保护性农业

Farmers in many parts of the world, because of human population growth, have little choice but to crop their land continuously, with scarce resources to replace nutrients withdrawn by each successive crop. Crop residues are often lost as a source of organic matter and mulch, usually through burning or by removal for animal feed or cooking fuel. Especially where nutrient reserves are already low, and topsoil is exposed to erosion, soils lose their capacity to sustain adequate crop yields. Additionally, extreme weather events, adverse changes in climate, human conflict, and sickness can all work against smallholder farmers’ abilities to sustain the productive capacity of their soils. Conservation Agriculture attempts to address these problems.

Conservation agriculture (CA) is a resource-saving land management approach that optimizes and sustains the capacity of soils to produce food. In CA, sustainability is linked to the ecological preservation of agricultural landscapes. This is achieved through 1) minimal soil disturbance, 2) keeping soils covered, and 3) crop diversification. Implementing these three elements requires a combination of practices, for which there are many options. Thinking of CA as an overall system, rather than a fixed set of techniques, gives farmers and practitioners the freedom to evaluate and adopt a set of CA-related practices appropriate to local needs.