Decomposition of chestnut leaves and burs under different soil management systems

Abstract

Decomposition of chestnut (Castanea sativa Mill.) leaves and burs, both incorporated into the soil and placed on its surface, were studied in a chestnut grove, in Northeast Portugal. The study was carried out during twenty-seven months, and the litterbag methodology was used. The mass loss and nutrient release (N, P, K, Ca, and Mg) showed by the buried organic residues was faster than that of those placed on the soil surface. The leaf litter placed beneath or beyond the influence of tree canopy did not show significant differences with regarding mass loss and nutrient release dynamics. For similar placement, decomposition and nutrient release from burs was slower than that observed for the leaf litter. Substitution of the traditional soil management in chestnut groves by the zero tillage system will lead to the buildup of surface organic layers, and temporarily to the reduction of nutrient fluxes from organic residues to the soil.