Decomposição e liberação de nutrientes de resíduos orgânicos em pomar de mangueiras irrigado no semiárido paraibano.

Abstract

The lack of information about the decomposition and nutrient release of organic wastes hampers their use in agriculture in a more discerning and efficient. This work aims to evaluate the decomposition and release of N, P and K at different organic wastes in the orchard mango under irrigation, in the semiarid in semiarid region of Paraíba, Brazil. This was evaluated by using the litter bag method. The experiment was conducted in a randomized design with five replications. The treatments were arranged in a factorial scheme 6 × 2 × 7, corresponding to six organic wastes [organic compost (OC), cattle manure (CaM); sheep manure (SM), chicken litter (CL), poultry manure (PoM) and pig manure (PiM)], two incorporation depths (0-10 and 10- 20 cm) and seven evaluation periods (0; 45, 60, 75, 90, 105 and 120 days after application - DAA). The decomposition was influenced by the type of organic waste, following sequence: PiM > SM > CaM > PoM > CL> OC. The decomposition was superior at a depth of 10-20 cm. After 120 DAA the dry matter lost was 71 % in PM, 66 % in CaM, PoM and SM, 58 % in CL and 54 % for OC. The release of N, P e K was influenced by the type of organic waste, with higher release of N and P in PM, and K for CaM and SM; the OC show the lowest release of these nutrients. The release of N, P and K did not vary between depths and the release of K was lower as N and P.