Agroforestry systems combine crop productivity with environmental sustainability while conserving fertilizer through nutrient cycling. Plant biomass production and nutrient inputs were measured in an alley cropping system and in native cerrado site at Botucatu, State of São Paulo, Brazil, and the influence of agroforestry practices on the soil chemical attributes were determined. Leucaena was planted in 1987, in hedgerows 6 m apart, following lime and P applications. Legume hedgerows were pruned annually, allowing for cereal intercropping of rye with oat and maize with beans during the dry and rainy season, respectively. Annual biomass production in the agroforestry system was 11,036 kg ha-1 (dry matter), and mineral inputs by plants, in kg ha-1, were 149.0-N, 9.4-P, 70.0-K, 75.2-Ca and 31.1-Mg. As a result, soil pH, Ca and Mg levels were higher than in the cerrado, which was attributed to a residual effect of liming. This kind of green manure, obtained mainly by leucaena biomass, contributed to increases in organic matter, as well as soil N and P levels, in the alley cropping system.
agroforestry system; alley cropping; nutrient cycling; oxisoil