Microorganisms perform a key role in nutrient cycling for sustaining the productivity of soils. Microbial status was studied in soil samples from nine long-term experiments at different locations, with different carbon sequestering systems in the semi-arid tropics of India, Microbial population counts were analyzed using spread plate method and were in turn compared with different parameters such as soil treatments, soil type, soil microbial biomass C, soil organic C (SOC), soil respiration rainfall and soil pH. The counts were high in the soil with different treatments. The counts were also high in treatments where a combination of organic and inorganic fertilizers was applied. Vertisols (28 x lO4 CFU g-1 soil) recorded four times more counts of microbial populations than Alfisols (7 x 1Q4 CFU g-1 soil). In few locations, significant correlation was observed with the values of soil microbial biomass C, SOC, soil respiration and microbial populations.