Nitrogen response studies of intercropped sorghum with pigeonpea.

To study the N response of sorghum (Sorghum bicolor) intercropped with pigeon pea (Cajanus cajan), 3 experiments were conducted in Vertisols. In experiment 1, sole sorghum (180 000 plant/ha), sole pigeon pea (40 000 plants/ha) and 3 intercrop population treatments (40: 40, 80: 80 and 120: 120% of sole optimum) were sown as main plots with 4 levels of N (0, 40, 80 and 120 kg/ha) only to sorghum as subplots. It is concluded that intercropped and sole sorghum responded similarly to applied N. Different sorghum populations in the intercrop performed similarly. Pigeon pea did not seem to be contributing any N to its companion sorghum. Sorghum at higher N levels had a greater effect on pigeon pea yield. Both crops did equally well at 45 cm and 90 cm when grown as sole crops