Crop Water Consumption Under Nonuniform Sprinkler Irrigation

Field experiments were conducted to observe winter wheat response to nonuniform sprinkler irrigation under various Christiansen uniformity coefficient (CU) levels ranging from 62% to 82%. Evaporation and drift losses were estimated during the whole irrigation season of winter wheat based on catch can data. The results demonstrated that sprinkler efficiency, defined in this article, varied in a range of 0.64～0.86, increasing with sprinkler uniformity but decreasing with wind speed. For the same yield level the amount of water consumed by winter wheat in the growing season was greater for low sprinkler uniformity than for high uniformity since low uniformity produced a reduced sprinkler efficiency. Experimental results also indicated that sprinkler uniformity had little effect on crop yield for the studied range of CU.