ABSTRACT

A field experiment was conducted to study the nutrient management through conventional and Nano DAP on growth and yield of soybean at Agriculture Research Station, Hukkeri, Belagavi, during kharif, 2023. The experiment was laid out in RCBD with 14 treatments viz.,25, 50, 75 and 100 per cent recommended dose of nitrogen and phosphorus (RDNP) as basal fertilizers with the rest as split sprays (two or three) of liquid Nano-DAP at 15, 30 and 45 days after sowing are replicated thrice.
RPP recorded significantly higher seed yield (2118 kg ha-1), haulm yield (2380 kg ha-1), number of pods per plant (45.28) and seed yield per plant (11.87 g) but it was found on par with of application of 75 per cent of RDNP as basal through fertilizers and rest 25 per cent in two or three equal split spray of liquid Nano DAP at 15, 30 and 45 DAS which recorded significantly higher seed yield (2061, 2083 and 2098 kg ha-1, respectively), haulm yield (2255, 2277 and 2304 kg ha-1, respectively), number of pods per plant (43.1, 44.43 and 45.43, respectively), seed yield per plant (11.45, 11.76 and 11.87 g, respectively) and also recorded higher uptake of NPK as compared to all other Nano DAP treatments. Nutrient use efficiencies viz., AENP and PFPNP were maximum in treatment receiving all 100 per cent RDNP applied as two or three equal split spray of liquid Nano DAP at 15, 30 and 45 DAS and the lowest with RPP. Applying 75% of the RDNP as a basal application and 25% through three split sprays of liquid Nano-DAP at 15, 30 and 45 DAS optimized the growth, yield, and economic returns in soybean cultivation. This approach resulted in the highest gross returns (₹1,01,704 ha⁻¹), net returns (₹62,263 ha⁻¹) and a BC ratio (2.62).