Moisture Regimes and Phosphobacteria Modulated Solubility of Labile and Non-Labile Phosphorus in Paddy soils

A pot culture experiment was conducted to study the solubilization of soil P without external fertilizer application to rice ADT(R) 45 as test crop. The experiment was laid out in complete randomized design with three factors and three replications. Four soil samples (low labile and non-labile P, low labile high non-labile P, high labile low non-labile P and high labile and non-labile P) were collected from PAJANCOA & RI, Karaikal Institute farm and tested under two moisture regimes (Continuous submergence and Alternate wetting and drying) and two levels of P solubilizers (Without and with Phosphobacteria). It was figured out that low and high non-labile P in rice plants resulted in taller plants with more tillers and high dry matter production(DMP),while soils with low labile and high non-labile P remained similar. The application of P-solubilizers like phosphobacteria with alternate wetting and drying led to higher number of filled grains/ panicle and higher grain yield, in soils with low labile and high non-labile P in comparison with continuous submergence. The study found that nutrient P availability, solubilization, absorption, and translocation within plants are a factor-driven phenomenon, affecting plant growth and yield. Soil with low labile and high non-labile P showed a higher response during early growth stages, while high labile and non-labile P showed equal responses at later stages. The study suggests that continuous P fertilization over and above crop demand alters nutrient availability, plant growth, and yield.