Emissões de gases de efeito estufa pela deposição de palha de cana-de-açúcar sobre o solo

Abstract

Biofuels are important to reduce greenhouse gases (GHGs) emissions to atmosphere. In Brazil, the main biofuel is ethanol from sugarcane. Beyond stalk, sugarcane sheets are also stating to be used to produce second generation ethanol. The objective of this work was evaluate soil GHGs (CO2, CH4 and N2O) emissions induced by sugarcane trash on soil surface. Three experiments were done in an Oxisol, in Piracicaba region, taking in account three periods: immediately after sugarcane harvest, six and twelve months after harvest. In each experiment, we evaluated the effects of three sugarcane trash rates (0%, 50% and 100% of the quantity available at soil surface). Immediately after harvest, CO2 and CH4 emissions increased linearly with trash rate on soil surface. Six months after harvest there were CH4 consumption by soil as trash on surface increased. Twelve months after harvest, emissions of the three gases were similar in all trash rates. Removing sugarcane straw from soil surface do not increase soil GHGs emissions as compared to the current management, in which 100% of trash is maintained on the soil surface. However, other studies are needed to investigate its effects under sugarcane yield, soil erosion and under other soil attributes.