Studies on application of graded levels of phosphorus through PROM and biofertilizers on irrigated blackgram (Vigna mungo)

Phosphorus is a major nutrient giving widespread response in different kinds of soil especially in legumes. In India, soils of nearly 46% of the area are in the low P category. Thus, there is a need for application of P for achieving higher yields in 98% of the soils of India. There is a vast scope for extension of area as well as increasing the productivity of blackgram. Besides bringing more area under pulses, yield maximization with agronomic practices such as phosphorus nutrient management through phosphate rich organic manure (PROM) source with biofertilizers to be adopted to increase the production of blackgram. Hence, there is a need to evaluate the appropriate nutrient management methods. The field experiment was conducted at Tiruvannamalai district of Tamil Nadu, India during June – August 2021 to study the graded levels of phosphorus and biofertilizers on irrigated blackgram. The experiment was laid out in a split plot design with four main plots (M1–Control, M2–20 kg P2O5/ha, M3–40 kg P2O5/ha and M4–60 kg P2O5/ha through PROM) and six sub-plots (S1–Control, S2–Seed treatment and soil application with Rhizobium, S3–Seed treatment and soil application with Phosphobacteria, S4–Seed treatment and soil application with Rhizophos, S5–Seed treatment and soil application with AM fungi and S6–Seed treatment and soil application with AM fungi + Rhizophos replicated thrice. Application of P2O5 @ 40 kg/ha through PROM along with seed treatment and soil application of AM fungi + Rhizophos was found to be superior to other treatments by producing higher number of branches (9.96), seed yield (1198 kg/ha), haulm yield (1685 kg/ha) and harvest index (41.55) and achieved the higher productivity and profitability.