|Han, Ming - Chinese Academy Of Sciences|
|Zhao, Chengyi - Chinese Academy Of Sciences|
|Yan, Yingyu - Chinese Academy Of Sciences|
|Sheng, Yu - Chinese Academy Of Sciences|
Submitted to: Water
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2015
Publication Date: 5/29/2015
Citation: Han, M., Zhao, C., Feng, G.G., Yan, Y., Sheng, Y. 2015. Evaluating the effects of mulch and irrigation amount on soil water distribution and root zone water balance using HYDRUS-2D. Water. 2015, 7, 2622-2670. doi:10.3390/w7062622.
Interpretive Summary: Proper irrigation management is crucial for sustainable cotton production all over the world. The performance of such irrigation system should be evaluated for proper design, management, operation, and efficient water use. The modeling approach has been used as a common tool to test and assess on-farm management strategies under different conditions worldwide. Hydrus-2D model is a promising tool of irrigation management for drip irrigation system and was evaluated using measured data. Results indicated that Hydrus-2D is able to simulate soil water variation under drip irrigation. Hydrus-2D can not only well predict soil water content but also efficiently simulate the influence of plant uptake and evaporation on soil water movement. Therefore, the model can be used as a tool to aid drip irrigation scheduling in cotton field.
Technical Abstract: Drip irrigation under mulch is a major water-saving irrigation method that has been widely practiced for cotton production. The performance of such irrigation systems should be evaluated for proper design, management, operation, and efficient water use. The modeling approach has been used as a common tool to test and assess on-farm management strategies under different conditions worldwide. The objectives of this study were: (1) to validate the Hydrus-2D model for the drip irrigation system under mulch using experimental data; (2) to examine soil water dynamic during cotton growth season under local irrigation strategies. The purpose was to determine a modeling approach that could be widely used in this region and provide basic information and data for development of farmland management practices. R2 (correlation coefficient) and RMSD (Root Mean Square Deviation) were used to evaluate the performance of the model. Results indicated that Hydrus-2D is able to simulate soil water variation under mulch drip irrigation in this region. Correlation coefficient R2 ranged from 0.85 to 0.98, while RMSD ranged from 0.01 to 0.05. Results of the experiment and simulation suggested that the maximum irrigation depth in the studied field was approximately 50 cm under the local irrigation schedule. The percolation due to irrigation from top 0-50 cm soil layer to deeper soil layers was 349.50 cm3. The water flow process of each irrigation event can be classified into three processes: 1) Soil water movement is controlled by irrigation flux; 2) Soil water movement is controlled by soil redistribution process; 3) Soil water movement is controlled by cotton root uptake and the soil evaporation process. Hydrus-2D could not only well predict soil water content but also efficiently simulated the influence of plant uptake and evaporation on soil water movement.