LONG TERM EFFECTS OF ORGANIC MANURES (FYM, SEWAGE SLUDGE) AMENDMENTS ON SOIL ENZYMATIC ACTIVITIES IN AN ALLUVIAL SOIL OF ALIGARH DISTRICT: A 20 YEARS STUDY
O.P. Bansal
ABSTRACT
The aim of the present study was to evaluate long-term effect (20 Years) of FYM and sewage sludge on changes in microbial biomass, microbial population and enzymatic activities (DHA, acid, alkaline phosphatase, catalase, invertase, and urease) under a wheat/ maize cropping system in the alluvial soil of Aligarh district. The results showed that application of FYM or sewage sludge @5t ha-1 enhances microbial population, biomass, and enzymatic activities as compared to control. The microbial population, biomass and enzymatic activities decreased in presence of 10 t ha-1 of sewage sludge than control, which may be due to adverse effects of heavy metals present in sewage sludge. The microbial population, biomass and enzymatic activities in presence of 10 tha-1 of FYM were lower than 5 t ha-1 of FYM but higher than control. From these results, it can be concluded that long-term application of FYM at the lower rate of the amendment is the best management option for improving soil quality and microbial activities.
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