Influence of FYM on Dynamics of Microbial Biomass and Its Turnover and Activity of Enzymes under a Soybean-Wheat System on a Typic Haplustert

Effect of four levels (0, 4, 8 and 16 t ha⁻¹) of farmyard manure on soil microbial biomass C, Nand P turnover and enzyme activities, viz., dehydrogenase, alkaline phosphatase and urease in Typic Haplustert under soybean-wheat system were studied. Farmyard manure applications @ 4 t FYM ha⁻¹ increased microbial biomass but further increase in FYM level caused reduction in biomass turnover. The N and P contents and microbial biomass were higher under soybean than under wheat crop. All the three enzyffie activities were positively correlated with biomass Nand P. There was significant correlation between soil organic carbon and microbial biomass C, N, dehydrogenase and urease activity.