MANAGEMENT OF SOLE AND INTERCROPPED GRASS CROPS WITH Brachiaria ruziziensis AND EFFICIENCY OF SIDEDRESS NITROGEN

This work aimed to quantify the efficiency of N-recovered from ammonium sulfate (AS) applied to thegrasses grown on an exclusive basis in sidedressing, to evaluate the performance of maize, pearl millet and sorghumin single-crop and intercropped management systems with Brachiaria ruziziensis, and dry matter production of bothmanagement systems. An experiment was carried out at the Polo Regional Noroeste Paulista, located in Votuporanga, S oPaulo State, Brazil, during the 2007/2008 season in a moderate eutrophic Argisol of sandy texture. The experiment wasset up in randomized blocks design, in triplicate, consisting of six treatments (crop-management). Each replicate consistedof seven 15 m long plant rows. The efficiency of the N-recovered from AS applied at a rate of 80 kg.ha-1 N split in twoequal times in grasses managed exclusively, grain yield and production of dry matter at.harvest of single and intercroppedgrasses were evaluated. The millet was more efficient in recovering the N-AS compared to maize and sorghum at the firstpart of nitrogen fertilization, being similar for all three grasses after applying the second parcel. The largest proportionof fertilizer-N was observed in shoots of millet and grains in maize. On the other hand, sorghum showed a similardistribution between shoots and grains. Grain yield of maize, millet and sorghum was not affected by the intercroppingwith pasture. Crops with greater plant growth (maize and millet) inhibited the development of B. ruziziensis. The lowestvegetative growth of sorghum favored the highest dry matter yield of the pasture. The management of the intercroppingeffectively increases the soil covering, important in regions with dry autumn/winter.