Variation of Soil Microbial Growth and Enzyme Activities by Application of Treated Distillery Effluent in Maize Crop Grown Under Sandy Loam Soils

Abstract

A field experiment was conducted to investigate the soil microbial growth and enzymatic activity of Treated Distillery Effluent (TDE) and Bio-compost (BC) applied in sandy loam soils grown with Maize crop (Zea mays). Under split plot design with five main plots with addition of organics viz., No organics; application of TDE @ 0.5 lakh litres ha-1; TDE @ 1.0 lakh litres ha-1; Bio compost @ 5 t ha-1 and FYM @ 12.5 t ha-1 + biofertilizers. In addition, five subplot treatments viz., addition of inorganic fertilizers at different levels of recommended dose of NP fertilizers (0 %, 50 %, 75 % and 100 %) compared with 100 per cent recommended dose of NPK @ 150 :75: 75 of kg N, P2O5 and K2O ha-1. Application of TDE 1.0 lakh litres ha-1 resulted higher bacterial, fungal and actinomycetes population over control at all stages of crop growth. Indeed, the soil bacterial population recorded the highest value of 20.1 and 19.3 x106 CFU g-1 of soil with the application of TDE @ 1.0 lakh litres ha-1 compared to control at post-harvest stage. There was an increase in the soil fungal population to the tune of 30.3 per cent over control at post-harvest stage. Furthermore, application of TDE @ 1.0 lakh litres ha-1 recorded the highest soil actinomycetes population at all stages of crop growth. The soil enzyme activities as phosphatase, dehydrogenase and urease recorded the highest values of 12.8 μg p-nitrophenol g-1 soil hr-1; 2.96 μg TPF g-1 soil hr-1 and 5.16 μg NH4-N g-1 soil hr-1 respectively with the application of TDE @ 1.0 lakh litres ha-1. The soil microbial population and enzyme activities increased with the application of distillery effluent over control. Hence, it was observed that, Soil microbial activity had a direct impact on the plant nutrient availability as well as other favorable properties associated with soil productivity