11. Land Suitability Evaluation for Jatropha (Jatropha Curcas L.) Plantation in Indonesia

In recent years, there is a growing interest in biofuels as substitute for fossil oils to counter greenhouse gas emission and global climate change. The Jatropha curcas, a tropical shrub is attracting the interests of policy makers and the energy industry as one of the promising sources of high quality biofuel, extracted from the seeds. Although Jatropha has been publicized as a wonder biofuel with unlimited potential, the key issue is the productivity under different environments and land types. In this regards it is essential to assure that the lands where Jatropha is to be grown has the potential to support such plantation. In Indonesia, we characterized the main producing areas of Jatropha in 2007–2008. The evaluation was made through studying soil morphologies, chemical properties and their relationship with plant growth and Jatropha oil content.The results showed that Jatropha can grow and develop over a wide range of soil textures (3–88 % clay), soil pH (4–8.2), soil available P and exchangeable K, cation exchange capacity, elevation of up to 900 m above sea level, and precipitation from 527 to 4,154 mm per annum. However, Jatropha does not develop satisfactorily at altitude > 1,000 m above sea level and in poorly drained soils. The variations in soil characteristics and climate lead the variation of the oil content (46–61 %), oil viscosity (72–86 centipoise), and the weight of 100 seeds (48.2–72.8 g). It has been generally observed that in areas with higher rainfall, the plant height leaf area, leaf weight and stem diameter were less than those in the low rainfall areas. The longer the dry months (> 8 months), the lower is the oil content. This land suitability criteria can be applied to develop land suitability maps and, in turn, Jatropha development in Indonesia.