Economic benefits of combining soil and water conservation measures with nutrient management in semiarid Burkina Faso

Nutrient limitation is the main cause of per capita decline in crop production in the Sahel, where water shortage also limits an efficient use of available nutrients. Combining soil and water conservation measures with locally available nutrient inputs may optimize crop production and economic benefit in cereal-based farming systems. A study conducted in 2001 and 2002 at Saria, Burkina Faso (annual rainfall 800 mm, PET of 2000 mm yr(-1)) assessed the combined effects of two types of semi-permeable barriers (stone rows and grass strips of Andropogon gayanus Kunth cv. Bisquamulatus (Hochst.) Hack.) and the application of compost or urea on sorghum performance and economic benefits. The field experiment was carried out on a Ferric Lixisol, 1.5 % slope and comprised 9 treatments in which the barriers were put along contours and combined with compost-N or urea-N. Installation of stone rows or grass strips without addition of nutrient inputs was not cost effective, although it induced sorghum yield increase (12-58 %) particularly under poor rainfall conditions. Combining compost with stone rows or grass strips significantly increased sorghum yield that induced positive interaction effects (mean added effects of 185 kg ha(-1) for stone rows combined with compost-N and 300 kg ha(-1) for grass strips combined with compost-N). Economic benefits were substantial (109 480 to 138 180 FCFA ha(-1)) when compost-N was added to both stone rows and grass strips, whereas limited economic benefits were observed with the application of urea-N (1120 to 22 120 FCFA ha(-1)). This may provide farmers with capital to invest in soil management and may also contribute to poverty alleviation in sub-Saharan Africa.