垦殖与自然条件下黄河三角洲土壤盐分的时空演化特征研究

发布时间：2019-05-25 04:40

【摘要】：为探究人为垦殖与自然条件下黄河三角洲土壤盐分的时空演化特征,实现黄河三角洲后备土地资源的高效开发,保障生态和环境安全,利用空间变换推演时间演替,沿黄河入海方向,自利津县北宋镇至黄河三角洲保护区内黄河入海口布设采样带,研究当地典型作物(小麦、棉花、水稻)和自然条件下土壤盐分的时空演化特性,随机选取28个主采样区,采集140个样点,每个样点以20cm为1个土层,测定0—100cm土层土壤含盐量。研究表明:整个研究区域0—20cm土壤平均含盐量为3.58g/kg,显著高于60—100cm土层(p0.05),属于中度盐化土,空间表现为强变异性(CV=131%),随着土层深度的增加,不同土地利用类型间盐分空间变异减小;土壤盐分剖面的空间分布特征体现了人为垦殖和自然条件的协同影响,表聚型盐分剖面主要分布在采样带的近海端(1972年后冲积区域中此类剖面占83.3%),作物以低产棉田和自然植被为主,85.7%的自然植被和45.5%棉花为表聚型,平均型主要分布在采样带的中部及内陆区域,1855年之前及1855—1972年间的冲积区域中此类剖面各占40.0%,作物主要以水稻、小麦和滩涂为主;底聚型主要分布在采样带的内陆地区,1855年之前的区域中此类剖面占31.3%,主要以农作田为主,棉花、小麦、水稻均衡分布;人为垦殖管理、植被类型等随机因素是导致0—80cm土层土壤含盐量变异的主要原因,随着土层深度的增加,随机因素影响减弱,地形、地下水位等结构性因素影响增强;基于盐分的空间分布,绘制农作物布局区划图,可为黄河三角洲地区盐渍土资源合理开发利用提供参考。该研究揭示了垦殖与自然条件下土壤盐分时空演化特征,自滩涂至内陆,土壤盐分剖面由表聚型向底聚型过渡,人为垦殖在一定程度上可以降低土壤的盐渍化程度,但人为垦殖与土壤盐渍化之间互为因果、相互推进。
[Abstract]:In order to explore the temporal and spatial evolution characteristics of soil salt in the Yellow River Delta under artificial reclamation and natural conditions, to realize the efficient development of reserve land resources in the Yellow River Delta, to ensure ecological and environmental security, and to deduce time succession by spatial transformation, Along the direction of the Yellow River entering the sea, a sampling zone was arranged at the mouth of the Yellow River from Beisong Town to the Yellow River Delta Reserve in Lijin County to study the temporal and spatial evolution characteristics of soil salt under local typical crops (wheat, cotton, rice) and natural conditions. 28 main sampling areas were randomly selected and 140 sample points were collected. 20cm was used as 1 soil layer to determine the soil salt content in 0-100cm soil layer. The results showed that the average salt content of 0-20cm soil in the whole study area was 3.58 g 路kg ~ (- 1), which was significantly higher than that in 60-100cm soil layer (p0.05). It belonged to moderately salinized soil and showed strong anisotropy (CV=131%) in space, with the increase of soil depth. The spatial variation of salt content among different land use types decreased. The spatial distribution characteristics of soil salt profile reflect the synergistic influence of artificial reclamation and natural conditions. The surface accumulation salt profile is mainly distributed near the seaside end of the sampling zone (83. 3% of the alluvial area after 1972). The crops were mainly low-yield cotton fields and natural vegetation, 85.7% of the natural vegetation and 45.5% of cotton were the surface accumulation type, and the average type was mainly distributed in the middle and inland areas of the sampling zone. Before 1855 and from 1855 to 1972, this kind of profile accounted for 40.0% respectively, and the crops were mainly rice, wheat and beach. The bottom accumulation type was mainly distributed in the inland area of the sampling zone. Before 1855, this kind of profile accounted for 31.3%, mainly agricultural field, cotton, wheat, rice balanced distribution. The random factors such as artificial reclamation management and vegetation type are the main reasons for the variation of soil salt content in 0-80cm soil layer. with the increase of soil depth, the influence of random factors is weakened, and the influence of structural factors such as topography and groundwater level is enhanced. Based on the spatial distribution of salt, the zoning map of crop layout can be used as a reference for the rational development and utilization of saline soil resources in the Yellow River Delta. This study reveals the temporal and spatial evolution characteristics of soil salt under reclamation and natural conditions. from beach to inland, soil salt profile changes from surface accumulation type to bottom accumulation type, and artificial reclamation can reduce the degree of soil salinization to a certain extent. However, man-made reclamation and soil salinization are causality and advance each other.
【作者单位】：青岛农业大学农学与植物保护学院;
【基金】：黄河三角洲学者岗位和青岛农业大学高层次人才启动基金项目(631409)
【分类号】：S156.4

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