Objective To study the impact of rising atmospheric aerosol concentration on crop photosynthesis and total primary productivity.

Methods Multi-source remote sensing data and meteorological data were used to obtain aerosol optical thickness, vegetation leaf area index, rainfall, solar radiation, and temperature data, and then the distribution of major crop planting areas in Aksu prefecture from 2003 to 2023 was extracted. Afterwards, based on these, the impact of a typical heavy rainfall event in this area on total primary productivity of cultivated land was analyzed.

Results (1) The total primary productivity and leaf area index showed a significant increasing trend, with an interannual variation of 0.01 m²a⁻¹ for leaf area index and 7.651 gCm⁻²a⁻¹ for total primary productivity, with a growth rate of 1957.36 TgC. The leaf area index and total primary productivity in areas near the Taklimakan Desert also showed a downtrend. (2) Atmospheric aerosol deposition particles affected crop growth by influencing carbon assimilation, consumption, and accumulation processes, leading to a reduction in total primary productivity during the seedling stage at critical locations. (3) According to the quantitative attribution algorithm for the change rate of total primary productivity, the leaf area index and rainfall had a positive increasing effect on the change rate of total primary productivity, with a response of 15.19 gCm²、14.26 gCm² and a relative response rate of 42.8%, 27.82%.

Conclusion Therefore, there is a positive correlation between leaf area index and precipitation, indicating that the erosion of leaf surface by rainwater can have a certain enhancing effect on the total primary productivity of cultivated land.