The impact of public policies on the sustainability of rice and wheat production on the Indo-Gangetic plains

The impressive growth rates in rice and wheat yields achieved in Asia during the 1960s and 1970s were not maintained in the 1980s and 1990s. Cereal yields are still increasing, but the rates of increase have slowed and many farmers are applying larger amounts of purchased inputs to maintain and extend earlier gains in productivity. The declining growth rates are caused largely by declining soil fertility, insufficient use of phosphorus fertilizer, waterlogging, salinization, and groundwater depletion. This paper describes how subsidy programs implemented to motivate adoption of Green Revolution technologies have contributed, over time, to the inappropriate use of inputs and the resource degradation that may be causing the declining rates of growth in crop yields. Alternative policies that encourage farmers to consider the true costs of scarce resources and the long-term impacts of their decisions may be helpful in restoring positive rates of growth in crop yields. Those policies are described within the context of a dynamic, farm-level crop production model in which economic incentives influence farm-level input use, and decisions made in one year may have long-term impacts on land and water resources.