Substitutional Effect of Molecular Phosphorus with Nano Particle on the Performance of Black Gram (Vigna mungo L.)

Black gram (Vigna mungo L.), a vital pulse crop in India, accounts for about 10% of total pulse production. Phosphorus is essential for legume growth, but its use efficiency is low in acidic soils due to fixation. Nano-phosphorus offers a potential alternative by releasing phosphorus gradually, improving uptake efficiency.

A field experiment was conducted using randomized block design with 8 treatments and 3 replications to evaluate black gram response to nano-phosphorus substitutions. Treatments included combinations of recommended dose of phosphorus (RDP) through single super phosphate (SSP) and foliar sprays (FS) of nano DAP or nano phosphorus at 15 days after sowing (DAS) and flowering.

Results showed that 75% RDP through SSP + FS of nano DAP @ 5 ml L^-1 significantly improved pod number (48.67), pod length (5.31 cm), seeds pod^-1 (7.33), seed index (5.43 g) and yielded 20.13% and 55.44% higher seed yield than 100% SSP and control, respectively. This treatment also recorded the highest phosphorus uptake (13.38 kg ha^-1) and net return (₹ 37,507.46 ha^-1) with a return per rupee investment of 1.09. The study suggests that substituting up to 75% of molecular phosphorus with nano DAP enhances growth, yield and profitability of black gram in the terai region when supplemented with 20 kg N and 40 kg K ha^-1. This approach offers a sustainable fertilization strategy for post-kharif black gram cultivation. The study was limited to a single location, which may restrict the generalization of results across varying soil and climatic conditions.