Higher yields with fewer external inputs? The system of rice intensification and potential contributions to agricultural sustainability

Although sustainable agriculture is not limited to production systems that use few or no purchased inputs, systems that are less dependent on external inputs have better prospects for sustainability - as long as they can meet the needs of producers and consumers as well as do conventional systems depending heavily on fossil fuel and other capital-intensive inputs. The system of rice intensification (SRI) developed in Madagascar can raise irrigated rice yields to about double the present world average without relying on external inputs, also offering environmental and equity benefits. SRI methods change they way plants, soil, water and nutrients are managed - rather than utilising new-variety seeds, inorganic fertilisers or other agrochemicals. SRI also reduces the need for irrigation water by about half and diminishes the requirements for capital and seed. SRI requires more knowledge and skill on the part of farmers and initially more labour per hectare. But greater labour intensity is compensated by farmers achieving higher returns for labour, and SRI can become labour-saving. SRI should make irrigated rice production more sustainable, as well as profitable. SRI experience may reveal other opportunities that can make agricultural systems more productive and beneficial for the long term.