Improving Village Irrigation Systems: An Example from India t
以印度为例，分析了降雨不稳定和生长季长导致的大规模灌溉投资，以及不同灌溉方式（如私人水井与政府大坝）在可靠性和质量上的差异，并探讨了高产品种和化肥对灌溉收益的影响。
A highly variable rainfall and a growing season which permits crop production much of the year has led to sizable investments in irrigation on the Indian subcontinent. Irrigation now reaches over one-fifth of the net sown area. In some areas irrigation provides supplemental water during the wet season, while in others it permits the growing of one or two crops during the dry season.1 There is wide variation in the dependability and quality of irrigation in India. Small private wells provide a relatively dependable water supply. In contrast, many large government-built dams operate with a substantial degree of uncertainty as to delivery time and quantity. The advent of high-yielding varieties (HYVs) and the expanded availability of fertilizers has increased returns from irrigation water in some areas of India. In. addition, the need to feed a growing population and to find a means of reducing disparity between regions has stimulated interest in water as an important input to improving agricultural production and regional income distribution.