Evaluating intercropping systems with sugarcane in Bihars’ north-west alluvial plains

Intercropping in sugarcane cultivation is an effective strategy to enhance productivity, optimise resource utilisation and improve farm profitability by incorporating short-duration companion crops within the cropping cycle. This study investigates the performance of diverse sugarcane-based intercropping systems in the North-West Alluvial Plain Zone of Bihar, India, with particular emphasis on key growth parameters, yield attributes and associated economic returns. The experiment was chalked out in randomized block design at the Krishi Vigyan Kendra located in Narkatiyaganj, West Champaran, Bihar. Notably, high-value intercrops such as potato and onion substantially enhanced both gross and net returns, achieving the highest benefit-cost ratios (BCRs). This was primarily due to their synergistic resource utilisation patterns and elevated market demand, which together contributed to superior profitability. Additionally, the inclusion of leguminous intercrops such as lentil and pea resulted in moderate yields. At the same time, these crops enhanced soil fertility through biological nitrogen fixation, making them an environmentally sustainable and economically viable option for smallholder and resource-limited farmers. Results revealed that intercropping significantly influenced growth, yield, system productivity and economic returns. Sugarcane intercropped with potato recorded the highest cane yield (1027 q/ha), land equivalent ratio (1.59), cane equivalent yield (1717 q/ha) and benefit-cost ratio (2.47), followed by lentil and pea intercropping systems. Leguminous intercrops improved yield attributes and system productivity while contributing to soil fertility enhancement. Correlation analysis revealed strong positive associations between germination percentage, plant survival rate, tiller population and cane morphological traits with final yield. These relationships highlight the critical role of vigorous crop establishment in maximising overall productivity. Overall, the study demonstrates that potato and legume-based intercropping systems are agronomically efficient and economically viable options for sustainable sugarcane production in the North-West Alluvial Plain Zone of Bihar.