Harnessing the Potential of Jatropha and Pongamia Plantations for Improving Livelihoods and Rehabilitating Degraded Lands

Current increase in demand of knowledge for alternative sources to fossil fuel has triggered \nlot of interest in use of non-edible oils as green knowledge source in de;eloped and developing \ncountries. ICRISAT is adopting pro-poor bio-fuel strategy to benefit vulnerable sections of the \nsociety through development of degraded common property resources and individual lands \nwhich are not suitable for food production by adopting consortium approach. Research and \ndevelopment options for harnessing the potential of Jatropha and Pongamia are undertaken \nto increase productivity of Jatropha and Pongamia plantations. Large vmiability in the \naccessions of Jatropha and Pongamia was observed for total oil content varying from 27.4% \nto 40.6% in case of Jatropha and from 21 to 41 % in case of Pongamia. These accessions \nare evaluated for different agronomic characters along with yield potential under rain-fed \nconditions at ICRISAT, Patancheru, India. Application of nitrogen and phosphorus at different \nlevels .indicated that during the 4'h year harvest index (pod to seed ratio) varied from 53-56% \nwith different fertilizer treatment. The plant yield of Jatropha within an accession with 3x2 \nspacing varied upto 1.4 to 1.6 kg ha per plant (2.3 to 2.7 t ho" under rainfed conditions).Water use efficiency of three years old Jatropha plantations indicated that evapo-transpiration \ndemand under no moisture stress for Jatropha varied from 1150-1350 mm per yem. Under \nthe semi-arid tropical conditions Jatropha is able to use water relatively 40-57% of nonstress \nsituation. Intercropping with Jatropha and Pongamia plantations is feasible and even \nduring 4'h year in pruned Jatropha plantations with yield of different crops varying from 0.29 \nt ho" in case of green gram to 1.5 t ha" for sorghum. Intercrops like sorghum, pearimillet, \npigeon pea, soybean, mung bean, chickpea, sunflower, safflower with Jatropha and pearl \nmillet and pigeon pea with Pongamia could be successfully grown. An additional income of \nRs.5,000 to Rs.16,OOO per ha can be obtained on low-quality (but reasonably able to support \ncrop growth) soil.Nutrient budgeting approach can -be used successfully to work aut nutrients requirement \nneeded to achieve targeted yields in crop like Jatropha_ Fallen leaves quantity and nutrient \ncontent of Jatropha varied with plant age and fertility treatment and contained 9500 mg N \nkg" which is lowest amongst different plant parts such as shoots and seeds as well as deoiled \nseed cake_ One year plantation returned 16 kg N ha,l and three-year plantation returned 21 \nkg N ha" through fallen leaves_ The fallen leaves also added 1 000 kg ha" organic C to soil \nin addition to carbon fixed in seeds which will replace fossil fuel C De-oiled seed cake after \nextracting necessary oil can be used as plant nutrient source on the farmers' fields, Benefits \nof oil seed cake application in terms of increased yields of maize, cotton and other crops \nwere higher than N applied through mineral fertilizer source.