滨海农田土壤入渗特性规律研究

Soil Infiltration Characteristics in Jiangsu Coastal Saline Soil

采用室内环刀法和室外圆盘入渗仪测定了滨海农田土壤不同处理方式下的水分入渗过程,分析对比了不同处理土壤初始入渗率、稳定入渗率、土壤吸湿率、导水率和30min累积入渗量及其主要影响因素。结果表明,有机肥处理和覆膜处理的入渗速率高于施用化肥、不施肥和石膏的处理,以入渗起始时段尤为明显,各处理在30-40min左右均达到稳定入渗,但覆膜处理延长了达到稳定入渗的时间,而石膏处理在水分入渗过程中溶解出Ca2＋,置换出Na＋,堵塞土壤孔隙,影响水分入渗率;覆膜、有机肥和化肥处理改善了土壤孔隙状况,增加了土壤的30min累积入渗量,而石膏处理减少了土壤的入渗累积量;不同处理的初始入渗率、稳定入渗率、吸湿率、导水率和30min累积入渗量受滨海地区特殊的土壤结构特性和盐分类型作用而主导因素不同。

Tension disc infiltrometer and Cutting ring indoor means were used to determine soil water infiltration of different treatments in coastal saline farmland in Jiangsu, in order to analyse and compare the initial soil infiltration rate, stable infiltration rate, water-absorption rate, hydraulic conductivity and cumulative infiltration in 30 min under different treatments and their main influencing factors. The results showed that the infiltration rate of organic manure and surface plaster coating were higher than those of fertilizer, gypsum and CK treatments, which was significant in initial period of infiltration process. Each treatment reached steady infiltration in about 30-40 minutes, but surface plaster coating prolonged the time. The Ca^2＋ of gypsum dissolved in water infiltration process and replaced Na^＋ , clogged soil pores, and affected water infiltration rate; Apart from gypsumtreatment, others treatments could increase cumulative infiltration in 30 minutes. Because of the special structural properties of soil and salinity in coastal area, the main influencing factors of soil infiltration characteristics were different.