The biomass productivity of traditional systems (corn and beans, buffel grass and prickly pear cactus) and agroforestry systems (crops betwenn lines of gliricídia or maniçoba) were compared in a split plot experiment, during 2006 to 2009, in Taperoá, Paraíba, Brazil. Mean annual rainfall in the region is 600 mm. The agroforestry alleys were 6 m apart with 1 m between trees. In the traditional systems, the crops produced 33% more biomass and the corn and beans double the biomass of the agroforestry systems. Buffel grass was the most productive crop in the agroforestry systems. In the traditional systems, buffel and intercrops corn and beans were the most productive crops. Gliricidia produced nine times more leaf, twig and fuel wood biomass than maniçoba. Including these biomasses the productivity of the agroforestry systems was 260% higher than that of the traditional systems. The coefficient of variation of the annual biomass productivity was lower for the agroforestry systems. Therefore, the presence of trees increases not only the productivity but also the stability of the systems.
agroecosystems; semiarid; Manihot glaziovii; Gliricidia sepium
