CAJ | 학술논문

由于淡水资源短缺,中国华北地区微咸地下水灌溉面积逐年增多.该文通过室内土柱淋洗试验,研究了灌溉水盐分浓度和钠吸附比(SAR)对华北地区非碱土(可交换钠百分比 ESP?0)和碱土(ESP?30)饱和水力传导性能的影响.灌溉水盐浓度分别为2.5、10和25 mmolc/L,SAR 分别为0、10和30(mmolc/L)0.5.去离子(盐浓度?0)作为对照处理.试验包括2个土壤碱度、9个灌溉水质组合和1个去离子水处理,共20个试验处理.试验结果显示,非碱土和碱土对微咸水应用的反应机理以及反应程度不同.当黏粒弥散程度较弱时,上部土壤的饱和水力传导度显著大于下层土壤;反之,则各层土壤的水力传导度均较小.在试验水质条件下,非碱土的平均饱和水力传导度的变化范围为0.75~13.25 cm/h,而碱土的变化范围为0.06~6.50 cm/h.碱土的稳定饱和水力传导度随着灌溉水盐浓度的增加或/和 SAR 的减小而增大,但在非碱土中稳定饱和水力传导度的变化规律与此基本相反.试验结果对合理应用微咸水灌溉非碱土和碱土具有指导意义.
유우담수자원단결,중국화북지구미함지하수관개면적축년증다.해문통과실내토주림세시험,연구료관개수염분농도화납흡부비(SAR)대화북지구비감토(가교환납백분비 ESP?0)화감토(ESP?30)포화수력전도성능적영향.관개수염농도분별위2.5、10화25 mmolc/L,SAR 분별위0、10화30(mmolc/L)0.5.거리자(염농도?0)작위대조처리.시험포괄2개토양감도、9개관개수질조합화1개거리자수처리,공20개시험처리.시험결과현시,비감토화감토대미함수응용적반응궤리이급반응정도불동.당점립미산정도교약시,상부토양적포화수력전도도현저대우하층토양;반지,칙각층토양적수력전도도균교소.재시험수질조건하,비감토적평균포화수력전도도적변화범위위0.75~13.25 cm/h,이감토적변화범위위0.06~6.50 cm/h.감토적은정포화수력전도도수착관개수염농도적증가혹/화 SAR 적감소이증대,단재비감토중은정포화수력전도도적변화규률여차기본상반.시험결과대합리응용미함수관개비감토화감토구유지도의의.
The area irrigated with slight saline groundwater increases in North China because of fresh water shortage. The effects of salt concentration and sodium adsorption ratio (SAR) in irrigation water on saturated hydraulic conductivity of nonsodic (exchangeable sodium percentage ESP?0) and sodic (ESP?30) soils in North China were studied by soil column experiments in laboratory. The designed salt concentrations in irrigation water were 2.5, 10, and 25 mmolc/L, and its SARs were 0, 10, and 30 (mmolc/L)0.5, respectively. Irrigation with distilled water (salt concentration?0) also was conducted as a control treatment. The experiments included 2 soil sodicity levels, 9 irrigation water qualities, and one distilled water treatment, and total experimental treatments were 20. Experimental results demonstrated that saturated hydraulic conductivities of nonsodic soil on surface layers were significantly bigger than those on lower soil layers, in which they were similar to each other, under slight saline water leaching. Saturated hydraulic conductivities of sodic soil at various depths were closely related to salt concentration and SAR level in leaching water. The saturated hydraulic conductivities at various soil depths were small (0.04-0.10 cm/h) when sodic soil was leached with SAR of 30 (mmolc/L)0.5 and salt concentration of 2.5 mmolc/L, however they were significantly increased (0.8-2.5 cm/h) when salt concentration in leaching water increased to 25 mmolc/L at the same SAR level. Meanwhile, the saturated hydraulic conductivities on upper soil layers were significantly bigger that those on lower layers. The results indicated that the response mechanism and degree of nonsodic soil to slight saline water irrigation were different, and the dispersion degree of nonsodic soil was bigger than that of sodic soil under same irrigation water quality. When the degree of clay dispersion was weak, saturated hydraulic conductivities on upper soil layers were significantly greater than those on lower layers. When salt concentration in leaching water was 25 mmolc/L, averaged saturated hydraulic conductivity of nonsodic soil significantly decreased with the increase of SAR level in leaching water, but the variation tendency did not exist when salt concentrations were 2.5 and 10 mmolc/L. Average saturated hydraulic conductivity of sodic soil decreased with the increased SAR level or decreased salt concentration in leaching water, but it was not obviously affected by salt concentration when SAR level in leaching water was 0. Generally, the variation extent of averaged saturated hydraulic conductivity of nonsodic soil over the whole soil columns was 0.75-13.25 cm/h, and that of sodic soil was 0.06-6.50 cm/h under all tested water qualities. Steady saturated hydraulic conductivity of sodic soil increased with the increased salt concentration or/and decreased SAR in leaching water, but that of nonsodic soil basically decreased with the increased salt concentration or/and decreased SAR in leaching water. This research result can provide references for arranging a reasonable irrigation scheme about slight saline groundwater on nonsodic and sodic soils.