Effect of Integrated Nutrient Management on Soil Enzymes, Microbial Biomass Carbon and Microbial Population under Okra Cultivation

Abstract

A field experiment was conducted at the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat during March to July 2016 to study the “Effect of integrated nutrient management on soil enzymes, microbial biomass carbon and microbial population under okra cultivation”. The results of the study indicated that there was the improvement in soil biological properties and soil enzymes in all plots over the initial value. However, the highest biological properties like Microbial Biomass Carbon (MBC) (244.86 µg g -1 ), bacterial population (8.24 log cfu g -1 soil), fungal population (3.89 log cfu g -1 soil), soil enzymes like fluorescein di-acetate (FDA) (7.28 µg fluorescein g -1 soil h -1 ), phosphomonoesterase (PME) (50.15 µg p-nitrophenol g -1 h -1 ), Deydrogenase (DH) (136.90 µg TPF g -1 soil 24 h -1 ), Arylsulphatase (14.16 µg p-nitrophenol g -1 h -1 ) and Arylesterase activity (113.92 µg p-nitrophenol g -1 h -1 ) was found in the treatment T 3 [at 50% recommended dose of N, P, K + Vermicompost at the rate of 2 t ha -1 (mixed with microbial consortium)]. Increased in microbial population and soil enzymatic activity is the indicator of good soil condition for crop growth. Therefore the addition of organic manure and biofertilizers along with the reduced amount of inorganic fertilizers should be advocated for maintaining high soil quality for longer the period.