Decomposição de resíduos de Nim (Azadiractha indica) em agroecossistemas no semi-árido da Paraíba.

Abstract

The objective of this study was to evaluate the decomposition rates from residues of neen plants (Azadirachta indica), soil respiration and soil microarthropods under neen agroecosystem and area of primary succession. The experiment was carried in the randomized blocks (rate decomposition), split pot (soil microarthtropods) and split split pot (soil respiration) design, with five replications, in São José de Espinharas, PB, Brazil. The residues were placed in 1.0 mm mesh nylon bags (20 cm x 20 cm) which were placed on soil surface and taken out at 30, 60, 90, 120, 150 and 180 days after. At each sampling date the material was dried at 65ºC, cleane and the amount of dry matter remaining were weighed to determine the loss percentage in relation to the initial weight. Micro-arthropods were collected in the Berlese-Tuligren extractor. The soil respiration was obtained with through of the CO2 release. The data showed that densities of Collembola were higer in the neen agroecosystem than those in primary succession and decomposition rates of neen residues not differed significantly in the two different systems; whereas the soil respiration was highest in the nocturnal period. The microarthropods population was highest when to long-distance of 40.0 cm stem of neen plants.