Influence of soybean–pigeonpea row ratio intercropping on growth dynamics, yield, and economic returns under semi-arid vertisols

Intercropping systems involving Soybean (Glycine max) and pigeonpea (Cajanus cajan) offer potential for sustainable intensification in semi-arid agroecosystems. Yet, the optimal spatial arrangement for maximizing growth, yield, and economic returns under vertisol soils remains inadequately defined. This study evaluated eight row ratio treatments of soybean and pigeonpea intercropping during the kharif seasons of 2023 and 2024 at Parbhani, Maharashtra, India. The treatments included strip cropping at varying row ratios (6:3 to 18:12 Soybean: pigeonpea), a 4:2 soybean-pigeonpea intercropping system, and sole crops, arranged in a randomized block design with three replications. Results demonstrated significant (p ' 0.05) variation across treatments. The 18:12 row ratio strip-cropping system (T₅) consistently outperformed others, producing the highest SEY of 3,950 kg/ha, a net return of Rs. 65,200/ha, and a B: C ratio 2.43. Soybean plant height increased from 19.83 ± 0.97 cm at 30 DAS to 63.60 ± 5.35 cm at harvest, while dry matter accumulation rose from 3.09 ± 0.99 g to 21.62 ± 2.79 g per plant. Pigeonpea attained a maximum height of 159.24 ± 8.54 cm and dry matter accumulation of 98.26 ± 10.35 g/plant at harvest. Enhanced leaf area duration and pod number under T₅ reflected improved photosynthetic capacity and reproductive efficiency. The study substantiates that the strategic spatial arrangement of Soybean and pigeonpea in an 18:12 row ratio optimizes growth, yield, and profitability under semi-arid vertisol conditions. Adopting this system can enhance resource use efficiency and farm income in rainfed environments. Further research should focus on long-term impacts on soil health and resilience under climatic variability.