Vol. 10, Issue 12 (2021)

Author(s):
Naveen Kumar A, G Balasubramanian, M Maheswari and K Iyanar

Abstract:
The paperboard mill treated effluent on land as irrigation water and a source of plant nutrients resolving disposal issues. In the present study, the pearl millet irrigated with well water, treated paperboard mill effluent as flood and drip irrigation added with amendment of effluent treatment plant (ETP) sludge and vermicompost ETP sludge. The soil microbiota, soil enzymes and yield attributes of pearl millet were studied under various treatments. Among all the treatments, soil application of ETP sludge vermicompost @5 t ha^-1 along with treated effluent through drip irrigation (T₈) showed that higher bacterial (29.49 × 10⁶ CFU ml^-1), fungal (15.50 × 10⁴ CFU ml^-1) and actinomycetes (9.75 × 10² CFU ml^-1) population at harvest stage. Correspondingly, soil enzyme activity showed higher range of 103.29 µg of NH₄-N released g^-1 of soil h^-1, 46.67 g PNPP g^-1 of soil, 61.64 µg TPF g^-1 of soil for soil urease, phosphatase and dehydrogenase, respectively at harvest stage. The grain yield of 3.45 tonnes/ha and green fodder yield of 178.54 Kg/ha for paperboard mill effluent added with vermicompost sludge (T₈) supplied pearl millet. The higher range of microbial population and enzyme activity in T₈ was associated with the presence of organic matter and adequate nutrient flow. The addition of vermicompost sludge improved the soil microbial activity which induces the soil enzyme. Hence, the soil application of ETP sludge vermicompost @5 t ha^-1 along with treated effluent through drip irrigation significantly improved the soil health which also increased the yield of the pearl millet.