Experimental Research on Crop Coefficients and Water Productivity under Drip Irrigation for Major Cash Crops in Arid Regions
In order to understand the change law of crop coefficients, water productivity and growth indicators of main cash crops under drip irrigation conditions in Xinjiang, a three-year plot experiment was conducted. The study focused on seven cash crops:cotton, rapeseed, industrial tomato, sugar beet, carrot, cucumber, and sunflower. Four levels of irrigation quotas were set: T1 (300m3/ha), T2 (375m3/ha), T3 (450m3/ha), and T4 (525m3/ha). A randomized irrigation experiment plan was used, employing pit sensors to measure the water demand for each treatment in different years. Crop reference evapotranspiration was calculated using meteorological data, and the relationship between yield and irrigation volume was analyzed through crop yield measurements. The changes in growth indicators of each crop over the years were recorded and analyzed. The results showed that the overall trend of drip irrigation crop coefficients was from small to large in the early stages, reaching a maximum during the peak growth period, and then gradually decreasing. The trend and distribution characteristics of crop coefficients at different growth stages were similar across crops. The order of irrigation water productivity from low to high was: rapeseed, cucumber, sunflower, cotton, sugar beet, carrot, industrial tomato. According to the established water productivity functions, which showed a good fit, the yield under T3 treatment was higher than the other three treatments. For the same crop, as the irrigation quota increased, both yield and irrigation volume increased, but water productivity decreased correspondingly. The results of the high-water treatments showed that an increase in irrigation volume led to a decrease in yield. Therefore, water productivity does not always improve with higher values, and more irrigation is not always better. Appropriate values are crucial to improve water use efficiency.
万方数据
维普
