GREENHOUSE GAS FROM CASTOR BEAN PRODUCTION AND THEIR SUBPRODUCTS

ABSTRACT:

The largest production of castor bean (Ricinus communis L.) focuses on Bahia savanna, where the change of land use to their cultivation has been considered a strategy of degraded areas recovery. However, changes in the native soil can arise environmental impacts as greenhouse gases (GHG) emissions. We have assumed that higher GHG emissions come from a change of land use for castor bean cultivation and their sub-products contribute to GHG emissions. The objective of this study was to make the inventory of the emission of GHG resulting from the castor bean cultivation and their sub-products. It was done a study in the municipality of Irecê-BA and were evaluated: changes in carbon (C) soil stocks in cultivated areas with castor bean and Local native forest; a number of senescent leaves and the biomass produced epigeal; GHG emissions from the sub- products of castor bean. The results showed that the sum of senescent leaves and epigeal biomass obtained by castor bean pruning is more than 1.6 Mg ha^-1ano^-1 and the castor bean residues used in this soil presented N₂O emissions close to 600 µg m^-2. The emissions from the use of castor oil biodiesel represented less than 10% of the emissions. The change in land use handled high emissions of greenhouse gases, accounting for 87% of the total in CO₂eq. Compared to emissions estimated for sugarcane ethanol, castor biodiesel showed emissions 32% lower.

Keywords:
Brazilian semiarid; Land use change; Castor bean phytomass; Biofuel.