Effects of fallow and pigeon pea on yield and nitrogen response of the succeeding sorghum on a Vertisol
Keywords:Mineral nitrogen accumulation, Nitrogen uptake, Residual effects, Yield, Weed-free fallow
AbstractThe effect of a weed-free fallow and short- and medium-duration pigeon pea in the first year's growing season on yield and N response of a succeeding sorghum crop on a Vertisol under dryland conditions in India was examined. In the second year, a sorghum crop was grown on all the treatments with four rates of applied N (0, 30, 60, and 90 kg N ha·1 as urea). The response of sorghum to N depended on the preceding crop. Weed-free fallow gave the largest grain and straw yield of sorghum without applied N, which was significantly higher than the yield obtained from other treatment with no added N. Both short- and medium-duration pigeon pea had a non-significant residual N effect on the yield and N uptake of the succeeding sorghum crop. Mineral N accumulated in the weed-free fallow was significantly higher than that accumulated in the other preceding crop treatments, and this significantly influenced sorghum grain and straw yields, uptake of N, and response to zero and 30 kg N ha·1 applied in the succeeding season.