For smooth and wide application of conservation agriculture(CA), remaining uncertainties about its impacts on crop yield need to be reduced. Based on previous field experiments in China, a meta-analysis was performed ...For smooth and wide application of conservation agriculture(CA), remaining uncertainties about its impacts on crop yield need to be reduced. Based on previous field experiments in China, a meta-analysis was performed to quantify the actual impacts of CA practices(NT: no/reduced-tillage only, CTSR: conventional tillage with straw retention, NTSR: NT with straw retention) on crop yields as compared to conventional tillage without straw retention(CT).Although CA practices increased crop yield by 4.6% on average, there were large variations in their impacts. For each CA practice, CTSR and NTSR significantly increased crop yield by 4.9%and 6.3%, respectively, compared to CT. However, no significant effect was found for NT. Among ecological areas, significant positive effects of CA practices were found in areas with an annual precipitation below 600 mm. Similar effects were found in areas with annual mean air temperature above 5 °C. For cropping regions, CA increased crop yield by 6.4% and 5.5%compared to CT in Northwest and South China, respectively, whereas no significant effects were found in the North China and Northeast China regions. Among crops, the positive effects of CA practices were significantly higher in maize(7.5%) and rice(4.1%) than in wheat(2.9%). NT likely decreased wheat yield. Our results indicate that there are great differences in the impacts of CA practices on crop yield, owing to regional variation in climate and crop types. CA will most likely increase maize yield but reduce wheat yield. It is strongly recommended to apply CA with crop straw retention in maize cropping areas and seasons with a warm and dry climate pattern.展开更多
Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the ...Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the loss of soil-organic-carbon (SOC), which further enhances soil fertility. Different fractions of SOC pools react to the alterations in management practices and indicate changes in SOC dynamics as compared to total C in the soil. Higher SOC levels in soil have been observed in case of reduced/no-till (NT) practices than conventional tillage (CT). However, between CT and zero tillage/NT, total SOC stocks diminished with an increase in soil depth, which demonstrated that the benefits of SOC are more pronounced in the topsoil under NT. Soil aggregation provides physical protection to C associated with different-sized particles, thus, the improvement in soil aggregation through CA is an effective way to mitigate soil C loss. Along with less soil disturbance, residual management, suitable crop rotation, rational application of manures and fertilizers, and integrated nutrient management have been found to be effective in not only improving soil C stock but also enhancing the soil health and productivity. Thus, CA can be considered as a potential method in the build-up of SOC of soil in rice-wheat system.展开更多
Achieving sustainability of the cereal system in the Indo-Gangetic Plains（IGP）of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food producti...Achieving sustainability of the cereal system in the Indo-Gangetic Plains（IGP）of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food production,adaptation and mitigation in a sustainable way.This paper examines conservation agriculture（CA）from the perspective of：（i）increased yield and farm income,（ii）adaptation to heat and water stresses,and（iii）reduction in greenhouse gas（GHGs）emissions.The analyses and conclusions are based on the literature and evidences from a large number of on-station as well as farmers’field trials on CA in the cereal systems of IGP.Our analyses show that CA-based system substantially reduces the production cost（up to 23%）but produces equal or even higher than conventional system;thereby increasing economic profitability of production system.CA-based production systems also moderated the effect of high temperature（reduced canopy temperature by 1–4°C）and increased irrigation water productivity by 66–100%compared to traditional production systems thus well adapting to water and heat stress situations of IGP.Our continuous monitoring of soil flux of CO2,N2O and CH4 revealed that CA-based rice-wheat systems emit 10–15%less GHGs than conventional systems.This is the first time that CA and its components are synthesized and analyzed from food security-climate change nexus.From this holistic analysis,we suggest that wide-scale promotion of suitable CA practices by integrating into national agriculture development strategy is a way forward to address food security,climate change adaptation and mitigation challenges faced by present agriculture.展开更多
气候智慧型农业(Climate-smart agriculture,CSA)已成为推动农业绿色发展议程的核心要素。深入探究全球范围内CSA研究进展,有助于提升学术界和实践者对该领域的理解和评估。本文基于Web of Science(WoS)数据库,检索2014-01-01至2023-08...气候智慧型农业(Climate-smart agriculture,CSA)已成为推动农业绿色发展议程的核心要素。深入探究全球范围内CSA研究进展,有助于提升学术界和实践者对该领域的理解和评估。本文基于Web of Science(WoS)数据库,检索2014-01-01至2023-08-11发表的814篇CSA相关主题的论文,运用文献计量学方法重点剖析国际CSA研究热点。结果表明:(1)2018年后CSA论文发表数量与被引用次数均快速上升,环境科学、可持续性研究、农学的多学科交叉领域是CSA研究核心;(2)气候型智慧农业、气候变化、采用、保护性农业、管理、粮食安全、减缓和农户等为热点关键词;(3)研究热点主要包括CSA重要实践模式之一的保护性农业、CSA对土壤有机碳的影响与量化、CSA在不同区域应用效果、影响农户采纳CSA的关键因素和CSA相关决策支持,揭示出不同国家和地区在实施CSA过程中效果不同,农户采纳CSA的关键因素呈多元化特点,提示政策制定者在设计和推行CSA策略时须全面考虑多元化因素,以确保在全球各地实现CSA措施的有效推广和本土化应用;(4)2014−2023年引文量激增的25篇论文主要集中在保护性农业、CSA的应用与挑战,以及气候变化对农业的影响及应对策略等核心问题上。展开更多
Conservation agriculture (CA) emerged as an alternative innovation to conventional agriculture due to losses in soil productivity as a result of soil degradation. This study investigated factors affecting the adoption...Conservation agriculture (CA) emerged as an alternative innovation to conventional agriculture due to losses in soil productivity as a result of soil degradation. This study investigated factors affecting the adoption of Conservation Agriculture in the Mpatsa Extension Planning Area in a southern district of Malawi, Nsanje. A quantitative method approach was followed where were collected from a sample of 110 targeted smallholder farmers in the study area using a semi-structured questionnaire where the majority (63.6%) were women. Focused Group Discussions (FGDs) were also done to triangulate data on questionnaires. Data were entered into a Microsoft Excel database and analyzed in SPSS version 20. Socio-economic, environmental factors and household income have a greater impact on the adoption of conservation agricultural innovations. Animals were found to cause permanent soil cover disturbance while feeding on crop residues leaving the soil bare. The study concluded that climatic factors and CA training have negatively affected the adoption of new agricultural innovations, therefore, recommending further training and extension support for CA adoption as well as more access to credit opportunities for increased households’ adoption of CA.展开更多
Biopesticides are derivatives of plants, microorganisms and insects. Substances from plants and animals have been used to manage diseases in crops, animals and humans. Reliance on nature to heal nature is a practise f...Biopesticides are derivatives of plants, microorganisms and insects. Substances from plants and animals have been used to manage diseases in crops, animals and humans. Reliance on nature to heal nature is a practise for many people around the world. Use of natural products was overtaken by synthetic chemicals due to their efficacy, reliability and quick knock down effect. However, synthetic pesticides have become a health hazards for humans and environment due to their toxicity and pollution. Biopesticides are potential alternatives to synthetic pesticides. Sources of biopesticides are readily available, easily biodegradable, exhibit various modes of action, are less expensive and have low toxicity to humans and non-target organisms. Neem, pyrethrum, cotton and tobacco are known sources of botanical pesticides and have already been commercialized. Other sources of botanical pesticides include garlic, euphorbia, citrus, pepper among others. Species of Trichoderma, Bacillus, Pseudomonas, Beauveria have been commercialized as microbial pesticides. Biopesticides are however faced with challenges of formulation, registration, commercialization, acceptance and adoption. This paper describes several aspects of biopesticide development, including but not limited to, their sources, production, formulation, commercialization, efficacy and role in sustainable agriculture.展开更多
Dryland areas are experiencing low agricultural yields due to severe water shortages and salinity, leading to food scarcity. Mungbean (Vigna radiate) is gaining attention as a short-season crop that can tolerate dryla...Dryland areas are experiencing low agricultural yields due to severe water shortages and salinity, leading to food scarcity. Mungbean (Vigna radiate) is gaining attention as a short-season crop that can tolerate dryland conditions, and fix atmospheric nitrogen, decreasing soil nutrient depletion. It is a source of high-quality protein for human consumption and can serve as a multipurpose crop, if harvest residues are used as fodder or green manure. However, little of this legume’s potential has been explored. This review aims to underline the importance of mungbean as an agricultural crop by reviewing relevant literature on the potential contribution of mungbean to food security and a balanced diet as well as the effect of mungbean cultivation on farm income and gender equality. The challenges of climate change in plant production are discussed, and how progress in mungbean breeding and the application of improved cultivation techniques, such as regulated deficit irrigation, conservation agriculture, and inoculation with plant growth promoting rhizobacteria can overcome them.展开更多
Zero-tillage (ZT) and crop residue retention on the soil surface—two components of Conservation Agriculture (CA)—have been identified as promising management practices for sustainable agri- cultural intensification ...Zero-tillage (ZT) and crop residue retention on the soil surface—two components of Conservation Agriculture (CA)—have been identified as promising management practices for sustainable agri- cultural intensification for some time. However, CA technology uptake by farmers in the dry areas of West Asia and North Africa (WANA) has yet to happen large-scale, even though the positive im- pact on yield has been demonstrated repeatedly. To explain the observed consistent increases in crop yield under ZT, a range of soil quality indicators were regularly monitored during 2008 to 2012 in the long-term ZT/CA trials at the headquarters of the International Center for Agricultural Research in the Dry Areas (ICARDA) in northern Syria. Results showed that CA had a positive im- pact on soil fertility. This was measurable by higher soil organic matter (SOM) and microbial bio- mass contents, increased levels of extractable phosphate, sometimes (but not always) higher amounts of larger water-stable soil aggregates, increased soil infiltration capacity and soil water retention. The buildup of SOM and associated carbon (C) sequestration was in the range of 0.29 Mg C/ha/yr, i.e. rather modest. High amounts of surface residues delayed the desiccation of the topsoil during the fallow period, but could not diminish the overall longer-term drying of the topsoil. The observed positive changes in soil quality were little, but nevertheless, in combination with the economic savings that ZT offers, this type of agricultural intensification provides an attractive op- tion for farmers in WANA, from the standpoints of economy and ecological efficiency.展开更多
Various physical, chemical and biological soil properties in surface (0-5 cm) and subsurface (5-15 cm) soil were determined in a 4-year field experiment conducted at Punjab Agricultural University Ludhiana, India with...Various physical, chemical and biological soil properties in surface (0-5 cm) and subsurface (5-15 cm) soil were determined in a 4-year field experiment conducted at Punjab Agricultural University Ludhiana, India with sixteen treatments consisted of different combinations of fertilizer N (0, 20 and 25 kg N ha-1), P (0, 60 and 75 kg P2O5 ha-1), FYM (0 and 10 t·ha-1) and wheat (Triticum aestivum L.) residue (WR) (0 and 6 t·ha-1) applied to summer-grown soybean (Glycine max L.) and fertilizer N (0, 120 and 150 kg N ha-1), P (0, 60 and 75 kg P2O5 ha-1), and soybean residue (SR) (0 and 3 t·ha-1) applied to winter-grown wheat crop continuously in both conventional tillage (CT) and conservation agriculture (CA), arranged in a split-split plot design with tillage system in main blocks, under irrigated subtropical conditions. Application of fertilizer N, P, FYM and crop residue (CR) significantly increased water stable aggregates and had profound effects in increasing the mean weight diameter as well as the formation of macro-aggregates, which were the highest in both surface (85%) and subsurface (81%) soil layers with application of 20 kg N + 60 kg P2O5 + 10 t FYM + 6 t WR ha-1 applied to soybean and 120 kg N + 60 kg P2O5 + 3 t SR ha-1 applied to wheat crop in CA, respectively, and were 83% and 77% in CT treatments after 2 years. Hence, better aggregation was found with 100% NP + FYM + CR, where macro-aggregates were greater than 50% of total soil mass. The same treatment also enhanced total organic C (TOC) from 3.8 g·kg-1 in no-NP-FYM-CR control to 5.8 g·kg-1 in surface layer and from 2.7 to 3.6 g·kg-1 in subsurface layer after 2 years leading to the 41% and 39% higher TOC stocks over CT-Control in 0-15 cm soil layers of CT and CA, respectively. The changes in TOC stocks after 4 years were 52% and 59%.展开更多
A study was conducted to assess the adoption and scaling-up of Conservation Agriculture in Arumeru district, Arusha region, northern Tanzania and Chamwino and Dodoma Urban districts in Dodoma region, Central Tanzania....A study was conducted to assess the adoption and scaling-up of Conservation Agriculture in Arumeru district, Arusha region, northern Tanzania and Chamwino and Dodoma Urban districts in Dodoma region, Central Tanzania. The study employed structured questionnaire survey and key informant interviews as the main data collection methods. Data analysis was done descriptively to determine factors that influence the adoption. Results showed that farmers in Arusha have highly adopted terraces, minimum tillage and cover cropping whereas their counterparts in Dodoma have highly adopted large planting pits, minimum tillage, and rippers. The intensity of adoption in Arusha is higher for the wealthy compared to the poor while in Dodoma the wealth status was not a factor that influenced adoption of the Conservation Agriculture (CA) technologies. The process of technology adoption should include the use of various participatory methods including farmer field schools, experimental plots, farmer exchange visits, and training of trainers among others. Use of farmer groups, incentives, and support instruments such as Savings and Credit Co-operative Society (SACCOS) or warehouse receipts systems are also important to ensure that farmers realize some acceptable profits from their efforts. Involvement of various stakeholders is also very important including local governments and agricultural change agents at national, regional, district, ward and village levels. Hence, the intention to promote CA technologies should not only look at the economic importance, but also its socio-economic importance to the local people in the area. Their desire to adopt and out-scale a technology should be among the most important investment factors that the government and development partners should consider.展开更多
Conservation agriculture (CA) is one option for dealing with such a challenge, but its main difficulty in West Africa is in maintaining permanent soil cover, particularly with crop residues, due to their preferential ...Conservation agriculture (CA) is one option for dealing with such a challenge, but its main difficulty in West Africa is in maintaining permanent soil cover, particularly with crop residues, due to their preferential use for livestock fodder. The aim of our study was to determine the effect of crop residue mulching on the efficiency of cropping systems based on the principles of conservation agriculture. The experimental design was based on on-station experiments, intended to assess the specific effect of different levels of crop residue mulching on the biological and chemical soil fertility parameters, while in on-farm experiments we mainly assessed the ability of farmers to actually collect crop residues for soil cover and the associated effects on weeds and yields. The on-station experimental design was in fully randomized factorial blocks comprising five treatments and three replicates. The treatments compared the conventional system, tillage and cropping without mulching, and CA systems with 1 ton, 2 tons, and 4 tons of straw per hectare in plots of 10 m<sup>2</sup>. The effects of CA on the macrofauna, respiratory activity, and soil chemical parameters were evaluated in the 2014 and 2015 growing seasons. For the on-farm experiments, the conventional and CA practices of 15 farmers were compared to conventional practices in 2013 and 2014 in plots of 626 m<sup>2</sup>. The on-station results showed that the presence of crop residue mulching induced an increase in the density of termites. A significant release of carbon dioxide (CO<sub>2</sub>) in the CA treatments compared to the conventional treatment was also observed. For the chemical parameters (pH, N, P and K) were significantly and positively affected by mulch in the top 5 centimeters of soil. The on-farm experiments confirmed the difficulty of farmers in collecting enough biomass, with negative effects on grass cover leading to generally lower yields than conventional treatments. Other practices also affected the results, such as the maize sowing date, 展开更多
基金jointly supported by the National Key Technology R&D Program of China(2011BAD16B14)the Natural Science Foundation of China(31201179)the Innovation Program of Chinese Academy of Agricultural Sciences
文摘For smooth and wide application of conservation agriculture(CA), remaining uncertainties about its impacts on crop yield need to be reduced. Based on previous field experiments in China, a meta-analysis was performed to quantify the actual impacts of CA practices(NT: no/reduced-tillage only, CTSR: conventional tillage with straw retention, NTSR: NT with straw retention) on crop yields as compared to conventional tillage without straw retention(CT).Although CA practices increased crop yield by 4.6% on average, there were large variations in their impacts. For each CA practice, CTSR and NTSR significantly increased crop yield by 4.9%and 6.3%, respectively, compared to CT. However, no significant effect was found for NT. Among ecological areas, significant positive effects of CA practices were found in areas with an annual precipitation below 600 mm. Similar effects were found in areas with annual mean air temperature above 5 °C. For cropping regions, CA increased crop yield by 6.4% and 5.5%compared to CT in Northwest and South China, respectively, whereas no significant effects were found in the North China and Northeast China regions. Among crops, the positive effects of CA practices were significantly higher in maize(7.5%) and rice(4.1%) than in wheat(2.9%). NT likely decreased wheat yield. Our results indicate that there are great differences in the impacts of CA practices on crop yield, owing to regional variation in climate and crop types. CA will most likely increase maize yield but reduce wheat yield. It is strongly recommended to apply CA with crop straw retention in maize cropping areas and seasons with a warm and dry climate pattern.
文摘Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the loss of soil-organic-carbon (SOC), which further enhances soil fertility. Different fractions of SOC pools react to the alterations in management practices and indicate changes in SOC dynamics as compared to total C in the soil. Higher SOC levels in soil have been observed in case of reduced/no-till (NT) practices than conventional tillage (CT). However, between CT and zero tillage/NT, total SOC stocks diminished with an increase in soil depth, which demonstrated that the benefits of SOC are more pronounced in the topsoil under NT. Soil aggregation provides physical protection to C associated with different-sized particles, thus, the improvement in soil aggregation through CA is an effective way to mitigate soil C loss. Along with less soil disturbance, residual management, suitable crop rotation, rational application of manures and fertilizers, and integrated nutrient management have been found to be effective in not only improving soil C stock but also enhancing the soil health and productivity. Thus, CA can be considered as a potential method in the build-up of SOC of soil in rice-wheat system.
基金Financial supports for these works come from Bayer CropScienceIndian Council of Agricultural Research(ICAR)CGIAR’s research program(CRP)on Climate Change Agriculture and Food Security(CCAFS)
文摘Achieving sustainability of the cereal system in the Indo-Gangetic Plains（IGP）of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food production,adaptation and mitigation in a sustainable way.This paper examines conservation agriculture（CA）from the perspective of：（i）increased yield and farm income,（ii）adaptation to heat and water stresses,and（iii）reduction in greenhouse gas（GHGs）emissions.The analyses and conclusions are based on the literature and evidences from a large number of on-station as well as farmers’field trials on CA in the cereal systems of IGP.Our analyses show that CA-based system substantially reduces the production cost（up to 23%）but produces equal or even higher than conventional system;thereby increasing economic profitability of production system.CA-based production systems also moderated the effect of high temperature（reduced canopy temperature by 1–4°C）and increased irrigation water productivity by 66–100%compared to traditional production systems thus well adapting to water and heat stress situations of IGP.Our continuous monitoring of soil flux of CO2,N2O and CH4 revealed that CA-based rice-wheat systems emit 10–15%less GHGs than conventional systems.This is the first time that CA and its components are synthesized and analyzed from food security-climate change nexus.From this holistic analysis,we suggest that wide-scale promotion of suitable CA practices by integrating into national agriculture development strategy is a way forward to address food security,climate change adaptation and mitigation challenges faced by present agriculture.
文摘气候智慧型农业(Climate-smart agriculture,CSA)已成为推动农业绿色发展议程的核心要素。深入探究全球范围内CSA研究进展,有助于提升学术界和实践者对该领域的理解和评估。本文基于Web of Science(WoS)数据库,检索2014-01-01至2023-08-11发表的814篇CSA相关主题的论文,运用文献计量学方法重点剖析国际CSA研究热点。结果表明:(1)2018年后CSA论文发表数量与被引用次数均快速上升,环境科学、可持续性研究、农学的多学科交叉领域是CSA研究核心;(2)气候型智慧农业、气候变化、采用、保护性农业、管理、粮食安全、减缓和农户等为热点关键词;(3)研究热点主要包括CSA重要实践模式之一的保护性农业、CSA对土壤有机碳的影响与量化、CSA在不同区域应用效果、影响农户采纳CSA的关键因素和CSA相关决策支持,揭示出不同国家和地区在实施CSA过程中效果不同,农户采纳CSA的关键因素呈多元化特点,提示政策制定者在设计和推行CSA策略时须全面考虑多元化因素,以确保在全球各地实现CSA措施的有效推广和本土化应用;(4)2014−2023年引文量激增的25篇论文主要集中在保护性农业、CSA的应用与挑战,以及气候变化对农业的影响及应对策略等核心问题上。
基金国家“十一五”科技支撑计划“水土保持耕作关键技术(2006BAD09B04)”专题Challenge Program on Water and Food“Conservation Agriculture Yellow River Drylands(CN288)”欧盟项目(DESIRE,037046)
文摘Conservation agriculture (CA) emerged as an alternative innovation to conventional agriculture due to losses in soil productivity as a result of soil degradation. This study investigated factors affecting the adoption of Conservation Agriculture in the Mpatsa Extension Planning Area in a southern district of Malawi, Nsanje. A quantitative method approach was followed where were collected from a sample of 110 targeted smallholder farmers in the study area using a semi-structured questionnaire where the majority (63.6%) were women. Focused Group Discussions (FGDs) were also done to triangulate data on questionnaires. Data were entered into a Microsoft Excel database and analyzed in SPSS version 20. Socio-economic, environmental factors and household income have a greater impact on the adoption of conservation agricultural innovations. Animals were found to cause permanent soil cover disturbance while feeding on crop residues leaving the soil bare. The study concluded that climatic factors and CA training have negatively affected the adoption of new agricultural innovations, therefore, recommending further training and extension support for CA adoption as well as more access to credit opportunities for increased households’ adoption of CA.
文摘Biopesticides are derivatives of plants, microorganisms and insects. Substances from plants and animals have been used to manage diseases in crops, animals and humans. Reliance on nature to heal nature is a practise for many people around the world. Use of natural products was overtaken by synthetic chemicals due to their efficacy, reliability and quick knock down effect. However, synthetic pesticides have become a health hazards for humans and environment due to their toxicity and pollution. Biopesticides are potential alternatives to synthetic pesticides. Sources of biopesticides are readily available, easily biodegradable, exhibit various modes of action, are less expensive and have low toxicity to humans and non-target organisms. Neem, pyrethrum, cotton and tobacco are known sources of botanical pesticides and have already been commercialized. Other sources of botanical pesticides include garlic, euphorbia, citrus, pepper among others. Species of Trichoderma, Bacillus, Pseudomonas, Beauveria have been commercialized as microbial pesticides. Biopesticides are however faced with challenges of formulation, registration, commercialization, acceptance and adoption. This paper describes several aspects of biopesticide development, including but not limited to, their sources, production, formulation, commercialization, efficacy and role in sustainable agriculture.
文摘Dryland areas are experiencing low agricultural yields due to severe water shortages and salinity, leading to food scarcity. Mungbean (Vigna radiate) is gaining attention as a short-season crop that can tolerate dryland conditions, and fix atmospheric nitrogen, decreasing soil nutrient depletion. It is a source of high-quality protein for human consumption and can serve as a multipurpose crop, if harvest residues are used as fodder or green manure. However, little of this legume’s potential has been explored. This review aims to underline the importance of mungbean as an agricultural crop by reviewing relevant literature on the potential contribution of mungbean to food security and a balanced diet as well as the effect of mungbean cultivation on farm income and gender equality. The challenges of climate change in plant production are discussed, and how progress in mungbean breeding and the application of improved cultivation techniques, such as regulated deficit irrigation, conservation agriculture, and inoculation with plant growth promoting rhizobacteria can overcome them.
文摘Zero-tillage (ZT) and crop residue retention on the soil surface—two components of Conservation Agriculture (CA)—have been identified as promising management practices for sustainable agri- cultural intensification for some time. However, CA technology uptake by farmers in the dry areas of West Asia and North Africa (WANA) has yet to happen large-scale, even though the positive im- pact on yield has been demonstrated repeatedly. To explain the observed consistent increases in crop yield under ZT, a range of soil quality indicators were regularly monitored during 2008 to 2012 in the long-term ZT/CA trials at the headquarters of the International Center for Agricultural Research in the Dry Areas (ICARDA) in northern Syria. Results showed that CA had a positive im- pact on soil fertility. This was measurable by higher soil organic matter (SOM) and microbial bio- mass contents, increased levels of extractable phosphate, sometimes (but not always) higher amounts of larger water-stable soil aggregates, increased soil infiltration capacity and soil water retention. The buildup of SOM and associated carbon (C) sequestration was in the range of 0.29 Mg C/ha/yr, i.e. rather modest. High amounts of surface residues delayed the desiccation of the topsoil during the fallow period, but could not diminish the overall longer-term drying of the topsoil. The observed positive changes in soil quality were little, but nevertheless, in combination with the economic savings that ZT offers, this type of agricultural intensification provides an attractive op- tion for farmers in WANA, from the standpoints of economy and ecological efficiency.
文摘Various physical, chemical and biological soil properties in surface (0-5 cm) and subsurface (5-15 cm) soil were determined in a 4-year field experiment conducted at Punjab Agricultural University Ludhiana, India with sixteen treatments consisted of different combinations of fertilizer N (0, 20 and 25 kg N ha-1), P (0, 60 and 75 kg P2O5 ha-1), FYM (0 and 10 t·ha-1) and wheat (Triticum aestivum L.) residue (WR) (0 and 6 t·ha-1) applied to summer-grown soybean (Glycine max L.) and fertilizer N (0, 120 and 150 kg N ha-1), P (0, 60 and 75 kg P2O5 ha-1), and soybean residue (SR) (0 and 3 t·ha-1) applied to winter-grown wheat crop continuously in both conventional tillage (CT) and conservation agriculture (CA), arranged in a split-split plot design with tillage system in main blocks, under irrigated subtropical conditions. Application of fertilizer N, P, FYM and crop residue (CR) significantly increased water stable aggregates and had profound effects in increasing the mean weight diameter as well as the formation of macro-aggregates, which were the highest in both surface (85%) and subsurface (81%) soil layers with application of 20 kg N + 60 kg P2O5 + 10 t FYM + 6 t WR ha-1 applied to soybean and 120 kg N + 60 kg P2O5 + 3 t SR ha-1 applied to wheat crop in CA, respectively, and were 83% and 77% in CT treatments after 2 years. Hence, better aggregation was found with 100% NP + FYM + CR, where macro-aggregates were greater than 50% of total soil mass. The same treatment also enhanced total organic C (TOC) from 3.8 g·kg-1 in no-NP-FYM-CR control to 5.8 g·kg-1 in surface layer and from 2.7 to 3.6 g·kg-1 in subsurface layer after 2 years leading to the 41% and 39% higher TOC stocks over CT-Control in 0-15 cm soil layers of CT and CA, respectively. The changes in TOC stocks after 4 years were 52% and 59%.
文摘A study was conducted to assess the adoption and scaling-up of Conservation Agriculture in Arumeru district, Arusha region, northern Tanzania and Chamwino and Dodoma Urban districts in Dodoma region, Central Tanzania. The study employed structured questionnaire survey and key informant interviews as the main data collection methods. Data analysis was done descriptively to determine factors that influence the adoption. Results showed that farmers in Arusha have highly adopted terraces, minimum tillage and cover cropping whereas their counterparts in Dodoma have highly adopted large planting pits, minimum tillage, and rippers. The intensity of adoption in Arusha is higher for the wealthy compared to the poor while in Dodoma the wealth status was not a factor that influenced adoption of the Conservation Agriculture (CA) technologies. The process of technology adoption should include the use of various participatory methods including farmer field schools, experimental plots, farmer exchange visits, and training of trainers among others. Use of farmer groups, incentives, and support instruments such as Savings and Credit Co-operative Society (SACCOS) or warehouse receipts systems are also important to ensure that farmers realize some acceptable profits from their efforts. Involvement of various stakeholders is also very important including local governments and agricultural change agents at national, regional, district, ward and village levels. Hence, the intention to promote CA technologies should not only look at the economic importance, but also its socio-economic importance to the local people in the area. Their desire to adopt and out-scale a technology should be among the most important investment factors that the government and development partners should consider.
文摘Conservation agriculture (CA) is one option for dealing with such a challenge, but its main difficulty in West Africa is in maintaining permanent soil cover, particularly with crop residues, due to their preferential use for livestock fodder. The aim of our study was to determine the effect of crop residue mulching on the efficiency of cropping systems based on the principles of conservation agriculture. The experimental design was based on on-station experiments, intended to assess the specific effect of different levels of crop residue mulching on the biological and chemical soil fertility parameters, while in on-farm experiments we mainly assessed the ability of farmers to actually collect crop residues for soil cover and the associated effects on weeds and yields. The on-station experimental design was in fully randomized factorial blocks comprising five treatments and three replicates. The treatments compared the conventional system, tillage and cropping without mulching, and CA systems with 1 ton, 2 tons, and 4 tons of straw per hectare in plots of 10 m<sup>2</sup>. The effects of CA on the macrofauna, respiratory activity, and soil chemical parameters were evaluated in the 2014 and 2015 growing seasons. For the on-farm experiments, the conventional and CA practices of 15 farmers were compared to conventional practices in 2013 and 2014 in plots of 626 m<sup>2</sup>. The on-station results showed that the presence of crop residue mulching induced an increase in the density of termites. A significant release of carbon dioxide (CO<sub>2</sub>) in the CA treatments compared to the conventional treatment was also observed. For the chemical parameters (pH, N, P and K) were significantly and positively affected by mulch in the top 5 centimeters of soil. The on-farm experiments confirmed the difficulty of farmers in collecting enough biomass, with negative effects on grass cover leading to generally lower yields than conventional treatments. Other practices also affected the results, such as the maize sowing date,
