Abstract
The water resources in the Yellow River irrigation area of Inner Mongolia are tight, and the utilization efficiency of farmland irrigation water is low. The shallow buried drip irrigation mode is adopted in the local oat double-cropping planting, but its growth and development and water consumption process are not clear. In-depth study of the growth and water consumption of forage oats in the whole growth period under this model is very important for optimizing irrigation system, improving water use efficiency and increasing crop yield. A field experiment was conducted in Tumotezuoqi, Inner Mongolia. The database was established according to the meteorological-soil-crop-irrigation factors in 2022 and 2023, and the AquaCrop model was used for simulation research. The AquaCrop model was calibrated and validated using measured data for 2022 and 2023. The simulation results showed that the simulated values of soil water content, canopy coverage and yield were in good agreement with the observed values. The performance index ( EF ) of the model is 0.70 to 0.94, indicating that the overall performance of the model is high. Specifically, the root mean square error (RMSE) of soil water content ranged from 2.04 to 3.42%, the RMSE of canopy coverage ranged from 8.27 to 9.54%, and the RMSE of yield ranged from 0.28 to 0.33 tons / ha. In addition, the coefficient of determination (R(2)) is between 0.85 and 0.94, which further verifies the high fitting degree and reliability of the model. The total water requirement of forage oats during the whole growth period was 230.7-333.1 mm, and the total water consumption was 214.7-315.4 mm. The drainage loss is 1.2-10.6 mm, accounting for 0.3%-5.40% of the total water demand. In 2022 and 2023, the water productivity (WP) of the second crop is 0.1-0.4 kg / m(3) higher than that of the first crop. These findings help to provide valuable insights for optimizing agricultural water management practices in the region.