The changes in enzyme activities, microbial diversity and nutrients availability in soil under long term fertilization (30 years) with inorganic fertilizers alone or in combination with organics/amendments were investigated in the present study. The experiment consisted of eleven treatments with four replications with the finger millet-maize cropping sequence. Significantly higher biomass C (276.53µg/g) and biomass N (27.20 µg/g) contents were recorded with 100 % NPK+FYM+lime and 100 % NPK+FYM application respectively. Soil enzyme activities (Acid Phosphotase and Dehydrogenase) were higher in these treatments. The general soil microflora was also higher on application of NPK, FYM and lime. The results also envisaged that application of inorganics alone resulted in decreased nutrients status (available NPK) over balanced fertilizer application. Soil acidification was accelerated with application of nitrogenous fertilizers alone (-1.87 unit reduction in soil pH over initial) and the soil pH was maintained in balanced fertilization (6.46). Available nutrients in soil were higher in 100 % NPK+FYM+lime and 100 % NPK+FYM application where the combined application of fertilizers, manure and amendments were undertaken.

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