Performance of Maize (Zea mays L.)–Green Gram (Vigna radiata (L.) Wilczek) Intercropping under Different Row Ratios with Uniform Organic Manure Application under Rainfed Conditions

Abstract

Intercropping cereals with legumes can improve resource-use efficiency, productivity and land-use efficiency, particularly under rainfed conditions. In maize–green gram intercropping, system performance is strongly influenced by the spatial arrangement and relative proportion of the component crops. Therefore, identifying an appropriate row ratio under uniform organic nutrient management is important for improving productivity, competitive balance and economic returns under rainfed conditions. A field experiment was conducted during the kharif season of 2025 at the Bothiya Research Farm, School of Agricultural Sciences, G H Raisoni University, Saikheda, Pandhurna district, Madhya Pradesh, to evaluate maize–green gram intercropping under different row ratios with uniform organic manure application under rainfed conditions. The experiment was laid out in a randomised block design with seven treatments, each replicated three times: T1 – sole maize; T2 – sole green gram; T3 – maize + green gram (1:1); T4 – (1:2); T5 – (2:1); T6 – (2:2); and T7 – (3:1). All treatments received the same mixed organic manure comprising 50% poultry manure and 50% vermicompost at a total rate of 10 t ha⁻¹ (8 t ha⁻¹ before ploughing and 2 t ha⁻¹ as top dressing). The crop was completely rainfed; no irrigation, herbicide or fungicide was used. Thiamethoxam 25% WG was sprayed at 1 g L⁻¹ at 20 and 35 days after sowing. Sowing was carried out on 13 June 2025; green gram and maize were harvested on 14 and 15 August 2025, respectively. Using confirmed prices of ₹24.10 kg⁻¹ for maize and ₹66.27 kg⁻¹ for green gram, T6 (2:2) recorded the highest maize equivalent yield (MEY; 5357 kg ha⁻¹) and gross return (₹129,113 ha⁻¹). T4 (1:2) recorded the highest total land equivalent ratio (LER; 1.40), while T5 (2:1) recorded the highest net return (₹79,292 ha⁻¹) and B:C ratio (2.61). Because the same manure mixture and rate were applied to all treatments, the independent effect of organic manure was not tested; the study is therefore interpreted strictly as a row-ratio experiment under uniform organic nutrient management.