The Experts below are selected from a list of 3795 Experts worldwide ranked by ideXlab platform
Jennie Barron - One of the best experts on this subject based on the ideXlab platform.
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A global and regional perspective of rainwater harvesting in sub-Saharan Africa's Rainfed Farming systems
Physics and Chemistry of The Earth, 2014Co-Authors: Timothy Karpouzoglou, Jennie BarronAbstract:In semi-arid and sub-humid sub-Saharan Africa highly variable rainfall, frequent droughts and low water productivity are consistently undermining food security. Rainwater harvesting technologies (RWHTs) help utilise water more productively whilst raising yield levels. In this article it is argued that realising the potential of RWHTs for resilience building and climate adaptation requires a better understanding of global and regional processes influencing RWHTs adoption combined with pre-existing analysis at the household scale. On the basis of a systematic literature review, processes of influence in the diffusion and uptake of RWHTs are identified. These relate to shifting ideology associated with food production systems; the scope of investments in agriculture science and technology; emergent actors shaping development assistance; and patterns of farmer mobility. Drawing insights from theory on transformations for sustainability and development, this article adds to the understanding of connectedness between farm-level adoption of RWHTs, and regional to global level actors, institutions and processes.
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Water productivity in Rainfed systems: overview of challenges and analysis of opportunities in water scarcity prone savannahs
Irrigation Science, 2007Co-Authors: Johan Rockström, Jennie BarronAbstract:Addressing the Millennium Development Goals on food and poverty over the coming decade puts enormous pressure on the world’s finite freshwater resources. Without water productivity (WP) gains, the additional freshwater in agriculture will amount to 5,600 km3 year−1 in 2050. This is three times the current global irrigation use. This paper focuses on the underlying processes and future opportunities of WP gains in water scarcity prone and poverty stricken savannah regions of the world. The paper studies the consumptive (green) WP dynamics Rainfed Farming systems, and shows that the often assumed linear relationship between evapotranspiration (ET) and yield (Y) does not translate into constant WP over a wide range of yields. Similarly, crop transpiration (T) and Y show non-linearity under on-farm and low yield conditions. This non-linearity is validated against several on-farm research experiments in semi-arid Rainfed Farming systems. With integrated soil and water management, focusing on dry spell mitigation and soil fertility can potentially more than double on-farm yields, while simultaneously improve green (ET) WP and productive green (T) WP. Through the adoption of appropriate soil and water management in semi-arid smallholder Farming systems, crop yields improve and result in improved livelihoods and WP gains.
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risk analysis and economic viability of water harvesting for supplemental irrigation in semi arid burkina faso and kenya
Agricultural Systems, 2005Co-Authors: Johan Rockström, Jennie BarronAbstract:Food insecurity affects a large portion of the population in sub-Saharan Africa (SSA). To meet future food requirements current Rainfed Farming systems need to upgrade yield output. One way is to i ...
Johan Rockström - One of the best experts on this subject based on the ideXlab platform.
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Water productivity in Rainfed systems: overview of challenges and analysis of opportunities in water scarcity prone savannahs
Irrigation Science, 2007Co-Authors: Johan Rockström, Jennie BarronAbstract:Addressing the Millennium Development Goals on food and poverty over the coming decade puts enormous pressure on the world’s finite freshwater resources. Without water productivity (WP) gains, the additional freshwater in agriculture will amount to 5,600 km3 year−1 in 2050. This is three times the current global irrigation use. This paper focuses on the underlying processes and future opportunities of WP gains in water scarcity prone and poverty stricken savannah regions of the world. The paper studies the consumptive (green) WP dynamics Rainfed Farming systems, and shows that the often assumed linear relationship between evapotranspiration (ET) and yield (Y) does not translate into constant WP over a wide range of yields. Similarly, crop transpiration (T) and Y show non-linearity under on-farm and low yield conditions. This non-linearity is validated against several on-farm research experiments in semi-arid Rainfed Farming systems. With integrated soil and water management, focusing on dry spell mitigation and soil fertility can potentially more than double on-farm yields, while simultaneously improve green (ET) WP and productive green (T) WP. Through the adoption of appropriate soil and water management in semi-arid smallholder Farming systems, crop yields improve and result in improved livelihoods and WP gains.
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risk analysis and economic viability of water harvesting for supplemental irrigation in semi arid burkina faso and kenya
Agricultural Systems, 2005Co-Authors: Johan Rockström, Jennie BarronAbstract:Food insecurity affects a large portion of the population in sub-Saharan Africa (SSA). To meet future food requirements current Rainfed Farming systems need to upgrade yield output. One way is to i ...
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Making the best of climatic variability: options for upgrading Rainfed Farming in water scarce regions
Water science and technology : a journal of the International Association on Water Pollution Research, 2004Co-Authors: Johan RockströmAbstract:Coping with climatic variability for livelihood security is part of everyday life for rural communities in semi-arid and dry sub-humid savannas. Water scarcity caused by rainfall fluctuations is common, causing meteorological droughts and dry spells. However, this paper indicates, based on experiences in sub-Saharan Africa and India, that the social impact on rural societies of climatically induced droughts is exaggerated. Instead, water scarcity causing food deficits is more often caused by management induced droughts and dry spells. A conceptual framework to distinguish between manageable and unmanageable droughts is presented. It is suggested that climatic droughts require focus on social resilience building instead of land and water resource management. Focus is then set on the manageable part of climatic variability, namely the almost annual occurrence of dry spells, short 2–4 week periods of no rainfall, affecting farmer yields. On-farm experiences in savannas of sub-Saharan Africa of water harvesting systems for dry spell mitigation are presented. It is shown that bridging dry spells combined with soil fertility management can double and even triple on-farm yield levels. Combined with innovative systems to ensure maximum plant water availability and water uptake capacity, through adoption of soil fertility improvement and conservation tillage systems, there is a clear opportunity to upgrade Rainfed Farming systems in vulnerable savanna environments, through appropriate local management of climatic variability.
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resilience building and water demand management for drought mitigation
Physics and Chemistry of The Earth, 2003Co-Authors: Johan RockströmAbstract:Abstract Doughts resulting in complete crop failure are common in Eastern and Southern Africa. We are at present experiencing a regional crisis, where crop failures related to drought are threatening the lives of millions of people in several countries in Southern Africa. A major challenge is to seek ways of mitigating and coping with droughts in small-holder Farming systems, particularly in semi-arid regions which are most hardly hit by the effects of drought. An entry-point for drought mitigation is to build water resilience of present Rainfed Farming systems. The water balance is a good starting point to assess the options. As has been argued for decades, the term drought is very debated, and the boundaries between droughts being politically and biophysically defined is not sharp. Often crop failures and social suffering are blamed on drought, while in reality the causes are more complex than only a decline in rainfall. A challenge is to find management strategies to deal with the unreliable and extremely variable rainfall in savannah environments. In this paper examples of small-scale management practices to mitigate drought in semi-arid Rainfed Farming are presented. Focus is on water harvesting systems for supplemental irrigation. It is shown that with relatively simple and cheap means it is possible to build resilience to deal with water scarcity in semi-arid Farming systems. If such measures are combined with efforts of maximising plant water availability and plant water uptake capacity, there are good chances of mitigating certain droughts. Conservation tillage systems have proven to maximise rainfall infiltration and storage of water in the soil, enabling even crops lacking supplemental irrigation to bridge severe dry spells. Interestingly, building resilience in Rainfed Farming systems is also a means of water demand management. More crop is produced per drop of water in resilient Farming systems, which reduces the amount of water needed to produce food. Despite the opportunities to build resilience to mitigate droughts, it is impossible to escape from the severe drought years. This is where coping mechanisms are required, which involve social, economic and institutional preparedness to cope with the social effects of climatic droughts.
Jeremy Cain - One of the best experts on this subject based on the ideXlab platform.
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Application of belief networks to water management studies
Agricultural Water Management, 1999Co-Authors: Charles Batchelor, Jeremy CainAbstract:Considerable effort has gone into studying the technical, social, economic and institutional constraints on improving water management in irrigated and Rainfed Farming systems. Although advances have been made, it can be argued that better progress could have been achieved if more water management studies had involved interdisciplinary data analysis. Such an integrated approach has been hampered primarily by the lack of a mathematical framework that facilitates interdisciplinary data capture and analysis. Belief and decision networks can provide this framework, allowing a simple, integrated methodology for the modelling of complex systems. This paper provides examples of the application of belief and decision networks to specific water management studies in Zimbabwe and Mauritius.
John Ryan - One of the best experts on this subject based on the ideXlab platform.
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Rainfed Farming Systems in the West Asia–North Africa (WANA) Region
Rainfed Farming Systems, 2011Co-Authors: John RyanAbstract:In dry, Rainfed lands of the world crop yield potential is usually limited by both low rainfall and degraded soil, as well as social and economic constraints. Though the Mediterranean region is the site of the origin of modern agriculture, the Mediterranean climate, with its characteristic relatively cool, moist growing season followed by a hot, dry period, imposes severe limitations on agriculture. The Rainfed cropping systems that have evolved in response to climate are also influenced by regional and global socio-economic forces, which contribute to increased land-use pressure. This chapter gives an overview of Rainfed Farming in the WANA lands bordering the Mediterranean Sea, the climatic environment that governs and the soil resources that sustain it. Emphasis is given to specific cropping systems, soil fertility and crop nutrition, water-use efficiency, cereal-based rotations in relation to cropping sustainability and to soil quality. While most of the studies cited are from the International Center for Agricultural Research in the Dry Areas (ICARDA) based in the northern Rainfed zone of Syria, the findings are generally applicable to the medium-range rainfall zone (300–500 mm/year) throughout the Mediterranean region. These studies also reflect the contributions of various national agricultural research systems and organisations that have cooperated with ICARDA especially in Morocco, Turkey and Pakistan. The chapter highlights some of the major changes that have impinged upon the region’s Rainfed Farming systems in the past few decades, with implications for the future of Rainfed cropping sustainability in the Mediterranean region.
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Plant Nutrient Management in Rainfed Farming Systems
Rainfed Farming Systems, 2011Co-Authors: John RyanAbstract:Global population growth and land-use pressure are placing increasing emphasis on expanding crop and animal output in Rainfed agriculture. Rainfed areas of the world have some common features, but some unique biophysical and socio-cultural conditions. Rainfed agriculture in the Mediterranean region is characterised by cropping systems that have evolved from antiquity. The limited and seasonally variable rainfall exerts a major influence on the Farming systems, which include production of cereals (wheat and barley) in harmony with livestock (sheep and goats). The region’s soils have been ‘nutrient mined’ for millennia and degraded through erosion; this poses constraints to output that are compounded by adverse socio-economic factors. The challenge to increase agricultural output centres on the adoption of technologies such as improved crop cultivars and enhanced crop nutrition. Chemical fertilisers are fundamental to producing more crop output from existing land in cultivation. The use of N and P, particularly has changed a once traditional low-input system to a high-input, relatively intensive one over the past 30 years. This chapter briefly examines the interactions of climatic and soil conditions in terms of how they impinge on crop nutrient use within a systems context, with emphasis on productivity and sustainability. Reference is made to the maintenance of chemical and physical fertility in Rainfed cropping systems, balanced fertilisation, efficient use of nutrients in relation to crop rotations and soil moisture, exploitation of biological N fixation, implications of spatial and temporal variability, and factors conditioning change in the region’s Rainfed agricultural sector.
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Rainfed Farming systems in the west asia north africa wana region
2011Co-Authors: John RyanAbstract:In dry, Rainfed lands of the world crop yield potential is usually limited by both low rainfall and degraded soil, as well as social and economic constraints. Though the Mediterranean region is the site of the origin of modern agriculture, the Mediterranean climate, with its characteristic relatively cool, moist growing season followed by a hot, dry period, imposes severe limitations on agriculture. The Rainfed cropping systems that have evolved in response to climate are also influenced by regional and global socio-economic forces, which contribute to increased land-use pressure. This chapter gives an overview of Rainfed Farming in the WANA lands bordering the Mediterranean Sea, the climatic environment that governs and the soil resources that sustain it. Emphasis is given to specific cropping systems, soil fertility and crop nutrition, water-use efficiency, cereal-based rotations in relation to cropping sustainability and to soil quality. While most of the studies cited are from the International Center for Agricultural Research in the Dry Areas (ICARDA) based in the northern Rainfed zone of Syria, the findings are generally applicable to the medium-range rainfall zone (300–500 mm/year) throughout the Mediterranean region. These studies also reflect the contributions of various national agricultural research systems and organisations that have cooperated with ICARDA especially in Morocco, Turkey and Pakistan. The chapter highlights some of the major changes that have impinged upon the region’s Rainfed Farming systems in the past few decades, with implications for the future of Rainfed cropping sustainability in the Mediterranean region.
Ch Srinivasarao - One of the best experts on this subject based on the ideXlab platform.
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Improving the Productivity of Rainfed Farming Systems of Small and Marginal Farmers in Adilabad District, Telangana
Indian Journal of Dryland Agricultural Research and Development, 2014Co-Authors: K.a. Gopinath, Ch Srinivasarao, G. Ravindra Chary, Sreenath Dixit, M. Osman, B. M. K. Raju, D.b.v. Ramana, D.g.m. Saroja, G. Venkatesh, M. MaheswariAbstract:On-farm trials were conducted during 2010 and 2011 to evaluate the effect of different interventions on productivity and profitability of Rainfed Farming systems of small and marginal farmers in Seethagondhi cluster, Adilabad district. Averaged across six farmers’ fields, the cotton equivalent yield (CEY) of cotton + pigeonpea intercropping was 7.99 q/ha with farmers’ practice. The CEY increased by 17.5% due to herbicide use for weed control, 28.3% with application of recommended NPK, and 35.8% with use of both herbicide and recommended NPK compared to farmers’ practice. Use of herbicide for weed control coupled with application of recommended NPK gave higher net return ( 10,300/ha) compared to other management practices. Among the Farming systems of marginal farmers, integrated Farming system involving crop production (cotton + pigeonpea intercropping) and livestock rearing (4 bullocks, 3 desi cows and 1 buffalo) gave higher net return ( 40,180/year) compared to other Farming systems. Similarly, among the three Farming systems of small farmers, integrated Farming system involving crop production (cotton + pigeonpea intercropping) and livestock rearing (2 bullocks, 1 desi cow and 40 goats) performed better with a net return of 89,937/year compared to other Farming systems.
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long term effects of fertilization and manuring on groundnut yield and nutrient balance of alfisols under Rainfed Farming in india
Nutrient Cycling in Agroecosystems, 2013Co-Authors: Ch Srinivasarao, Sumanta Kundu, B Venkateswarlu, Rattan Lal, A K Singh, G Balaguravaiah, M Vijayasankarbabu, K P R Vittal, Sharan Bhoopal Reddy, Rupendra V ManideepAbstract:Drought stress, uncertain and variable rainfall, low soil quality and nutrient deficiencies are among principal constraints for enhancing and sustaining agronomic productivity in Rainfed Farming in semiarid tropical regions of India. Therefore, long-term (1985–2004) effects of cropping, fertilization, manuring (groundnut shells, GNS; farmyard manure, FYM) and integrated nutrient management practices were assessed on pod yields, nutrient status and balances for a groundnut (Arachis hypogaea) monocropping system. The five nutrient management treatments were: control (no fertilizer); 100 % recommended dose of fertilizer (RDF) (20:40:40 N, P, K); 50 % RDF + 4 Mg ha−1 GNS; 50 % RDF + 4 Mg ha−1 FYM and 100 % organic (5 Mg ha−1 FYM). All treatments were replicated four times. The experiment was conducted at Anantapur district, Andhra Pradesh on an Alfisol using a Randomized Complete Block design. The gap in pod yields between control and different nutrient treatments widened with increase in duration of cultivation. Use of diverse fertilizer and manurial treatments produced significantly higher yields than control (P < 0.05). Amount and distribution of rainfall during critical growth stages was more important to agronomic yield than total and seasonal rainfall. Thus, the amount of rainfall received during pegging stage (r = 0.47; P < 0.05) and pod formation stage (r = 0.50; P < 0.05) was significantly correlated with the mean pod yields. Whereas, use of diverse fertility management practices improved nutrient status in soil profiles (N, P, K, S, Ca, Mg, Zn, Fe, Mn and B) after 20 years of cropping, yet soil available N, K and B remained below the critical limits. Long-term cultivation also caused deficiency of S, Zn and B, which limited the groundnut productivity. Crop removal of N, P and K during 20 years of cultivation was more in 50 % RDF + 4 Mg ha−1 GNS at 523, 210 and 598 kg ha−1, respectively. With the exception of control, there was a positive nutrient balance of NPK in all other treatments. Higher positive balance of N and K were observed in 50 % RDF + 4 Mg ha−1 GNS (616 and 837 kg ha−1, respectively), and those of P in 100 % RDF (655 kg ha−1) treatment. There was also a net depletion of available S, Zn, Cu and Mn, but a buildup of available Ca, Mg and Fe. Application of equal amount of GNS was as effective as or even better than FYM in terms of pod yields and nutrient buildup in the soil.
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Long-term effects of fertilization and manuring on groundnut yield and nutrient balance of Alfisols under Rainfed Farming in India
Nutrient Cycling in Agroecosystems, 2013Co-Authors: Ch Srinivasarao, Sumanta Kundu, B Venkateswarlu, A K Singh, G Balaguravaiah, M Vijayasankarbabu, K P R Vittal, Sharan Bhoopal Reddy, V. Rupendra ManideepAbstract:Drought stress, uncertain and variable rainfall, low soil quality and nutrient deficiencies are among principal constraints for enhancing and sustaining agronomic productivity in Rainfed Farming in semiarid tropical regions of India. Therefore, long-term (1985–2004) effects of cropping, fertilization, manuring (groundnut shells, GNS; farmyard manure, FYM) and integrated nutrient management practices were assessed on pod yields, nutrient status and balances for a groundnut ( Arachis hypogaea ) monocropping system. The five nutrient management treatments were: control (no fertilizer); 100 % recommended dose of fertilizer (RDF) (20:40:40 N, P, K); 50 % RDF + 4 Mg ha^−1 GNS; 50 % RDF + 4 Mg ha^−1 FYM and 100 % organic (5 Mg ha^−1 FYM). All treatments were replicated four times. The experiment was conducted at Anantapur district, Andhra Pradesh on an Alfisol using a Randomized Complete Block design. The gap in pod yields between control and different nutrient treatments widened with increase in duration of cultivation. Use of diverse fertilizer and manurial treatments produced significantly higher yields than control ( P
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Improving the Existing Rainfed Farming Systems of Small and Marginal Farmers in Anantapur District, Andhra Pradesh
Indian Journal of Dryland Agricultural Research and Development, 2012Co-Authors: K.a. Gopinath, Ch Srinivasarao, G. Ravindra Chary, Sreenath Dixit, M. Osman, B. M. K. Raju, D.b.v. Ramana, K. C. Nataraja, K. Gayatri Devi, G. VenkateshAbstract:On-farm trials were conducted during 2010 and 2011 to evaluate the effect of different interventions on productivity and profitability of Rainfed Farming systems of small and marginal farmers in Y. Kothapalli, Anantapur district. There was a complete failure of intercropped pigeonpea in both the years due to drought. On an average, groundnut pod yield under farmers’ practice was 194 kg ha−1. The increase in groundnut yields due to different interventions was 21% with herbicide use and 51% with use of recommended NPK. The yield increased by 155% with use of both herbicide for weed control and recommended NPK compared with farmers’ practice. However, the net returns from groundnut + pigeonpea intercropping system were negative in all the treatments ( -190 to -8,800 ha−1) due to complete failure of pigeonpea and poor groundnut yields in both the years. Among the Farming systems of marginal farmers, integrated Farming system involving crop production (groundnut + pigeonpea intercropping) and rearing of small ruminants (90 sheep and 30 goats) was found better with a net return of 1,57,855 year−1 compared to other Farming systems. Similarly, among the three Farming systems of small farmers, integrated Farming system involving crop production (groundnut + pigeonpea intercropping) and livestock rearing (2 desi cows and 100 sheep) gave higher net returns ( 1,09,650 year−1) compared to other Farming systems.
