Jatropha production on wastelands in India: opportunities and trade-offs for soil and water management at the watershed scale
Artikel i vetenskaplig tidskrift, 2011
Biofuel production from feedstocks grown on wastelands is considered a means of addressing concerns about climate change and improving energy security while at the same time providing an additional source of income for the land users. The establishment of biomass plantations on wastelands is likely to affect local livelihoods and can affect surrounding ecosystems by influencing hydrologic flows and processes such as erosion. We present an assessment of Jatropha plantation establishment on wastelands, using the ArcSWAT modeling tool. The assessment was made for a wasteland located in the Velchal watershed, Andhra Pradesh, India, which recently was converted to a biofuel plantation with Jatropha. The previous land use, in this case grazing, could continue in the Jatropha plantations. Several desirable effects occurred as a result of the land-use conversion: non-productive soil evaporation was reduced as a larger share of the rainfall was channeled to productive plant transpiration and groundwater recharge, and at the same time a more stable (less erosive) runoff resulted in reduced soil erosion and improved downstream water conditions. A win-win situation between improved land productivity and soil carbon content was observed for the Jatropha plantations. On the other hand, the results indicate that at the sub-basin scale, reductions in runoff generation as a result of large-scale conversion of wastelands to Jatropha cropping may pose problems to downstream water users and ecosystems. From a livelihoods perspective, Jatropha production was generally positive, creating a complementary source of income to the farmers, thus strengthening the resilience of the local community. In the future, the potential gain from Jatropha cropping is expected to increase as cropping systems improve and growing biofuel markets result in better conditions for biofuel producers.