Effect of irrigation, nitrogen and potassium on seed yield and oil content of Jatropha curcas in coarse textured soils of northwest India

Potential of Jatropha curcas L. for producing energy from marginal land without inputs has recently drawn the attention, resulting in the planning of large commercial plantations in India and other countries. Major challenge for the extended use of J. curcas seems to be the lack of information on agro-technology and specially the water and nutrient management on its potential yield under sub-optimal and marginal conditions. Therefore, it is very difficult to estimate the yields from future plantations under sub-optimal growth conditions, the situations where J. curcas is supposed to grow. The impacts of irrigation and nutrients on seed and oil yield of J. curcas in semi-arid conditions of northwest India are discussed here. An experiment was conducted for consecutive three years (2009–2011) at CCS HAU, Regional Research Station, Bawal (Haryana), India, in three years old J. curcas plantation raised at spacing of 3 m × 3 m in loamy sand, N deficient and medium K status soil. The treatments were comprised of three levels of irrigations viz.; no irrigation (I0), one irrigation (I1) and two irrigations (I2), four levels of nitrogen (N) i.e.; 0, 30, 60 and 90 kg N ha−1 and four levels of potassium (K) i.e.; 0, 30, 45 and 60 kg K2O ha−1. J. curcas seed yield increased from 163.71 kg ha−1 with no irrigation to 472.51 kg ha−1 at 90 kg N and 60 kg K2O ha−1 with two irrigations. J. curcas seed yield increased significantly at 60 kg N ha−1 with no irrigation whereas seed yield increased significantly up to 90 kg N ha−1 with one and two irrigations. The significant effect of potassium application on seed yield was found up to 45 K2O ha−1 in the absence of irrigation but its effect was significant up to 60 kg K2O ha−1 with one and two irrigations. The seed oil content and oil yield of J. curcas also increased due to irrigation, nitrogen and potassium application .The maximum oil content (34.52%) and oil yield (163.31 kg ha−1) was recorded at 90 kg N and 60 kg K2O ha−1 with two irrigations. However, poor seed and oil yield of 291.55 and 89.13 kg ha−1 respectively was obtained under sub-optimal conditions i.e.; one irrigation with 30 kg N and 30 kg K2O ha−1.