Competition for and conservation of water and nutrients in agroforestry systems in semi-arid West Africa

acacia holosericea agroforesteria agroforesterie agroforestry albizia albizia lebbeck azadirachta indica biological competition burkina faso contenido de agua en el suelo coppice system coppicing corta de renuevos coupe de rajeunissement cubrimiento del suelo developing countries fertilidad del suelo leucaena leucocephala mulch mulches mulching paillage sahel semiarid zones sistema de renuevos de cepa soil fertility soil water content sorghum bicolor teneur en eau du sol