不同暗管布设方式对滨海重度盐碱地脱盐效应研究

Study on Desalination Effect of Buried Pipe on Coastal Severe Saline-alkali Land

为了探究在无人工灌洗条件下布设暗管对黄河三角洲重度盐碱地的改良效果,以东营市垦利区盐碱荒地为研究对象,设置了间距8 m、埋深0.8 m(T1)和间距8 m、埋深1.1 m(T2)和间距12 m、埋深0.8 m(T3)和间距12 m、埋深1.1 m(T4)4个暗管布设组合,对比了不同暗管布设措施下土壤盐分分布规律及脱盐效果。结果表明:T1、T2、T3、T4,4个暗管布设处理,在水平空间上,两暗管之间距暗管不同位置的土壤含盐量变化一致:0处<1/2处<1/4处,且0处与1/2处含盐量显著低于1/4处含盐量;在垂直空间上,各处理土壤含盐量均随土层深度增加而先降低后升高。4个暗管布设处理小区土壤pH值均随土层深度增加呈先升高后降低分布趋势,且各处理0~20 cm(表层)土壤pH值均显著低于无暗管布设(CK)表层土壤pH值。T1、T2、T3和T4表层土壤含盐量分别为2.78、3.59、3.85、6.85 g/kg,分别比CK表层土壤含盐量降低了80.44%、74.74%、72.91%和51.80%。在土层剖面上,土壤含盐量与含水量呈负相关性,0~60 cm土层上4个暗管布设处理的脱盐率均显著高于CK,其中T2在0~100 cm上平均脱盐率最高,达到58.93%。综合分析,推荐间距8 m、埋深1.1 m为无人工灌洗下黄河三角洲滨海重度盐碱地的最佳布设参数,既能降低表层土壤盐分,又在土壤剖面的整体脱盐上具有明显效果。

In order to explore the improvement effect of buried pipe layout on severe saline-alkali land in the Yellow River Delta without artificial irrigation,the saline-alkali wasteland in Kenli District of Dongying City was taken as the research object.Four buried pipe layout combinations were set up,including spacing 8 m,buried depth 0.8 m(T1)and spacing 8 m,buried depth 1.1 m(T2)and spacing 12 m,buried depth 0.8 m(T3)and spacing 12 m,buried depth 1.1 m(T4).The soil salt distribution and desalination effect under different buried pipe layout measures were compared.The results showed that:T1,T2,T3,T4,four subsurface pipes were arranged.In the horizontal space,the soil salt content at different positions from the subsurface pipes between the two subsurface pipes was consistent:0<1/2<1/4,and the salt content at 0 and 1/2 was significantly lower than that at 1/4.In the vertical space,the soil salt content of each treatment decreased first and then increased with the increase of soil depth.The soil pH values of the four subsurface pipe layout treatments increased first and then decreased with the increase of soil depth,and the soil pH values of O-20 cm(surface layer)of each treatment were significantly lower than those of the surface soil without subsurface pipe layout(CK).The surface soil salt content of T1,T2,T3 and T4 were 2.78,3.59,3.85 and 6.85 g/kg,respectively,which were 80.44%,74.74%,72.91%and 51.80%lower than that of CK,respectively.In the soil profile,there was a negative correlation between soil salt content and water content.The desalination rate of the four subsurface pipe layout treatments in the O~60 cm soil layer was significantly higher than that of CK,and the average desalination rate of T2 in the 0~100 cm was the highest,reaching 58.93%.Based on the comprehensive analysis,it is recommended that the spacing of 8 m and the buried depth of 1.1 m are the best layout parameters for the coastal severe saline-alkali land in the Yellow River Delta without artificial irrigation,which can not only reduce the salt content of the surface soil,but also reduce the salt content of the soil.