Comparing productivity of millet-based cropping systems in unstable environments of the Sahel: possibilities and challenges

Falling per capita food production, increasing population pressure on arable land and soil nutrient mining that occurs under traditional cropping systems in West Africa have generated a strong demand for more productive yet sustainable cropping systems. Total factor productivity methodology was used to analyse millet (Pennisetum glaucum)-based cropping systems developed for the Sahel. The traditional cropping system uses low plant densities of intercropped millet and cowpeas, with manual cultivation and no applied P, while non-traditional systems tested in trials in Niger included P application and higher plant densities of sole- or intercropped millet grown with animal or manual tillage. Interspatial total factor productivity comparisons indicate that the new cropping systems were more profitable than the traditional cropping system. However, the determination of the sustainability of the tested systems was constrained by lack of appropriate time series data to cope with environmental instability in the Sahel and changes in resource stocks. In designing new cropping system technologies for areas prone to degradation, a multidisciplinary research strategy is needed to identify and measure resource stock changes that affect productivity. It is also imperative to use crops and system models, particularly in unstable climatic environments, to generate adequate time series data for the measurement of sustainability. Finally, cropping systems evaluated should include both packages and components. This will permit the formulation of recommendations that fit resources or preferences of different farmer