| To identify the limiting factors of nitrogen, phosphorus, and potassium nutrients in drip-irrigated cotton fields and their comprehensive effects on the crop–soil system, and to further optimize a high-yield and high-efficiency fertilization model for cotton in Shaya County, Xinjiang, a field positioning experiment was conducted from 2021 to 2025 in Hailou Town, Shaya County, Aksu Prefecture. Five treatments were established: no fertilizer application (CK), nitrogen omission (PK), phosphorus omission (NK), potassium omission (NP), and an optimized fertilization treatment (NPK). The results after five years of the positioning experiment showed that compared with the optimized fertilization treatment, the soil alkali-hydrolyzable nitrogen, available phosphorus, and available potassium contents in the PK, NK, and NP treatments decreased by 41.16%, 36.92%, and 12.23%, respectively. Meanwhile, the uptake of nitrogen, phosphorus, and potassium by cotton plants decreased by 40.62%, 20.68%, and 18.79%, respectively, resulting in average reductions in seed cotton yield of 36.37%, 18.67%, and 12.18%. Under straw return conditions, the average utilization rates of nitrogen, phosphorus, and potassium fertilizers in the optimized fertilization treatment were 55.22%, 19.19%, and 42.29%, respectively, with annual average surpluses of soil nitrogen and phosphorus of 85.23 kg/hm2 and 71.23 kg/hm2, while potassium remained essentially balanced. In summary, based on straw return, the recommended fertilization rates for drip-irrigated cotton fields in this region are N 300 kg/hm2, P2O5 150 kg/hm2, and K2O 90 kg/hm2. This model can achieve continuous improvement of soil nitrogen and phosphorus nutrients and maintain potassium balance, providing a scientific basis for green, high-yield, and high-efficiency cotton cultivation in the region. |