Growing Jatropha Curcas with Rainwater Harvesting in Hilly Tract of South Western Rajasthan, India

Survival and growth of Jatropha curcas was examined in relation to slope gradient and rainwater harvesting treatments with a view to use this species in revegetation of degraded hilly area with its socio-economic benefits. Varying slopes were <20%, 10-20% and >20%, whereas rainwater harvesting treatments were control (CL), contour trench, (CT), Gardonie (G), Box trench (BT) and V-ditch (V). Soil water content (SWC) was greater (p < 0.05) <10% area and decrease in order <10% <>20%<10-20% slope areas. SWC was lowest in the CL plots, whereas it was highest in Gradonie plots in August. The increase in SWC over control was by 16% and 24% in August 2006 and 2007, respectively. SWC was highest in CT in June 2006 and in BT in June 2007, and the improvement in SWC resulted from rainwater harvesting was by 51% and 15% in the respective treatments influencing survival and growth of J. curcas. The lowest survival in >20% slope area indicated its susceptibility to water stress, further supported by the highest growth in BT plots with the highest soil water. Plants were tallest (p < 0.05) in <10% and smallest in >20% slope area. The plants growing along the contour trench were tallest (p < 0.05), whereas plants growing in the control plots were smallest (p < 0.05) suggesting the beneficial effects of water harvesting on the growth of J. curcas in degraded areas. Conclusively Jatropha curcascan be used to restore degraded hilly tract utilizing rainwater harvesting.