Abstract:
The total nitrogen (TN), total phosphorus (TP), and nitrogen/phosphorus ratio (N/P) of soil are important indicators of soil fertility and quality. The study of their spatial heterogeneity is of great significance for the formulation of policies concerning soil nutrient management and ecological environment monitoring. Using methods such as geostatistical analysis and geographic information system (GIS), this study analyzed the spatial variation and influencing factors for the ecological stoichiometry of nitrogen and phosphorus in the surface soil (depth: 0~20 cm) of the Jiansanjiang area through soil sampling and laboratory tests. The results are as follows. The soil in the study area has average TN, TP, and N/P of 2.49×10-3, 0.81×10-3, and 3.20, respectively. The TN and N/P of the soil have high spatial autocorrelations, while the TP of the soil has a moderate spatial autocorrelation, all in line with the index model. Regarding the spatial distribution, zones with high TN content are mainly scattered in the form of patches in the east, south, and northwest of the Jiansanjiang area, while zones with low TN content are mainly scattered in the northwestern, central, and western portions of the area. Zones with high TP content are mainly distributed in the east and northwest, while zones with low TP content are in the central portion. Moreover, the N/P ratio is distributed in a mosaic-like pattern. Specifically, zones with high N/P ratios are distributed in the form of patches in the central, southern, and northeastern portions, while zones with low high N/P ratios are mainly distributed in the northwest. The types of the soil, the Quaternary, and land uses of the study area are important structural and random factors affecting the ecological stoichiometric characteristics of soil nitrogen and phosphorus, while the types of the soil parent materials and landforms have little effect on these characteristics.