Multifunctionality of Sawah Eco-Technology: Why Sawah-Based Rice Farming Is Critical for Africa's Green Revolution.

The sawah system of lowland rice production is increasingly becoming popular in West Africa. Balanced application at farmers’ fields of both ecotechnology and biotechnology is needed to sustain rice production. However, ecotechnology has, compared to biotechnology, received less research attention in sub-Saharan Africa in the last 40 years. We believe that this is the core technology missing in the quest for green revolution (GR) in Africa. Consequently, ecotechnological development is still at its infancy in the region. Although there is research concept to improve natural resource management, there is no specific concept to improve soil and water conditions in African lowlands traditionally under rice. That would explain why irrigation and other inputs have not been effective at farmers’ fields. Despite the advances in varietal improvement and upsurge in the use of agrochemicals, there is apparent failure to achieve self sufficiency in rice production and GR in the region. Improving the ecological environment is a prerequisite for realizing potential yield benefits of growing high-yielding varieties (HYV) with irrigation and fertilization.

Although an Asian concept, we have been able to adapt the sawah system into the edaphological, topographical and hydrological conditions of West African lowlands during our long-term (1986-2010) basic and action researches. Some of the essential components of the system include proper site selection, demarcation by bunding, puddling and levelling, installation of simple irrigation-drainage facilities, use of HYV and appropriate fertilization. A well-managed sawah is multifunctional because it conserves soil and water, controls erosion while promoting geological fertilization. Through an array of biochemical reactions under sawah-managed soils, the system promotes C sequestration, cushions the effects of poor nutrients supply, promotes N fixation and P availability, and neutralizes the soil reaction thereby improving micronutrient supply. The system improves irrigation-water and fertilizer use efficiency and sustains rice grain yield above 4 tons ha⁻¹.