Integrated Nutrient Management Strategies for Red Gram, Sorghum and Blackgram-Based Intercropping Systems

Abstract

A field experiment was conducted at the National Pulses Research Centre, Vamban, Pudukkottai District, during the kharif seasons of 2022 and 2023 to evaluate integrated nutrient management strategies for redgram-based intercropping systems. The study included two intercropping treatments: (I₁) Redgram + Sorghum (1:2) and (I₂) Redgram + Blackgram (1:2), along with three organic fertilizer treatments: (F₁) Recommended Dose of Fertilizer (RDF), (F₂) RDF + Vermicompost @ 2.5 t ha-1, and (F₃) RDF + Farmyard Manure (FYM) @ 5 t ha-1. Two biofertilizer treatments were also evaluated: (B₁) without Phosphorus Solubilizing Bacteria (PSB) and (B₂) with PSB. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. The study utilized the red gram variety VBN 3, intercropped with the sorghum variety K 11 and the black gram variety VBN 6. Results indicated that the redgram + blackgram (1:2) intercropping system produced the highest redgram plant height (347.6 cm), branches per plant (21.2), and number of pods (295.8 per plant). This system also achieved the highest redgram seed yield (858 kg ha-1), redgram grain equivalent yield (1139 kg ha-1), and benefit-cost ratio (2.69). The application of RDF + vermicompost at 2.5 t ha-1 produced the tallest redgram plants (348.8 cm) and the highest number of branches (21.6), with significantly higher pod numbers (300.6 per plant) and seed yield (856 kg ha-1). PSB application further enhanced seed yields, with the highest redgram grain equivalent yield (1122 kg ha-1) and benefit-cost ratio (2.76). The study concluded that the combination of redgram + blackgram intercropping, RDF + vermicompost, and PSB application offers an effective integrated nutrient management strategy, optimizing both grain yields and profitability.