptation to climate change. These biological assets could be efficiently exploited as bioenergy feedstocks. Bioenergy crops are versatile renewable sources with the potential to alternatively contribute on a daily basis towards the coverage of modern society's energy demands. Biotechnology may facilitate the breeding of elite energy crop genotypes, better suited for bio-processing and subsequent use that will improve efficiency, further reduce costs, and enhance the environmental benefits of biofuels. Innovative molecular techniques may improve a broad range of important features including biomass yield, product quality and resistance to biotic factors like pests or microbial diseases or environmental cues such as drought, salinity, freezing injury or heat shock. The current review intends to assess the capacity of biotechnological applications to develop a beneficial bioenergy pipeline extending from feedstock development to sustainable biofuel production and provide examples of the current state of the art on future energy crops.

  16. Soil physical properties response to tillage practices during summer fallow of dryland winter wheat field on the Loess Plateau.

    Science.gov (United States)

    Xue, Jian-Fu; Ren, Ai-Xia; Li, Hui; Gao, Zhi-Qiang; Du, Tian-Qing

    2018-01-01

    Soil physical properties are a greatly important part of the soil and indicator of soil quality, which can directly affect soil nutrient turnover and crop yields in dryland. This study was carried out with three tillage practices during the summer fallow season since 2011, including no tillage (NT), plow tillage (PT), and subsoiling (ST) in dryland winter wheat fields of the Loess Plateau. Results showed that soil tillage during the summer fallow had a small effect on soil bulk density (ρ b) in the 0-50-cm soil profile before sowing and after harvesting of winter wheat. Soil ρ b under NT at a depth of 20-30 cm was significantly greater than those under PT in both seasons. Both soil gravimetric water content (θ g) and volumetric moisture content (θ v) after harvesting increased by 28.8-78.6% and 37.5-87.3%, respectively, compared with those before sowing. Adoption of PT significantly increased soil θ g and θ v in the entire 0-50-cm profile before sowing compared with NT and ST (P < 0.05). In addition, there was a small effect on soil porosity (e.g., total porosity, air-filled porosity, and capillary porosity) in the profile of 0-50 cm both before sowing and after harvesting. Overall, short-term tillage during summer fallow mainly affected soil water content in the 0-50-cm soil profile, and it had a slight effect on other physical soil properties.

  17. Integrated crop-livestock systems and cover crop grazing in the Northern Great Plains

    Science.gov (United States)

    Integrating crops and livestock has been identified as an approach to sustainably intensify agricultural systems, increasing production while reducing the need for external inputs, building soil health, and increasing economic returns. Cover crops and grazing these cover crops are a natural fit with...

  18. A multi-attribute decision method for assessing the overall sustainability of crop protection strategies: a case study based on apple production in Europe

    NARCIS (Netherlands)

    Mouron, P.; Aubert, U.; Heijne, B.; Naef, A.; Strassemeyer, J.; hayer, F.; Gaillard, G.

    2012-01-01

    In this study, we investigated the elements that must be considered to obtain a clear and useful assessment of sustainability. We present a system-description tool created especially for life cycle assessment (assessment of energy use and ecotoxicity), environmental risk assessment, and full-cost

  19. Systems Biology for Smart Crops and Agricultural Innovation: Filling the Gaps between Genotype and Phenotype for Complex Traits Linked with Robust Agricultural Productivity and Sustainability

    Science.gov (United States)

    Pathak, Rajesh Kumar; Gupta, Sanjay Mohan; Gaur, Vikram Singh; Pandey, Dinesh

    2015-01-01

    Abstract In recent years, rapid developments in several omics platforms and next generation sequencing technology have generated a huge amount of biological data about plants. Systems biology aims to develop and use well-organized and efficient algorithms, data structure, visualization, and communication tools for the integration of these biological data with the goal of computational modeling and simulation. It studies crop plant systems by systematically perturbing them, checking the gene, protein, and informational pathway responses; integrating these data; and finally, formulating mathematical models that describe the structure of system and its response to individual perturbations. Consequently, systems biology approaches, such as integrative and predictive ones, hold immense potential in understanding of molecular mechanism of agriculturally important complex traits linked to agricultural productivity. This has led to identification of some key genes and proteins involved in networks of pathways involved in input use efficiency, biotic and abiotic stress resistance, photosynthesis efficiency, root, stem and leaf architecture, and nutrient mobilization. The developments in the above fields have made it possible to design smart crops with superior agronomic traits through genetic manipulation of key candidate genes. PMID:26484978

  20. Vegetation in drylands: Effects on wind flow and aeolian sediment transport

    Science.gov (United States)

    Drylands are characterised by patchy vegetation, erodible surfaces and erosive aeolian processes. Empirical and modelling studies have shown that vegetation elements provide drag on the overlying airflow, thus affecting wind velocity profiles and altering erosive dynamics on desert surfaces. However...

  1. Lights and shadows of sustainable development and combat against desertification: economic rationalities in the eye of the storm. Case study involving goat producers in drylands (Mendoza, Argentina Claroscuros del desarrollo sustentable y la lucha contra la desertificación: las racionalidades económicas en el ojo de la tormenta: Estudio de caso con productores caprinos de tierras secas [Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    Laura Torres

    2010-01-01

    Full Text Available This work analyses the conflict situation present in the province's drylands between goat producers and programmes to combat desertification regarding production practices and the use producers make of natural resources. The case study tackled comprises the north-eastern extreme of Mendoza province. The , which is the hyperarid spot of the region, severely affected by desertification processes, covering an extent of 10,007 km2, and with 3015 inhabitants, where small goat breeding farms predominate. Previous studies indicate that the major causes of desertification in the area are logging of the native woodland and overgrazing which have led to improper livestock production practices. In response to this, the actions to combat desertification commonly point out the need to "raise awareness" and "build capacities" of the producers by initiating processes of change in the production systems. The proposals insist that, if the current level of pressure on resources is maintained, the already serious poverty conditions will grow worse in the future. Nevertheless, despite the efforts and funds invested, the producers seem to stubbornly persist in their present production strategies and in the dynamics of natural resource use derived from them. How to explain their refusal to consider other production options likely to result in higher profit and better environmental balance? How to explain that they act, at least apparently, against their own benefits? Against the explanations that place the producers' "culture" is the most important problem, the present work seeks to cooperate in clarifying these questions through an analysis of the different rationalities that, held by different actors, converge in the area. By using a mixed methodology, the paper analyse three dimensions: 1- The environmental resource supply, which is the basis of production activities, 2- The income attained by goat production units, and 3- The expenditures they face in terms of

  2. Sustainable use of pig slurry, with and without treatment, as an amendment organic in almond crop; Utilizacion sostenible de purines de cerdo, con y sin tratamiento, como enmienda organica en cultivos de almendro

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez Oliver, S. G.; Faz Cano, A.

    2009-07-01

    This study consists in the use of different forms of slurry, as an organic fertilizer, on almond trees located in La Aljorra (Cartegena, Murcia). The slurry used comes from a farm near the area of study, which has a treatment system composed by tree parts: a phase separator, a bioreactor and 5 constructed wetlands of vertical flow. Different phases of slurry are obtained from each part of the system. The results show the reduction of most of the parameters lime salinity, BOD{sub 5} QOD, nitrate, etc. The use of these effluents as an organic amend in different doses, supposes a sustainable way of management of these residues; at the same time it improves the soil properties and the agronomic quality of the almond tree crop. (Author) 4 refs.

  3. Effects of Controlled Release Fertilizer on the Flag Leaves Senescence in Dry-land Wheat

    OpenAIRE

    Dandan Liu; Yan Shi

    2013-01-01

    In order to select a reasonable controlled release fertilizer application method to slow down the senescence of flag leaf in dry-land wheat. The effects of controlled release fertilizer on soluble protein content, MDA content, the Catalase (CAT) activity, the Superoxide Dismutase (SOD) activity on the flag leaves senescence in dry-land wheat had been studied in the open field with the variety wheat Jimai22. The results indicated that, the combination application of controlled release fertiliz...

  4. Increasing aridity reduces soil microbial diversity and abundance in global drylands

    OpenAIRE

    Maestre, Fernando T.; Delgado-Baquerizo, Manuel; Thomas C Jeffries; Eldridge, David J.; Ochoa, Victoria; Gozalo, Beatriz; Quero, José Luis; García-Gómez, Miguel; Gallardo, Antonio; Ulrich, Werner; Bowker, Matthew A.; Arredondo, Tulio; Barraza-Zepeda, Claudia; Bran, Donaldo; Florentino, Adriana

    2015-01-01

    Climate change is increasing the degree of aridity in drylands, which occupy 41% of Earth’s surface and support 38% of its population. Soil bacteria and fungi are largely responsible for key ecosystem services, including soil fertility and climate regulation, yet their responses to changes in aridity are poorly understood. Using a field survey conducted in drylands worldwide and DNA-sequencing approaches, we found that increases in aridity reduce the diversity and abundance of soil bacteria a...

  5. Evaluation of herbacceous biomass crops in the northern Great Plains. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, D.W.; Norby, W.E.; Erickson, D.O.; Johnson, R.G. [North Dakota State Univ., Fargo, ND (United States)

    1994-08-01

    Herbaceous lignocellulose crops are a potential renewable feedstock for biochemical conversion systems second in size to wood products. Several herbaceous crops are utilized as forage crops in the northern Great Plains, but forage quality considerations usually dictates a early harvest. Biomass cropping does not have this constraint; therefore, little information was available on herbaceous crops utilized as energy crops prior to this project. Our primary objectives were to evaluate the biomass yield and select chemical components of several herbaceous crops for energy crops in the northern Great Plains, compare the economic feasibility of energy crops with common competing crops, and evaluate biomass cropping on summer fallow lands. Three good, two marginal, and one irrigated sites were used during 1988 to 1992 for the first component. At least six perennial and four annual biomass species were included at all sites. Three to four nitrogen (N) levels and a crop-recrop comparison (annuals only) were management intensities included. Biomass cropping on idled lands was performed on dryland at Carrington and evaluated the effects of removing leguminous biomass on fallowed lands. This report summarizes results from the 5-year project.

  6. Climate contributions to vegetation variations in Central Asian drylands

    DEFF Research Database (Denmark)

    Zhou, Yu; Zhang, Li; Fensholt, Rasmus

    2015-01-01

    Central Asia comprises a large fraction of the world's drylands, known to be vulnerable to climate change. We analyzed the inter-annual trends and the impact of climate variability in the vegetation greenness for Central Asia from 1982 to 2011 using GIMMS3g normalized difference vegetation index...... differed between these two periods. The warming trend in Central Asia initially enhanced the vegetation greenness before 1991, but the continued warming trend subsequently became a suppressant of further gains in greenness afterwards. Precipitation expanded its influence on larger vegetated areas in 1992...... on vegetation was significantly different for the different sub-regions before and after 1992, coinciding with the collapse of the Union of Soviet Socialist Republics (USSR). It was suggested that these spatio-temporal patterns in greenness change and their relationship with climate change for some regions...

  7. A case study of energy use and economical analysis of irrigated and dryland wheat production systems

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Reza; Mondani, Farzad; Amirmoradi, Shahram; Feizi, Hassan; Khorramdel, Surror; Teimouri, Mozhgan; Sanjani, Sara; Anvarkhah, Sepideh; Aghel, Hassan [Faculty of Agriculture, Ferdowsi University of Mashhad, P.O. Box 91775-1163, Mashhad (Iran)

    2011-01-15

    Current conventional agricultural systems using intensive energy has to be re-vitalized by new integrated approaches relying on renewable energy resources, which can allow farmers to stop depending on fossil resources. The aim of the present study was to compare wheat production in dryland (low input) and irrigated (high input) systems in terms of energy ratio, energy efficiency, benefit/cost ratio and amount of renewable energy use. Data were collected from 50 irrigated and 50 dryland wheat growers by using a face-to-face questionnaire in 2009. The results showed that the total energy requirement under low input was 9354.2 MJ ha{sup -1}, whereas under high input systems it was 45367.6 MJ ha{sup -1}. Total energy input consumed in both dryland and irrigated systems could be classified as direct, indirect, renewable and non-renewable energies which average in two wheat production systems were 47%, 53%, 24% and 76%, respectively. Energy ratios of 3.38 in dryland and 1.44 in irrigated systems were achieved. The benefit-cost ratios were 2.56 in dryland and 1.97 in irrigated wheat production systems. Based on the results of the present study, dry-land farming can have a significant positive effect on energy-related factors especially in dry and semi-dry climates such as Iran. (author)

  8. Multifunctional Dryland Forestry: Accumulating Experience From the East-Mediterranean

    Science.gov (United States)

    Osem, Y.; Shachack, M.; Moshe, I.

    2014-12-01

    Although small in size the landscapes of East Mediterranean Israel extend over a wide geo-climatic gradient ranging from dry sub-humid to hyper-arid lands. Thousands of years under intense human exploitation in this region, involving cutting, livestock grazing, agricultural practice and fire have resulted in severe degradation of these water limited ecosystems. The highly degraded state of the native vegetation as found by the new settlers coming to Israel in the beginning of the previous century, has provided the basic motivation for an extensive afforestation enterprise carried out during the last 100 years. This talk will present an overview on the accumulating experience in establishing and managing multifunctional forests in this dryland region. Given their very limited timber value, dryland forests are designed and managed under various goals the important of which are landscape aesthetics, recreation opportunities, grazing land, ecosystem restoration and soil conservation. Being subjected to water scarcity of high temporal and spatial variation, these manmade systems are managed to withstand water deficiency of unpredictable magnitude through the manipulation of both water input and water consumption. In the dry subhumid regions, forest management focuses mainly on controlling water consumption through the manipulation of vegetation structure using thinning and livestock grazing as primary silvicultural tools. Going into the semiarid zone, practices of rainfall redistribution and runoff harvesting become crucial for tree establishment and growth. The implementation of these practices varies depending on topography, rainfall amount and forest goals. The talk will provide a brief description of these unique silvicultural systems, review some of the recent scientific work in them and refer to critical gaps in knowledge. The relevancy to intercrop agroforestry in rainfed ecosystems will be discussed.

  9. BLACK PEPPER: IMPORTANCE OF CROP DEFENSE TO THE SUSTAINABILITY OF THE ACTIVITY IN THE NORTH OF THE ESPÍRITO SANTO

    Directory of Open Access Journals (Sweden)

    Bruno Sérgio Oliveira e Silva

    2011-07-01

    Full Text Available The fusarium wilt disease is the main crop, whether restricted to Brazil. The disease is caused by the fungus Fusarium solani f. sp. piperis., and in the last years the disease has reduced the life of peppers ranging 12-15 years, for a range of four to six years. Discussing subjects about etiology, symptoms, epidemiology and control, this research is part of a larger project being developed with the Postgraduate Program in Tropical Agriculture in the Centro Universitário Norte do Espírito Santo / UFES. The disease can start from the roots or branches with the evolution of the disease is observed in a drying plant. Conditions of high humidity favor the production of conidia and more efficient control methods to be adopted in the control of fusarium wilt of black pepper are preventive yet.

  10. Effects of rainfall intensity and intermittency on woody vegetation cover and deep soil moisture in dryland ecosystems

    Science.gov (United States)

    Zhang, Ding-Hai; Li, Xin-Rong; Zhang, Feng; Zhang, Zhi-Shan; Chen, Yong-Le

    2016-12-01

    Identifying the relationship between the stochastic daily rainfall regime and the dynamics of plants and soil moisture is fundamental for the sustainable management of dryland ecosystems in a context of global climate change. An eco-hydrological model that couples the dynamics of woody vegetation cover and deep soil moisture (typically with a depth interval of 30-150 cm) was used to investigate the effect of stochastic intensity and the intermittency of precipitation on soil moisture in this deep interval, which affects woody vegetation cover. Our results suggest that the precipitation intensity and intermittency play an important role in the dynamics of wood vegetation cover and deep soil moisture. In arid and semiarid regions, as the annual precipitation increased, the rate of woody vegetation cover increased as a power-law function, and the deep soil moisture increased exponentially. For a given annual rainfall, there were positive correlations between the rainfall intensity (or rainfall intermittency) and both the woody vegetation cover and deep soil moisture. The positive correlations between wood vegetation cover and both rainfall intensity and intermittency may decrease with increases in the precipitation intensity or precipitation intermittency. The positive correlations between deep soil moisture and both rainfall intensity and rainfall intermittency increase as the precipitation intensity or precipitation intermittency increases. Moreover, these positive correlations may increase with increases in the mean annual rainfall. Our results emphasize the importance of daily precipitation variations in controlling the responses of woody vegetation cover and deep soil moisture to climate variations in arid and semiarid regions. Our model can aid the understanding of rainfall processes and indicates that increases in rainfall intensity or rainfall intermittency may lead to an increase in woody vegetation cover and deep soil moisture given an invariable annual

  11. Linking Carbon Flux Dynamics and Soil Structure in Dryland Soils

    Science.gov (United States)

    DeCarlo, K. F.; Caylor, K. K.

    2016-12-01

    Biological sources in the form of microbes and plants play a fundamental role in determining the magnitude of carbon flux. However, the geophysical structure of the soil (which the carbon must pass through before entering the atmosphere) often serves as a constraining entity, which has the potential to serve as instigators or mitigators of those carbon and hydrologic flux processes. We characterized soil carbon dynamics in three dryland soil systems: bioturbated soils, biocompacted soils, and undisturbed soils. Carbon fluxes were characterized using a closed-system respiration chamber, with CO2 concentration differences measured using an infrared gas analyzer (IRGA). Structure of the soil systems, with a focus on the macro-crack structure, were characterized using a combined resin-casting/X-ray imaging technique. Results show fundamental differences in carbon dynamics between the different soil systems/structures: control soils have gaussian distributions of carbon flux that decrease with progressive drying of the soil, while biocompacted soils exhibit exponentially distributed fluxes that do not regularly decrease with increased drying of the soil. Bioturbated soils also exhibit an exponential distribution of carbon flux, though at a much higher magnitude. These differences are evaluated in the context of the underlying soil structure: while the control soils exhibit a shallow and narrow crack structure, the biocompacted soils exhibit a "systematic" crack network with moderate cracking intensity and large depth. The deep crack networks of the biocompacted soils may serve to physically enhance an otherwise weak source of carbon via advection and/or convection, inducing fluxes that are equal or greater than an otherwise carbon-rich soil. The bioturbated soils exhibit a "surficial" crack network that is shallow but extensive, but additionally have deep holes known to convectively vent carbon, which may explain their periodically large carbon fluxes. Our results

  12. Plant-plant interactions in the restoration of Mediterranean drylands

    Science.gov (United States)

    Valdecantos, Alejandro; Fuentes, David; Smanis, Athanasios

    2014-05-01

    Plant-plant interactions are complex and dependent of both local abiotic features of the ecosystem and biotic relationships with other plants and animals. The net result of these interactions may be positive, negative or neutral resulting in facilitation, competition or neutralism, respectively (role of phylogeny). It has been proposed that competition is stronger between those individuals that share functional traits than between unrelated ones. The relative interaction effect of one plant on a neighbour may change in relation to resource availability - especially water in drylands. In addition, plants develop above and belowground biomass with time increasing the level and, eventually, changing the intensity and/or the direction of the interaction. In the framework of the restoration of degraded drylands, many studies have focused on the positive (nurse) effects of adult trees, shrubs and even grasses on artificially planted seedlings by improving the microclimate or providing protection against herbivores, but little is known about the interactions between seedlings of different life traits planted together under natural field conditions. In 2010 we established planting plots in two contrasted sites under semiarid Mediterranean climate and introduced one year old seedlings in different combinations of three species, two shrubs (Olea europaea and Pistacia lentiscus) and one grass (Stipa tenacissima). Half of the planting holes in each site were implemented with low-cost ecotechnological inputs to increase water availability by forcing runoff production and promoting deep infiltration (small plastic fabric + dry well). This resulted in four levels of abiotic stress. Biotic interactions were assessed by monitoring seedling survival and growth for three years after planting. The Relative Interaction Index (RII) of S. tenacissima on O. europaea was almost flat and close to 0 along the stress gradient since the beginning of the study suggesting limited interaction

  13. Institutional Factors Influencing Crop Farmers Adoption of ...

    African Journals Online (AJOL)

    This study examined the institutional factors influencing adoption of recommended agrochemical practices (RAPs) among crop farmers in Nigeria. A total of 260 crop farmers who have sustained the use of agrochemicals for at least five years were selected for the study using multi-stage sampling technique. Data were ...

  14. Adoption of Recommended Agrochemical Practices among Crop ...

    African Journals Online (AJOL)

    This study assessed the level of adoption of recommended agrochemical practices among crop farmers in Kaduna and Ondo States of Nigeria. It measured the perception of farmers on pesticides and their knowledge on the harmful effects of pesticides. A total of 260 crop farmers who have sustained the use of ...

  15. Land Degradation States and Trends in the Northwestern Maghreb Drylands, 1998–2008

    Directory of Open Access Journals (Sweden)

    Gabriel del Barrio

    2016-07-01

    Full Text Available States of ecological maturity and temporal trends of drylands in Morocco, Algeria and Tunisia north of 28°N are reported for 1998–2008. The input data were Normalized Difference Vegetation Index databases and corresponding climate fields, at a spatial resolution of 1 km and a temporal resolution of one month. States convey opposing dynamics of human exploitation and ecological succession. They were identified synchronically for the full period by comparing each location to all other locations in the study area under equivalent aridity. Rain Use Efficiency (RUE at two temporal scales was used to estimate proxies for biomass and turnover rate. Biomass trends were determined for every location by stepwise regression using time and aridity as predictors. This enabled human-induced degradation to be separated from simple responses to interannual climate variation. Some relevant findings include large areas of degraded land, albeit improving over time or fluctuating with climate, but rarely degrading further; smaller, but significant areas of mature and reference vegetation in most climate zones; very low overall active degradation rates throughout the area during the decade observed; biomass accumulation over time exceeding depletion in most zones; and negative feedback between land states and trends suggesting overall landscape persistence. Semiarid zones were found to be the most vulnerable. Those results can be disaggregated by country or province. The combination with existing land cover maps and national forest inventories leads to the information required by the two progress indicators associated with the United Nations Convention to Combat Desertification strategic objective to improve the conditions of ecosystems and with the Sustainable Development Goal Target 15.3 to achieve land degradation neutrality. Beyond that, the results are also useful as a basis for land management and restoration.

  16. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

    Science.gov (United States)

    Rutherford, William A.; Painter, Thomas H.; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S.; Flagg, Cody; Reed, Sasha C.

    2017-03-01

    Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness—changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate.

  17. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts.

    Science.gov (United States)

    Rutherford, William A; Painter, Thomas H; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S; Flagg, Cody; Reed, Sasha C

    2017-03-10

    Drylands represent the planet's largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness-changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate.

  18. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

    Science.gov (United States)

    Rutherford, William A.; Painter, Thomas H.; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S.; Flagg, Cody B.; Reed, Sasha C.

    2017-01-01

    Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness—changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate.

  19. Grain Amaranths Are Defoliation Tolerant Crop Species Capable of Utilizing Stem and Root Carbohydrate Reserves to Sustain Vegetative and Reproductive Growth after Leaf Loss

    Science.gov (United States)

    Vargas-Ortiz, Erandi; Espitia-Rangel, Eduardo; Tiessen, Axel; Délano-Frier, John Paul

    2013-01-01

    Tolerance to defoliation can be defined as the degree to which productivity is affected by photosynthetic area reduction. This trait was studied in grain amaranth (Amaranthus cruentus and A. hypochondriacus), which are considered to be a highly defoliation-tolerant species. The physiological and biochemical responses to increasing levels of mechanical leaf removal up to total defoliation were quantified. Tolerance appeared to be dependent on various factors: ( i) amount of lost tissue; (ii) mechanics of leaf tissue removal; (iii) environment, and (iv) species tested. Thus, grain amaranth was found to be a highly tolerant species under green-house conditions when leaf tissue loss was performed by gradual perforation. However, tolerance was compromised under similar conditions when defoliation was done by gradual cutting of the leaf. Also tolerance in completely defoliated plants tended to decrease under field conditions, where differences between A. cruentus and A. hypochondriacus were observed. All non-structural carbohydrate (NSC) levels were reduced in stems and roots of totally defoliated amaranths one day after treatment. Such depletion probably provided the carbon (C) resources needed to sustain the early recovery process in the absence of photosynthetic capacity. This was corroborated by shading of intact plants, which produced the same rapid and drastic reduction of NSC levels in these tissues. These results emphasize the role of stored NSCs, particularly starch, in buffering the impact of severe defoliation in amaranth. The fall in sucrose synthase and cell wall invertase activity observed in stems and roots soon after defoliation was consistent with their predicted shift from sink to source tissues. It is concluded that mobilization of C stores in stems and roots, is a physiologically important trait underlying tolerance to defoliation in grain amaranth. PMID:23861825

  20. Grain amaranths are defoliation tolerant crop species capable of utilizing stem and root carbohydrate reserves to sustain vegetative and reproductive growth after leaf loss.

    Directory of Open Access Journals (Sweden)

    Erandi Vargas-Ortiz

    Full Text Available Tolerance to defoliation can be defined as the degree to which productivity is affected by photosynthetic area reduction. This trait was studied in grain amaranth (Amaranthus cruentus and A. hypochondriacus, which are considered to be a highly defoliation-tolerant species. The physiological and biochemical responses to increasing levels of mechanical leaf removal up to total defoliation were quantified. Tolerance appeared to be dependent on various factors: ( i amount of lost tissue; (ii mechanics of leaf tissue removal; (iii environment, and (iv species tested. Thus, grain amaranth was found to be a highly tolerant species under green-house conditions when leaf tissue loss was performed by gradual perforation. However, tolerance was compromised under similar conditions when defoliation was done by gradual cutting of the leaf. Also tolerance in completely defoliated plants tended to decrease under field conditions, where differences between A. cruentus and A. hypochondriacus were observed. All non-structural carbohydrate (NSC levels were reduced in stems and roots of totally defoliated amaranths one day after treatment. Such depletion probably provided the carbon (C resources needed to sustain the early recovery process in the absence of photosynthetic capacity. This was corroborated by shading of intact plants, which produced the same rapid and drastic reduction of NSC levels in these tissues. These results emphasize the role of stored NSCs, particularly starch, in buffering the impact of severe defoliation in amaranth. The fall in sucrose synthase and cell wall invertase activity observed in stems and roots soon after defoliation was consistent with their predicted shift from sink to source tissues. It is concluded that mobilization of C stores in stems and roots, is a physiologically important trait underlying tolerance to defoliation in grain amaranth.

  1. Dynamic Hydrological Modeling in Drylands with TRMM Based Rainfall

    Directory of Open Access Journals (Sweden)

    Elena Tarnavsky

    2013-12-01

    Full Text Available This paper introduces and evaluates DryMOD, a dynamic water balance model of the key hydrological process in drylands that is based on free, public-domain datasets. The rainfall model of DryMOD makes optimal use of spatially disaggregated Tropical Rainfall Measuring Mission (TRMM datasets to simulate hourly rainfall intensities at a spatial resolution of 1-km. Regional-scale applications of the model in seasonal catchments in Tunisia and Senegal characterize runoff and soil moisture distribution and dynamics in response to varying rainfall data inputs and soil properties. The results highlight the need for hourly-based rainfall simulation and for correcting TRMM 3B42 rainfall intensities for the fractional cover of rainfall (FCR. Without FCR correction and disaggregation to 1 km, TRMM 3B42 based rainfall intensities are too low to generate surface runoff and to induce substantial changes to soil moisture storage. The outcomes from the sensitivity analysis show that topsoil porosity is the most important soil property for simulation of runoff and soil moisture. Thus, we demonstrate the benefit of hydrological investigations at a scale, for which reliable information on soil profile characteristics exists and which is sufficiently fine to account for the heterogeneities of these. Where such information is available, application of DryMOD can assist in the spatial and temporal planning of water harvesting according to runoff-generating areas and the runoff ratio, as well as in the optimization of agricultural activities based on realistic representation of soil moisture conditions.

  2. Fertility Island Formation and Evolution in Dryland Ecosystems

    Directory of Open Access Journals (Sweden)

    Luca Ridolfi

    2008-06-01

    Full Text Available Vast dryland regions around the world are affected by the encroachment of woody vegetation, with important environmental and economical implications. Grassland-to-shrubland conversions are often triggered by disturbance of grassland vegetation, and the consequent formation of barren areas prone to erosion-induced nutrient losses. Inhibition of encroachment by erosion-induced depletion of soil nutrients contributes to the emergence of highly heterogeneous landscapes with shrub-dominated fertility islands surrounded by nutrient-poor bare soil. Here, we develop a process-based simplistic model thataccounts for the two competing processes of resource depletion and shrub encroachment by a non-linear diffusion mechanism. The proposed model is able to generate stable vegetation patterns with the same statistical properties as those observed in areas with well-developed fertility islands. We also show how a subsequent disturbance of shrubland vegetation can shift the dynamics toward states with smaller vegetation biomass. The process of land degradation may then occur through a number of irreversible intermediate transitions associated with losses in ecosystem function.

  3. Perceived profitability and well-being in Australian dryland farmers and irrigators.

    Science.gov (United States)

    Peel, Dominic; Berry, Helen L; Schirmer, Jacki

    2015-08-01

    To describe the relationship between self-reported farm profitability and farmer well-being, and to explore potential implications for farmer assistance policy. Cross-sectional analysis of farmers from Regional Wellbeing Survey data (wave 1, 2013) and comparison between groups. Participants were 1172 dryland farmers (35% women) and 707 irrigators (24% women). The Personal Wellbeing Index and the Kessler 10-item measure of general psychological distress. There is a consistent and significant relationship between higher profitability, greater well-being and less distress among dryland farmers and irrigators. The relationship between farm profitability and the well-being of Australian dryland farmers and irrigators has the potential to inform farmer assistance policy. Assistance programs can be more effective if they explicitly incorporate a profitability assessment into their targeting and eligibility requirements and a well-being component into program design and delivery. Rural Australia. Not applicable. © 2015 National Rural Health Alliance Inc.

  4. Hydrologic variability in dryland regions: impacts on ecosystem dynamics and food security.

    Science.gov (United States)

    D'Odorico, Paolo; Bhattachan, Abinash

    2012-11-19

    Research on ecosystem and societal response to global environmental change typically considers the effects of shifts in mean climate conditions. There is, however, some evidence of ongoing changes also in the variance of hydrologic and climate fluctuations. A relatively high interannual variability is a distinctive feature of the hydrologic regime of dryland regions, particularly at the desert margins. Hydrologic variability has an important impact on ecosystem dynamics, food security and societal reliance on ecosystem services in water-limited environments. Here, we investigate some of the current patterns of hydrologic variability in drylands around the world and review the major effects of hydrologic fluctuations on ecosystem resilience, maintenance of biodiversity and food security. We show that random hydrologic fluctuations may enhance the resilience of dryland ecosystems by obliterating bistable deterministic behaviours and threshold-like responses to external drivers. Moreover, by increasing biodiversity and the associated ecosystem redundancy, hydrologic variability can indirectly enhance post-disturbance recovery, i.e. ecosystem resilience.

  5. Transforming Innovation for Sustainability

    Directory of Open Access Journals (Sweden)

    Melissa Leach

    2012-06-01

    Full Text Available The urgency of charting pathways to sustainability that keep human societies within a "safe operating space" has now been clarified. Crises in climate, food, biodiversity, and energy are already playing out across local and global scales and are set to increase as we approach critical thresholds. Drawing together recent work from the Stockholm Resilience Centre, the Tellus Institute, and the STEPS Centre, this commentary article argues that ambitious Sustainable Development Goals are now required along with major transformation, not only in policies and technologies, but in modes of innovation themselves, to meet them. As examples of dryland agriculture in East Africa and rural energy in Latin America illustrate, such "transformative innovation" needs to give far greater recognition and power to grassroots innovation actors and processes, involving them within an inclusive, multi-scale innovation politics. The three dimensions of direction, diversity, and distribution along with new forms of "sustainability brokering" can help guide the kinds of analysis and decision making now needed to safeguard our planet for current and future generations.

  6. Dryland salinity: threatening water resources in the semi-arid Western Cape

    CSIR Research Space (South Africa)

    Bugan, Richard DH

    2010-11-01

    Full Text Available : THREATENING WATER RESOURCES IN THE SEMI-ARID WESTERN CAPE Increased dryland salinity in the Swartland and Overberg regions poses a threat to the bread basket of the Western Cape, water resources in an already water-stressed area, water supply... an increase in salt concentrations, particularly in the mid- to lower reaches of the river, thereby impacting on drinking water quality and agriculture. Dryland salinity poses a major threat to water quality, particularly in semi-arid areas. It is usually...

  7. Pastoral mobility as a response to climate variability in African drylands

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    1999-01-01

    The article outlines aspects of ‘the new paradigm’ for dryland ecosystems and pastoral production systems. Rationality of pastoralism was claimed by parts of the research community for decades, but especially among policy and development planners pastoralism was perceived as an irrational and des...... in West Africa. In an example from Ferlo, Senegal, different types of pastoral mobility are discussed with special focus on the importance of scale. It is concluded that pastoral mobility is a rational response to climate variability and unpredictability in African drylands....

  8. Assessing commercial livestock appropriation of the productive capacity of US drylands: A remote sensing approach

    Science.gov (United States)

    Washington-Allen, R. A.; Mitchell, J. E.; Oslen, H. E.

    2008-12-01

    The "State of Nation's Ecosystems" by the Heinz Institute and the recent "Millennium Ecosystem Assessment of Drylands" concluded that the amount of desertification and the extent to which human management actions contribute to this process is unknown at national to global spatial scales. This is primarily due to lack of studies at these large spatial scales and the temporal scales (> a 15-year time series of data) necessary to separate the effects of anthropogenic practices from climate change on Drylands. Consequently, this research seeks to develop procedures for determining 1) the area of Drylands within the United States where commercial grazing livestock occur or the livestock ecological footprint and 2) the impact of the footprint on the US's productive capacity. Our approach has been to develop a pilot geodatabase of year 2002 data that includes administrative boundaries, the Moderate Resolution Infrared Spectroradiometer's (MODIS) measures of gross and net primary productivity (GPP and NPP, respectively), US Department of Agriculture's National Agricultural Statistics Service's (USDA-NASS) county-level data on cattle, sheep, and goat inventories, transportation and power consumption networks, dryland extent, and land cover/land use. Secondly, the ratio of 1-km2 gridded mean annual potential evapotranspiration (MAPET) to mean annual precipitation (MAP) data were used to define the 50-year mean dryland extent in accordance with the United Nations Convention to Combat Desertification's definition of Drylands, the aridity index (AI) ≤ 0.65. Urban features, including transportation, power consumption, and land use/land cover, were subtracted from this dryland map to further refine it. The NASS tabular data was then related to the counties boundary map thus producing a county-level livestock number map that was then intersected with the dryland extent map to yield the US livestock ecological footprint. Lastly, this footprint map was then converted to a

  9. Simulating Effects of Drainage Design Parameters on Optimum Crop ...

    African Journals Online (AJOL)

    Agricultural water management system aims to provide crop water requirements to sustain optimum yield. Some of the factors influencing optimum crop yield are drainage design parameters in water-logged soils. Hence, the impact of drainage design parameters on optimum crop yield was examined. Field experimentation ...

  10. Yield gap analysis of feed-crop livestock systems

    NARCIS (Netherlands)

    Linden, van der Aart; Oosting, Simon J.; Ven, van de Gerrie W.J.; Veysset, Patrick; Boer, de Imke J.M.; Ittersum, van Martin K.

    2018-01-01

    Sustainable intensification is a strategy contributing to global food security. The scope for sustainable intensification in crop sciences can be assessed through yield gap analysis, using crop growth models based on concepts of production ecology. Recently, an analogous cattle production model

  11. Can we forecast farmers' yields? The relationships between rainfall variability, farmers' expectations, and actual yields in a tropical dryland

    Science.gov (United States)

    Zeng, Z.; Tian, D.; Estes, L. D.; Evans, T. P.; Wood, E. F.; Caylor, K. K.

    2016-12-01

    Climate variability is one of the most important drivers of global crop yield variability. This is particularly true in dryland ecosystems, where vegetation dynamics, including agricultural production, are strongly shaped by both the pronounced seasonality of rainfall and its intra-seasonal distribution, both of which can exhibit substantial variability. This variability plays a key role not only in impacting end of season yields, but is also likely to influence farmers' expectations of final yields and thus their management decisions. Both these values are typically collected using farmer surveys, and their values influence higher-level policy decisions related to food security. It is unclear, however, whether farmers' expectations are shaped by the rainfall variables that most influence final yields, which has important ramifications for food security. In this study, we use agricultural survey data combined with a bias-corrected gridded meteorological forcing dataset to investigate the relationships between farmers' expected yields, end-of-season yields, and several different indices of seasonal rainfall and rainfall variability. We focus on Zambia, a country that relies heavily on smallholder agricultural production for the majority of its food production. Our goals are to identify which aspects of rainfall variability have the greatest influence on farmers' yield expectations, which have the greatest impact on actual yield, how well actual and expected yields are correlated with one another, and how these relationship differ throughout the country. Understanding these connections can help to improve seasonal crop yield forecasting and farmer decision-making, and thereby lead to improved food security policy in a region where rainfall variability is increasing.

  12. Sugarcane Water Sustainability Assessment Through the Indicators Extracted from Spatial Models: Case Study of Sugarcane Expansion Hotspots in Brazil

    Science.gov (United States)

    Ferraz, R. P.; Simoes, M.; Dubreuil, V.

    2012-12-01

    The CanaSat project data from INPE (2010) has evidenced the trend of sugarcane expansion into savanna areas in the Midwest region of Brazil that has a great potential for the sugarcane development, in terms of topography and suitable soils, according to Sugarcane Agroecological Zoning (EMBRAPA, 2009). However, in this region the climatic water availability has limitations, once the climate is marked by drought season with a strong water deficiency due to reduction of rainfall (SILVA et al. 2008). There may be serious risks to the sugarcane culture conducted in dryland crop system without any support from additional irrigation. Silva et al. (2008) state that, for the expansion of sugarcane cultivation in the Cerrado region will be necessary supplemental irrigation with 80 to 120 mm of water applied after cutting or planting. In the Brazilian Midwest the sugarcane agroindustry expansion is technically viable, but for the sustainable development of this activity it is necessary an adequate planning based on knowledge about water demand and availability. The aim of this study was to conduct an assessment of the potential water sustainability for the sugarcane cultivation in four microregions in Goiás State, Brazil, through the use of indicators proposed in Indicators System of Sugarcane Water Sustainability Assessment (Ferraz, 2012), that was thought to subsidize the public policies proposals and sectoral planning in strategic level by means of indicators that enable to perform diagnostic and prognostic analysis. These indicators are direct and relevant indexes obtained from data extracted through geoprocessing techniques from integration of many spatial models. The used indicators were: (i) Three indexes expressing the land favorability for sugarcane development conducted in dryland or irrigation system through the establishment of the ratio between the sugarcane suitable area for each different system and the total area of territorial unit of analysis (micro

  13. Desertification, salinization, and biotic homogenization in a dryland river ecosystem.

    Science.gov (United States)

    Miyazono, Seiji; Patiño, Reynaldo; Taylor, Christopher M

    2015-04-01

    This study determined long-term changes in fish assemblages, river discharge, salinity, and local precipitation, and examined hydrological drivers of biotic homogenization in a dryland river ecosystem, the Trans-Pecos region of the Rio Grande/Rio Bravo del Norte (USA/Mexico). Historical (1977-1989) and current (2010-2011) fish assemblages were analyzed by rarefaction analysis (species richness), nonmetric multidimensional scaling (composition/variability), multiresponse permutation procedures (composition), and paired t-test (variability). Trends in hydrological conditions (1970s-2010s) were examined by Kendall tau and quantile regression, and associations between streamflow and specific conductance (salinity) by generalized linear models. Since the 1970s, species richness and variability of fish assemblages decreased in the Rio Grande below the confluence with the Rio Conchos (Mexico), a major tributary, but not above it. There was increased representation of lower-flow/higher-salinity tolerant species, thus making fish communities below the confluence taxonomically and functionally more homogeneous to those above it. Unlike findings elsewhere, this biotic homogenization was due primarily to changes in the relative abundances of native species. While Rio Conchos discharge was>2-fold higher than Rio Grande discharge above their confluence, Rio Conchos discharge decreased during the study period causing Rio Grande discharge below the confluence to also decrease. Rio Conchos salinity is lower than Rio Grande salinity above their confluence and, as Rio Conchos discharge decreased, it caused Rio Grande salinity below the confluence to increase (reduced dilution). Trends in discharge did not correspond to trends in precipitation except at extreme-high (90th quantile) levels. In conclusion, decreasing discharge from the Rio Conchos has led to decreasing flow and increasing salinity in the Rio Grande below the confluence. This spatially uneven desertification and

  14. Biological Dimensions of Crack Morphology in Dryland Soils

    Science.gov (United States)

    DeCarlo, K. F.; Spiegel, M.; Caylor, K. K.

    2014-12-01

    Macropores and cracks have an integral role in soil hydrology, and the physicochemical factors that induce them have been the subject of much laboratory research. How these processes translate to field soils, however, is often obfuscated by the biological elements present that complicate its formation and dynamics. In this study, we investigated the biological influence of herbivores and vegetation on 3D crack morphology in a dryland swelling soil (black cotton/vertisol). Fieldwork was conducted at and near the Kenya Long-Term Exclosure Experiment (KLEE) plots in Mpala, central Kenya, where three different soil regions were identified: highly vegetated areas, animal trails, and termite mounds. Crack networks were physically characterized by pouring liquid resin into the soil and excavating them when dry, after which they were imaged and quantified using medical magnetic resonance imaging (MRI). Cracking intensity of each cast was corrected via soil moisture and bulk density measurements at 5 cm intervals over 30 cm. 3D characterization of the soil system shows that mechanical compaction is a major influence in the formation of extensive and deep cracks in animal trails, with megaherbivores (e.g. elephants) inducing the most extreme cracks. Bioturbation is seen as a major influence in the formation of shallower cracks in termite mounds, as termites loosen and aerate the soil and reduce the soil's cohesive properties. Highly vegetated soils show a large degree of variability: small, disconnected soil patches induced by vegetative cover and a larger root network results in smaller and shallower cracks, but full vegetative cover induces deep and irregular cracks, possibly due to diverted rainfall. Our results highlight the intricate connections between the biology and physics that dictate soil processes in a complex soil system at the field scale.

  15. Crop rotation and its ability to suppress perennial weeds

    OpenAIRE

    Askegaard, Margrethe

    2016-01-01

    The appropriate combination of crops and green manures prevents spread of perennial weeds and increases crop yields and quality. Weed-suppressing crop rotations are absolutely essential for sustainable organic arable farming. Practical recommendation Basic rules • Implement green manures, such as clover or lucerne, in at least 20 % of the rotation. • Do not grow more than 50 % of cereals with low weed competitiveness in the rotation. Do not cultivate such crops for more than 2 con...

  16. The evaluation of dryland Cenchrus ciliaris l. cv Molopo for weaner ...

    African Journals Online (AJOL)

    Weaner calf production from a dryland C. ciliaris pasture was evaluated at three stocking rates under continuous grazing (1978 -1983). Differences in available above ground phytomass (AAP) weaning mass and economic returns were investigated. The AAP decreased with increased stocking rates. At the high and medium ...

  17. The Effect of Land use/cover change on Biomass Stock in Dryland ...

    African Journals Online (AJOL)

    section of both rural and urban folks. However in the face of population pressure, drylands are increasingly in the path of conversion and degradation. This study therefore, performed an assessment of the effect of land use/cover change on ...

  18. Using Remote Sensing, Geomorphology, and Soils to Map Episodic Streams in Drylands

    Science.gov (United States)

    Thibodeaux-Yost, S. N. S.

    2016-12-01

    Millions of acres of public land in the California deserts are currently being evaluated and permitted for the construction of large-scale renewable energy projects. The absence of a standard method for identifying episodic streams in arid and semi-arid (dryland) regions is a source of conflict between project developers and the government agencies responsible for conserving natural resources and permitting renewable energy projects. There is a need for a consistent, efficient, and cost-effective dryland stream delineation protocol that accurately reflects the extent and distribution of active watercourses. This thesis evaluates the stream delineation method and results used by the developer for the proposed Ridgecrest Solar Power Project on the El Paso Fan, Ridgecrest, Kern County, California. This evaluation is then compared and contrasted with results achieved using remote sensing, geomorphology, soils, and GIS analysis to identify stream presence on the site. This study's results identified 105 acres of watercourse, a value 10 times greater than that originally identified by the project developer. In addition, the applied methods provide an ecohydrologic base map to better inform project siting and potential project impact mitigation opportunities. This study concludes that remote sensing, geomorphology, and dryland soils can be used to accurately and efficiently identify episodic stream activity and the extent of watercourses in dryland environments.

  19. Contributions of radiative factors to enhanced dryland warming over East Asia

    Science.gov (United States)

    Zhang, Yanting; Guan, Xiaodan; Yu, Haipeng; Xie, Yongkun; Jin, Hongchun

    2017-08-01

    Enhanced near-surface atmospheric warming has occurred over East Asia in recent decades, especially in drylands. Although local factors have been confirmed to provide considerable contributions to this warming, such factors have not been sufficiently analyzed. In this study, we extracted the radiatively forced temperature (RFT) associated with the built-up greenhouse gases, aerosol emission, and various other radiative forcing over East Asia and found a close relationship between RFT and CO2. In addition, using climate model experiments, we explored the responses of temperature changes to black carbon (BC), CO2, and SO4 and found that the enhanced dryland warming induced by CO2 had the largest magnitude and was strengthened by the warming effect of BC. Moreover, the sensitivity of daily maximum and minimum temperature changes to BC, CO2, and SO4 was examined. It showed asymmetric responses of daily maximum and minimum temperature to radiative factors, which led to an obvious change of diurnal temperature range (DTR), especially in drylands. The DTR's response to CO2 is the most significant. Therefore, CO2 not only plays a dominant role in enhanced warming but also greatly affects the decrease of DTR in drylands. However, the mechanisms of these radiative factors' effects in the process of DTR change are not clear and require more investigation.

  20. Climate change may restrict dryland forest regeneration in the 21st century

    Science.gov (United States)

    M. D. Petrie; J. B. Bradford; R. M. Hubbard; W. K. Lauenroth; C. M. Andrews; D. R. Schlaepfer

    2017-01-01

    The persistence and geographic expansion of dryland forests in the 21st century will be influenced by how climate change supports the demographic processes associated with tree regeneration. Yet, the way that climate change may alter regeneration is unclear. We developed a quantitative framework that estimates forest regeneration potential (RP) as a function of key...

  1. Revisiting the coupling between NDVI trends and cropland changes in the Sahel drylands

    DEFF Research Database (Denmark)

    Tong, Xiaoye; Brandt, Martin Stefan; Hiernaux, Pierre

    2017-01-01

    The impact of human activities via land use/cover changes on NDVI trends is critical for an improved understanding of satellite-observed changes in vegetation productivity in drylands. The dominance of positive NDVI trends in the Sahel, the so-called re-greening, is sometimes interpreted as a com...

  2. Impacts of Global Change on Water Resources in Dryland East Asia

    Science.gov (United States)

    Ge Sun; Xiaoming Feng; Jingfeng Xiao; Alex Shiklomanov; Shengping Wang; Zhiqiang Zhang; Nan Lu; Shuai Wang; Liding Chen; Bojie Fu; Yaning Chen; Jiquan Chen

    2013-01-01

    The vast Dryland East Asia (DEA) area consists of several large geographic regions including the Qinghai-Tibet Plateau, Loess Plateau, and Mongolia Plateau. T he region is of great importance to the functioning of the earth system under a changing climate. In the past three decades, due to the unprecedented land use/land cover change, urbanization, industrialization...

  3. Milking drylands : gender networks, pastoral markets and food security in stateless Somalia

    NARCIS (Netherlands)

    Nori, M.

    2010-01-01

    The Milking Drylands research initiative addresses the critical issues of food security, market integration, gender roles and governance matters in a peculiar area of the world, the Somali ecosystem. The research aims at exploring interesting dynamics of ongoing social change, in order to stimulate

  4. Dryland salinity management in the semi-arid Western Cape (South Africa)

    CSIR Research Space (South Africa)

    Bugan, Richard DH

    2011-07-01

    Full Text Available Dryland salinity is a major factor affecting the water quality of the mid-to-lower-reaches of the Berg River, a pivotal source of water to Cape Town. The implementation of salinity management strategies is therefore essential. Distributed...

  5. Procedures for estimation of the livestock ecological footprint of US drylands

    Science.gov (United States)

    Robert A. Washington-Allen; John E. Mitchell

    2008-01-01

    The ecological condition and trend of the United States' 3,902,000 of Drylands and the extent to which human management actions contribute to degradation are unknown at the national spatial scale. (Washington-Allen et al. 2006). Our research seeks to develop procedures for determining the impact or ecological footprint of livestock grazing on the productive...

  6. Assessing woody vegetation trends in Sahelian drylands using MODIS based seasonal metrics

    DEFF Research Database (Denmark)

    Brandt, Martin Stefan; Hiernaux, Pierre; Rasmussen, Kjeld

    2016-01-01

    Woody plants play a major role for the resilience of drylands and in peoples' livelihoods. However, due to their scattered distribution, quantifying and monitoring woody cover over space and time is challenging. We develop a phenology driven model and train/validate MODIS (MCD43A4, 500 m) derived...

  7. Multi-element accumulation near Rumex crispus roots under wetland and dryland conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kissoon, La Toya T., E-mail: latoya.kissoon@ndsu.ed [Wet Ecosystem Research Group, Department of Biological Sciences, North Dakota State University, NDSU Department 2715, P.O. Box 6050 Fargo, ND 58108-6050 (United States); Jacob, Donna L.; Otte, Marinus L. [Wet Ecosystem Research Group, Department of Biological Sciences, North Dakota State University, NDSU Department 2715, P.O. Box 6050 Fargo, ND 58108-6050 (United States)

    2010-05-15

    Rumex crispus was grown under wet and dry conditions in two-chamber columns such that the roots were confined to one chamber by a 21 mum nylon mesh, thus creating a soil-root interface ('rhizoplane'). Element concentrations at 3 mm intervals below the 'rhizoplane' were measured. The hypothesis was that metals accumulate near plant roots more under wetland than dryland conditions. Patterns in element distribution were different between the treatments. Under dryland conditions Al, Ba, Cu, Cr, Fe, K, La, Mg, Na, Sr, V, Y and Zn accumulated in soil closest to the roots, above the 'rhizoplane' only. Under wetland conditions Al, Fe, Cr, K, V and Zn accumulated above as well as 3 mm below the 'rhizoplane' whereas La, Sr and Y accumulated 3 mm below the 'rhizoplane' only. Plants on average produced 1.5 times more biomass and element uptake was 2.5 times greater under wetland compared to dryland conditions. - Patterns of element accumulation near the roots of plants differ between dryland and wetland conditions.

  8. New ecology education: Preparing students for the complex human-environmental problems of dryland East Asia

    Science.gov (United States)

    Present-day environmental problems of Dryland East Asia are serious, and future prospects look especially disconcerting owing to current trends in population growth and economic development. Land degradation and desertification, invasive species, biodiversity losses, toxic waste and air pollution, a...

  9. Climate change impacts on yields and soil carbon in dryland agriculture

    Science.gov (United States)

    Dryland agroecosystems could be a sizable sink for atmospheric carbon (C) due to their spatial extent and level of degradation, providing climate change mitigation. We examined productivity and soil C dynamics under two IPCC climate change scenarios (RCP 4.5; RCP 8.5), utilizing long-term experiment...

  10. Major faults and the development of dryland salinity in the western wheatbelt of Western Australia

    Directory of Open Access Journals (Sweden)

    C. J. Clarke

    1998-01-01

    Full Text Available Dryland salinity poses a major threat to agricultural production in the wheatbelt of Western Australia and much time and effort is expended on understanding the mechanisms which cause it and on developing techniques to halt or reverse its development. Whilst the location of much dryland salinity can be explained by its topographic position, a significant proportion of it cannot. This study investigated the hypothesis that major faults in the Yilgarn Craton represented in aeromagnetic data by intense curvilinear lows explained the location of areas of dryland salinity not explained by topography. Moreover, the causal mechanisms that might underpin a spatial relationship between major faults and dryland salinity were sought. In one fourth order catchment, nearly 85% of the salinity that was not explained topographically was within 2km of the centre line of a major fault, the remaining 15% being in the other 12km of the catchment. Three groups of similar third order catchments in the western wheatbelt of Western Australia were also investigated; in each case the catchment that was underlain by a major fault had dryland salinity an order of magnitude more than the unfaulted catchment(s. This evidence demonstrates a strong spatial association between major faults and the development of dryland salinity. Other evidence suggests that the underlying mechanism is hydraulic conductivity 5.2 to 2.9 times higher inside the fault zone compared to outside it and shows that geomorphology, salt store, regolith thickness, and degree of clearing are not the underlying mechanisms. In one of the groups of catchments, it has been calculated that an amount of recharge, significant in relation to recharge from rainfall, was entering from an adjacent catchment along a major fault. The paper concludes that geological features such as major faults affect the development of dryland salinity in the wheatbelt of Western Australia because of permeability differences in the

  11. Dryland feedbacks to climatic change: Results from a climate manipulation experiment on the Colorado Plateau

    Science.gov (United States)

    Reed, S.; Belnap, J.; Ferrenberg, S.; Wertin, T. M.; Darrouzet-Nardi, A.; Tucker, C.; Rutherford, W. A.

    2015-12-01

    Arid and semiarid ecosystems cover ~40% of Earth's terrestrial surface and make up ~35% of the U.S., yet we know surprisingly little about how climate change will affect these widespread landscapes. Like many dryland regions, the Colorado Plateau in the southwestern U.S. is predicted to experience climate change as elevated temperature and altered timing and amount of annual precipitation. We are using a long-term (>10 yr) factorial warming and supplemental rainfall experiment on the Colorado Plateau to explore how predicted changes in climate will affect vascular plant and biological soil crust community composition, biogeochemical cycling, and energy balance (biocrusts are a surface soil community of moss, lichen, and cyanobacteria that can make up as much as 70% of the living cover in drylands). While some of the responses we have observed were expected, many of the results are surprising. For example, we documented biocrust community composition shifts in response to altered climate that were significantly faster and more dramatic than considered likely for these soil communities that typically change over decadal and centennial timescales. Further, while we continue to observe important climate change effects on carbon cycling - including reduced net photosynthesis in vascular plants, increased CO2 losses from biocrust soils during some seasons, and changes to the interactions between water and carbon cycles - we have also found marked treatment effects on the albedo and spectral signatures of dryland soils. In addition to demonstrating the effects of these treatments, the strong relationships we observed in our experiments between biota and climate provide a quantitative framework for improving our representation of dryland responses to climate change. In this talk we will cover a range of datasets that, taken together, show: (1) large climate-driven changes to dryland biogeochemical cycling may be the result of both effects on existing communities, as well

  12. Impact of cash cropping and perennial crops on food crop ...

    African Journals Online (AJOL)

    synergies or trade-offs between the two crops are scant to address the concerns that cash cropping can ..... production and productivity, we develop indices of intensity of PCC and enset cultivation. We define household i's ... study the impact of these indices on food crop production and productivity, we specify models for i.

  13. Soil microbiology and sustainable crop production

    National Research Council Canada - National Science Library

    Dixon, Geoffrey R; Tilston, Emma L

    2010-01-01

    ... population and diminishing land supply. Increasing food production in parallel with conserving and protecting our environment while allowing producers adequate financial returns are the primary challenges facing agricultural science research in the twenty-first century. These factors of food production, environmental protection and producers' profit form a t...

  14. Relating soil biochemistry to sustainable crop production

    Science.gov (United States)

    Amino acids, amino sugars, carbohydrates, phenols, and fatty acids together comprise appreciable proportions of soil organic matter (SOM). Their cycling contribute to soil processes, including nitrogen availability, carbon sequestration and aggregation. For example, soil accumulation of phenols has ...

  15. Can nitrogen fertilization aid restoration of mature tree productivity in degraded dryland riverine ecosystems?

    Science.gov (United States)

    Andersen, Douglas C.; Adair, Elizabeth Carol; Nelson, Sigfrid Mark; Binkley, Dan

    2014-01-01

    Restoration of riparian forest productivity lost as a consequence of flow regulation is a common management goal in dryland riverine ecosystems. In the northern hemisphere, dryland river floodplain trees often include one or another species of Populus, which are fast-growing, nutrient-demanding trees. Because the trees are phreatophytic in drylands, and have water needs met in whole or in part by a shallow water table, their productivity may be limited by nitrogen (N) availability, which commonly limits primary productivity in mesic environments. We added 20 g N m−2 in a 2-m radius around the base of mature Populus fremontii along each of a regulated and free-flowing river in semiarid northwest Colorado, USA (total n = 42) in order to test whether growth is constrained by low soil N. Twelve years after fertilization, we collected increment cores from these and matched unfertilized trees and compared radial growth ratios (growth in the 3-year post-fertilization period/growth in the 3-year pre-fertilization period) in paired t tests. We expected a higher mean ratio in the fertilized trees. No effect from fertilization was detected, nor was a trend evident on either river. An alternative test using analysis of covariance (ANCOVA) produced a similar result. Our results underscore the need for additional assessment of which and to what extent factors other than water control dryland riverine productivity. Positive confirmation of adequate soil nutrients at these and other dryland riparian sites would bolster the argument that flow management is necessary and sufficient to maximize productivity and enhance resilience in affected desert riverine forests.

  16. Climate and soil attributes determine plant species turnover in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Gotelli, Nicholas J.; Quero, José L.; Delgado-Baquerizo, Manuel; Bowker, Matthew A.; Eldridge, David J.; Ochoa, Victoria; Gozalo, Beatriz; Valencia, Enrique; Berdugo, Miguel; Escolar, Cristina; García-Gómez, Miguel; Escudero, Adrián; Prina, Aníbal; Alfonso, Graciela; Arredondo, Tulio; Bran, Donaldo; Cabrera, Omar; Cea, Alex; Chaieb, Mohamed; Contreras, Jorge; Derak, Mchich; Espinosa, Carlos I.; Florentino, Adriana; Gaitán, Juan; Muro, Victoria García; Ghiloufi, Wahida; Gómez-González, Susana; Gutiérrez, Julio R.; Hernández, Rosa M.; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Mau, Rebecca L.; Hughes, Frederic Mendes; Miriti, Maria; Monerris, Jorge; Muchane, Muchai; Naseri, Kamal; Pucheta, Eduardo; Ramírez-Collantes, David A.; Raveh, Eran; Romão, Roberto L.; Torres-Díaz, Cristian; Val, James; Veiga, José Pablo; Wang, Deli; Yuan, Xia; Zaady, Eli

    2015-01-01

    Aim Geographic, climatic, and soil factors are major drivers of plant beta diversity, but their importance for dryland plant communities is poorly known. This study aims to: i) characterize patterns of beta diversity in global drylands, ii) detect common environmental drivers of beta diversity, and iii) test for thresholds in environmental conditions driving potential shifts in plant species composition. Location 224 sites in diverse dryland plant communities from 22 geographical regions in six continents. Methods Beta diversity was quantified with four complementary measures: the percentage of singletons (species occurring at only one site), Whittake’s beta diversity (β(W)), a directional beta diversity metric based on the correlation in species occurrences among spatially contiguous sites (β(R2)), and a multivariate abundance-based metric (β(MV)). We used linear modelling to quantify the relationships between these metrics of beta diversity and geographic, climatic, and soil variables. Results Soil fertility and variability in temperature and rainfall, and to a lesser extent latitude, were the most important environmental predictors of beta diversity. Metrics related to species identity (percentage of singletons and β(W)) were most sensitive to soil fertility, whereas those metrics related to environmental gradients and abundance ((β(R2)) and β(MV)) were more associated with climate variability. Interactions among soil variables, climatic factors, and plant cover were not important determinants of beta diversity. Sites receiving less than 178 mm of annual rainfall differed sharply in species composition from more mesic sites (> 200 mm). Main conclusions Soil fertility and variability in temperature and rainfall are the most important environmental predictors of variation in plant beta diversity in global drylands. Our results suggest that those sites annually receiving ~ 178 mm of rainfall will be especially sensitive to future climate changes. These

  17. Crop-insurance

    NARCIS (Netherlands)

    Wijk, van der S.

    1945-01-01

    Crop insurance was fairly new in the Netherlands but there was no legal objection or limitation to particular crops. If a crop were insured, it was important that the whole area of the crop were insured. Speculative insurance seemed preferable to mutual insurance.

    Crop insurance covered all risks

  18. Feedbacks between vegetation pattern and resource loss dramatically decrease ecosystem resilience and restoration potential in a simple dryland model

    NARCIS (Netherlands)

    Mayor, A.G.; Kefi, S.; Bautista, S.; Rodriguez, F.; Carteni, F.; Rietkerk, M.

    2013-01-01

    Conceptual frameworks of dryland degradation commonly include ecohydrological feedbacks between landscape spatial organization and resource loss, so that decreasing cover and size of vegetation patches result in higher water and soil losses, which lead to further vegetation loss. However, the

  19. Assessing gender roles in a changing landscape: diversified agro-pastoralism in drylands of West Pokot, Kenya

    National Research Council Canada - National Science Library

    Karmebäck, Vera N; Wairore, John Ndung’u; Jirström, Magnus; Nyberg, Gert

    2015-01-01

    .... This study reviewed in which ways these rangeland enclosures have influenced gender roles in the dryland systems of Chepareria in West Pokot, with specific regard to division of labour, financial...

  20. Dual cropping winter camelina with soybean in the northern Corn Belt

    Science.gov (United States)

    Sustainably balancing biofuel crop production with food, feed, and fiber on agricultural lands will require developing new cropping strategies. Double- and/or relay-cropping winter camelina (Camelina sativa L.) with soybean [Glycine max (L.) Merr.] may be a means to produce an energy and food crop o...

  1. Satellite-based assessment of crop coefficient for sugarcane in Maui, Hawaii

    Science.gov (United States)

    Water availability is one of the limiting factors for sustainable production of biofuel crops. A common method for determining crop water requirement is to multiply daily potential evapotranspiration (ETo) calculated from meteorological parameters by a crop coefficient (Kc) to obtain actual crop eva...

  2. Allelopathic potential of oil seed crops in production of crops: a review.

    Science.gov (United States)

    Shah, Adnan Noor; Iqbal, Javaid; Ullah, Abid; Yang, Guozheng; Yousaf, Muhammad; Fahad, Shah; Tanveer, Mohsin; Hassan, Waseem; Tung, Shahbaz Atta; Wang, Leishan; Khan, Aziz; Wu, Yingying

    2016-08-01

    Agricultural production enhancement has been realized by more consumption of fossil energy such as fertilizer and agrochemicals. However, the production provides the present human with sufficient and diversified commodities, but at the same time, deprives in some extent the resources from the future human as well. In the other hand, it is known that synthetic herbicides face worldwide threats to human's health and environment as well. Therefore, it is a great challenge for agricultural sustainable development. The current review has been focussed on various oilseed crop species which launch efficient allelopathic intervention, either with weeds or other crops. Crop allelopathic properties can make one species more persistent to a native species. Therefore, these crops are potentially harmful to both naturalized as well as agricultural settings. On the other side, allelopathic crops provide strong potential for the development of cultivars that are more highly weed suppressive in managed settings. It is possible to utilize companion plants that have no deleterious effect on neighbor crops and can be included in intercropping system, thus, a mean of contributing to agricultural sustainable development. In mixed culture, replacement method, wherein differing densities of a neighbor species are planted, has been used to study phytotoxic/competitive effects. So, to use alternative ways for weed suppression has become very crucial. Allelochemicals have the ability to create eco-friendly products for weed management, which is beneficial for agricultural sustainable development. Our present study assessed the potential of four oilseed crops for allelopathy on other crops and associated weeds.

  3. Physiology-based prognostic modeling of the influence of changes in precipitation on a keystone dryland plant species.

    Science.gov (United States)

    Coe, Kirsten K; Sparks, Jed P

    2014-12-01

    Fluctuations in mean annual precipitation (MAP) will strongly influence the ecology of dryland ecosystems in the future, yet, because individual precipitation events drive growth and resource availability for many dryland organisms, changes in intra-annual precipitation may disproportionately influence future dryland processes. This work examines the hypothesis that intra-annual precipitation changes will drive dryland productivity to a greater extent than changes to MAP. To test this hypothesis, we created a physiology-based model to predict the effects of precipitation change on a widespread biocrust moss that regulates soil structure, water retention, and nutrient cycling in drylands. First, we used the model to examine moss productivity over the next 100 years driven by alterations in MAP by ± 10, 20 and 30%, and changes in intra-annual precipitation (event size and frequency). Productivity increased as a function of MAP, but differed among simulations where intra-annual precipitation was manipulated under constant MAP. Supporting our hypothesis, this demonstrates that, even if MAP does not change, changes in the features of individual precipitation events can strongly influence long-term performance. Second, we used the model to examine 100-year productivity based on projected dryland precipitation from published global and regional models. These simulations predicted 25-63% reductions in productivity and increased moss mortality rates, declines that will likely alter water and nutrient cycling in dryland ecosystems. Intra-annual precipitation in model-based simulations was a stronger predictor of productivity compared to MAP, further supporting our hypothesis, and illustrating that intra-annual precipitation patterns may dominate dryland responses to altered precipitation in a future climate.

  4. Food for Thought: Crop Yields in the Columbia River Basin in an Altered Future

    Science.gov (United States)

    Rajagopalan, K.; Chinnayakanahalli, K.; Nelson, R.; Stockle, C.; Kruger, C.; Brady, M.; Adam, J. C.

    2013-12-01

    Growth of global population and food consumption in the next several decades is expected to result in a food security challenge. Strategies to address this challenge, such as enhancing agricultural productivity and resiliency, need to be considered within the context of a full range of plausible consequences so as to identify investments that create win-win-win scenarios for the environment, economy, and society. Regional earth systems models can provide the necessary scale-appropriate framework to inform the decision making context for adaptation strategies, especially in the context of global change. In an altered future, changes to climate, technology and socioeconomics affect regional agriculture both directly and indirectly. These effects are not independent and an integrated process-based model may better capture unanticipated non-linear and non-monotonic responses and feedbacks over time . BioEarth is a research initiative designed to explore the coupling of multiple stand-alone earth systems models to generate usable information for agricultural and natural resource decision making at the regional scale at decadal time-steps. This project focuses on the U.S. Pacific Northwest (PNW) region and is a framework that integrates atmospheric, terrestrial, aquatic, and economic models. We apply component models of BioEarth to the Columbia River basin in the PNW to study the direct and indirect impacts of climate change on regional irrigated and dryland crop yields for a variety of annual and perennial crops. Results indicate that the net effect of climate change on crop yields is dependent on the crop type. There is a negative effect of temperature on yields for most crops. Dryland winter wheat is a notable exception. With warming, although the available growing season increases, faster thermal accumulation results in a shorter time to maturity. Precipitation changes in the region have a positive impact on dryland agriculture. Carbon dioxide (CO2) fertilization has

  5. Sensitivity of potential evapotranspiration estimation to the Thornthwaite and Penman-Monteith methods in the study of global drylands

    Science.gov (United States)

    Yang, Qing; Ma, Zhuguo; Zheng, Ziyan; Duan, Yawen

    2017-12-01

    Drylands are among those regions most sensitive to climate and environmental changes and human-induced perturbations. The most widely accepted definition of the term dryland is a ratio, called the Surface Wetness Index (SWI), of annual precipitation to potential evapotranspiration (PET) being below 0.65. PET is commonly estimated using the Thornthwaite (PET Th) and Penman-Monteith equations (PET PM). The present study compared spatiotemporal characteristics of global drylands based on the SWI with PET Th and PET PM. Results showed vast differences between PET Th and PET PM; however, the SWI derived from the two kinds of PET showed broadly similar characteristics in the interdecadal variability of global and continental drylands, except in North America, with high correlation coefficients ranging from 0.58 to 0.89. It was found that, during 1901-2014, global hyper-arid and semi-arid regions expanded, arid and dry sub-humid regions contracted, and drylands underwent interdecadal fluctuation. This was because precipitation variations made major contributions, whereas PET changes contributed to a much lesser degree. However, distinct differences in the interdecadal variability of semi-arid and dry sub-humid regions were found. This indicated that the influence of PET changes was comparable to that of precipitation variations in the global dry-wet transition zone. Additionally, the contribution of PET changes to the variations in global and continental drylands gradually enhanced with global warming, and the Thornthwaite method was found to be increasingly less applicable under climate change.

  6. Crop-water-environment models; selected papers to the workshop organized by the ICID Working Group on `Sustainable Crops and Water Use' at the occasion of the 16th Congress of the International Commission on Irrigation and Drainage at Cairo, Egypt

    NARCIS (Netherlands)

    Ragab, R.; El-Din El-Quosy, D.; Broek, van den B.J.; Pereira, L.S.

    1996-01-01

    The main aim of this workshop was to bring individuals and organizations together who contribute to the development and upgrading of crop-water-environment models. Twenty-four model papers were presented in three sessions: pesticides and nitrates, salinity, and crop water balance. Each presentation

  7. [Mechanism on biodiversity managing crop diseases].

    Science.gov (United States)

    Yang, Jing; Shi, Zhu-Feng; Gao, Dong; Liu, Lin; Zhu, You-Yong; Li, Cheng-Yun

    2012-11-01

    Reasonable utilization of natural resource and protection of ecological environment is the foundation for implementing agricultural sustainable development. Biodiversity research and protection are becoming an important issue concerned commonly in the world. Crop disease is one of the important natural disasters for food production and safety, and is also one of the main reasons that confine sustainable development of agricultural production. Large-scale deployment of single highly resistant variety results in reduction of agro-biodiversity level. In this case, excessive loss of agro-biodiversity has become the main challenge in sustainable agriculture. Biodiversity can not only effectively alleviate disease incidence and loss of crop production, but also reduce pollution of agricultural ecological environment caused by excessive application of pesticides and fertilizers to the agricultural ecological environment. Discovery of the mechanism of biodiversity to control crop diseases can reasonably guide the rational deployment and rotation of different crops and establish optimization combinations of different crops. This review summarizes recent advances of research on molecular, physiological, and ecological mechanisms of biodiversity managing crop diseases, and proposes some research that needs to be strengthened in the future.

  8. Ethical reflections on herbicide-resistant crops

    DEFF Research Database (Denmark)

    Sandøe, Peter; Madsen, Kathrine Hauge

    2005-01-01

    The introduction of genetically modified (GM) crops has caused a fierce public debate in Europe.Much of the controversy centres on possible risks to the environment. A specific problem here is thatrisk perception of the scientific experts differs from that of the public. In this paper, risks...... associatedwith herbicide-resistant crops are presented from the point of view of experts and lay people. In thepublic perception, herbicide-resistant (HR) crops are troublesome because of their association with twotechnologies: genetic engineering of crops and the use of herbicides. These technologies...... are perceived asrisky because they seem to share certain features: in particular, their long-term effects are unknown andthey are dreaded. Other value questions also come into play. The public seems to be concerned that risksare not outweighed by usefulness, that using HR crops is the wrong path to sustainable...

  9. Crop residue management in arable cropping systems under a temperate climate. Part 2: Soil physical properties and crop production. A review

    Directory of Open Access Journals (Sweden)

    Hiel, MP.

    2016-01-01

    Full Text Available Introduction. Residues of previous crops provide a valuable amount of organic matter that can be used either to restore soil fertility or for external use. A better understanding of the impact of crop residue management on the soil-water-plant system is needed in order to manage agricultural land sustainably. This review focuses on soil physical aspects related to crop residue management, and specifically on the link between soil structure and hydraulic properties and its impact on crop production. Literature. Conservation practices, including crop residue retention and non-conventional tillage, can enhance soil health by improving aggregate stability. In this case, water infiltration is facilitated, resulting in an increase in plant water availability. Conservation practices, however, do not systematically lead to higher water availability for the plant. The influence of crop residue management on crop production is still unclear; in some cases, crop production is enhanced by residue retention, but in others crop residues can reduce crop yield. Conclusions. In this review we discuss the diverse and contrasting effects of crop residue management on soil physical properties and crop production under a temperate climate. The review highlights the importance of environmental factors such as soil type and local climatic conditions, highlighting the need to perform field studies on crop residue management and relate them to specific pedo-climatic contexts.

  10. Hydroclimatic dynamics in southwestern Romania drylands over the ...

    Indian Academy of Sciences (India)

    3Ion Mincu University of Architecture and Urbanism, 18–20 Academiei Blvd., District 1, 010014, Bucharest,. Romania. 4National Institute for Research and Development in Constructions, Urban Planning and Sustainable Spatial. Development URBAN-INCERC, 266 Pantelimon Blvd., District 2, 021652, Bucharest, Romania.

  11. Legacy effects in linked ecological-soil-geomorphic systems of drylands

    Science.gov (United States)

    Monger, Curtis; Sala, Osvaldo E.; Duniway, Michael C.; Goldfus, Haim; Meir, Isaac A.; Poch, Rosa M.; Throop, Heather L.; Vivoni, Enrique R.

    2015-01-01

    A legacy effect refers to the impacts that previous conditions have on current processes or properties. Legacies have been recognized by many disciplines, from physiology and ecology to anthropology and geology. Within the context of climatic change, ecological legacies in drylands (eg vegetative patterns) result from feedbacks between biotic, soil, and geomorphic processes that operate at multiple spatial and temporal scales. Legacy effects depend on (1) the magnitude of the original phenomenon, (2) the time since the occurrence of the phenomenon, and (3) the sensitivity of the ecological–soil–geomorphic system to change. Here we present a conceptual framework for legacy effects at short-term (days to months), medium-term (years to decades), and long-term (centuries to millennia) timescales, which reveals the ubiquity of such effects in drylands across research disciplines.

  12. Mapping gains and losses in woody vegetation across global tropical drylands

    DEFF Research Database (Denmark)

    Tian, Feng; Brandt, Martin Stefan; Liu, Yi Y

    2017-01-01

    , the actual changes in the woody vegetation are always hidden by interannual fluctuations of the leaf density, because the most widely used remote sensing data are primarily related to the photosynthetically active vegetation components. Here, we quantify the temporal trends of the nonphotosynthetic woody......Woody vegetation in global tropical drylands is of significant importance for both the interannual variability of the carbon cycle and local livelihoods. Satellite observations over the past decades provide a unique way to assess the vegetation long-term dynamics across biomes worldwide. Yet...... components (i.e., stems and branches) in global tropical drylands during 2000-2012 using the vegetation optical depth (VOD), retrieved from passive microwave observations. This is achieved by a novel method focusing on the dry season period to minimize the influence of herbaceous vegetation and using...

  13. African Crop Science Journal

    African Journals Online (AJOL)

    The African Crop Science Journal, a quarterly publication, publishes original research papers dealing with all aspects of crop agronomy, production, genetics and breeding, germplasm, crop protection, post harvest systems and utilisation, agro-forestry, crop-animal interactions, information science, environmental science ...

  14. Energy crops for biogas plants. Bavaria; Energiepflanzen fuer Biogasanlagen. Bayern

    Energy Technology Data Exchange (ETDEWEB)

    Aigner, A.; Biertuempel, A.; Conrad, M. (and others)

    2012-08-15

    For agriculturists in Bavaria (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

  15. COMMON PROPERTY, PRIVATE PROPERTY AND REGULATION THE CASE OF DRYLAND SALINITY

    OpenAIRE

    Quiggin, John C.

    1986-01-01

    The term 'common property' has frequently been misapplied to situations where no property rights exist. Common property rights have provided a workable alternative to private property in many historical situations. Common property concepts and institutions can also play a major role in analysing and responding to current environmental problems. In this paper, the problem of dryland salinity is examined and solutions based on common property, private property and regulation are compared.

  16. The potential roles of biological soil crusts in dryland hydrologic cycles

    Science.gov (United States)

    Belnap, J.

    2006-01-01

    Biological soil crusts (BSCs) are the dominant living cover in many drylands of the world. They possess many features that can influence different aspects of local hydrologic cycles, including soil porosity, absorptivity, roughness, aggregate stability, texture, pore formation, and water retention. The influence of biological soil crusts on these factors depends on their internal and external structure, which varies with climate, soil, and disturbance history. This paper presents the different types of biological soil crusts, discusses how crust type likely influences various aspects of the hydrologic cycle, and reviews what is known and not known about the influence of biological crusts on sediment production and water infiltration versus runoff in various drylands around the world. Most studies examining the effect of biological soil crusts on local hydrology are done by comparing undisturbed sites with those recently disturbed by the researchers. Unfortunately, this greatly complicates interpretation of the results. Applied disturbances alter many soil features such as soil texture, roughness, aggregate stability, physical crusting, porosity, and bulk density in ways that would not necessarily be the same if crusts were not naturally present. Combined, these studies show little agreement on how biological crusts affect water infiltration or runoff. However, when studies are separated by biological crust type and utilize naturally occurring differences among these types, results indicate that biological crusts in hyperarid regions reduce infiltration and increase runoff, have mixed effects in and regions, and increase infiltration and reduce runoff in semiarid cool and cold drylands. However, more studies are needed before broad generalizations can be made on how biological crusts affect infiltration and runoff. We especially need studies that control for sub-surface soil features such as bulk density, micro- and macropores, and biological crust structure. Unlike

  17. Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes

    Directory of Open Access Journals (Sweden)

    Jessica Walker

    2015-08-01

    Full Text Available Baseline information about dryland forest phenology is necessary to accurately anticipate future ecosystem shifts. The overarching goal of our study was to investigate the variability of vegetation phenology across a dryland forest landscape in response to climate alterations. We analyzed the influence of site characteristics and climatic conditions on the phenological patterns of an Arizona, USA, ponderosa pine (Pinus ponderosa forest during a five-year period (2005 to 2009 that encompassed extreme wet and dry precipitation regimes. We assembled 80 synthetic Landsat images by applying the spatial and temporal adaptive reflectance fusion method (STARFM to 500 m MODIS and 30 m Landsat-5 Thematic Mapper (TM data. We tested relationships between site characteristics and the timing of peak Normalized Difference Vegetation Index (NDVI to assess the effect of climatic stress on the green-up of individual pixels during or after the summer monsoon. Our results show that drought-induced stress led to a fragmented phenological response that was highly dependent on microsite parameters, as both the spatial autocorrelation of peak timing and the number of significant site variables increased during the drought year. Pixels at lower elevations and with higher proportions of herbaceous vegetation were more likely to exhibit dynamic responses to changes in precipitation conditions. Our study demonstrates the complexity of responses within dryland forest ecosystems and highlights the need for standardized monitoring of phenology trends in these areas. The spatial and temporal variability of phenological signals may provide a quantitative solution to the problem of how to evaluate dryland land surface trends across time.

  18. Rangeland management and climate hazards in drylands: dust storms, desertification and the overgrazing debate

    OpenAIRE

    Middleton, N

    2016-01-01

    This paper examines the theory and supporting evidence for links between desertification, drought and dust storms with a particular focus on studies undertaken in and around the Gobi Desert. Overgrazing of rangeland by pastoralists has been the most commonly cited cause of desertification in global drylands for more than 30 years, but the evidence supporting this link is not always convincing. Nonetheless, overgrazing, desertification and dust storms are frequently connected, regardless. Drou...

  19. Climate contributions to vegetation variations in Central Asian drylands:Pre- and post-USSR collapse

    OpenAIRE

    Yu Zhou; Li Zhang; Rasmus Fensholt; Kun Wang; Irina Vitkovskaya; Feng Tian

    2015-01-01

    Central Asia comprises a large fraction of the world's drylands, known to be vulnerable to climate change. We analyzed the inter-annual trends and the impact of climate variability in the vegetation greenness for Central Asia from 1982 to 2011 using GIMMS3g normalized difference vegetation index (NDVI) data. In our study, most areas showed an increasing trend during 1982-1991, but experienced a significantly decreasing trend for 1992-2011. Vegetation changes were closely coupled to climate va...

  20. Functional diversity enhances the resistance of ecosystem multifunctionality to aridity in Mediterranean drylands

    Science.gov (United States)

    Valencia-Gómez, Enrique; Maestre, Fernando T.; Le Bagousse-Pinguet, Yoann; Quero, José Luis; Tamme, Riin; Börger, Luca; García-Gómez, Miguel; Gross, Nicolas

    2015-01-01

    SUMMARY We used a functional trait-based approach to assess the impacts of aridity and shrub encroachment on the functional structure of Mediterranean dryland communities (functional diversity and community-weighted mean trait values [CWM]), and to evaluate how these functional attributes ultimately affect multifunctionality (i.e., the provision of several ecosystem functions simultaneously). Shrub encroachment (the increase in the abundance/cover of shrubs) is a major land cover change that is taking place in grasslands worldwide. Studies conducted on drylands have reported positive or negative impacts of shrub encroachment depending on the functions and the traits of the sprouting or non-sprouting shrub species considered. Functional diversity and CWM were equally important as drivers of multifunctionality responses to both aridity and shrub encroachment. Size traits (e.g., vegetative height or lateral spread) and leaf traits (e.g., specific leaf area and leaf dry matter content) captured the effect of shrub encroachment on multifunctionality with a relative high accuracy (r2=0.63). Functional diversity also improved the resistance of multifunctionality along the aridity gradient studied. Maintaining and enhancing functional diversity in plant communities may help to buffer negative effects of ongoing global environmental change on dryland multifunctionality. PMID:25615801

  1. Climate change may restrict dryland forest regeneration in the 21st century

    Science.gov (United States)

    Petrie, M.D.; Bradford, John B.; Hubbard, R.M.; Lauenroth, W.K.; Andrews, Caitlin; Schlaepfer, D.R.

    2017-01-01

    The persistence and geographic expansion of dryland forests in the 21st century will be influenced by how climate change supports the demographic processes associated with tree regeneration. Yet, the way that climate change may alter regeneration is unclear. We developed a quantitative framework that estimates forest regeneration potential (RP) as a function of key environmental conditions for ponderosa pine, a key dryland forest species. We integrated meteorological data and climate projections for 47 ponderosa pine forest sites across the western United States, and evaluated RP using an ecosystem water balance model. Our primary goal was to contrast conditions supporting regeneration among historical, mid-21st century and late-21st century time frames. Future climatic conditions supported 50% higher RP in 2020–2059 relative to 1910–2014. As temperatures increased more substantially in 2060–2099, seedling survival decreased, RP declined by 50%, and the frequency of years with very low RP increased from 25% to 58%. Thus, climate change may initially support higher RP and increase the likelihood of successful regeneration events, yet will ultimately reduce average RP and the frequency of years with moderate climate support of regeneration. Our results suggest that climate change alone may begin to restrict the persistence and expansion of dryland forests by limiting seedling survival in the late 21st century.

  2. Changes to dryland rainfall result in rapid moss mortality and altered soil fertility

    Science.gov (United States)

    Reed, Sasha C.; Coe, Kirsten K.; Sparks, Jed P.; Housman, David C.; Zelikova, Tamara J.; Belnap, Jayne

    2012-01-01

    Arid and semi-arid ecosystems cover ~40% of Earth’s terrestrial surface, but we know little about how climate change will affect these widespread landscapes. Like many drylands, the Colorado Plateau in southwestern United States is predicted to experience elevated temperatures and alterations to the timing and amount of annual precipitation. We used a factorial warming and supplemental rainfall experiment on the Colorado Plateau to show that altered precipitation resulted in pronounced mortality of the widespread moss Syntrichia caninervis. Increased frequency of 1.2 mm summer rainfall events reduced moss cover from ~25% of total surface cover to fertility. Mosses are important members in many dryland ecosystems and the community changes observed here reveal how subtle modifications to climate can affect ecosystem structure and function on unexpectedly short timescales. Moreover, mortality resulted from increased precipitation through smaller, more frequent events, underscoring the importance of precipitation event size and timing, and highlighting our inadequate understanding of relationships between climate and ecosystem function in drylands.

  3. Species richness patterns and water-energy dynamics in the drylands of Northwest China.

    Directory of Open Access Journals (Sweden)

    Liping Li

    Full Text Available Dryland ecosystems are highly vulnerable to climatic and land-use changes, while the mechanisms underlying patterns of dryland species richness are still elusive. With distributions of 3637 native vascular plants, 154 mammals, and 425 birds in Xinjiang, China, we tested the water-energy dynamics hypothesis for species richness patterns in Central Asian drylands. Our results supported the water-energy dynamics hypothesis. We found that species richness of all three groups was a hump-shaped function of energy availability, but a linear function of water availability. We further found that water availability had stronger effects on plant richness, but weaker effects on vertebrate richness than energy availability. We conducted piecewise linear regressions to detect the breakpoints in the relationship between species richness and potential evapotranspiration which divided Xinjiang into low and high energy regions. The concordance between mammal and plant richness was stronger in high than in low energy regions, which was opposite to that between birds and plants. Plant richness had stronger effects than climate on mammal richness regardless of energy levels, but on bird richness only in high energy regions. The changes in the concordance between vertebrate and plant richness along the climatic gradient suggest that cautions are needed when using concordance between taxa in conservation planning.

  4. Multi-element accumulation near Rumex crispus roots under wetland and dryland conditions.

    Science.gov (United States)

    Kissoon, La Toya T; Jacob, Donna L; Otte, Marinus L

    2010-05-01

    Rumex crispus was grown under wet and dry conditions in two-chamber columns such that the roots were confined to one chamber by a 21 mum nylon mesh, thus creating a soil-root interface ('rhizoplane'). Element concentrations at 3 mm intervals below the 'rhizoplane' were measured. The hypothesis was that metals accumulate near plant roots more under wetland than dryland conditions. Patterns in element distribution were different between the treatments. Under dryland conditions Al, Ba, Cu, Cr, Fe, K, La, Mg, Na, Sr, V, Y and Zn accumulated in soil closest to the roots, above the 'rhizoplane' only. Under wetland conditions Al, Fe, Cr, K, V and Zn accumulated above as well as 3 mm below the 'rhizoplane' whereas La, Sr and Y accumulated 3 mm below the 'rhizoplane' only. Plants on average produced 1.5 times more biomass and element uptake was 2.5 times greater under wetland compared to dryland conditions. Copyright 2009 Elsevier Ltd. All rights reserved.

  5. Vegetation in Drylands: Effects on Wind Flow and Aeolian Sediment Transport

    Directory of Open Access Journals (Sweden)

    Jerome R. Mayaud

    2017-09-01

    Full Text Available Drylands are characterised by patchy vegetation, erodible surfaces and erosive aeolian processes. Empirical and modelling studies have shown that vegetation elements provide drag on the overlying airflow, thus affecting wind velocity profiles and altering erosive dynamics on desert surfaces. However, these dynamics are significantly complicated by a variety of factors, including turbulence, and vegetation porosity and pliability effects. This has resulted in some uncertainty about the effect of vegetation on sediment transport in drylands. Here, we review recent progress in our understanding of the effects of dryland vegetation on wind flow and aeolian sediment transport processes. In particular, wind transport models have played a key role in simplifying aeolian processes in partly vegetated landscapes, but a number of key uncertainties and challenges remain. We identify potential future avenues for research that would help to elucidate the roles of vegetation distribution, geometry and scale in shaping the entrainment, transport and redistribution of wind-blown material at multiple scales. Gaps in our collective knowledge must be addressed through a combination of rigorous field, wind tunnel and modelling experiments.

  6. Ecological Factors Preventing Restoration of Degraded Short Tussock Landscapes in New Zealand’s Dryland Zone

    Directory of Open Access Journals (Sweden)

    Rodrigues Anna P.

    2017-08-01

    Full Text Available Biotic factors such as the presence of invasive animal and/or plant species are well known as major causes of ecological degradation and as limiting either natural or assisted (human-induced ecological restoration. However, abiotic aspects of the landscape, such as water availability and soil physical/chemical conditions can also potentially limit restoration and should be considered. Dryland ecosystems are amongst the world’s most threatened and least protected. New Zealand’s drylands have been drastically changed, initially through burning, agricultural and grazing practices and the impacts of introduced herbivores and plants. This research aimed at identifying some of the key environmental factors preventing the reestablishment of native woody species in a New Zealand dryland ecosystem. The experiments involved a combination of shading, irrigation and grazing exclusion. The results showed that supplemental water was not beneficial for the survival and growth of the native seedlings, unless combined with shade. Fencing proved important for establishment, even though the species used are regarded in the literature as unpalatable to herbivores. The results indicated that the presence of shade was fundamental for the establishment and growth of the native seedlings likely due to improvements in the microclimate, soil aeration, and water availability to seedlings.

  7. Impact of cash cropping and perennial crops on food crop ...

    African Journals Online (AJOL)

    Increased crop production and sale of part of production during the main harvest season led households to ... Ethiopia, crop income accounts for the largest share of total income, 71%, followed by share of off-farm ... and Olinto (2001), in Colombia, off-farm employment contributes a significant share. (45%) to household ...

  8. Soil and water conservation strategies and impact on sustainable livelihood in Cape Verde - Case study of Ribeira Seca watershed

    Science.gov (United States)

    Baptista, I.; Ferreira, A. D.; Tavares, J.; Querido, A. L. E.; Reis, A. E. A.; Geissen, V.; Ritsema, C.; Varela, A.

    2012-04-01

    Cape Verde, located off the coast of Senegal in western Africa, is a volcanic archipelago where a combination of human, climatic, geomorphologic and pedologic factors has led to extensive degradation of the soils. Like other Sahelian countries, Cape Verde has suffered the effects of desertification through the years, threatening the livelihood of the islands population and its fragile environment. In fact, the steep slopes in the ore agricultural islands, together with semi-arid and arid environments, characterized by an irregular and poorly distributed rainy season, with high intensity rainfall events, make dryland production a challenge. To survive in these fragile conditions, the stabilization of the farming systems and the maintenance of sustainable yields have become absolute priorities, making the islands an erosion control laboratory. Soil and water conservation strategies have been a centerpiece of the government's agricultural policies for the last half century. Aiming to maintain the soil in place and the water inside the soil, the successive governments of Cape Verde have implemented a number of soil and water conservation techniques, the most common ones being terraces, half moons, live barriers, contour rock walls, contour furrows and microcatchments, check dams and reforestation with drought resistant species. The soil and water conservation techniques implemented have contributed to the improvement of the economical and environmental conditions of the treated landscape, making crop production possible, consequently, improving the livelihood of the people living on the islands. In this paper, we survey the existing soil and water conservation techniques, analyze their impact on the livelihood condition of the population through a thorough literature review and field monitoring using a semi-quantitative methodology and evaluate their effectiveness and impact on crop yield in the Ribeira Seca watershed. A brief discussion is given on the cost and

  9. Alcohol co-production from tree crops

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, M.; Folger, G.; Milne, T.

    1982-06-01

    A concept for the sustainable production of alcohol from fermentable substrates produced on an annual basis by the reproductive organs (pods, fruits, nuts, berries, etc.) of tree crops is presented. The advantages of tree-crop systems include suitability for use on marginal land, potential productivity equivalent to row crops, minimal maintenance and energy-input requirements, environmental compatibility, and the possibility of co-product production. Honeylocust, mesquite, and persimmon are examined as potential US tree-crop species. Other species not previously considered, including osage orange and breadfruit, are suggested as tree-crop candidates for North America and the tropical developing world, respectively. Fermentation of tree-crop organs and the economics of tree-crop systems are also discussed. Currently the greatest area of uncertainty lies in actual pod or fruit yields one can expect from large tree farms under real life conditions. However, ballpark ethanol yield estimates of from 880 to 3470 l hectare/sup -1/ (94 to 400 gal acre/sup -1/) justify further consideration of tree crop systems.

  10. Effect of Mixed Systems on Crop Productivity

    Science.gov (United States)

    Senturklu, Songul; Landblom, Douglas; Cihacek, Larry; Brevik, Eric

    2017-04-01

    The goals of this non-irrigated research has been to determine the effect of mixed systems integration on crop, soil, and beef cattle production in the northern Great Plains region of the United States. Over a 5-year period, growing spring wheat (HRSW-C) continuously year after year was compared to a 5-year crop rotation that included spring wheat (HRSW-R), cover crop (dual crop consisting of winter triticale/hairy vetch seeded in the fall and harvested for hay followed by a 7-species cover crop that was seeded in June after hay harvest), forage corn, field pea/barley, and sunflower. Control 5-year HRSW yield was 2690 kg/ha compared to 2757 kg/ha for HRSW grown in rotation. Available soil nitrogen (N) is often the most important limitation for crop production. Expensive fertilizer inputs were reduced in this study due to the mixed system's complementarity in which the rotation system that included beef cattle grazing sustained N availability and increased nutrient cycling, which had a positive effect on all crops grown in the rotation. Growing HRSW continuously requires less intensive management and in this research was 14.5% less profitable. Whereas, when crop management increased and complementing crops were grown in rotation to produce crops and provide feed for grazing livestock, soil nutrient cycling improved. Increased nutrient cycling increased crop rotation yields and yearling beef cattle steers that grazing annual forages in the rotation gain more body weight than similar steers grazing NGP native range. Results of this long-term research will be presented in a PICO format for participant discussion.

  11. Linkages between Land Surface Phenology Metrics and Natural and Anthropogenic Events in Drylands (Invited)

    Science.gov (United States)

    de Beurs, K.; Brown, M. E.; Ahram, A.; Walker, J.; Henebry, G. M.

    2013-12-01

    Tracking vegetation dynamics across landscapes using remote sensing, or 'land surface phenology,' is a key mechanism that allows us to understand ecosystem changes. Land surface phenology models rely on vegetation information from remote sensing, such as the datasets derived from the Advanced Very High Resolution Radiometer (AVHRR), the newer MODIS sensors on Aqua and Terra, and sometimes the higher spatial resolution Landsat data. Vegetation index data can aid in the assessment of variables such as the start of season, growing season length and overall growing season productivity. In this talk we use Landsat, MODIS and AVHRR data and derive growing season metrics based on land surface phenology models that couple vegetation indices with satellite derived accumulated growing degreeday and evapotranspiration estimates. We calculate the timing and the height of the peak of the growing season and discuss the linkage of these land surface phenology metrics with natural and anthropogenic changes on the ground in dryland ecosystems. First we will discuss how the land surface phenology metrics link with annual and interannual price fluctuations in 229 markets distributed over Africa. Our results show that there is a significant correlation between the peak height of the growing season and price increases for markets in countries such as Nigeria, Somalia and Niger. We then demonstrate how land surface phenology metrics can improve models of post-conflict resolution in global drylands. We link the Uppsala Conflict Data Program's dataset of political, economic and social factors involved in civil war termination with an NDVI derived phenology metric and the Palmer Drought Severity Index (PDSI). An analysis of 89 individual conflicts in 42 dryland countries (totaling 892 individual country-years of data between 1982 and 2005) revealed that, even accounting for economic and political factors, countries that have higher NDVI growth following conflict have a lower risk of

  12. Soil Water Balance and Water Use Efficiency of Dryland Wheat in Different Precipitation Years in Response to Green Manure Approach

    Science.gov (United States)

    Zhang, Dabin; Yao, Pengwei; Na, Zhao; Cao, Weidong; Zhang, Suiqi; Li, Yangyang; Gao, Yajun

    2016-05-01

    Winter wheat (Triticum aestivum L.) monoculture is conventionally cultivated followed by two to three months of summer fallow in the Loess Plateau. To develop a sustainable cropping system, we conducted a six-year field experiment to investigate the effect of leguminous green manure (LGM) instead of bare fallow on the yield and water use efficiency (WUE) of winter wheat and the soil water balance (SWB) in different precipitation years in a semi-arid region of northwest China. Results confirmed that planting LGM crop consumes soil water in the fallow season can bring varied effects to the subsequent wheat. The effect is positive or neutral when the annual precipitation is adequate, so that there is no significant reduction in the soil water supplied to wheat. If this is not the case, the effect is negative. On average, the LGM crop increased wheat yield and WUE by 13% and 28%, respectively, and had considerable potential for maintaining the SWB (0-200 cm) compared with fallow management. In conclusion, cultivation of the LGM crop is a better option than fallow to improve the productivity and WUE of the next crop and maintain the soil water balance in the normal and wet years in the Loess Plateau.

  13. Effects of temporal changes in climate variables on crop production ...

    African Journals Online (AJOL)

    Administrator

    Key words: Climate variability, crop yield and production, regional climate projections, South-western Nigeria. INTRODUCTION. The variability of the ... continuously facing an immediate risk of increased crop failure and loss of livestock. ... ral productivity may assist in proffering management strategies for a sustainable and ...

  14. Investigating an Ethical Approach to Genetically Modified Crops in ...

    African Journals Online (AJOL)

    Genetically modified (GM) crops gained attention in southern Africa in the context of broader debates about the struggle for food security and poverty alleviation to achieve sustainable development. The prospects of GM crops as a technological innovation have provoked numerous debates and environmental concern ...

  15. Energy crops for biogas plants. Brandenburg; Energiepflanzen fuer Biogasanlagen. Brandenburg

    Energy Technology Data Exchange (ETDEWEB)

    Adam, L.; Barthelmes, G.; Biertuempfel, A. (and others)

    2012-06-15

    In the brochure under consideration, the Agency for Renewable Resources (Guelzen-Pruezen, Federal Republic of Germany) reported on recommendations on alternative cropping systems for energy crop rotations in order to achieve high yields in combination with high diversity, risk spreading and sustainability. In particular, the natural site conditions in the Federal State of Brandenburg (Federal Republic of Germany) are determined.

  16. The essential need for GM crops

    OpenAIRE

    Pickett, John

    2016-01-01

    The need for GM crops is growing rapidly as a consequence of the overriding priority for the sustainable generation of vastly increased food production. Although demands for energy and raw materials from the bioeconomy remain, they may become eclipsed by the quest for more food.

  17. Energy crops in rotation. A review

    Energy Technology Data Exchange (ETDEWEB)

    Zegada-Lizarazu, Walter; Monti, Andrea [Department of Agroenvironmental Science and Technology, University of Bologna, Viale G. Fanin, 44 - 40127, Bologna (Italy)

    2011-01-15

    The area under energy crops has increased tenfold over the last 10 years, and there is large consensus that the demand for energy crops will further increase rapidly to cover several millions of hectares in the near future. Information about rotational systems and effects of energy crops should be therefore given top priority. Literature is poor and fragmentary on this topic, especially about rotations in which all crops are exclusively dedicated to energy end uses. Well-planned crop rotations, as compared to continuous monoculture systems, can be expected to reduce the dependence on external inputs through promoting nutrient cycling efficiency, effective use of natural resources, especially water, maintenance of the long-term productivity of the land, control of diseases and pests, and consequently increasing crop yields and sustainability of production systems. The result of all these advantages is widely known as crop sequencing effect, which is due to the additional and positive consequences on soil physical-chemical and biological properties arising from specific crops grown in the same field year after year. In this context, the present review discusses the potential of several rotations with energy crops and their possibilities of being included alongside traditional agriculture systems across different agro-climatic zones within the European Union. Possible rotations dedicated exclusively to the production of biomass for bioenergy are also discussed, as rotations including only energy crops could become common around bio-refineries or power plants. Such rotations, however, show some limitations related to the control of diseases and to the narrow range of available species with high production potential that could be included in a rotation of such characteristics. The information on best-known energy crops such as rapeseed (Brassica napus) and sunflower (Helianthus annuus) suggests that conventional crops can benefit from the introduction of energy crops in

  18. Relative Efficacy of Liquid Nitrogen Fertilizers in Dryland Spring Wheat

    Directory of Open Access Journals (Sweden)

    Olga S. Walsh

    2016-01-01

    Full Text Available The study was conducted in 2012 and 2013 at three locations in North Central and Western Montana (total of 6 site-years to evaluate the relative efficacy of three liquid nitrogen (N fertilizer sources, urea ammonium nitrate (UAN, 32-0-0, liquid urea (LU, 21-0-0, and High NRGN (HNRGN, 27-0-0-1S, in spring wheat (Triticum aestivum L.. In addition to at-seeding urea application at 90 kg N ha−1 to all treatments (except for the unfertilized check plot, the liquid fertilizers were applied utilizing an all-terrain vehicle- (ATV- mounted stream-bar equipped sprayer at a rate of 45 kg N ha−1 at Feekes 5 growth stage (early tillering. Three dilution ratios of fertilizer to water were accessed: 100/0 (undiluted, 66/33, and 33/66. The effects of N source and the dilution ratio (fertilizer/water on N uptake (NUp, N use efficiency (NUE, spring wheat grain yield (GY, grain protein (GP content, and protein yield (PY were assessed. The dilution ratios had no effect on GY, GP, PY, NUp, and NUE at any of the site-years in this study. Taking into account agronomic and economic factors, LU can be recommended as the most suitable liquid N fertilizer source for spring wheat cropping systems of the Northern Great Plains.

  19. Rainfed intensive crop systems

    DEFF Research Database (Denmark)

    Olesen, Jørgen E

    2014-01-01

    This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed....

  20. Impacts of crop insurance on water withdrawals for irrigation

    Science.gov (United States)

    Deryugina, Tatyana; Konar, Megan

    2017-12-01

    Agricultural production remains particularly vulnerable to weather fluctuations and extreme events, such as droughts, floods, and heat waves. Crop insurance is a risk management tool developed to mitigate some of this weather risk and protect farmer income in times of poor production. However, crop insurance may have unintended consequences for water resources sustainability, as the vast majority of freshwater withdrawals go to agriculture. The causal impact of crop insurance on water use in agriculture remains poorly understood. Here, we determine the empirical relationship between crop insurance and irrigation water withdrawals in the United States. Importantly, we use an instrumental variables approach to establish causality. Our methodology exploits a major policy change in the crop insurance system - the 1994 Federal Crop Insurance Reform Act - which imposed crop insurance requirements on farmers. We find that a 1% increase in insured crop acreage leads to a 0.223% increase in irrigation withdrawals, with most coming from groundwater aquifers. We identify farmers growing more groundwater-fed cotton as an important mechanism contributing to increased withdrawals. A 1% increase in insured crop acreage leads to a 0.624% increase in cotton acreage, or 95,602 acres. These results demonstrate that crop insurance causally leads to more irrigation withdrawals. More broadly, this work underscores the importance of determining causality in the water-food nexus as we endeavor to achieve global food security and water resources sustainability.

  1. The Soil Program of the Restoration Seedbank Initiative: addressing knowledge gaps in degraded soils for use in dryland restoration

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Bateman, Amber; Erickson, Todd E.; Turner, Shane; Merritt, David J.

    2017-04-01

    Global environmental changes and other anthropogenic impacts are rapidly transforming the structure and functioning of ecosystems worldwide. These changes are leading to land degradation with an estimated 25 % of the global land surface being affected. Landscape-scale restoration of these degraded ecosystems has therefore been recognised globally as an international priority. In the resource-rich biodiverse semi-arid Pilbara region of north-west Western Australia hundreds of thousands of hectares are disturbed due to established and emerging iron-ore mine operations. At this scale, the need to develop cost-effective large-scale solutions to restore these landscapes becomes imperative to preserve biodiversity and achieve functionality and sustainability of these ecosystems. The Restoration Seedbank Initiative (RSB) (http://www.plants.uwa.edu.au/ research/restoration-seedbank-initiative) is a five-year multidisciplinary research project that aims to build knowledge and design strategies to restore mine-impacted landscapes in the Pilbara and other arid and semi-arid landscapes worldwide (Kildiseheva et al., 2016). The RSB comprises four research programs that focus on seedbank management and curation, seed storage, seed enhancement, and the use of alternative soil substrates (soil or growing medium program) respectively. These multi-disciplinary programs address the significant challenges of landscape scale restoration in arid systems. In the soil program we follow an integrated approach that includes the characterization of undisturbed ecosystems, assessment of restored soils with the use of soil quality indicators, and design of alternative soil substrates to support the establishment of native plant communities. A series of glasshouse studies and field trials have been conducted in the last three years to advance our knowledge on soil limitations and to provide solutions to effectively overcome these challenges in arid ecosystem restoration. These studies include

  2. Plant diversity and ecosystem multifunctionality peak at intermediate levels of woody cover in global drylands

    Science.gov (United States)

    Soliveres, Santiago; Maestre, Fernando T.; Eldridge, David J.; Delgado-Baquerizo, Manuel; Quero, José Luis; Bowker, Matthew A.; Gallardo, Antonio

    2015-01-01

    Aim The global spread of woody plants into grasslands is predicted to increase over the coming century. While there is general agreement regarding the anthropogenic causes of this phenomenon, its ecological consequences are less certain. We analyzed how woody vegetation of differing cover affects plant diversity (richness and evenness) and multiple ecosystem functions (multifunctionality) in global drylands, and how this changes with aridity. Location 224 dryland sites from all continents except Antarctica widely differing in their environmental conditions (from arid to dry-subhumid sites) and woody covers (from 0 to 100%). Methods Using a standardized field survey, we measured the cover, richness and evenness of perennial vegetation. At each site, we measured 14 ecosystem functions related to soil fertility and the build-up of nutrient pools. These functions are critical for maintaining ecosystem function in drylands. Results Species richness and ecosystem multifunctionality were strongly influenced by woody vegetation, with both variables peaking at relative woody covers (RWC) of 41-60%. This relationship shifted with aridity. We observed linear positive effects of RWC in dry-subhumid sites. These positive trends shifted to hump-shaped RWC-diversity and multifunctionality relationships under semiarid environments. Finally, hump-shaped (richness, evenness) or linear negative (multifunctionality) effects of RWC were found under the most arid conditions. Main conclusions Plant diversity and multifunctionality peaked at intermediate levels of woody cover, although this relationship became increasingly positive under wetter environments. This comprehensive study accounts for multiple ecosystem attributes across a range of woody covers and environmental conditions. Our results help us to reconcile contrasting views of woody encroachment found in current literature and can be used to improve predictions of the likely effects of encroachment on biodiversity and ecosystem

  3. Signal and noise in vegetation patterns in drylands: distinguishing the baby from the bath water

    Science.gov (United States)

    Parsons, Anthony; Wainwright, John; Stewart, Jill; Okin, Gregory

    2014-05-01

    Patterns, and particularly banded patterns, are widely reported in dryland vegetation, and have been the subject of considerable modelling effort. However, much of this modelling effort is predicated on a mathematical approach that is designed to produce patterns and relies on physical processes that are unreasonable. In consequence, whereas in nature dryland vegetation patterns are irregular, disjointed and discontinuous, those produced by such models tend to be regular, continuous and even. The question, therefore, arises "Is it the irregularity, disjointed and discontinuous character of these patterns that holds the key to their formation rather than any apparent, human-imposed semblance of regularity and continuity?" By focusing on this apparent patterning have such models rejected as noise the key to understanding the signal? Models that produce regular vegetation patterns, typically do so by imposing global rules (largely for the distribution of water). Is it not more likely that vegetation responds to the local supply of water, nutrients and propagules? Here, we present a model for the growth of vegetation in deserts that is predicated on the local conditions of input of water, nutrients and propagules and output, such as loss of biomass by herbivory. The approach represents our best quantitative understanding of how desert ecosystems work. Patterns emerge that show the irregularity and discontinuity seen in nature. By focusing on the process rather than the patterns per se our model has the ability to address specific questions of the role of such patterns in land degradation. Further, it has the potential to provide quantitative estimates of the response of the landscape to specific management strategies, as well as the identification of the key thresholds and tipping points that are so important to the management of drylands. In providing a way to understand and predict the vegetation patterns that may develop during desertification, the approach also

  4. Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change

    Science.gov (United States)

    McCluney, Kevin E.; Belnap, Jayne; Collins, Scott L.; González, Angélica L.; Hagen, Elizabeth M.; Holland, J. Nathaniel; Kotler, Burt P.; Maestre, Fernando T.; Smith, Stanley D.; Wolf, Blair O.

    2012-01-01

    Species interactions play key roles in linking the responses of populations, communities, and ecosystems to environmental change. For instance, species interactions are an important determinant of the complexity of changes in trophic biomass with variation in resources. Water resources are a major driver of terrestrial ecology and climate change is expected to greatly alter the distribution of this critical resource. While previous studies have documented strong effects of global environmental change on species interactions in general, responses can vary from region to region. Dryland ecosystems occupy more than one-third of the Earth's land mass, are greatly affected by changes in water availability, and are predicted to be hotspots of climate change. Thus, it is imperative to understand the effects of environmental change on these globally significant ecosystems. Here, we review studies of the responses of population-level plant-plant, plant-herbivore, and predator-prey interactions to changes in water availability in dryland environments in order to develop new hypotheses and predictions to guide future research. To help explain patterns of interaction outcomes, we developed a conceptual model that views interaction outcomes as shifting between (1) competition and facilitation (plant-plant), (2) herbivory, neutralism, or mutualism (plant-herbivore), or (3) neutralism and predation (predator-prey), as water availability crosses physiological, behavioural, or population-density thresholds. We link our conceptual model to hypothetical scenarios of current and future water availability to make testable predictions about the influence of changes in water availability on species interactions. We also examine potential implications of our conceptual model for the relative importance of top-down effects and the linearity of patterns of change in trophic biomass with changes in water availability. Finally, we highlight key research needs and some possible broader impacts

  5. An ecohydrological approach to predicting hillslope-scale vegetation patterns and dynamics in dryland ecosystems

    Science.gov (United States)

    Franz, Trenton; King, Elizabeth

    2015-04-01

    Drylands are an important ecosystem, as they cover over 40% of the Earth's land surface and are know to exhibit threshold behavior in response to climatic change and anthropogenic disturbance. Where dryland vegetation supports pastoralist livestock production, catastrophic ecological shifts present a grave concern because of the direct coupling between the livestock forage available and human livelihoods. In this research we investigate the spatiotemporal organization of grazing resources on hillslopes by developing a relatively simple spatially explicit daily stochastic ecohydrological 1-layer bucket model with dynamic vegetation and grazing components. The model, MVUA MINGI (Mosaic Vegetation Using Agent-based Modeling Incorporating Non-linear Grazing Impacts), was constructed using a 2-year observational study in central Kenya combining in-situ sensors with near surface hydrogeophysical surveys. The data were used to derive an empirical patch water balance of three representative patch types, bare soil, grass, and tree. Visual and hydrogeophysical observations indicated the system is dominated by Hortonian runoff, overland flow, and vertical infiltration of water into vegetation patches. The patch-based water balances were next incorporated into a Cellular Automata model allowing us to simulate a range of surface flowpath convergence states across the hillslope during a rain event. The model also allows the root to canopy radius of the tree patches to vary affecting the length scale of water competition. By changing the length scales of facilitation and competition, we find the model demonstrates a range of most efficient static vegetation patterns from random to highly organized. In order simulate the vegetation dynamics we incorporated continuous transition probabilities for each patch type based on the frequency and duration of drought and grazing intensity. The modeled vegetation dynamics indicate various stable states and the timescales between the state

  6. Increasing aridity reduces soil microbial diversity and abundance in global drylands

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Jeffries, Thomas C.; Eldridge, David J.; Ochoa, Victoria; Gozalo, Beatriz; Quero, José Luis; García-Gómez, Miguel; Gallardo, Antonio; Ulrich, Werner; Bowker, Matthew A.; Arredondo, Tulio; Barraza-Zepeda, Claudia; Bran, Donaldo; Florentino, Adriana; Gaitán, Juan; Gutiérrez, Julio R.; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Mau, Rebecca L.; Miriti, Maria; Naseri, Kamal; Ospina, Abelardo; Stavi, Ilan; Wang, Deli; Woods, Natasha N.; Yuan, Xia; Zaady, Eli; Singh, Brajesh K.

    2015-01-01

    Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and α-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands. PMID:26647180

  7. Adapting a regularized canopy reflectance model (REGFLEC) for the retrieval challenges of dryland agricultural systems

    KAUST Repository

    Houborg, Rasmus

    2016-08-20

    A regularized canopy reflectance model (REGFLEC) is applied over a dryland irrigated agricultural system in Saudi Arabia for the purpose of retrieving leaf area index (LAI) and leaf chlorophyll content (Chll). To improve the robustness of the retrieved properties, REGFLEC was modified to 1) correct for aerosol and adjacency effects, 2) consider foliar dust effects on modeled canopy reflectances, 3) include spectral information in the red-edge wavelength region, and 4) exploit empirical LAI estimates in the model inversion. Using multi-spectral RapidEye imagery allowed Chll to be retrieved with a Mean Absolute Deviation (MAD) of 7.9 μg cm− 2 (16%), based upon in-situ measurements conducted in fields of alfalfa, Rhodes grass and maize over the course of a growing season. LAI and Chll compensation effects on canopy reflectance were largely avoided by informing the inversion process with ancillary LAI inputs established empirically on the basis of a statistical machine learning technique. As a result, LAI was reproduced with good accuracy, with an overall MAD of 0.42 m2 m− 2 (12.5%). Results highlighted the considerable challenges associated with the translation of at-sensor radiance observations to surface bidirectional reflectances in dryland environments, where issues such as high aerosol loadings and large spatial gradients in surface reflectance from bright desert soils to dark vegetated fields are often present. Indeed, surface reflectances in the visible bands were reduced by up to 60% after correction for such adjacency effects. In addition, dust deposition on leaves required explicit modification of the reflectance sub-model to account for its influence. By implementing these model refinements, REGFLEC demonstrated its utility for within-field characterization of vegetation conditions over the challenging landscapes typical of dryland agricultural regions, offering a means through which improvements can be made in the management of these globally

  8. Precipitation pulse size and frequency controls on dryland litter decomposition rates

    Science.gov (United States)

    Kurupas, K. L.; Throop, H.

    2014-12-01

    Drylands are an important component of the global carbon (C) cycle, accounting for 40% of the land area and 20% of the soil organic C globally. Litter decomposition is a key biogeochemical process, controlling C and nutrient cycling. While simple decomposition models successfully predict decomposition rates in many systems based on climate variables, there is a disconnect between the modeled and measured rates decomposition in drylands. This disconnect may stem from abiotic factors of importance in drylands, such as photodegradation and soil-litter mixing, not being taken into account. Soil-litter mixing can accelerate decomposition, but the underlying mechanisms are poorly understood. Potential mechanisms include microclimate buffering, physical abrasion, and enhanced microbial colonization. Recent work suggests that litter decomposition is remarkably insensitive to climate variables, at least when variables are presented as long temporal-scale values (e.g., annual precipitation). We hypothesized that decomposition would be more strongly affected by litter moisture content than total precipitation (PPT) alone. Thus, frequent, small PPT pulses would accelerate decomposition more than larger, but infrequent pulses. Furthermore, soil-litter mixing would enhance decomposition by buffering litter moisture content. To test the combined influence of soil-litter mixing and PPT pulses on decomposition, we incubated litter and soil in a semi-controlled greenhouse which simulated dryland summer temperatures. Two litter types (grass and shrub) were incubated under two levels of soil-litter mixing (no mixing and complete soil-litter mixing) and with 16 different PPT treatments (a factorial combination of four PPT pulses sizes and four PPT frequencies). We measured instantaneous CO2 flux throughout the 30 day incubation and mass loss at the end of the incubation. Shrub litter decomposed faster than grass litter. Flux rates generally peaked at day 8 and declined thereafter. CO2

  9. Modeling the impacts of dryland agricultural reclamation on groundwater resources in Northern Egypt using sparse data

    Science.gov (United States)

    Switzman, Harris; Coulibaly, Paulin; Adeel, Zafar

    2015-01-01

    Demand for freshwater in many dryland environments is exerting negative impacts on the quality and availability of groundwater resources, particularly in areas where demand is high due to irrigation or industrial water requirements to support dryland agricultural reclamation. Often however, information available to diagnose the drivers of groundwater degradation and assess management options through modeling is sparse, particularly in low and middle-income countries. This study presents an approach for generating transient groundwater model inputs to assess the long-term impacts of dryland agricultural land reclamation on groundwater resources in a highly data-sparse context. The approach was applied to the area of Wadi El Natrun in Northern Egypt, where dryland reclamation and the associated water use has been aggressive since the 1960s. Statistical distributions of water use information were constructed from a variety of sparse field and literature estimates and then combined with remote sensing data in spatio-temporal infilling model to produce the groundwater model inputs of well-pumping and surface recharge. An ensemble of groundwater model inputs were generated and used in a 3D groundwater flow (MODFLOW) of Wadi El Natrun's multi-layer aquifer system to analyze trends in water levels and water budgets over time. Validation of results against monitoring records, and model performance statistics demonstrated that despite the extremely sparse data, the approach used in this study was capable of simulating the cumulative impacts of agricultural land reclamation reasonably well. The uncertainty associated with the groundwater model itself was greater than that associated with the ensemble of well-pumping and surface recharge estimates. Water budget analysis of the groundwater model output revealed that groundwater recharge has not changed significantly over time, while pumping has. As a result of these trends, groundwater was estimated to be in a deficit of

  10. Combining Sustainable Land Management Technologies to Combat Land Degradation and Improve Rural Livelihoods in Semi-arid Lands in Kenya

    Science.gov (United States)

    Mganga, K. Z.; Musimba, N. K. R.; Nyariki, D. M.

    2015-12-01

    Drylands occupy more than 80 % of Kenya's total land mass and contribute immensely to the national economy and society through agriculture, livestock production, tourism, and wild product harvesting. Dryland ecosystems are areas of high climate variability making them vulnerable to the threats of land degradation. Consequently, agropastoralists inhabiting these ecosystems develop mechanisms and technologies to cope with the impacts of climate variability. This study is aimed to; (1) determine what agropastoralists inhabiting a semi-arid ecosystem in Kenya attribute to be the causes and indicators of land degradation, (2) document sustainable land management (SLM) technologies being undertaken to combat land degradation, and (3) identify the factors that influence the choice of these SLM technologies. Vegetation change from preferred indigenous forage grass species to woody vegetation was cited as the main indicator of land degradation. Land degradation was attributed to recurrent droughts and low amounts of rainfall, overgrazing, and unsustainable harvesting of trees for fuelwood production. However, despite the challenges posed by climate variability and recurrent droughts, the local community is engaging in simple SLM technologies including grass reseeding, rainwater harvesting and soil conservation, and dryland agroforestry as a holistic approach combating land degradation and improving their rural livelihoods. The choice of these SLM technologies was mainly driven by their additional benefits to combating land degradation. In conclusion, promoting such simple SLM technologies can help reverse the land degradation trend, improve agricultural production, food security including access to food, and subsequently improve livelihoods of communities inhabiting dryland ecosystems.

  11. Combining Sustainable Land Management Technologies to Combat Land Degradation and Improve Rural Livelihoods in Semi-arid Lands in Kenya.

    Science.gov (United States)

    Mganga, K Z; Musimba, N K R; Nyariki, D M

    2015-12-01

    Drylands occupy more than 80% of Kenya's total land mass and contribute immensely to the national economy and society through agriculture, livestock production, tourism, and wild product harvesting. Dryland ecosystems are areas of high climate variability making them vulnerable to the threats of land degradation. Consequently, agropastoralists inhabiting these ecosystems develop mechanisms and technologies to cope with the impacts of climate variability. This study is aimed to; (1) determine what agropastoralists inhabiting a semi-arid ecosystem in Kenya attribute to be the causes and indicators of land degradation, (2) document sustainable land management (SLM) technologies being undertaken to combat land degradation, and (3) identify the factors that influence the choice of these SLM technologies. Vegetation change from preferred indigenous forage grass species to woody vegetation was cited as the main indicator of land degradation. Land degradation was attributed to recurrent droughts and low amounts of rainfall, overgrazing, and unsustainable harvesting of trees for fuelwood production. However, despite the challenges posed by climate variability and recurrent droughts, the local community is engaging in simple SLM technologies including grass reseeding, rainwater harvesting and soil conservation, and dryland agroforestry as a holistic approach combating land degradation and improving their rural livelihoods. The choice of these SLM technologies was mainly driven by their additional benefits to combating land degradation. In conclusion, promoting such simple SLM technologies can help reverse the land degradation trend, improve agricultural production, food security including access to food, and subsequently improve livelihoods of communities inhabiting dryland ecosystems.

  12. Dryland soil hydrological processes and their impacts on the nitrogen balance in a soil-maize system of a freeze-thawing agricultural area.

    Directory of Open Access Journals (Sweden)

    Wei Ouyang

    Full Text Available Understanding the fates of soil hydrological processes and nitrogen (N is essential for optimizing the water and N in a dryland crop system with the goal of obtaining a maximum yield. Few investigations have addressed the dynamics of dryland N and its association with the soil hydrological process in a freeze-thawing agricultural area. With the daily monitoring of soil water content and acquisition rates at 15, 30, 60 and 90 cm depths, the soil hydrological process with the influence of rainfall was identified. The temporal-vertical soil water storage analysis indicated the local albic soil texture provided a stable soil water condition for maize growth with the rainfall as the only water source. Soil storage water averages at 0-20, 20-40 and 40-60 cm were observed to be 490.2, 593.8, and 358 m3 ha-1, respectively, during the growing season. The evapo-transpiration (ET, rainfall, and water loss analysis demonstrated that these factors increased in same temporal pattern and provided necessary water conditions for maize growth in a short period. The dry weight and N concentration of maize organs (root, leaf, stem, tassel, and grain demonstrated the N accumulation increased to a peak in the maturity period and that grain had the most N. The maximum N accumulative rate reached about 500 mg m-2d-1 in leaves and grain. Over the entire growing season, the soil nitrate N decreased by amounts ranging from 48.9 kg N ha-1 to 65.3 kg N ha-1 over the 90 cm profile and the loss of ammonia-N ranged from 9.79 to 12.69 kg N ha-1. With soil water loss and N balance calculation, the N usage efficiency (NUE over the 0-90 cm soil profile was 43%. The soil hydrological process due to special soil texture and the temporal features of rainfall determined the maize growth in the freeze-thawing agricultural area.

  13. Responsive Polymers for Crop Protection

    Directory of Open Access Journals (Sweden)

    Serban F. Peteu

    2010-08-01

    Full Text Available This review outlines the responsive polymer methods currently in use with their potential application to plant protection and puts forward plant-specific mechanisms as stimuli in newly devised methods for smart release of crop protection agents (CPAs. CPAs include chemicals (fungicides, insecticides, herbicides, biochemicals (antibiotics, RNA-based vaccines for plant viruses, semiochemicals (pheromones, repellents, allomones, microbial pesticides, growth regulators (insect and plant or micronutrients, all with crop protection effects. This appraisal focuses on emerging uses of polymer nano-encapsulated CPAs. Firstly, the most interesting advances in controlled release methods are critically discussed with their advantages and drawbacks. Secondly, several plant-specific stimuli-based smart methods are anticipated for use alongside the polymer nano- or micro-capsules. These new CPA release methods are designed to (i protect plants against infection produced by fungi or bacteria, and (ii apply micro-nutrients when the plants need it the most. Thus, we foresee (i the responsive release of nano- encapsulated bio-insecticides regulated by plant stress enzymes, and (ii the delivery of micro-nutrients synchronized by the nature or intensity of plant root exudates. Such continued advances of nano-scale smart polymer-based CPAs for the protection of crops herald a “small revolution” for the benefit of sustainable agriculture.

  14. MODELING WORLD BIOENERGY CROP POTENTIAL

    Science.gov (United States)

    Hagiwara, Kensuke; Hanasaki, Naota; Kanae, Shinjiro

    Bioenergy is regarded as clean energy due to its characteristics and expected to be a new support of world energy de¬mand, but there are few integrated assessments of the potential of bioenergy considering sustainable land use. We esti¬mated the global bioenergy potential with an integrated global water resources model, the H08. It can simulate the crop yields on global-scale at a spatial resolution of 0.50.5. Seven major crops in the world were considered; namely, maize, sugar beet, sugar cane, soybean, rapeseed, rice, and wheat, of which the first 5 are commonly used to produce biofuel now. Three different land-cover types were chosen as potential area for cultivation of biofuel-producing crop: fallow land, grassland, and portion of forests (excluding areas sensitive for biodiversity such as frontier forest). We attempted to estimate the maximum global bioenergy potential and it was estimated to be 1120EJ. Bioenergy potential depends on land-use limitations for the protection of bio-diversity and security of food. In another condition which assumed more land-use limitations, bioenergy potential was estimated to be 70-233EJ.

  15. Forest Landscape Restoration in the Drylands of Latin America

    Directory of Open Access Journals (Sweden)

    Adrian C. Newton

    2012-03-01

    Full Text Available Forest Landscape Restoration (FLR involves the ecological restoration of degraded forest landscapes, with the aim of benefiting both biodiversity and human well-being. We first identify four fundamental principles of FLR, based on previous definitions. We then critically evaluate the application of these principles in practice, based on the experience gained during an international, collaborative research project conducted in six dry forest landscapes of Latin America. Research highlighted the potential for FLR; tree species of high socioeconomic value were identified in all study areas, and strong dependence of local communities on forest resources was widely encountered, particularly for fuelwood. We demonstrated that FLR can be achieved through both passive and active restoration approaches, and can be cost-effective if the increased provision of ecosystem services is taken into account. These results therefore highlight the potential for FLR, and the positive contribution that it could make to sustainable development. However, we also encountered a number of challenges to FLR implementation, including the difficulty of achieving strong engagement in FLR activities among local stakeholders, lack of capacity for community-led initiatives, and the lack of an appropriate institutional and regulatory environment to support restoration activities. Successful implementation of FLR will require new collaborative alliances among stakeholders, empowerment and capacity building of local communities to enable them to fully engage with restoration activities, and an enabling public policy context to enable local people to be active participants in the decision making process.

  16. Production of N2O and CO2 in Tillage and no Till Dryland and Irrigated Wheat Systems in Response to Additions of Water and N Fertilizer

    Science.gov (United States)

    Kostyanovsky, K.; Huggins, D.; Stockle, C.; Smith, J. L.; Morrow, J.; Lamb, B. K.; Pressley, S. N.; Waldo, S.; Brown, D. J.; Pan, W.

    2013-12-01

    Rainfall, irrigation and soil N fertilization are significant processes which drive emissions of highly potent greenhouse gas nitrous oxide, the major contributor to climate change from agriculture. Changing climate is likely to result in shifting of agroecozones due to increased temperatures, and expansion of irrigated agriculture as well as increase in irrigation requirements. An accurate assessment of N2O in irrigation and dryland scenarios is required for predicting the effects of these agricultural management practices on global climate change. The effects of N application and water additions on CO2 and N2O emissions were evaluated on long-term no-tillage and conventional tillage sites of dryland and irrigated wheat cropping systems in the Pacific Northwest. We implemented the system of Li-Cor 8100A automatic chambers coupled with LGR 23r N2O analyzer for continuous IRGA monitoring of CO2 and N2O emissions in the short term microplot study with the following treatments: 1) no water; 2) water added to 80% water filled pore space and amended with 150 kg NH4NO3-N ha-1; 3) water added to 80% water filled pore space. Application of N and water took place at 9:00 and the measurements continued from that time until 7:00 the following day for 22 hrs. The study was conducted in the summer and repeated in fall, which are most likely to be affected by increased temperatures. Nitrogen and water treatments resulted in higher N2O peaks than water only treatments. Both N plus water and only water treatments had higher N2O emissions than the no water treatments. Conventional tillage treatments resulted in N2O emissions 30-40% than no-till treatments. Emissions of CO2 tended to be increased in the fertilized and water added treatments compared to just water added treatments, and both of these treatments had higher CO2 emissions than treatments without water added. Tillage treatments also tended to have higher CO2 emissions than no-till treatments. Emissions of CO2 and N2O were

  17. The visibility of using water boxes and mulch in dryland revegetation

    Science.gov (United States)

    Alhamad, Mohammad Noor; Alrababah, Mohammad; Athamneh, Hanaa

    2017-04-01

    Drylands cover more than 41% of the world's surface area and are homeland for about one-third of the world's population, 90% of them in developing countries. Land degradation in the drylands is hot environmental topic as it impacts environmental quality and jeopardizes food security in developing countries. The climate of Jordan varies from dry sub-humid Mediterranean in northwestern areas to desert conditions over a distance of 100 km, where more than 90 % of the county's area receives annual rainfall of less than 200 mm. In Jordan revegetation programs are rainfed; rainfall in Jordan is characterized by variable nature, thus, these programs faces a major challenge of the low survival rate of transplanted seedlings. The present study ought to explore the visibility of using water boxes and plastic mulch as an innovative approach to enhance seedling survival and establishment of four forest tress species ( Carob, Cupressus, Quercus, and Pinus). The experiment results showed that Cupressus, and Pinus seedlings expressed the highest survival rate of 88% and 84 % respectively, flowed by Crob (64%) and Querrcus (16%). The plastic mulch significantly enhanced the seedling survival rate b y40 % over the control while the water boxes resulted in an increase of 32 % over the control.

  18. A methodology to estimate the future extent of dryland salinity in the southwest of Western Australia.

    Science.gov (United States)

    Caccetta, Peter; Dunne, Robert; George, Richard; McFarlane, Don

    2010-01-01

    In the southwestern agricultural region of Western Australia, the clearing of the original perennial vegetation for annual vegetation-based dryland agriculture has lead to rising saline groundwater levels. This has had effects such as reduced productivity of agricultural land, death of native vegetation, reduced stream water quality and infrastructure damage. These effects have been observed at many locations within the 18 million ha of cleared land. This has lead to efforts to quantify, in a spatially explicit way, the historical and likely future extent of the area affected, with the view to informing management decisions. This study was conducted to determine whether the likely future extent of the area affected by dryland salinity could be estimated by means of developing spatially explicit maps for use in management and planning. We derived catchment-related variables from digital elevation models and perennial vegetation presence/absence maps. We then used these variables to predict the salinity hazard extent by applying a combination of decision tree classification and morphological image processing algorithms. Sufficient objective data such as groundwater depth, its rate of rise, and its concentration of dissolved salts were generally not available, so we used regional expert opinion (derived from the limited existing studies on salinity hazard extent) as training and validation data. We obtained an 87% agreement in the salinity hazard extent estimated by this method compared with the validation data, and conclude that the maps are sufficient for planning. We estimate that the salinity hazard extent is 29.7% of the agricultural land.

  19. Biocrust-forming mosses mitigate the negative impacts of increasing aridity on ecosystem multifunctionality in drylands.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Maestre, Fernando T; Eldridge, David J; Bowker, Matthew A; Ochoa, Victoria; Gozalo, Beatriz; Berdugo, Miguel; Val, James; Singh, Brajesh K

    2016-03-01

    The increase in aridity predicted with climate change will have a negative impact on the multiple functions and services (multifunctionality) provided by dryland ecosystems worldwide. In these ecosystems, soil communities dominated by mosses, lichens and cyanobacteria (biocrusts) play a key role in supporting multifunctionality. However, whether biocrusts can buffer the negative impacts of aridity on important biogeochemical processes controlling carbon (C), nitrogen (N), and phosphorus (P) pools and fluxes remains largely unknown. Here, we conducted an empirical study, using samples from three continents (North America, Europe and Australia), to evaluate how the increase in aridity predicted by climate change will alter the capacity of biocrust-forming mosses to modulate multiple ecosystem processes related to C, N and P cycles. Compared with soil surfaces lacking biocrusts, biocrust-forming mosses enhanced multiple functions related to C, N and P cycling and storage in semiarid and arid, but not in humid and dry-subhumid, environments. Most importantly, we found that the relative positive effects of biocrust-forming mosses on multifunctionality compared with bare soil increased with increasing aridity. These results were mediated by plant cover and the positive effects exerted by biocrust-forming mosses on the abundance of soil bacteria and fungi. Our findings provide strong evidence that the maintenance of biocrusts is crucial to buffer negative effects of climate change on multifunctionality in global drylands. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. Dryland soil microbial communities display spatial biogeographic patterns associated with soil depth and soil parent material

    Science.gov (United States)

    Steven, Blaire; Gallegos-Graves, La Verne; Belnap, Jayne; Kuske, Cheryl R.

    2013-01-01

    Biological soil crusts (biocrusts) are common to drylands worldwide. We employed replicated, spatially nested sampling and 16S rRNA gene sequencing to describe the soil microbial communities in three soils derived from different parent material (sandstone, shale, and gypsum). For each soil type, two depths (biocrusts, 0–1 cm; below-crust soils, 2–5 cm) and two horizontal spatial scales (15 cm and 5 m) were sampled. In all three soils, Cyanobacteria and Proteobacteria demonstrated significantly higher relative abundance in the biocrusts, while Chloroflexi and Archaea were significantly enriched in the below-crust soils. Biomass and diversity of the communities in biocrusts or below-crust soils did not differ with soil type. However, biocrusts on gypsum soil harbored significantly larger populations of Actinobacteria and Proteobacteria and lower populations of Cyanobacteria. Numerically dominant operational taxonomic units (OTU; 97% sequence identity) in the biocrusts were conserved across the soil types, whereas two dominant OTUs in the below-crust sand and shale soils were not identified in the gypsum soil. The uniformity with which small-scale vertical community differences are maintained across larger horizontal spatial scales and soil types is a feature of dryland ecosystems that should be considered when designing management plans and determining the response of biocrusts to environmental disturbances.

  1. Pastoralism in the drylands of Latin America: Argentina, Chile, Mexico and Peru.

    Science.gov (United States)

    Grünwaldt, J M; Castellaro, G; Flores, E R; Morales-Nieto, C R; Valdez-Cepeda, R D; Guevera, J C; Grünwaldt, E G

    2016-11-01

    This article discusses various aspects of pastoralism in the Latin American countries with the largest dryland areas. The topics covered include: social, economic and institutional issues; grasslands and their carrying capacity; production systems and productivity rates; competition for forage resources between domestic livestock and wildlife; and the health status of livestock and wildlife. Most grasslands exhibit some degree of degradation. The percentage of offspring reaching weaning age is low: 47-66% of calves and 40-80% of lambs. Some pastoralists adopt patterns of transhumance. In the main, pastoralists experience a high poverty rate and have poor access to social services. For many pastoralists, wildlife is a source of food and by-products. Argentina, Chile, Mexico and Peru have animal health control agencies, are members of the World Organisation for Animal Health (OIE) and have signed the United Nations Convention to Combat Desertification. Pastoral systems subsist mainly on income unrelated to pastoral farming. The OIE recognises all four countries as free from infection with peste des petits ruminants virus, and from rinderpest and African horse sickness. It is difficult to predict the future of pastoralism in Latin America because the situation differs from country to country. For instance, pastoralism is more important in Peru than in Argentina, where it is a more marginal activity. In the future, lack of promotion and protection policies could lead to a decline in pastoralism or to an adverse environmental impact on drylands.

  2. Ecological thresholds as a basis for defining management triggers for National Park Service vital signs: case studies for dryland ecosystems

    Science.gov (United States)

    Bowker, Matthew A.; Miller, Mark E.; Belote, R. Travis; Garman, Steven L.

    2013-01-01

    Threshold concepts are used in research and management of ecological systems to describe and interpret abrupt and persistent reorganization of ecosystem properties (Walker and Meyers, 2004; Groffman and others, 2006). Abrupt change, referred to as a threshold crossing, and the progression of reorganization can be triggered by one or more interactive disturbances such as land-use activities and climatic events (Paine and others, 1998). Threshold crossings occur when feedback mechanisms that typically absorb forces of change are replaced with those that promote development of alternative equilibria or states (Suding and others, 2004; Walker and Meyers, 2004; Briske and others, 2008). The alternative states that emerge from a threshold crossing vary and often exhibit reduced ecological integrity and value in terms of management goals relative to the original or reference system. Alternative stable states with some limited residual properties of the original system may develop along the progression after a crossing; an eventual outcome may be the complete loss of pre-threshold properties of the original ecosystem. Reverting to the more desirable reference state through ecological restoration becomes increasingly difficult and expensive along the progression gradient and may eventually become impossible. Ecological threshold concepts have been applied as a heuristic framework and to aid in the management of rangelands (Bestelmeyer, 2006; Briske and others, 2006, 2008), aquatic (Scheffer and others, 1993; Rapport and Whitford 1999), riparian (Stringham and others, 2001; Scott and others, 2005), and forested ecosystems (Allen and others, 2002; Digiovinazzo and others, 2010). These concepts are also topical in ecological restoration (Hobbs and Norton 1996; Whisenant 1999; Suding and others, 2004; King and Hobbs, 2006) and ecosystem sustainability (Herrick, 2000; Chapin and others, 1996; Davenport and others, 1998). Achieving conservation management goals requires the

  3. Can genetically modified cotton contribute to sustainable development in Africa?

    OpenAIRE

    Morse, S.; Mannion, AM

    2009-01-01

    Genetically modified (GM) crops and sustainable development remain the foci of much media attention, especially given current concerns about a global food crisis. However, whilst the latter is embraced with enthusiasm by almost all groups GM crops generate very mixed views. Some countries have welcomed GM, but others, notably those in Europe, adopt a cautious stance. This paper aims to review the contribution that GM crops can make to agricultural sustainability in the developing world. Follo...

  4. A House Full of Trap Doors. Identifying barriers to resilient drylands in the toolbox of pastoral development

    Science.gov (United States)

    Krätli, Saverio; Kaufmann, Brigitte; Roba, Hassan; Hiernaux, Pierre; Li, Wenjun; Easdale, Marcos H.; Huelsebusch, Christian

    2016-04-01

    The theoretical understanding of drylands and pastoral systems has long undergone a U-turn from the initial perspective rooted in classical ecology. The shift has hinged on the way to represent asymmetric variability, from a disturbance in an ecosystem that naturally tends towards uniformity and stability, to a constitutive part of a dynamic ecosystem. Operationalising the new reversed perspective, including the need to update the methodological infrastructure to plan around drylands and pastoral development, remains a challenge. Underlying assumptions about stability and uniformity, that are a legacy of equilibrium thinking, remain embedded in the toolbox of pastoral development, starting from the technical language to talk about the subject. This effectively gets in the way of operationalizing state of the art understanding of pastoral systems and the drylands. Unless these barriers are identified, unpacked and managed, even the present calls for increasing the rigour and intensity of data collection - for example as part of the ongoing global process to revise and improve agricultural data - cannot deliver a realistic representation of pastoral systems in statistics and policy making. This contribution presents the case for understanding variability as an asset, and provides a range of examples of methodological barriers, including classifications of livestock systems, scale of observation, key parameters in animal production, indicators in the measurement of ecological efficiency, concepts of ecological fragility, natural resources, and pastoral risk. The need to update this legacy is a pressing challenge for policy makers concerned with both modernisation and resilience in the drylands.

  5. Using radiometric surface temperature for surface energy flux estimation in Mediterranean drylands from a two-source perspective

    Science.gov (United States)

    The recent paper by Morillas et al. [Morillas, L. et al. Using radiometric surface temperature for surface energy flux estimation in Mediterranean drylands from a two-source perspective, Remote Sens. Environ. 136, 234-246, 2013] evaluates the two-source model (TSM) of Norman et al. (1995) with revi...

  6. Applying the successional weed management model for revegetating a yellow starthistle-infested dryland pasture in the Chihuahuan Desert

    Science.gov (United States)

    William D. Sommers; Larry D. Howery; Rosemary L. Pendleton; Richard D. Lee; Burton K. Pendleton

    2011-01-01

    A three-year study was conducted in the Chihuahuan Desert in Southwestern New Mexico to evaluate the effectiveness of revegetating a dryland pasture that was heavily infested with yellow starthistle within the context of the successional weed management model. A prescribed burn treatment of the entire study site (designed disturbance) was followed by single-entry...

  7. Effects of Trampling on Morphological and Mechanical Traits of Dryland Shrub Species Do Not Depend on Water Availability

    NARCIS (Netherlands)

    Xu, L.; Freitas, S.M.A.; Yu, F.H.; Dong, M.; Anten, N.P.R.; Werger, M.J.A.

    2013-01-01

    In semiarid drylands water shortage and trampling by large herbivores are two factors limiting plant growth and distribution. Trampling can strongly affect plant performance, but little is known about responses of morphological and mechanical traits of woody plants to trampling and their possible

  8. Advancing environmental risk assessment for transgenic biofeedstock crops

    Directory of Open Access Journals (Sweden)

    Wolt Jeffrey D

    2009-11-01

    Full Text Available Abstract Transgenic modification of plants is a key enabling technology for developing sustainable biofeedstocks for biofuels production. Regulatory decisions and the wider acceptance and development of transgenic biofeedstock crops are considered from the context of science-based risk assessment. The risk assessment paradigm for transgenic biofeedstock crops is fundamentally no different from that of current generation transgenic crops, except that the focus of the assessment must consider the unique attributes of a given biofeedstock crop and its environmental release. For currently envisioned biofeedstock crops, particular emphasis in risk assessment will be given to characterization of altered metabolic profiles and their implications relative to non-target environmental effects and food safety; weediness and invasiveness when plants are modified for abiotic stress tolerance or are domesticated; and aggregate risk when plants are platforms for multi-product production. Robust risk assessments for transgenic biofeedstock crops are case-specific, initiated through problem formulation, and use tiered approaches for risk characterization.

  9. Molecular, Genetic and Agronomic Approaches to Utilizing Pulses as Cover Crops and Green Manure into Cropping Systems.

    Science.gov (United States)

    Tani, Eleni; Abraham, Eleni; Chachalis, Demosthenis; Travlos, Ilias

    2017-06-05

    Cover crops constitute one of the most promising agronomic practices towards a more sustainable agriculture. Their beneficial effects on main crops, soil and environment are many and various, while risks and disadvantages may also appear. Several legumes show a high potential but further research is required in order to suggest the optimal legume cover crops for each case in terms of their productivity and ability to suppress weeds. The additional cost associated with cover crops should also be addressed and in this context the use of grain legumes such as cowpea, faba bean and pea could be of high interest. Some of the aspects of these grain legumes as far as their use as cover crops, their genetic diversity and their breeding using conventional and molecular approaches are discussed in the present review. The specific species seem to have a high potential for use as cover crops, especially if their noticeable genetic diversity is exploited and their breeding focuses on several desirable traits.

  10. Confronting Climate Change Challenges to Dryland Cereal Production: A Call for Collaborative, Transdisciplinary Research, and Producer Engagement

    Directory of Open Access Journals (Sweden)

    Sanford D. Eigenbrode

    2018-01-01

    Full Text Available Semi-arid cereal systems face challenges worldwide that are driven by ongoing and projected climate change. These challenges include ensuring cropping system resilience and productivity under changing water and temperature regimes while reversing soil degradation, reducing crop susceptibility to pests, pathogens and weed competition, and exploiting genetic resources to develop cultivars with resilience to climate stresses and improved compatibility with cropping system innovations. Meeting these interdependent challenges requires transdisciplinary efforts that integrate knowledge across many scientific domains. The USDA-NIFA-funded coordinated agricultural project, “Regional Approaches to Climate Change for Pacific Northwest Agriculture” (REACCH, employed this transdisciplinary approach to address climate change and sustainability challenges for rain-fed cereal-based systems in the semi-arid intermountain Pacific Northwest. To engage with and contribute to similar efforts globally, REACCH sponsored a workshop “Transitioning Cereal Systems to Adapt to Climate Change” (TCSACC in November 2015. Participants from 17 countries and five continents with expertise in agronomy, crop physiology, crop modeling, crop protection, breeding and genetics, sociology and economics shared their perspectives, successes, and challenges to achieving transdisciplinary research integration for semi-arid cereal systems under changing climates. Conference goals were to: (1 strengthen the global network of researchers addressing climate change effects on semi-arid cereal-based systems, (2 share the approaches to achieving transdisciplinary collaboration to advance climate change resilience in cereal systems, and (3 identify the elements of a collaborative research agenda that are needed to advance global food security in the twenty-first century. This paper distills the conference themes and summarizes the calls to action that were discussed: Establish coordinated

  11. Monitoring Sustainability Certification of Bioenergy: Impacts of sustainability certification on bioenergy markets and trade

    NARCIS (Netherlands)

    Goh, C.S.; Junginger, H.M.; et al,; Goovaerts, L.

    2013-01-01

    At present numerous biomass and biofuel sustainability certification schemes are being developed or implemented by a variety of private and public organisations. Schemes are applicable to different feedstock production sectors (forests, agricultural crops), different bioenergy products (wood

  12. Sustainable Biofuels Development Center

    Energy Technology Data Exchange (ETDEWEB)

    Reardon, Kenneth F. [Colorado State Univ., Fort Collins, CO (United States)

    2015-03-01

    The mission of the Sustainable Bioenergy Development Center (SBDC) is to enhance the capability of America’s bioenergy industry to produce transportation fuels and chemical feedstocks on a large scale, with significant energy yields, at competitive cost, through sustainable production techniques. Research within the SBDC is organized in five areas: (1) Development of Sustainable Crops and Agricultural Strategies, (2) Improvement of Biomass Processing Technologies, (3) Biofuel Characterization and Engine Adaptation, (4) Production of Byproducts for Sustainable Biorefining, and (5) Sustainability Assessment, including evaluation of the ecosystem/climate change implication of center research and evaluation of the policy implications of widespread production and utilization of bioenergy. The overall goal of this project is to develop new sustainable bioenergy-related technologies. To achieve that goal, three specific activities were supported with DOE funds: bioenergy-related research initiation projects, bioenergy research and education via support of undergraduate and graduate students, and Research Support Activities (equipment purchases, travel to attend bioenergy conferences, and seminars). Numerous research findings in diverse fields related to bioenergy were produced from these activities and are summarized in this report.

  13. Sustainable Food & Sustainable Economics

    OpenAIRE

    Alvarez, Mavis Dora

    2012-01-01

    Cuba today is immersed in a very intense process of perfecting its agricultural production structures with the goal of making them more efficient and sustainable in their economic administration and in their social and environmental management. Agricultural cooperatives in Cuba have the responsibility of producing on 73% of the country's farmland. Their contributions are decisive to developing agricultural production and to ensuring more and better food for the population, in addition to redu...

  14. Numerical simulation of cropping

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Hutchinson, John W.

    2014-01-01

    Cropping is a cutting process whereby opposing aligned blades create a shearing failure by exerting opposing forces normal to the surfaces of a metal sheet or plate. Building on recent efforts to quantify cropping, this paper formulates a plane strain elastic-plastic model of a plate subject to s...

  15. CO2 exchange and evapotranspiration across dryland ecosystems of southwestern North America.

    Science.gov (United States)

    Biederman, Joel A; Scott, Russell L; Bell, Tom W; Bowling, David R; Dore, Sabina; Garatuza-Payan, Jaime; Kolb, Thomas E; Krishnan, Praveena; Krofcheck, Dan J; Litvak, Marcy E; Maurer, Gregory E; Meyers, Tilden P; Oechel, Walter C; Papuga, Shirley A; Ponce-Campos, Guillermo E; Rodriguez, Julio C; Smith, William K; Vargas, Rodrigo; Watts, Christopher J; Yepez, Enrico A; Goulden, Michael L

    2017-10-01

    Global-scale studies suggest that dryland ecosystems dominate an increasing trend in the magnitude and interannual variability of the land CO2 sink. However, such analyses are poorly constrained by measured CO2 exchange in drylands. Here we address this observation gap with eddy covariance data from 25 sites in the water-limited Southwest region of North America with observed ranges in annual precipitation of 100-1000 mm, annual temperatures of 2-25°C, and records of 3-10 years (150 site-years in total). Annual fluxes were integrated using site-specific ecohydrologic years to group precipitation with resulting ecosystem exchanges. We found a wide range of carbon sink/source function, with mean annual net ecosystem production (NEP) varying from -350 to +330 gCm(-2) across sites with diverse vegetation types, contrasting with the more constant sink typically measured in mesic ecosystems. In this region, only forest-dominated sites were consistent carbon sinks. Interannual variability of NEP, gross ecosystem production (GEP), and ecosystem respiration (Reco ) was larger than for mesic regions, and half the sites switched between functioning as C sinks/C sources in wet/dry years. The sites demonstrated coherent responses of GEP and NEP to anomalies in annual evapotranspiration (ET), used here as a proxy for annually available water after hydrologic losses. Notably, GEP and Reco were negatively related to temperature, both interannually within site and spatially across sites, in contrast to positive temperature effects commonly reported for mesic ecosystems. Models based on MODIS satellite observations matched the cross-site spatial pattern in mean annual GEP but consistently underestimated mean annual ET by ~50%. Importantly, the MODIS-based models captured only 20-30% of interannual variation magnitude. These results suggest the contribution of this dryland region to variability of regional to global CO2 exchange may be up to 3-5 times larger than current estimates

  16. Biological soil crusts emit large amounts of NO and HONO affecting the nitrogen cycle in drylands

    Science.gov (United States)

    Tamm, Alexandra; Wu, Dianming; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Steinkamp, Jörg; Meusel, Hannah; Elbert, Wolfgang; Behrendt, Thomas; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul J.; Su, Hang; Pöschl, Ulrich; Weber, Bettina

    2016-04-01

    Dryland systems currently cover ˜40% of the world's land surface and are still expanding as a consequence of human impact and global change. In contrast to that, information on their role in global biochemical processes is limited, probably induced by the presumption that their sparse vegetation cover plays a negligible role in global balances. However, spaces between the sparse shrubs are not bare, but soils are mostly covered by biological soil crusts (biocrusts). These biocrust communities belong to the oldest life forms, resulting from an assembly between soil particles and cyanobacteria, lichens, bryophytes, and algae plus heterotrophic organisms in varying proportions. Depending on the dominating organism group, cyanobacteria-, lichen-, and bryophyte-dominated biocrusts are distinguished. Besides their ability to restrict soil erosion they fix atmospheric carbon and nitrogen, and by doing this they serve as a nutrient source in strongly depleted dryland ecosystems. In this study we show that a fraction of the nitrogen fixed by biocrusts is metabolized and subsequently returned to the atmosphere in the form of nitric oxide (NO) and nitrous acid (HONO). These gases affect the radical formation and oxidizing capacity within the troposphere, thus being of particular interest to atmospheric chemistry. Laboratory measurements using dynamic chamber systems showed that dark cyanobacteria-dominated crusts emitted the largest amounts of NO and HONO, being ˜20 times higher than trace gas fluxes of nearby bare soil. We showed that these nitrogen emissions have a biogenic origin, as emissions of formerly strongly emitting samples almost completely ceased after sterilization. By combining laboratory, field, and satellite measurement data we made a best estimate of global annual emissions amounting to ˜1.1 Tg of NO-N and ˜0.6 Tg of HONO-N from biocrusts. This sum of 1.7 Tg of reactive nitrogen emissions equals ˜20% of the soil release under natural vegetation according

  17. Winter cover crops decrease weediness in organic cropping systems

    OpenAIRE

    Madsen, Helena; Talgre, Liina; Eremeev, Vyacheslav; Alaru, Maarika; Maeorg, Erkki; Luik, Anne

    2017-01-01

    By inserting cover crops into organic cropping systems, the number and biomass of weeds decreased. Winter cover crops clearly have a suppressive effect on weeds by providing competition for light, water and space.

  18. Pendulous Crop in Broilers

    Directory of Open Access Journals (Sweden)

    PD Ebling

    2015-09-01

    Full Text Available ABSTRACTPendulous crop is a physiological disorder, which etiology is still unknown and it is characterized by abnormal dilation of the crop of poultry. This article aims at reporting a case of high incidence of pendulous crop in male and female broilers Cobb 500, as well as to discuss its possible causes and consequences. In an experiment with broilers performed at the experimental facilities of Laboratório de Ensino Zootécnico of UFRGS, a high incidence (9.5% of pendulous crop was observed. Genetic predisposition is the most frequently documented and accepted cause of that condition. Despite presenting the same live weight as normal broilers, birds with pendulous crop had lower carcass weight due to dehydration and malnourishment, and should be culled after diagnosis. Therefore, further studies on the origin and control of this physiological disorder are warranted.

  19. Protein crop production at the northern margin of farming: to boost or not to boost

    Directory of Open Access Journals (Sweden)

    Pirjo Peltonen-Sainio

    2012-12-01

    Full Text Available Global changes in food demand resulting from population growth and more meat-intensive diets require an increase in global protein crop production, not least as climate change and increasing scarcity of fresh water could restrict future production. In contrast to many other regions, in Finland climate change could open new opportunities through enabling more diverse cropping systems. It is justified to re-enquire whether the extent and intensity of protein crop production are optimized, resources are used efficiently and sustainably, cropping systems are built to be resilient and whether ecological services that protein crops provide are utilized appropriately. This paper aims to analyze in a descriptive manner the biological grounds for sustainable intensification of protein crop production in Finland. Production security is considered by evaluating the effects of and likelihood for constraints typical for northern conditions, examining historical and recent crop failures and estimating ecosystem services that more extensive introduction of protein crops potentially provide for northern cropping systems now and in a changing climate. There is an evident potential to expand protein crop production sustainably to a couple of times its current area. In general, variability in protein yields tends to be higher for protein crops than spring cereals. Nevertheless, protein yield variability was not necessarily systematically higher for Finland, when compared with other European regions, as it was for cereals. Protein crops provide significant ecological services that further support their expanded production. By this means protein self-sufficiency remains unrealistic, but increased production of protein crops can be achieved. The expansion of rapeseed and legumes areas also seems to be economically feasible. From the economic viewpoint, an increase in domestic protein supply requires that farmers have economic incentives to a cultivate protein

  20. Spatial-Temporal Dynamics of Cropping Frequency in Hubei Province over 2001–2015

    Directory of Open Access Journals (Sweden)

    Jianbin Tao

    2017-11-01

    Full Text Available Mapping crop patterns with remote sensing data is of great importance for agricultural production, food security and agricultural sustainability. In this paper, a hierarchical clustering method was proposed to map cropping frequency from time-series Moderate Resolution Imaging Spectroradiometer (MODIS Enhanced Vegetation Indices (EVI data and the spatial and temporal patterns of cropping frequency from 2001 to 2015 in Hubei Province of China were analyzed. The results are as follows: (1 The total double crop areas decreased slightly, while total single crop areas decreased significantly during 2001 and 2015; (2 The transfer between double crop and single crop was frequent in Hubei with about 11~15% croplands changed their cropping frequency every 5 years; (3 The crop system has obvious regional differentiation for their change trend at the county level.

  1. Spatial-Temporal Dynamics of Cropping Frequency in Hubei Province over 2001–2015

    Science.gov (United States)

    Tao, Jianbin; Wu, Wenbin; Liu, Wenbin

    2017-01-01

    Mapping crop patterns with remote sensing data is of great importance for agricultural production, food security and agricultural sustainability. In this paper, a hierarchical clustering method was proposed to map cropping frequency from time-series Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Indices (EVI) data and the spatial and temporal patterns of cropping frequency from 2001 to 2015 in Hubei Province of China were analyzed. The results are as follows: (1) The total double crop areas decreased slightly, while total single crop areas decreased significantly during 2001 and 2015; (2) The transfer between double crop and single crop was frequent in Hubei with about 11~15% croplands changed their cropping frequency every 5 years; (3) The crop system has obvious regional differentiation for their change trend at the county level. PMID:29135953

  2. UNMANNED AERIAL VEHICLE (UAV) HYPERSPECTRAL REMOTE SENSING FOR DRYLAND VEGETATION MONITORING

    Energy Technology Data Exchange (ETDEWEB)

    Nancy F. Glenn; Jessica J. Mitchell; Matthew O. Anderson; Ryan C. Hruska

    2012-06-01

    UAV-based hyperspectral remote sensing capabilities developed by the Idaho National Lab and Idaho State University, Boise Center Aerospace Lab, were recently tested via demonstration flights that explored the influence of altitude on geometric error, image mosaicking, and dryland vegetation classification. The test flights successfully acquired usable flightline data capable of supporting classifiable composite images. Unsupervised classification results support vegetation management objectives that rely on mapping shrub cover and distribution patterns. Overall, supervised classifications performed poorly despite spectral separability in the image-derived endmember pixels. Future mapping efforts that leverage ground reference data, ultra-high spatial resolution photos and time series analysis should be able to effectively distinguish native grasses such as Sandberg bluegrass (Poa secunda), from invasives such as burr buttercup (Ranunculus testiculatus) and cheatgrass (Bromus tectorum).

  3. Land use management: A dryland salinity mitigation measure (Western Cape, South Africa)

    CSIR Research Space (South Africa)

    Bugan, Richard DH

    2013-06-01

    Full Text Available of Geoinformatics, Hydrology and Modelling, Friedrich-Schiller-University Jena (Germany) Locality 2 3Background and Motivation Berg River WMA Min = 0.5 mS/m Average = 10.8 mS/m Max = 42.6 mS/m Min = 6.5 mS/m Average = 21.4 mS/m Max = 111.8 mS/m Min = 12.7 mS/m... Average = 102.3 mS/m Max = 737 mS/m • The increase in salinity is a combination of naturally saline geology as well as land use change • Land use change has resulted in DRYLAND SALINIZATION! Sandspruit River Min = 4 mS/m Average = 813 mS/m Max = 1 780...

  4. Crop Biometric Maps: The Key to Prediction

    Directory of Open Access Journals (Sweden)

    Francisco Rovira-Más

    2013-09-01

    Full Text Available The sustainability of agricultural production in the twenty-first century, both in industrialized and developing countries, benefits from the integration of farm management with information technology such that individual plants, rows, or subfields may be endowed with a singular “identity.” This approach approximates the nature of agricultural processes to the engineering of industrial processes. In order to cope with the vast variability of nature and the uncertainties of agricultural production, the concept of crop biometrics is defined as the scientific analysis of agricultural observations confined to spaces of reduced dimensions and known position with the purpose of building prediction models. This article develops the idea of crop biometrics by setting its principles, discussing the selection and quantization of biometric traits, and analyzing the mathematical relationships among measured and predicted traits. Crop biometric maps were applied to the case of a wine-production vineyard, in which vegetation amount, relative altitude in the field, soil compaction, berry size, grape yield, juice pH, and grape sugar content were selected as biometric traits. The enological potential of grapes was assessed with a quality-index map defined as a combination of titratable acidity, sugar content, and must pH. Prediction models for yield and quality were developed for high and low resolution maps, showing the great potential of crop biometric maps as a strategic tool for vineyard growers as well as for crop managers in general, due to the wide versatility of the methodology proposed.

  5. Crop biometric maps: the key to prediction.

    Science.gov (United States)

    Rovira-Más, Francisco; Sáiz-Rubio, Verónica

    2013-09-23

    The sustainability of agricultural production in the twenty-first century, both in industrialized and developing countries, benefits from the integration of farm management with information technology such that individual plants, rows, or subfields may be endowed with a singular "identity." This approach approximates the nature of agricultural processes to the engineering of industrial processes. In order to cope with the vast variability of nature and the uncertainties of agricultural production, the concept of crop biometrics is defined as the scientific analysis of agricultural observations confined to spaces of reduced dimensions and known position with the purpose of building prediction models. This article develops the idea of crop biometrics by setting its principles, discussing the selection and quantization of biometric traits, and analyzing the mathematical relationships among measured and predicted traits. Crop biometric maps were applied to the case of a wine-production vineyard, in which vegetation amount, relative altitude in the field, soil compaction, berry size, grape yield, juice pH, and grape sugar content were selected as biometric traits. The enological potential of grapes was assessed with a quality-index map defined as a combination of titratable acidity, sugar content, and must pH. Prediction models for yield and quality were developed for high and low resolution maps, showing the great potential of crop biometric maps as a strategic tool for vineyard growers as well as for crop managers in general, due to the wide versatility of the methodology proposed.

  6. Genetic transformation of major cereal crops.

    Science.gov (United States)

    Ji, Qing; Xu, Xing; Wang, Kan

    2013-01-01

    Of the more than 50,000 edible plant species in the world, at least 10,000 species are cereal grains. Three major cereal crops, rice (Oryza sativa), maize (Zea mays), and wheat (Triticum sp.), provide two-thirds of the world's food energy intake. Although crop yields have improved tremendously thanks to technological advances in the past 50 years, population increases and climate changes continue to threaten the sustainability of current crop productions. Whereas conventional and marker-assisted breeding programs continue to play a major role in crop improvement, genetic engineering has drawn an intense worldwide interest from the scientific community. In the past decade, genetic transformation technologies have revolutionized agricultural practices and millions of hectares of biotech crops have been cultured. Because of its unique ability to insert well-characterized gene sequences into the plant genome, genetic engineering can also provide effective tools to address fundamental biological questions. This technology is expected to continue to be an indispensable approach for both basic and applied research. Here, we overview briefly the development of the genetic transformation in the top seven cereals, namely maize, rice, wheat, barley (Hordeum vulgare), sorghum (Sorghum sp.), oat (Avena sativa), and millets. The advantages and disadvantages of the two major transformation methods, Agrobacterium tumefaciens-mediated and biolistic methods, are also discussed.

  7. Biological soil crusts accelerate the nitrogen cycle through large NO and HONO emissions in drylands.

    Science.gov (United States)

    Weber, Bettina; Wu, Dianming; Tamm, Alexandra; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Steinkamp, Jörg; Meusel, Hannah; Elbert, Wolfgang; Behrendt, Thomas; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul J; Su, Hang; Pöschl, Ulrich

    2015-12-15

    Reactive nitrogen species have a strong influence on atmospheric chemistry and climate, tightly coupling the Earth's nitrogen cycle with microbial activity in the biosphere. Their sources, however, are not well constrained, especially in dryland regions accounting for a major fraction of the global land surface. Here, we show that biological soil crusts (biocrusts) are emitters of nitric oxide (NO) and nitrous acid (HONO). Largest fluxes are obtained by dark cyanobacteria-dominated biocrusts, being ∼20 times higher than those of neighboring uncrusted soils. Based on laboratory, field, and satellite measurement data, we obtain a best estimate of ∼1.7 Tg per year for the global emission of reactive nitrogen from biocrusts (1.1 Tg a(-1) of NO-N and 0.6 Tg a(-1) of HONO-N), corresponding to ∼20% of global nitrogen oxide emissions from soils under natural vegetation. On continental scales, emissions are highest in Africa and South America and lowest in Europe. Our results suggest that dryland emissions of reactive nitrogen are largely driven by biocrusts rather than the underlying soil. They help to explain enigmatic discrepancies between measurement and modeling approaches of global reactive nitrogen emissions. As the emissions of biocrusts strongly depend on precipitation events, climate change affecting the distribution and frequency of precipitation may have a strong impact on terrestrial emissions of reactive nitrogen and related climate feedback effects. Because biocrusts also account for a large fraction of global terrestrial biological nitrogen fixation, their impacts should be further quantified and included in regional and global models of air chemistry, biogeochemistry, and climate.

  8. Pulse-drought atop press-drought: unexpected plant responses and implications for dryland ecosystems

    Science.gov (United States)

    Hoover, David L.; Duniway, Michael C.; Belnap, Jayne

    2015-01-01

    In drylands, climate change is predicted to cause chronic reductions in water availability (press-droughts) through reduced precipitation and increased temperatures as well as increase the frequency and intensity of short-term extreme droughts (pulse-droughts). These changes in precipitation patterns may have profound ecosystem effects, depending on the sensitivities of the dominant plant functional types (PFTs). Here we present the responses of four Colorado Plateau PFTs to an experimentally imposed, 4-year, press-drought during which a natural pulse-drought occurred. Our objectives were to (1) identify the drought sensitivities of the PFTs, (2) assess the additive effects of the press- and pulse-drought, and (3) examine the interactive effects of soils and drought. Our results revealed that the C3 grasses were the most sensitive PFT to drought, the C3shrubs were the most resistant, and the C4 grasses and shrubs had intermediate drought sensitivities. Although we expected the C3 grasses would have the greatest response to drought, the higher resistance of C3 shrubs relative to the C4 shrubs was contrary to our predictions based on the higher water use efficiency of C4 photosynthesis. Also, the additive effects of press- and pulse-droughts caused high morality in C3 grasses, which has large ecological and economic ramifications for this region. Furthermore, despite predictions based on the inverse texture hypothesis, we observed no interactive effects of soils with the drought treatment on cover or mortality. These results suggest that plant responses to droughts in drylands may differ from expectations and have large ecological effects if press- and pulse-droughts push species beyond physiological and mortality thresholds.

  9. Pulse-drought atop press-drought: unexpected plant responses and implications for dryland ecosystems.

    Science.gov (United States)

    Hoover, David L; Duniway, Michael C; Belnap, Jayne

    2015-12-01

    In drylands, climate change is predicted to cause chronic reductions in water availability (press-droughts) through reduced precipitation and increased temperatures as well as increase the frequency and intensity of short-term extreme droughts (pulse-droughts). These changes in precipitation patterns may have profound ecosystem effects, depending on the sensitivities of the dominant plant functional types (PFTs). Here we present the responses of four Colorado Plateau PFTs to an experimentally imposed, 4-year, press-drought during which a natural pulse-drought occurred. Our objectives were to (1) identify the drought sensitivities of the PFTs, (2) assess the additive effects of the press- and pulse-drought, and (3) examine the interactive effects of soils and drought. Our results revealed that the C3 grasses were the most sensitive PFT to drought, the C3 shrubs were the most resistant, and the C4 grasses and shrubs had intermediate drought sensitivities. Although we expected the C3 grasses would have the greatest response to drought, the higher resistance of C3 shrubs relative to the C4 shrubs was contrary to our predictions based on the higher water use efficiency of C4 photosynthesis. Also, the additive effects of press- and pulse-droughts caused high morality in C3 grasses, which has large ecological and economic ramifications for this region. Furthermore, despite predictions based on the inverse texture hypothesis, we observed no interactive effects of soils with the drought treatment on cover or mortality. These results suggest that plant responses to droughts in drylands may differ from expectations and have large ecological effects if press- and pulse-droughts push species beyond physiological and mortality thresholds.

  10. Cumulative drought and land-use impacts on perennial vegetation across a North American dryland region

    Science.gov (United States)

    Munson, Seth M.; Long, A. Lexine; Wallace, Cynthia; Webb, Robert H.

    2016-01-01

    Question The decline and loss of perennial vegetation in dryland ecosystems due to global change pressures can alter ecosystem properties and initiate land degradation processes. We tracked changes of perennial vegetation using remote sensing to address the question of how prolonged drought and land-use intensification have affected perennial vegetation cover across a desert region in the early 21st century? Location Mojave Desert, southeastern California, southern Nevada, southwestern Utah and northwestern Arizona, USA. Methods We coupled the Moderate-Resolution Imaging Spectroradiometer Enhanced Vegetation Index (MODIS-EVI) with ground-based measurements of perennial vegetation cover taken in about 2000 and about 2010. Using the difference between these years, we determined perennial vegetation changes in the early 21st century and related these shifts to climate, soil and landscape properties, and patterns of land use. Results We found a good fit between MODIS-EVI and perennial vegetation cover (2000: R2 = 0.83 and 2010: R2 = 0.74). The southwestern, far southeastern and central Mojave Desert had large declines in perennial vegetation cover in the early 21st century, while the northeastern and southeastern portions of the desert had increases. These changes were explained by 10-yr precipitation anomalies, particularly in the cool season and during extreme dry or wet years. Areas heavily impacted by visitor use or wildfire lost perennial vegetation cover, and vegetation in protected areas increased to a greater degree than in unprotected areas. Conclusions We find that we can extrapolate previously documented declines of perennial plant cover to an entire desert, and demonstrate that prolonged water shortages coupled with land-use intensification create identifiable patterns of vegetation change in dryland regions.

  11. Anticipating Vulnerability to Climate Change in Dryland Pastoral Systems: Using Dynamic Systems Models for the Kalahari

    Directory of Open Access Journals (Sweden)

    Andrew J. Dougill

    2010-06-01

    Full Text Available It is vitally important to identify agroecosystems that may cease functioning because of changing climate or land degradation. However, identifying such systems is confounded on both conceptual and methodological grounds, especially in systems that are moving toward thresholds, a common trait of dryland environments. This study explores these challenges by analyzing how a range of external pressures affect the vulnerability of dryland pastoral systems in the Kalahari. This is achieved by employing dynamic systems modeling approaches to understand the pathways by which communities became vulnerable to drought. Specifically, we evaluate how external pressures have changed: (1 different agroecosystems' abilities to tolerate drought, i.e., ecosystem resilience; (2 rural communities' abilities to adapt to drought, mediated via their access to assets; and (3 the ability of institutions and policy interventions to play a role in mediating drought-related crises, i.e., socio-political governance. This is done by reanalyzing ecological and participatory research findings along with farm-scale livestock offtake data from across the Kalahari in Botswana. An iterative process was followed to establish narratives exploring how external drivers led to changes in agroecosystem resilience, access to assets, and the institutional capacity to buffer the system. We use "causal loop diagrams" and statistical dynamic system models to express key quantitative relationships and establish future scenarios to help define where uncertainties lie by showing where the system is most sensitive to change. We highlight how that greater sharing of land management knowledge and practices between private and communal land managers can provide 'win-win-win' benefits of reducing system vulnerability, increasing economic income, and building social capital. We use future scenario analyses to identify key areas for future studies of climate change adaptation across the Kalahari.

  12. Effects of salinity on leaf breakdown: Dryland salinity versus salinity from a coalmine.

    Science.gov (United States)

    Sauer, Felix G; Bundschuh, Mirco; Zubrod, Jochen P; Schäfer, Ralf B; Thompson, Kristie; Kefford, Ben J

    2016-08-01

    Salinization of freshwater ecosystems as a result of human activities represents a global threat for ecosystems' integrity. Whether different sources of salinity with their differing ionic compositions lead to variable effects in ecosystem functioning is unknown. Therefore, the present study assessed the impact of dryland- (50μS/cm to 11,000μS/cm) and coalmine-induced (100μS/cm to 2400μS/cm) salinization on the leaf litter breakdown, with focus on microorganisms as main decomposer, in two catchments in New South Wales, Australia. The breakdown of Eucalyptus camaldulensis leaves decreased with increasing salinity by up to a factor of three. Coalmine salinity, which is characterised by a higher share of bicarbonates, had a slightly but consistently higher breakdown rate at a given salinity relative to dryland salinity, which is characterised by ionic proportions similar to sea water. Complementary laboratory experiments supported the stimulatory impact of sodium bicarbonates on leaf breakdown when compared to sodium chloride or artificial sea salt. Furthermore, microbial inoculum from a high salinity site (11,000μS/cm) yielded lower leaf breakdown at lower salinity relative to inoculum from a low salinity site (50μS/cm). Conversely, inoculum from the high salinity site was less sensitive towards increasing salinity levels relative to inoculum from the low salinity site. The effects of the different inoculum were the same regardless of salt source (sodium bicarbonate, sodium chloride and artificial sea salt). Finally, the microorganism-mediated leaf litter breakdown was most efficient at intermediate salinity levels (≈500μS/cm). The present study thus points to severe implications of increasing salinity intensities on the ecosystem function of leaf litter breakdown, while the underlying processes need further scrutiny. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  13. Evaporative isotope enrichment as a constraint on reach water balance along a dryland river.

    Science.gov (United States)

    Gibson, John J; Sadek, Mostafa A; Stone, D J M; Hughes, Catherine E; Hankin, S; Cendon, Dioni I; Hollins, Suzanne E

    2008-03-01

    Deuterium and oxygen-18 enrichment in river water during its transit across dryland region is found to occur systematically along evaporation lines with slopes of close to 4 in (2)H-(18)O space, largely consistent with trends predicted by the Craig-Gordon model for an open-water dominated evaporating system. This, in combination with reach balance assessments and derived runoff ratios, strongly suggests that the enrichment signal and its variability in the Barwon-Darling river, Southeastern Australia is acquired during the process of evaporation from the river channel itself, as enhanced by the presence of abundant weirs, dams and other storages, rather than reflecting inherited enrichment signals from soil water evaporation in the watershed. Using a steady-state isotope mass balance analysis based on monthly (18)O and (2)H, we use the isotopic evolution of river water to re-construct a perspective of net exchange between the river and its contributing area along eight reaches of the river during a drought period from July 2002 to December 2003, including the duration of a minor flow event. The resulting scenario, which uses a combination of climatological averages and available real-time meteorological data, should be viewed as a preliminary test of the application rather than as a definitive inventory of reach water balance. As expected for a flood-driven dryland system, considerable temporal variability in exchange is predicted. While requiring additional real-time isotopic data for operational use, the method demonstrates potential as a non-invasive tool for detecting and quantifying water diversions, one that can be easily incorporated within existing water quality monitoring activities.

  14. Climate Contributions to Vegetation Variations in Central Asian Drylands: Pre- and Post-USSR Collapse

    Directory of Open Access Journals (Sweden)

    Yu Zhou

    2015-03-01

    Full Text Available Central Asia comprises a large fraction of the world’s drylands, known to be vulnerable to climate change. We analyzed the inter-annual trends and the impact of climate variability in the vegetation greenness for Central Asia from 1982 to 2011 using GIMMS3g normalized difference vegetation index (NDVI data. In our study, most areas showed an increasing trend during 1982–1991, but experienced a significantly decreasing trend for 1992–2011. Vegetation changes were closely coupled to climate variables (precipitation and temperature during 1982–1991 and 1992–2011, but the response trajectories differed between these two periods. The warming trend in Central Asia initially enhanced the vegetation greenness before 1991, but the continued warming trend subsequently became a suppressant of further gains in greenness afterwards. Precipitation expanded its influence on larger vegetated areas in 1992–2011 when compared to 1982–1991. Moreover, the time-lag response of plants to rainfall tended to increase after 1992 compared to the pre-1992 period, indicating that plants might have experienced functional transformations to adapt the climate change during the study period. The impact of climate on vegetation was significantly different for the different sub-regions before and after 1992, coinciding with the collapse of the Union of Soviet Socialist Republics (USSR. It was suggested that these spatio-temporal patterns in greenness change and their relationship with climate change for some regions could be explained by the changes in the socio-economic structure resulted from the USSR collapse in late 1991. Our results clearly illustrate the combined influence of climatic/anthropogenic contributions on vegetation growth in Central Asian drylands. Due to the USSR collapse, this region represents a unique case study of the vegetation response to climate changes under different climatic and socio-economic conditions.

  15. Assessing the benefits and costs of dryland forest restoration in central Chile.

    Science.gov (United States)

    Schiappacasse, Ignacio; Nahuelhual, Laura; Vásquez, Felipe; Echeverría, Cristian

    2012-04-30

    Investment in natural capital restoration is increasing as a response to the widespread ecological degradation of dryland forests. However, finding efficient mechanisms to promote restoration among private landowners is a significant challenge for policy makers with limited financial resources. Furthermore, few attempts have been made to evaluate the costs and benefits of restoration interventions even though this information is relevant to orient decision making. Hence, our goal was to estimate the benefits and costs of dryland forest restoration by means of reforestation with native trees in a study area in central Chile. To determine benefits we applied a Contingent Valuation questionnaire that allowed for the calculation of willingness to pay measures. Restoration costs were calculated based on market prices following existing technical recommendations developed for the study area. The results showed that the restoration project had a negative NPV irrespective of the discount rate applied in the analysis. Thus, the NPV varied between -US$71,000 and -US$258,000. The NPV attained positive results only for negative discount rates (US$15,039 for -2%) and only when the national subsidy available for forest restoration was taken into account. This shows that landowners in Colliguay do not have incentives for carrying out restoration interventions due to a classic market failure: that in which ecosystems are mismanaged because many of their benefits are externalities from the perspective of landowners. Overall, these results stress the need for developing new compensation mechanisms and enhancing those in existence, with the aim of making restoration competitive with other land uses. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Applied crop protection 2016

    DEFF Research Database (Denmark)

    Jørgensen, Lise Nistrup; Nielsen, Bent Jørgen; Jensen, Peter Kryger

    This publication contains results from crop protection trials which were carried out at the Department of Agroecology within the area of agricultural crops. Most of the results come from field trials, but results from greenhouse and semi-field trials are also included. The report contains results...... that throw light upon: • Effects of new pesticides • Results of different control strategies, including how to control specific pests, as part of an integrated control strategy involving both cultivars and control thresholds • Results with pesticide resistance • Trial results from different cropping systems...

  17. Crop Depredation by Birds in Deccan Plateau, India

    Directory of Open Access Journals (Sweden)

    Manoj Ashokrao Kale

    2014-01-01

    Full Text Available Extent of crop depredation in agricultural fields of groundnut, pearl millet, peas, sorghum and sunflower was assessed in Pune, Akola and Amravati, the three productive districts of Maharashtra, India. The study included interviews with the farmers, identification of the bird species responsible for the crop depredation and actual field assessment of damage. The problem of crop depredation is severe for the crops mostly during harvesting season. Most farmers were not satisfied with the conventional bird repelling techniques. A maximum depredation was observed by Sorghum crops by house sparrows Passer domesticus, baya weavers Ploceus philippinus, and rose-ringed parakeets Psittacula krameri, accounting to 52% of the total damage. Blue rock pigeons Columba livia damaged 42% of the peas crop (chick peas and pigeon peas, while house sparrows and baya weaver damaged the groundnut crop by 26% in the sampling plots. House sparrow Passer domesticus and baya weaver Ploceus philippinus damaged the groundnut crop in the sampling plots just after the sowing period. The sustainable solution for reducing crop depredation is a need for the farmers and also such techniques will help avoid direct or indirect effects of use of lethal bird control techniques on bird species.

  18. Cereal Crops Research Unit

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Cereal Crops Research Unit is to 1) conduct basic research to identify and understand the biological processes affecting the growth, development...

  19. Sustainable agriculture

    National Research Council Canada - National Science Library

    Lichtfouse, Eric

    2009-01-01

    ... : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 Part I CLIMATE CHANGE Soils and Sustainable Agriculture: A Review : : : : : : : : : : : : : : : : : : : : : : : : : : Rattan Lal 15 Soils and Food Sufficiency...

  20. Radioactivity in food crops

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.