Effect of spatial arrangement and phosporus fertilization in pigeonpea (Cajanus cajan)-soybean (Glycine max) intercropping system

A 2-year experiment was conducted on a clayey deep Vertisols of Bhopal to study the effect of row ratios and phosphorus fertilization on pigeonpea [Cajanus cajan (L.) Millsp.]-soybean [Glycine max (L.) (Men.)] intercropping system. At 120 cm row spacing higher, number of branches, grains/pod and yield were recorded in sole cropping compared with intercropping systems. Among intercropping, 1 : 3 ratio gave significantly higher number of branches, pods, grains/pod, 1,000-grain weight and grain yield than 1 : 1 ratio, and pigeonpea-yield equivalent increased by 31.6 and 35.3% over 1 : 1 ratio and sole pigeonpea at 60 cm row spacing respectively. The highest land-equivalent ratio (1.39), monetary yield advantage (Rs 6,712/ha/a) and benefit : cost ratio of 2.8 were recorded at 1 : 3 row ratio, followed by 1 : 2 row ratio (27.5% higher pigeonpea-grain-yield equivalent over sole pigeonpea at 60 cm row spacing). Consumptive water use and water-use efficiency also increased with intercropping at higher row ratios of 1 : 2 and 1 : 3. Increase in the dose of 30 kg to 90 kg P2O5/ha resulted in increase of grain yield of both pigeonpea and soybean. The pigeonpea-grain-yield equivalent was increased by 28.2%, the water-use efficiency by 7.7 kg/ha-cm, net profit by Rs 5,733/ha and benefit: cost ratio by 3.45.