Soil chemical properties, microbial biomass and soil enzyme dynamics on transplanted rice with organic amendments

Abstract A field experiment was conducted at the farm of Tamil Nadu Agricultural University, India, during the Kharif season to study 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, which are: T1 –100% N through dhaincha + balance P and K through inorganic fertilizers, T2 – 50% N through dhaincha + balance N, P and K through inorganic fertilizers, T3 –100% N through vermicompost + balance P and K through inorganic fertilizers, T4 –50% N through vermicompost + balance N, P and K through inorganic fertilizers, T5 –100% NPK (150: 50: 50 kg ha-1) through inorganic fertilizers, T6 –100% NPK through inorganic fertilizers + 12.5 t farmyard manure, T7 – 100% NPK through inorganic fertilizers + 6.25 t dhaincha, T8 – 100% NPK through inorganic fertilizers + 5 t vermicompost, and T9 – Control. The results revealed that maximum microbial population (bacteria, fungal, and actinomycetes), soil enzyme dynamics (urease, dehydrogenase, and soil phosphatase activity), soil available macronutrients (N, P, K) and micronutrients (Fe, Zn, Mn, and Cu) were significantly influenced with the application of 100% of N through dhaincha + balance P and K through inorganic fertilizers followed by application of 100% NPK through inorganic fertilizers + 6.25 t dhaincha. Most minor enzyme activity, microbial population & soil available nutrients of rice were registered in absolute control.