Has the green revolution been sustained? The quantitative impact of the seed-fertilizer revolution in Pakistan revisited

Abstract

Quantitative impacts of the Green Revolution on food production in the Pakistan Punjab are reviewed and the effects of different technologies on wheat yields over the past two decades decomposed. New quantitative evidence of sustainability problems in irrigated systems is presented. The yield increases expected in the post-Green Revolution period from the further spread of modern wheat varieties, a tripling of fertilizer dosage, and the release of newer higher yielding varieties have been cancelled by problems resulting from increased cropping intensity, the use of poor quality groundwater, low fertilizer efficiency, and increased weed and disease losses. New directions in institutional policies and research and extension strategies are outlined to improve efficiency and sustainability in wheat production and to prevent Pakistan from becoming a major food grain importer in the coming decades. The major source of growth over the next decade has to be in irrigated areas that have already adopted modern varieties and are already using moderate to high doses of fertilizer. It will be important to reduce the effects of factors that are apparently leading to a deterioration in the quality of the resource base and causing a long-term tendency for yields to decline. A reorientation of institutional policies and strategies is required, especially for research and extension