The Dryland Eco-Farm: A Potential Solution to the Main Constraints of Rain-Fed Agriculture in the Semi-Arid Tropics of Africa

Abstract

This chapter presents the results of studies on a production system called Dryland Eco-Farm (DEF) that addresses a range of constraints to agricultural productivity in dryland Africa. It combines the use of live hedges and alleys of Acacia colei, ?demi-lunes? in which are planted domesticated Ziziphus mauritiania. Annual crops like pearl millet (Pennisetum glaucum (L.) R.Br.), cowpeas and roselle (Hibiscus sabdariffa) are planted in rotation. This trial tests the effect of the system on (1) soil erosion control, soil fertility and water use efficiency, (2) crop yield and biomass production, and (3) improving income generation and diversification. Average pearl millet yields in the DEF were twice the control (880 vs. 430 kg ha?1) when no mineral fertilizer was applied. With the application of NPK, millet yields were almost similar under both conditions (950 vs. 780 kg ha?1). Cowpea yields were on average seven times higher than the control without NPK (1,400 vs. 200 kg ha?1 total biomass) and three times with NPK (1,850 vs. 650 kg ha?1 total biomass). Roselle yield increased four times on average without NPK (205 vs. 60 kg ha?1 calices yield) and two times with NPK (234 vs. 114 kg ha?1). Therefore, the system has the potential to produce yield response similar to that of the recommended rate of 100 kg of the 15-15-15 fertilizer per ha. The return to land is estimated at US 224 for the DEF compared to US224fortheDEFcomparedtoUS77 for the traditional millet?cowpea system. This system has the potential to improve productivity and rural livelihood in the drylands of Africa while sustaining the natural resources base.