Conventional "arable" agriculture is normally based on soil tillage as the main operation. The most widely known tool for this operation is the plough, which has become a symbol of agriculture. Soil tillage has in the past been associated with increased fertility, which originated from the mineralization of soil nutrients as a consequence of soil tillage. This process leads in the long term to a reduction of soil organic matter. Soil organic matter is not only providing nutrients, but also is, more than anything else, a crucial element for the stabilization of soil structure. Therefore most soils degrade under long lasting intensive arable agriculture. This structural degradation of the soils results in the formation of crusts and compactions and leads in the end to soil erosion. The process is dramatic under tropical climatic situations but can be noticed all over the world. Mechanization of soil tillage, allowing higher working depths and speeds and the use of certain implements like ploughs, disk harrows and rotary cultivators have particularly detrimental effects on soil structure.
Soil erosion resulting from soil tillage has forced to look for alternatives and to reverse the process of soil degradation. The natural approach to this is to reduce tillage. This led finally to movements promoting conservation- or even zero-tillage, particularly in southern Brazil, in North America, in New Zealand and Australia. Over the last two decades the technologies were perfected and adapted for nearly all farm sizes, soil and crop types and climatic zones and experience was gained with this new approach to agriculture.
Many individual practices can be integrated into a conservation farming program. These include:no-tillageminimum and reduced tillageagro-forestrytrap croppingcover and green manure croppingalley croppingcontour farming & strip croppingorganic and biodynamic farmingstubble mulchingintegrated pest (IPM) and weeds (IWM) managementcrop and pasture rotation
CA is a concept for resource-saving agricultural crop production that strives to achieve acceptable profits together with high and sustained production levels while concurrently conserving the environment. CA is based on enhancing natural biological processes above and below the ground. Interventions such as mechanical soil tillage are reduced to an absolute minimum, and the use of external inputs such as agrochemicals and nutrients of mineral or organic origin are applied at an optimum level and in a way and quantity that does not interfere with, or disrupt, the biological processes. At field level, CA is characterized by three principles which are linked to each other, namely:Continuous minimum mechanical soil disturbance.Permanent organic soil cover.Diversified crop rotations in the case of annual crops or plant associations in case of perennial crops. Experience has shown that these techniques, summarized as conservation tillage methods, are much more than just reducing the mechanical ti ...
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