不同暗沟排盐效果试验研究

发布时间：2018-01-20 21:26

本文关键词： 宁夏盐碱地暗沟间距暗沟埋深　出处：《宁夏大学》2017年硕士论文　论文类型：学位论文

【摘要】：针对宁夏吴忠地区土壤盐碱化程度高、地下水矿化度高且地下水水位高的情况,结合国内外暗沟(管)排盐改碱技术的经验,主要研究了暗沟(管)不同间距设置(T1-3 m、T2-6 m、T3-9 m、T4-15 m)及不同埋深设置(H1-0.8 m、H2-1.0 m、H3-1.2 m)对该地区盐渍化土壤含盐量、PH值等指标及垂柳生长状况的影响,主要结论如下:(1)不同暗沟间距设置条件下,地下水位下降速度T1T2T3T4。不同暗沟埋深设置条件下,地下水位下降速度H3H2H1。排水前期地下水水位下降较慢,排水后期,地下水水位降落速度加快。且各不同处理间,地下水水位下降速度差异较大。(2)暗沟处理能够明显降低土壤PH值,但是暗沟间距与埋深对PH值变化的影响不呈现明显的规律性。不同暗沟间距设置条件下,T1、T2处理对土壤含盐量影响程度相似且远高于T3、T4;而T3、T4暗沟对土壤含盐量影响程度相似。不同暗沟埋深设置条件下,H2、H3对土壤含盐量影响程度相似,且明显高于H1。(3)不同暗沟间距设置条件下,暗沟间土壤脱盐的均匀程度T1T2T3T4。不同暗沟埋深设置条件下,暗沟间土壤脱盐的均匀程度H1H2H3。(4)分析比较试验区及对照区不同层次土壤含盐量的年内变化趋势,就年内含盐量的变化趋势来看:不同暗沟间距设置条件下,0-20 cm 土层T1、T2的年内变化趋势相似,T3、T4的年内变化趋势相似;0-60 cm及0-100 cm 土层T1、T2、T3的年内变化趋势相似。不同暗沟埋深设置条件下,0-20 cm 土层H1与H2的年内变化趋势相似,明显低于H3;0-60 cm及0-100 cm 土层H2与H3的年内变化趋势相似,明显高于H1。(5)不同暗沟间距设置条件下,T1、T2、T3对垂柳树高及胸径的影响程度相似,远大于T4的树高、胸径增长率;T2、T3、T4对冠幅的影响程度相似,远小于T1的影响程度。不同暗沟埋深设置条件下,H2、H3对树高、胸径、冠幅的影响程度相似,远大于H1的影响程度。综合以上各向指标,推荐暗沟间距3 m到9 m、埋深1.0 m到1.2 m为宁夏吴忠盐碱地暗沟(管)排盐的合理设置范围。
[Abstract]:Aiming at the situation of high degree of soil salinization, high degree of groundwater mineralization and high groundwater level in Wu Zhong area of Ningxia, combined with the experience of domestic and foreign technology of removing salt from underground ditch (tube) to alkali. This paper mainly studies the setting of different spacing of dark ditch (pipe) and the setting of H1-0.8 m with different depth of burying, T1-3 mT2-6 mT3-9 mT4-15 m. The effects of H2-1.0 mH3-1.2 m) on the salinization soil salinity and PH value and the growth status of weeping willow were studied. The main conclusions are as follows: 1) under the conditions of different dark furrow spacing. Under the conditions of different buried depth of the deep ditch, the rate of water level falling is H _ 3H _ 2H _ 1. The groundwater level decreases slowly in the early stage of drainage, but in the later stage of drainage. The rate of groundwater level falling was quickened, and among different treatments, the difference of groundwater level drop rate was great. 2) the soil PH value could be obviously reduced by dark ditch treatment. However, the effect of dark ditch spacing and buried depth on PH value was not obvious. The effect of T1T 2 treatment on soil salt content was similar and much higher than that of T3 + T4 treatment. However, the effect of T _ 3N _ T _ 4 dark ditch on soil salt content was similar, and that of H _ 2N _ H _ 3 on soil salt content was similar under the condition of different buried depth. And it was obviously higher than that of H1.t3) under the conditions of different spacing between dark ditches, the uniform degree of desalination of soil was T1T2T3T4. under the conditions of different buried depth of dark ditches. The homogeneity of soil desalination between dark ditches (H1 H 2H 3. 4)) the variation trend of salt content in different layers of soil in experimental area and control area was analyzed and compared. According to the variation trend of salt content in the year, the variation trend of T _ 1 / T _ 2 in 0-20 cm soil layer is similar to that of T _ 3N _ T _ 4 under the condition of different spacing of dark ditch. The variation trend of T _ (1) T _ (2) T _ (2) T _ (3) in 0-60 cm and 0-100 cm soil layers was similar during the year. The variation trend of H _ 1 and H _ 2 in 0-20 cm soil layer is similar to that in H _ 2 layer, which is obviously lower than that in H _ 3. The variation trend of H _ 2 and H _ 3 in 0-60 cm and 0-100 cm soil layers was similar to that in H _ 3 layer, which was significantly higher than that in H _ (1. 5)) T _ (1) T _ (2) T _ (2). The effect of T3 on the height and DBH of weeping willow was similar, which was much larger than that of T4 and the growth rate of DBH. The effect of T _ 2 ~ (2 +) T _ (3) T _ (3) on crown width was similar to that of T _ (1), and the influence of H _ (2) H _ (2) H _ (3) on tree height, DBH and crown width was similar under different conditions of buried depth. The influence degree of H1 is much greater than that of H1. According to the above indexes, it is recommended that the spacing of dark trenches is 3 m to 9 m, and the depth of buried depth is 1.0 m to 1.2 m, which is the reasonable setting range of salt discharge from saline trenches (pipes) in Ningxia Wu Zhong.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S156.4;S792.12

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