不同潜水埋深下浅层土壤的水盐分布特征

浅层土壤水盐分布是影响植物幼苗生长的主要因子.为探讨潜水埋深对浅层土壤水盐分布特征的影响,以黄河三角洲建群种3年生柽柳苗木栽植的土壤柱体为研究对象,在咸水矿化度下(6.0 g/L),模拟设置0.3、0.6、0.9、1.2、1.5和1.8m共6种潜水水位,测定分析不同潜水埋深下,土壤表层0～ 10和10 ～ 20 cm土层的土壤相对含水量、含盐量及土壤溶液绝对浓度等水盐参数.结果表明:10 ～20 cm土壤相对含水量高于0～10 cm,随潜水水位的增加,土壤相对含水量均显著降低,且0～ 10cm土壤相对含水量随潜水水位降低幅度远高于10 ～20 cm,均在1.2～1.5m处土壤相对含水量减少率最大;0～ 10 cm土层含盐量随潜水水位的增加,表现为先升高后降低,在1.2m潜水水位处含盐量达到最大值(1.38％),比0.3m处增加106.35％.10 ～ 20 cm土层土壤含盐量随不同潜水水位的变化较为复杂,在潜水水位0.3 ～0.9m变化平稳,在1.2m处升高,在1.5～1.8m降低,在1.2m潜水水位处含盐量达到最大值(1.33％),比0.3m处增加304.04％;0～ 10 cm土层土壤溶液绝对浓度随潜水水位的增加,呈指数函数增加,以1.2m处最大(17.12％),10～ 20 cm土层土壤溶液绝对浓度随潜水水位的增加,先升高后降低,以1.2m处最大(10.10％).在0～ 20 cm土层土壤相对含水量与潜水水位呈显著负相关(P＜0.01),与土壤含盐量呈显著正相关(P＜0.05),土壤溶液绝对浓度在0 ～10 cm与潜水水位呈显著(P＜0.01)正相关,与土壤相对含水量呈显著(P＜0.01)负相关,却在10～ 20 cm与土壤含盐量呈显著(P＜0.01)正相关.该研究为黄河三角洲土壤次生盐渍化的防治及柽柳栽植管理,提供理论依据和技术参考.

Water and salt distribution characteristics of shallow soil at different diving water levels

[Background] Water and salt distribution of shallow soil are the main affecting factors of seedling growth.Taking soil columns planted with Tamarix chinensis Lour.(3-year-old),a constructive species in the Yellow River Delta as the research object,we aimed at studying how the diving water level (DWL) affects the water and salt distribution.[Methods] The experiment was carried out as such,first,planting the T.chinensis Lour.to soil column in the greenhouse,configuring the salt water in which mineralization degree was 6 grams per liter with sea salt,then setting up 6 diving water levels of 0.3 m,0.6 m,0.9m,1.2m,1.5m,and1.8m,and each level set 3 repeats.In the use of drying method and residue drying method,the relative water content (RWC),salt content and absolute concentration at soil depths of 0-10 cm and 10-20 cm in a simulated device with DWL of 0.3 m,0.6 m,0.9 m,1.2 m,1.5 m and 1.8 m were measured.[Results] The RWC in 10-20 cm was higher than that in 0-10 cm and decreased significantly with the DWL increased (0-20 cm),but the decreasing degree in 0-10 cm was much higher than that in 10-20 cm,the highest reduction of the RWC was at both 1.2 m and 1.5 m.The salt content (0-10 cm) increased at first and then decreased with the DWL increasing,reached peak at 1.2 m (1.38％) and increased byl06.35％ compared with that at 0.3 m.The salt content (10-20 cm) was complex with the DWL changing,it changed smoothly at 0.3-0.9 m and increased at 1.2 m then decreased at 1.5-1.8 m,reached maximum at 1.2 m (1.33％) and increased by 304.04％ compared with 0.3 m.The absolute concentration (0-10 cm) exponentially increased with the DWL increasing and maximum at 1.2 m (17.12％).The absolute concentration (10-20 cm) increased at first and then decreased with the DWL increasing and was maximal at 1.2 m (10.10％).[Conclusions] The RWC was significantly negative with the DWL (P ＜ 0.01) while significantly positive for the salt level (P ＜ 0.05);the absolute concentration (0-10 cm) was significantly positive with the DWL (P ＜ 0.01) but significantly negative with the DWL (P ＜ 0.01),the absolute concentration (10-20 cm) was significantly positive with the salt level (P ＜ 0.01).This study provides theoretical basis and technical reference for the prevention of soil salinization in the Yellow River Delta and the planting management of T.chinensis Lour.