Capacity Development Portal
Good Practices
 

Crop production systems management

  1. Conservation Agriculture
  2. Plant Nutrients/Fertilizer


Dealing with soil erosion and land degradation

What problem did it address, where?

Problems of soil erosion and land degradation frequently occur where countries are attempting to adopt strategies to intensify crop production (such as introduction of double cropping). These problems have been addressed through Conservation Agriculture approaches by FAO project work in Tanzania, Kenya, Uzbekistan and DPR Korea. In these cases, the key principle of Conservation Agriculture is the maintenance of organic cover to protect the underlying soil.

How?

Conservation Agriculture (CA) maintains a permanent or semi-permanent organic soil cover. This can be a growing crop or a dead mulch. Its function is to protect the soil physically from sun, rain and wind and to feed soil biota. The soil micro-organisms and soil fauna take over the tillage function and soil nutrient balancing. Mechanical tillage disturbs this process. Therefore, zero or minimum tillage and direct seeding are important elements of CA. A varied crop rotation is also important to avoid disease and pest problems. Rather than incorporating biomass such as green manure crops, cover crops or crop residues, in CA this is left on the soil surface. The dead biomass serves as physical protection of the soil surface and as substrate for the soil fauna. In this way mineralization is reduced and suitable soil levels of organic matter are built up and maintained. As a result CA also implies planting through the soil cover using specialised equipment (the costs are offset by a reduced need for conventional equipment). Low or zero tillage may also involve the use of chemical herbicides, particularly in the early stages of adoption of the technique, for weed control. Under this broad definition, CA may be implemented in different ways in different farming systems depending on the particular crops, the sizes of plots, labour and farm power constraints, etc. It has also been introduced in conjunction with a Farmer Fields Schools approach to allow farmers to participate in active learning and test the approaches for themselves, rather than through more traditional agricultural extension.

Where next?

Conservation Agriculture could be considered in all cases where authorities are looking to promote sustainable intensification of production and/or have previously experienced soil erosion-related problems.

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