Author: Victor Jetten

Introduction
In the dry Secano interior in Chile, farmers face problems of soil fertility depletion which affects the sustainability of traditional crop production. Another problem associated with fertility depletion is erosion because of periods in the crop rotation cycle where the soil is bare. Experiments were carried out to introduce crop rotation with legumes to replace wheat mono culture and to solve the problem of soil fertility depletion, while at the same time providing a better soil cover and also improving the soil structure, which improves infiltration.

Also the problems of soil erosion and soil degradation are caused by the Mediterranean type of climate (heavy rainfall in winter) and inappropriate land management practices. Experiments were carried out on the experimental farm to decrease surface runoff and soil losses and to improve soil water availability for growing crops.

Desertification indices
The desertification risk calculated is water erosion. The calculated risk is moderate (2.52). Introducing a rotation system will presumably increase the soil cover which is an option in the tool. This lowers the risk to low (2.30) while the minimum tillage also results in an even lower risk (2.18) because the ploughing is stopped.

Conclusions
The desertification risk assessment tool correctly identifies the risk for water erosion in this area and the effect of the mitigation measures.