The potential of biochar as an acid soil amendment to support indonesian food and energy security - A Review

The future of Indonesian food and energy security is challenged by the limited availability of productive land due to the land conversion issue and, in particular, the leveling-off of rice soil productivity. Acid soils as major contributor to marginal soils occupy approximately 55% of the total terrestrial land in Indonesia. To support the Indonesian policy on food and energy security, acid dryland soil areas have targeted for agricultural land expansion. However, managing such soils for crop productivity with conventional amendments, such as lime was challenged by the availability of lime, its cost and the adverse effects of over-liming. Recent research findings indicate that biochar, with its liming capacity and other beneficial effects, could serve as an amendment to acid soils. A question then can be asked : can biochar be a potential solution for the multiple constraints of Indonesian acid soil? The objectives of this review are to explore the potential of biochar as an amendment to Indonesian acid dryland soils and to develop a research framework for future studies involving biochar so as to support the future of Indonesian food and energy security. Articles and conference papers were selected, studied and critically reviewed. Specific problems with Indonesian acid dryland soils and the utilization of biochar as a potential amendment to the suboptimal soil in Indonesia were investigated. Biochar is alkaline in nature and recent research findings strongly indicate that with its liming effect, water and nutrient retention capability, highly recalcitrant nature, and carbon sequestration capacity could be a potential solution for improving upland acid soil productivity. This could be supported by the huge and sustainable production of feedstock in Indonesia.