保水剂对土壤积水入渗特征的影响

Effect of Super Absorbent Polymer on the Ponding Infiltration Characteristics of Soil Water

【目的】水分在田间的入渗过程是发展节水型农业的重要依据之一,比较研究保水剂对土壤积水入渗特征及其变化过程的影响,以期为保水剂的研发和大田合理应用提供理论参考。【方法】模拟大田积水入渗过程,分别层施(L)和混施(M)不同浓度(0、0.2%、0.4%和0.6%)的2种保水剂——日本触媒(JP)和德国巴斯夫(BF),比较分析保水剂对土壤水分垂直入渗的3个特征量:累积入渗量、入渗速率和稳定入渗率的影响。【结果】2种保水剂对土壤水分累积入渗量和入渗速率的影响具有稳定性和一致性。同时,层施和混施保水剂都能不同程度地增加土壤入渗;不同的是,层施保水剂对土壤入渗增加的效应是有限的,JP以浓度0.2%,BF以0.4%为界,大于此浓度不仅会抑制土壤入渗,而且抑制效应会随着保水剂浓度的进一步增加而加剧;但是混施条件下,保水剂可使120min内土壤累积入渗量增加1.1—2.1倍,且土壤入渗的增加与保水剂浓度正相关。【结论】在本试验条件下,保水剂对土壤水分向下运动的影响与保水剂自身的吸水倍率和膨胀性能密切相关。

【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.