Econometric estimation of groundwater irrigation efficiency of cotton cultivation farms in Pakistan

Abstract

Study region: Lodhran and Jhang districts in the Central and South Punjab province of Pakistan. Study focus: Pakistan is amongst the largest groundwater withdrawing countries. With 5.2 million hectares groundwater irrigated area, Pakistan irrigates 4.6% of the global groundwater-fed cropland. However, over the last few decades the groundwater resources are under immense pressure due to overdrafting to meet escalating irrigation water demands. Since most of the groundwater is being extracted for irrigation purposes, examining irrigation water efficiency have become has become inevitable for sustainable groundwater management. This study estimates farm level technical efficiency (TE) and irrigation water-use efficiency (IWE) of groundwater irrigated cotton farms in the Punjab province of Pakistan. New hydrological insights for the region: Irrigation water-use efficiency (IWE) is generally defined from three perspectives: (i) efficiency of the irrigation system, i.e., water conveyance efficiency; (ii) efficiency in water application at the farm gate and; (iii) the response of a crop to irrigation water application, i.e., the amount of water actually utilized by the crop compared to the amount of water supplied to that crop. These measures of IWE are devoid of economic principles. Hence, irrigation water efficiency has expanded its boundaries from hydrological and engineering principles to economic rationale which is useful to guide targeted farms to improve their irrigation efficiencies. This study advances the frontier of existing economic measure of IWE by employing a restricted production frontier model.

Keywords

• Irrigation water efficiency
• Groundwater irrigation
• Cotton cultivation
• Stochastic frontier analysis
• Restricted translog model