Nutrient quantity or nutrient access?: a new understanding of how to maintain soil fertility in the tropics
2001
R. Bunch
Argues that the conventional view of the relationship between soil nutrients and crop productivity in the tropics is leading to both damaging agricultural policies and inefficient and damaging farm-level practices. It describes a new conception of the fertility of tropical soils, the Nutrient Access Concept, and then ways in which that theory can be put into practiceBenefits of the nutrient access concept include:even those farmers with heavily depleted soils should be able to increase their yields dramatically with very little investment other than that of more increased knowledge and the adoption of new agricultural techniques. Gm/cc's provide cheaper nitrogen than fertilizer factories, while zero tillage and cover crops can eliminate the comparative advantage provided by tractors. Whether most villager farmers will ever be able to compete with European or American farmers is still doubtful, but at least they should be able to produce enough for their own consumption to eat wellthe world's agriculture will become a good deal more sustainable. Increased sustainability will come from the reduced use of chemical fertilizers (reducing groundwater and stream pollution, nutrient imbalances and soil acidification), from the positive impacts on the environment of increased biomass production, soil cover, soil o.m. and biodiversity, and from the decrease of farmer dependency on increasingly expensive fossil fuels
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