Influence of Soil Ameliorants, Manures and Fertilizers on Bacterial Populations, Enzyme Activities, N Fixation and P Solubilization in Peanut Rhizosphere under Lateritic Soil

The aim of this study was to investigate relative efficacy of different organic wastes like farmyard manure (FYM) and water hyacinth (WH) and industrial wastes like paper factory sludge (PFS) on balancing with chemical fertilizers (CF) along with soil ameliorants viz., lime (L) or rice husk ash (RHA), another industrial waste, on dry matter production and biological properties of the rhizosphere soil of peanut (Arachis hypogaea), grown as intercrop with sabai grass (Eulaliopsis binata) in acid lateritic soil. Population of symbiotic nitrogen fixing and phosphorus solubilizing bacteria, activity of dehydrogenase and phosphatase enzymes (i.e. acid and alkaline phosphomonoesterases), nitrogen accumulation in nodules and phosphorus solubilizing power of rhizosphere soil were measured after 25, 50, 75 and 100 days after sowing (DAS) of peanut for two years. Results showed significant effects of nutrient sources and growth stages of the crop on the microbial activities. Higher values of all the biological properties and plant growth parameters were recorded significantly under the integrated application of CF and any of the organic or industrial wastes over sole application of CF. Among three organic or industrial wastes WH was superior to others regarding microbial activities at 25 DAS, whereas PFS became superior at 50, 75 and 100 DAS. Application of lime or RHA improved the activity of dehydrogenase and alkaline phosphomonoesterase enzymes, while decreased acid phosphomonoesterase activity. This study revealed that integrated application of organic or industrial wastes, soil ameliorants and inorganic fertilizer, could improve the biological properties of an acid lateritic soil as well as the dry matter production of peanut, intercropped with sabai grass under lateritic soil.