[Soil Fertility and Influencing Factors of Cultivated Land Based on the Geodetector].

Taihe County in Jiangxi Province was chosen as the study area to analyze the soil fertility condition and affecting elements of cultivation at the county level. Classical statistics, geostatistics, and geodetector were utilized to examine soil fertility quality and investigate its primary affecting aspects based on experimental data from 206 cultivated soil samples. The results showed that： ① Taihe County had an average soil pH of 4.87, indicating slightly acidic soil. A total of 97.39% of the sample sites had CEC contents of four and five levels, and the EC content levels were concentrated in the second level, 63.48% of the SOC contents were in the medium levels, 73.92% of the TN contents were higher than 1.5 g·kg, 72.17% of the TP contents were lower than 0.6 g·kg, and the AP contents were in the high level, greater than 20 mg·kg, accounting for 86.09% of the sample sites. The soil fertility in the research area was poor, and the soil was of light and medium salinization, lacking organic matter and total phosphorus. The lump gold effect values of pH, EC, AP, SOC, TN, and TP were 0.17, 0.21, 0.18, 0.52, 0.45, and 0.59, respectively. The spatial correlation between soil pH, EC, and AP was strong, while soil SOC, TN, and TP had a moderate degree of spatial correlation. The spatial variation of soil fertility in Taihe County was influenced by both structural factors （topography, climate, and soil type） and random factors （fertilization, cultivation methods, soil pollution, etc.）. ② The results of the weight coefficients of farmland soil fertility were TN （0.210）, SOC （0.195）, EC （0.190）, CEC （0.171）, TP （0.170）, AP （0.117）, and pH （-0.053）. Soil TN, SOC, and EC were key indicators that affected farmland soil fertility in the study area. The comprehensive score grading of soil fertility quality showed that most of the soil fertility quality in the study area was level three, and the soil fertility in Shangmo Township was relatively fertile. The soil fertility quality level was Level 2 and Level 3. The soil fertility in Yanxi Town and Wanhe Town was relatively poor, and the soil fertility quality level was Level 3 and Level 4. ③ , , , , and were the main driving factors affecting farmland soil fertility. The explanatory power of each factor interaction was greater than that of single factor interactions, manifested in two types： double factor enhancement and nonlinear synergistic effect. The soil fertility of farmland was the result of the joint action of multiple influencing factors. The results of the research revealed the status quo and spatial distribution characteristics of soil fertility in the study area, investigated the factors influencing soil fertility in farmland, and analyzed the foundation for improving the intrinsic quality and output capacity of cultivable land and the ecological environment of agriculture.