Infiltration characteristics under intermittent combined irrigation in moderately saline-alkali soil
LIU Xiaoyuan1, YANG Daming1, GAO Peiling1,2*, ZhANG Qingwen3, ZHAO Yadong1, ZHANG Yuhang1
1. School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, Shandong 255000, China; 2. School of Resources and Environmental Engineering, Shandong University of Technology, Zibo, Shandong 255000, China; 3. Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100086, China
Abstract：In order to reveal the infiltration mechanism of intermittent combined irrigation, one-dimension vertical water infiltration experiments were conducted using a vertical soil column. The laboratory experiment comprised four intermittent times: 0 min, 30 min, 60 min and 120 min, with two combination sequences of F-B and B-F. Based on the measured data，the applicability of three infiltration models to predict and evaluate infiltration characteristics under intermittent combined irrigation in moderately saline-alkali soil was explored. The results show that the sequence of cumulative infiltration is intermittent combined irrigation (0 min)>intermittent combined irrigation (30 min)>intermittent combined irrigation (60 min)>intermittent combined irrigation (120 min) at the same infiltration time. Besides, significant difference exists in the cumulative infiltration with time. For the laboratory conditions used, the uniform and efficient intermittent combined irrigation could be achieved by considering the irrigation in two stages, the initial and steady infiltration stages. The results of simulation model indicate that the Kostiakov model can more acclrately describe the soil infiltration characteristics, compared with the Green-Ampt model and the Philip model. However, the Kostiakov model shows lower predictive power in F-B, which indicates that the combination sequences between fresh water and brackish water has a great influence on fitting precision
