3D spatial distribution characteristics of soil organic matter and total nitrogen in farmland

The three-dimensional (3D) spatial distribution characteristics of farmlands' soil organic matter and total nitrogen were revealed in Xinzheng City, and the related technical methods and train of thought were provided. The methods of 3D Kriging interpolation and 3D inverse distance weighted interpolation were comprehensively used to simulate the 3D spatial distribution characteristics of soil organic matter and total nitrogen content in different depths, and their prediction accuracies were compared by using the cross validation method. The results showed that soil organic matter and total nitrogen had significantly different spatial distribution difference along the different soil depths (0~20 cm, 20~40 cm, 40~60 cm), the mean range of soil organic matter content in three depths varied from 11.31 g/kg to 15.48 g/kg, and the mean range of soil total nitrogen content was 0.48~0.79 g/kg, and both of them were decreased with the increase of soil depth. The amount of information that 3D spatial distribution of soil organic matter and total nitrogen expressed was more abundant, which was able to directly show the distribution information of the nutrient content in soil arbitrary section. The prediction accuracy of interpolation results of organic matter obtained through 3D Kriging method was higher than that obtained through inverse distance weighting method, and the result of total nitrogen was the same. 3D Kriging interpolation method could more veritably reflect the 3D spatial distribution characteristics of soil nutrients. © 2015, Chinese Society of Agricultural Machinery. All right reserved.