Improved irrigation and groundwater management for reducing CO2 emissions: a case study of Indian Punjab

The groundwater irrigation of high water requiring crops has started imposing negative impacts on environment in terms of increased energy requirement and depletion of green agriculture. Thus, shifting from gravity-fed (surface) irrigation to drip irrigation is a possible way of saving a substantial amount of water in relation to decreased groundwater pumping. Keeping this in view, the present study compared the change in crop water demand, energy consumption and CO2 emission by shifting from gravity-fed/surface irrigation to drip irrigation. In the future, the potential area that can be brought under drip irrigation in the state would be about 26 times higher than that being irrigated using pressured irrigation at present. With the adoption of drip irrigation in groundwater irrigated areas, the crop water demand, energy consumption and CO2 emission can be reduced by about 35-42%, 23-31%, and 23-31%, respectively, with water application efficiencies of 85 to 95%. In canal irrigated areas, if drip irrigation is adopted over gravity-fed irrigation, up to 32-39% water demand can be reduced, whereas the energy consumption and CO2 emission would increase. Until, unless, water saving is not an issue in canal irrigated areas, gravity-fed irrigation methods may be adopted. Whereas in areas dominated with groundwater irrigation, pressurized irrigation methods particularly the drip system should be essentially adopted.