Browsing by Author "Sanchez, P. A."

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  • Biological Approaches to Sustainable Soil Systems
    Uphoff, N. T.; Ball, A. S.; Fernandez, E.; Herren, H.; Husson, O.; Laing, M.; Palm, C.; Pretty, Jules; Sanchez, P. A.; Sanginga, N. (Boca Raton, FL: CRC Press, 2006)
    Sustainable Soil Systems are critical to expanding agricultural output. This book aims to increase knowledge of biological processes of the soil in order to advance understanding of effective soil systems management. The editors have assembled contributing authors from a variety of disciplines and countries to create a comprehensive resource on soil biological systems. Part I offers a base for understanding soil system management in tropical, temperate, and arid regions. Part II provides a multidisciplinary overview of soil agents and processes, examining soil ecology through topics such as the rhizosphere, the role of fauna and fungi in soil systems, and allelopathy. Part III presents strategies for soil management, exploring methods as diverse as conservation agriculture and deep tillage. Part IV broadens the scope to contextualize biological approaches to soils systems management, analyzing effects on crop pests on diseases, economic and policy contexts, and approaches for monitoring and assessment.
  • Fertility capability soil classification: A tool to help assess soil quality in the tropics
    Sanchez, P. A.; Palm, C. A.; Buol, S. W. (Elsevier Science B.V., 2003)
    The soil quality paradigm was originally developed in the temperate region with the overarching objective of approaching air quality and water quality standards. Although holistic and systems oriented, soil quality focused principally on issues arising from large nutrient and energy inputs to agricultural lands. Soil quality in the tropics, however, focuses on three overarching concerns: food insecurity, rural poverty and ecosystem degradation. Soil science in the tropics relies heavily on quantitative attributes of soils that can be measured. The emotional, value-laden and 'measure everything' approach proposed by some proponents of the soil quality paradigm has no place in the tropics. Soil quality in the tropics must be considered a component of an integrated natural resource management framework (INRM). Based on quantitative topsoil attributes and soil taxonomy, the fertility capability soil classification (FCC) system is probably a good starting point to approach soil quality for the tropics and is widely used. FCC does not deal with soil attributes that can change in less than one year, but those that are either dynamic at time scales of years or decades with management, as well as inherent ones that do not change in less than a century. FCC attributes can be positive or negative depending on the land use as well as the temporal and spatial scales in question. Version 4 is introduced in this paper. The main changes are to include the former h condition modifier (acid, but not Al-toxic) with no major chemical limitations because field experience has shown little difference between the two and to introduce a new condition modifier m that denotes organic carbon saturation deficit. Additional modifiers are needed for nutrient depletion, compaction, surface sealing and other soil biological attributes, but there is no sufficient evidence to propose robust, quantitative threshold values at this time. The authors call on those actively involved in linking these attributes with plant growth and ecosystem functions to provide additional suggestions that would enhance FCC. The use of diffuse reflectance spectroscopy (DRS) shows great potential on a wide range of tropical soils. The evolution of soil science from a qualitative art into a quantitative science has progressed well in the tropics. Regressing to qualitative and vaguely defined soil quality attributes would be a step backwards.
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    Halving hunger: It can be done
    Sanchez, P. A.; Swaminathan, M. S.; Dobie, P.; Yuksel, N. (New York, Ny: United Nations Millennium Project 2005, 2005)
    In 2002, the UN Millennium Project's Task Force on Hunger was established for the purpose of developing a plan to reduce world hunger by 50 percent by the year 2015, and hopefully to eliminate it altogether. This report discusses the causes and consequences of hunger, and summarizes the task force's seven recommendations of actions and interventions necessary to reduce the problem. These include: 1)global political action to implement strategies that reduce poverty and hunger; 2) reform national policies in developing countries to promote poverty and hunger reduction; to create an environment that enables women and the poor to become more productive, and to strengthen agricultural research and trade; 3) help smallholder farmers to increase their agricultural productivity; 4) improve nutrition of those vulnerable to malnourishment and malnutrition, especially pregnant and lactating mothers, and infants and children; 5) establish "safety nets" such as local and national disaster warning systems, emergency response systems, and food banks to reduce the vulnerability to food insecurity that occurs due to natural disasters, catastrophic events, political unrest, etc.; 6) strengthen the market system infrastructure and improve access by the poor to market information, markets for selling products and buying inputs, credit and other financial services, and employment and income opportunities outside of farming; 7) reverse environmental and resource degradation, and conserve the natural resources necessary for food security.