Estimation of evaporation of different cover types using a stable isotope method: Pan, bare soil, and crop fields in the North China Plain

The North China Plain (NCP) is one of the major crop production areas in China. However, severe water shortageis the primary limiting factor in this area. Quantifying evaporation loss under different cover types will make ahuge contribution to reduce water consumption. This research estimated the evaporation from pan, bare soil, andirrigated winter wheat–summer maize field in the NCP using the isotope method. The results showed that theevaporation from the pan was the highest, followed by bare soil, while that from the soil surface with crop coverwas the lowest. Water loss associated with soil particles and crop cover was decreased for 9 %~77 %. The sourceof soil moisture was primary groundwater during the wheat season (April–June) and precipitation in the maizeseason (July–September). The crop field soil evaporation depth was 0–30 cm, which will be beneficial indetermining the subsurface drip irrigation depth. This research will provide a scientific basis for developing anagricultural water-saving strategy for the NCP.