为认识绿洲农田表层掺砂和覆砂后层状土的入渗规律及农业生产实践提供依据,通过模拟试验研究了绿洲农田表层掺砂、覆砂对土壤水分入渗的影响。试验以不同掺砂量和覆砂厚度为影响因子,设置0%(对照)、25%、50%、75%、100%(纯砂)5个掺砂量处理,折合为覆砂厚度分别是0、1.7、3.6、5.7、8cm。结果表明:表层掺砂(除100%)能显著提高土壤入渗能力,并随着掺砂量(除100%)的增加而增加,且提高了掺砂层下部含水量;覆砂抑制了土壤入渗能力,且随着覆砂厚度增加抑制减弱;经Philip和Kostiakov入渗模型参数拟合和I200验证得出:Philip和Kostiakov入渗模型均有较高的实用性,其中Kostiakov入渗模型更佳。
Simulated experiments were conducted to study the effects of sand mixture and sand mulch on soil water infiltration in the surface of oasis field.The mixing rate of sand with 0%(control),25%,50%,75%,100%(pure sand),corresponding to the mulching sand thickness of 0,1.7,3.6,5.7,8 cm were used in the experiment.The results showed that it was a significantly great effect on soil water infiltration capacity that it was mixed on the surface of soil(except 100%),the higher mixing rate of sand(except 100%),the stronger infiltration capacity,and increased soil water moistrue under the layer of sand mixture.Compared with sand mixture,sand mulch had a bad effect on soil water infiltration capacity,but such inhibiting capacity showed a week trend with the increments of mulching sand thickness.Through fitting parameters of Philip infiltration model and Kostiakov infiltration model,and testing those models precision with the correlations between measured-200 min(I) and calculated cumulative infiltration(Ic),however,the results show that both infiltration modeles had great practicability in such experiment,and the Kostiakov infiltration model had better effects.