Research on Three Dimensional Spatial Distribution of Soil Salinity in a Typical Field of Lubotan Area

To acquire the spatial distribution information of soil salinity in field scale and to guide the agricultural production, electromagnetic induction(EM) technique was introduced in this paper to measure the apparent electrical conductivity(ECa). The soil salinity in different depth was interpreted by establishing the EM interpretation model of soil salinity. And then, the three dimensional distribution of soil salinity was obtained by spatial analysis. The result indicated, there were good correlations between the soil salinity and ECa(r2were 0.875, 0.839,0.851, 0.866, 0.926 and 0.861 in 5 cm, 15 cm, 30 cm, 50 cm, 70 cm and 90 cm depth, respectively), which could benefit quick measurement of soil salinity; the three dimensional distribution of soil salinity contained enough information, it could supply spatial distribution information in any section of the soil solid. The result of precision test indicated, the forcast precision of spatial distribution was higher with 3D research than 2D, and it was more accurate with Kriging than IDW method. Comparing the spatial distribution of soil salinity, it could be found that top accumulation of soil salinity in vertical direction appreared in the areas with higher salt content, which could restrict the agricultural production, and the salinity survey should be continued for promoting the sustainable use of the land.