MICROBIAL BIOMASS CARBON OF SOILS IN SUGARCANE CULTIVATION SYSTEMS

Resumo

THE OBJECTIVE OF THIS WORK WAS TO VERIFY THE MICROBIAL BIOMASS CARBON PRESENT IN THE SOILS MANAGED WITH DIFFERENT CROPPING SYSTEMS IN GOIAN�SIA, GOI�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�S - FAPEG.