Langzeit-Systemvergleiche in Kenia und Indien: Konventionelle und biologische Erträge aus dem ersten Umstellungsjahr

Summary

Organic agriculture is more and more perceived as a promising approach to increase food security in developing countries. However, only few attempts have been made so far to assess agronomic and economic performance of organic agriculture in these^regions in a systematic way. This article reports the first year’s results of two long-term
farming systems comparison field trials in Kenya and India. In sub-humid Central Kenya, on a high potential site in Meru South District (Chuka), there were no differences between yields of conventional and organic systems for the first maize and brassica crops. In contrast, organic yields were 14 to 60% lower than conventional yields on a trial site in a medium potential zone in Maragua District (Thika). It is assumed that the organic crops in Chuka could benefit from N and P mobilisation from the soil. In Thika, where N and P were less available, the crop depended on the easily soluble nutrients applied in the conventional treatments. In the semi-arid cotton belt of^Central India, biodynamic, organic, conventional and genetically modified (GM) cotton are compared. Soya and wheat are also part of the crop rotation under study.
Biodynamic and organic cotton and wheat yields were 30% lower than conventional and GM yields. Soya yields did not differ between the treatments. It is suggested that yield in organic farming systems in conversion depends on initial inherent soil fertility and crop.