Abstract:

【Objective】 Field infiltration process is one of the bases of water-saving agricultural development. The effects of super absorbent polymers (SAPs) on the characteristics of soil infiltration were studied. 【Method】 The cumulative infiltration, infiltration rate and stable infiltration rate during the ponding infiltration process were investigated. Two types of SAPs, JP and BF, with layered and mixed application concentrations of 0, 0.2%, 0.4% and 0.6%, were compared in a field experiment. 【Result】 The influences of JP and BF on cumulative infiltration and infiltration rate were stable and consistent. Layered application could increase infiltration capacity of soil, but this increasing effect was limited, and would be restricted when the concentrations of SAPs were larger than the critical values, which were 0.2% for JP, and 0.4% for BF. Moreover, the inhibitory effect would be more obvious in the even larger concentration of SAP. Whereas, mixed application could lead soil cumulative infiltration to be 1.1-2.1 times larger than the control within 120 min, and the increasing effect had positive correlation with the applied concentration. 【Conclusion】 The effects of SAPs on soil infiltration capacity had close relations with its water absorbency and swelling characters under the conditions of this experiment.

Key words: water-saving agriculture, super absorbent polymer, ponding infiltration, infiltration rate