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Browsing by Author "Dixon, John"

Now showing 1 - 6 of 6
  • Adapting no-tillage agriculture to the conditions of smallholder maize and wheat farmers in the tropics and sub-tropics
    Erenstein, Olaf; Sayre, Ken D.; Wall, Patrick C.; Dixon, John; Hellin, Jonathan (2006)
    "The purpose of this paper is to summarize some of CIMMYT's experiences with the adaptation of NT to smallholder conditions in the tropics and sub-tropics. The scope of the present paper is too narrow to review all of CIMMYT's NT experiences over the years. Instead, this chapter will focus on three contrasting cases of ongoing research and development across the developing world. These cases follow a section that discusses NT in relation to CA. Following the case studies, the paper continues with a discussion on NT innovation systems and impact pathways." (Excerpt from Introduction)
  • Adoption and economic impact of improved wheat varieties in the developing world
    Dixon, John; Nalley, L.; Kosina, P.; La Rovere, R.; Hellin, Jonathan; Aquino, P. (United Kingdom: Cambridge University Press, 2006)
    This paper discusses the impacts of the adoption of genetically improved wheat lines and varieties. The increasing wheat productivity that has occurred during the past century has contributed to increased food security and poverty reduction. The adoption of improved wheat varieties occurs at different rates for different regions. Adoption rates are dependent on the level of education of the farmer, the resource base, the availability of credit, and the methods of technology transfer. While studies have shown that the largest benefits have gone to farmers in irrigated areas, there are many other benefits involved with improved wheat varieties such as lower food prices and poverty reduction. [summary by record creator]
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    CIMMYT's strategy for catalyzing the adoption of conservation agriculture in southern Africa
    Neely, Constance L.; Dixon, John; Wall, P. (CIMMYT (International Wheat and Maize Improvement Center), 2008)
    "Conservation Agriculture (CA) is a term that has been coined in the last 10 years to describe agricultural systems that include three major components: minimal soil movement, permanent cover of the soil surface generally with crops and crop residues, and crop rotation. ... There were several conceptual pillars upon which the project was built apart from the three basic principles of CA. These concepts, a result of CIMMYTs close involvement with CA work in South Asia and Latin America, included the following:
  • Conservation agriculture and soil carbon sequestration: Between myth and farmer reality
    Govaerts, Bram; Verhulst, N.; Castellanos-Navarrete, A.; Sayre, Ken D.; Dixon, John; Dendooven, L. (Taylor & Francis, 2009)
    Improving food security, environmental preservation and enhancing livelihood should be the main targets of the innovators of today's farming systems. Conservation agriculture (CA), based on minimum tillage, crop residue retention, and crop rotations, has been proposed as an alternative system combining benefits for the farmer with advantages for the society. This paper reviews the potential impact of CA on C sequestration by synthesizing the knowledge of carbon and nitrogen cycling in agriculture; summarizing the influence of tillage, residue management, and crop rotation on soil organic carbon stocks; and compiling the existing case study information. To evaluate the C sequestration capacity of farming practices, their influence on emissions from farming activities should be considered together with their influence on soil C stocks. The largest contribution of CA to reducing emissions from farming activities is made by the reduction of tillage operations. The soil C case study results are not conclusive. In 7 of the 78 cases withheld, the soil C stock was lower in zero compared to conventional tillage, in 40 cases it was higher, and in 31 of the cases there was no significant difference. The mechanisms that govern the balance between increased or no sequestration after conversion to zero tillage are not clear, although some factors that play a role can be distinguished, e.g., root development and rhizodeposits, baseline soil C content, bulk density and porosity, climate, landscape position, and erosion/deposition history. Altering crop rotation can influence soil C stocks by changing quantity and quality of organic matter input. More research is needed, especially in the tropical areas where good quantitative information is lacking. However, even if C sequestration is questionable in some areas and cropping systems, CA remains an important technology that improves soil processes, controls soil erosion and reduces production cost. (CabAbstracts)
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    Holistic management and value chains with a livelihoods perspective: Including and transcending to make a difference
    Neely, Constance L.; Dixon, John (Gorgonzola (MI), Italy: Global Print, 2007)
    This paper discusses the value of a fused holistic and value chain framework in decision making for farming systems. The irrigated rice-wheat system of the Indo-Gangetic Plain is used to illustrate the Holistic Management and Value Chain (HM-VC) framework approach to decision making. This method tests decisions that affect the whole (including the things that must be created and/or produced to achieve the whole) system to ensure their viability. The HM-VC framework will result in more effective decision-making methods that will lead to livelihoods improvement and poverty reduction.
  • U-impact pathway for diagnosis and impact assessment of crop improvement
    Dixon, John; Hellin, Jonathan; Erenstein, Olaf; Kosina, Petr (United Kingdom: Cambridge University Press, 2007)
    Agricultural research has contributed enormously to poverty reduction and increased food security worldwide. Wheat crop improvement is a good example of this contribution. Public investments in wheat research from the Green Revolution onwards led to significant productivity increases: following the widespread adoption of semi-dwarf varieties, annual yield growth rates peaked at 2.75% p.a. in the 1980s. Since then, public and private investments in crop (including wheat) research have been modest despite the potential of such research to contribute substantially to the first Millennium Development Goal (MDG) of halving hunger and poverty by 2015. Drawing on a wide spectrum of recent literature, the present paper broadens the usual frame of reference for diagnosing the adoption of improved technology and measuring impact. The adoption of improved varieties and management practices is influenced on the supply side by the nature and performance of the input delivery pathway from research to the farm (input value chains), and on the demand side by the characteristics of the farm household system and the marketing or value-adding chains from the farm to the consumer (output value chains). These three elements (input value chains, farm household system characteristics, and output value chains) can be viewed as a U-impact pathway. This pathway determines the rate and extent of adoption of improved varieties and practices, the magnitude of direct and indirect impacts, and the potential for feedback loops leading to improved functioning of the input and output value chains. The U-impact pathway provides a framework to identify an expanded set of beneficiaries from crop improvement which extend beyond the common focus on producers and final consumers; conventional surplus analysis can then be used to estimate the wider benefits to crop improvement. Additional metrics may be needed to estimate impact related to non-economic benefits, such as poverty, health and social capital. The implication of this fuller accounting of impacts is that the benefits accruing to agricultural research may be greater, and more widely distributed across the economy, than previously recognized by research managers and policy-makers. This strengthens the case for maintained or increased public and private sector investment in crop improvement.