LIBERAÇÃO DE NUTRIENTES DE ESTERCOS EM LUVISSOLO NO SEMIÁRIDO PARAIBANO

Abstract

The use of manure as a nutrient source is of fundam ental importance in the restoration and maintenance of soil fertility, especially in semiar id regions. The purpose of this study was to evalua te the nutri- ent release during decomposition of different manur es in the Paraíba semiarid region. The experiment w as con- ducted at the Experimental Field belonging Embrapa, in Patos/PB. The treatments were arranged in block s with split plot with four replications using a factorial arrangement 4 x 2 x 6, referring to four types of manure (donkey, cow, goat and sheep), two forms of deposit ion (surface soil and buried 10 cm deep) and six sa mpling times for assessment (30, 60, 90, 120, 150 and 180 days after the experiment). Were determined the con centra- tions of N, P, K, Ca and Mg. The N in goat and shee p manure were higher than 50% of the donkey and cat tle manure and also showed the highest levels of calciu m and magnesium. The sheep and cattle manure showed the highest levels of phosphorus and potassium, res pectively. The goat and sheep manure showed the hig hest levels of N, Ca and Mg. The release of nutrients fr om manure spread on the soil surface and incubated showed little variation in the initial phase of the experi mental period. Increases in soil water content prov ided higher activity of the microbial community, with more inte nse release of nutrients in the manure treatments were in- cubated in soil.