Effect of row ratios on yield and resource efficiency of red gram and groundnut intercropping systems

The study was conducted to evaluate the effect of different cropping geometries on productivity, yield, and biological efficiency of red gram [Cajanus cajan (L.) Millsp] and groundnut (Arachis hypogaea L.) intercropping system under Southern Lateritic conditions of Agroecological Unit (AEU) 8 at Vellayani, Thiruvananthapuram, Kerala. The experiment, laid out in factorial randomized block design with seven treatments and three replications included sole crops and intercropping systems with varying red gram and groundnut row ratios (1:4, 1:6, 1:8, 2:4, and 4:5). Among different cropping geometries, T5 (red gram + groundnut in 4:5 ratio) recorded significantly the highest red gram seed yield (1113.49 kg ha-1) compared to other intercropping treatments though the sole crop produced higher seed yield (1305.44 kg ha⁻¹) than the crop under intercropping. While the highest kernel yield of groundnut (1186.36 kg ha⁻¹) was observed with sole crop, the highest kernel yield among the intercropping treatments was recorded with 1:6 ratio (1050.11 kg ha⁻¹). The red gram + groundnut in 1:6 ratio (T2) resulted in the highest red gram equivalent yield (REY) of 1751.10 kg ha⁻¹, demonstrating optimal resource utilization. Land equivalent ratio (LER) values exceeded 1 in all intercropping treatments, with T2 (1.37) showing the greatest advantage. Intercropping in 1:6 ratio enhanced the productivity, profitability, and sustainability by leveraging spatial and temporal resource complementarities. These findings highlighted the potential of intercropping red gram with groundnut for enhancing land-use efficiency and crop yields, making it a viable strategy for rainfed farming systems of Kerala.