Chemical Properties, Microbial Biomass and Enzyme Dynamics of Post-Harvest Soil on Transplanted Rice with Effect of Organic Amendments

A field experiment was conducted at the farm of Tamil Nadu Agricultural University, Coimbatore during kharif season to study the effect of soil chemical properties, microbial biomass and soil enzyme dynamics on transplanted rice with organic amendments. Rice CO(R) 48 was used as a test variety. The experiment was laid out in randomized block design (RBD) with three replications and nine treatments. The treatment consists Recommended Dose of Fertilizers 100% NPK (150 : 50 : 50 kg ha-1) through inorganic fertilizers, Based on N equivalent basis, required quantities of organic manures (Dhaincha, vermicompost and Farmyard Manure @ 50% and 100%) were incorporated into the soil one week before transplanting of rice. The P and K requirement was supplied separately through inorganic sources as per treatment schedule. In the present investigation, an attempt was made to examine the influence of different levels and sources of fertilization on dynamics of soil chemical properties, microbial biomass and enzyme activities under anaerobic rice cultivation. Soil samples were taken before the start of experiment and harvest of rice for analysis of soil chemical characteristics, microbial biomass and enzyme activity. The results revealed that maximum microbial population (bacteria, fungal & actinomycetes), soil enzyme dynamics (urease, dehydrogenase & soil phosphatase activity), soil available macro nutrients (N, P, K) & micro nutrients (Fe, Zn, Mn, Cu) were significantly influenced with application of 100% N through dhaincha + balance P & K through inorganic fertilizers followed by application of 100% NPK through inorganic fertilizers + 6.25 t dhaincha. Least enzyme activity, microbial population & soil available nutrients of rice were registered in absolute control.