Serapilheira acumulada de eucalipto em sistema integrado de lavoura-pecuária-floresta

Abstract

Litter importance points on the return of accumulated organic matter and nutrients to the soil, being so important for restoring its fertility, and also for maintaing the productive capacity of the area. In integrated systems, such as crop-forest-livestock system (CLFS), the decomposition of organic matter is a way of synergism and complementarity that benefits the cycling of nutrients, allowing greater efficiency for production. The objective of this study was to evaluate the biomass production in the dry and rainy seasons in a 5 years old Eucalyptus urograndis stand, planted in a CLFS. The study was carried out in Cachoeira Dourada county, at Fazenda Boa Vereda, Goiás, GO, Brazil. For the accumulated litter sampling, four rows were used, with two treatments - one between plants and one between eucalyptus lines. Fifty samples were randomly collected in the row, 25 samples between plants and 25 between lines. A wooden frame (0,0625 m2) was used to collect the accumulated litter. After drying the material in an oven for 72 hours at 65 ° C, it was separated in components (leaf, branches / bark, misce-llaneous) and obtained its total weight. The values obtained in the study were: 11,16 Mg ha-1 in the rainy season and 12,66 Mg ha-1 in the dry period, with an increase of 1,49 Mg ha-1 (13.43%), in the accumulated total biomass. The highest absolute amounts were from the branches / bark portion, but the largest increment was the miscellaneous followed by the leaves. There was a higher percentage of leaf and miscellaneous deposition between plants and the branches/ bark fraction and miscellaneous between rows. The dry period showed the highest accumulation of biomass, mainly by the percentage of accumulated biomass of the leaves and branches / bark fraction.