@inproceedings{orgprints14308,
           title = {Langzeit-Systemvergleiche in Kenia und Indien: Konventionelle
und biologische Ertr\"age aus dem ersten Umstellungsjahr},
          author = {C. Zundel and M. Musyoka and R. Baruah and L. Kilcher and A. Muriuki and B. Vanlauwe and A. Chabi-Olaye and M. Mucheru and P. M\"ader},
            year = {2009},
        keywords = {Long-term experiments, production systems, tropics, crop farming},
             url = {http://orgprints.org/14308/},
        abstract = {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.}
}