Spatial Heterogeneity Of Soil Water And Salt At Field Scale In High-water Salinized Region

Soil salinization,as one of the four major ecological environment problems in the world,has seriously hindered the sustainable development of regional ecological environment and caused huge economic losses to agricultural development due to its wide distribution area and difficult control.Due to natural reasons,coastal salinization is widely distributed in the eastern coastal areas of China.Under the background of accelerating the modernization development of eastern China,soil salinization is undoubtedly an environmental problem that must be overcome.The Nandagang experimental field of THE Chinese Academy of Sciences is located in Huanghua,a coastal area of Hebei Province.The experimental field is adjacent to the Bohai Sea in the east.In this paper,taking nandagang experimental field of Chinese Academy of Sciences as an example,the spatial heterogeneity of water and salt was studied in0-20 cm,20-40 cm and 40-60 cm soil layers with the combined methods of 10 m *10 m grid sampling and random sampling.Geostatistics and classical statistics were combined.The soil properties of the test field were described and statistically analyzed to grasp the overall situation of the soil in the test field and analyze the spatial variation and distribution characteristics of soil water,salt and pH.Based on the spatial variation of soil,the experimental plots were rationally divided to provide a theoretical basis for farmland management in coastal saline-alkali areas.The main conclusions are as follows:(1)The average soil water content,pH value,EC value and salt content in the experimental area were 16.59%,8.07,1227.93us/cm and 4.55g/kg,respectively.The type of salinization was slightly alkaline and strong alkaline soil,and the soil water content in the experimental site was relatively high.The soil salinity mainly consists of sulfide and sulfide,and the content of sodium chloride is the highest.The variation degree of soil water content and pH was medium and weak,while the variation degree of soil EC value and salt content was medium and strong,and the variation degree decreased with the increase of soil depth.(2)Salt content and pH in the experimental area is caused by random and structural factors,and the influence of the two factors is different in different soil depths,and they all have strong spatial autocorrelation within the range of variation.In terms of distribution characteristics,the distribution characteristics of soil water and salt are basically the same.The water content and salt content are lower in the northeast part of the test site,while the water content and salt content are higher in the central and southwest part of the test site.(3)Based on the spatial variation of soil properties,the test plots were divided into three categories: Category 1: soil salt content was the lowest,pH value was the highest,water content was in the middle level,and the distribution area was the widest.Category 2: soil water content is the highest,salt content and pH in the middle level.The soil moisture content was the lowest,the soil salt content was the highest,the soil pH was the lowest,and the distribution area was the smallest.Among them,type 1 and 2 are more suitable for crop cultivation than type 3.