Decomposição de diferentes resíduos orgânicos e efeito na atividade microbiana em um latossolo vermelho de cerrado

Abstract

The maintenance of organic residues in the soil brings several benefits such as improvements on physical attributes (aggregation, moisture, soil bulk density), chemical (increased organic carbon, nitrogen, nutrient cycling) and biological (increased microbial activity and soil enzymatic). The aim of this study was to evaluate the contribution of green matter of different grasses and legumes species in the microbial activity in an Oxisol under Cerrado vegetation. Despite the high microbial activity, sorghum showed greater resistance to decomposition and mineralization of phosphorus promoted according to acid phosphatase values. Napier had the lowest microbial activity, but contributed in mineralization, as the enzyme activity. Despite the intense microbial activity in sugarcane and Brachiaria, promoted increases in BM-C and mineralization. Leucaena and Crotalaria legumes were more resistant to decomposition, despite the high microbial activity, while pigeon pea, with lower microbial activity, showed greater loss of biomass by rapid decomposition and mineralization. Bean-to-pig and leucaena contributed to increases in BM-C and mineralization. The green matters of bean-to-pork, bean, pigeon pea can be used as green manure for rapid availability of nutrients for crop later. Leucaena and Crotalaria are species that can be used for green manure and greater persistence in soil. Napier grass has greater resistance to decomposition and contributes significantly in the BM-C and enzyme activity, mineralization occurring slowly, cane and brachiaria also contribute to a lower degree.