Abstract: We aimed to clarify the distribution characteristics and ecological risks of major pesticides in the soil of a typical economic crop production area in the Sichuan Basin by examining the residue levels of five major pesticides in 121 soil samples from the crop planting area using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Key influencing factors of the main pesticide residues were analyzed by combining soil factors with residue levels, and their ecological risks were assessed using the risk quotient (RQ) method. The results showed that four pesticides (carbendazim, imidacloprid, trichlorfon, and phoxim) except abamectin were detected in the soil samples. There were seasonal variations in surface soil pesticide residues, with significantly higher residue levels in summer (19.67-733.97 μg·kg^-1) than in winter (11.33-114.7 μg·kg^-1) (P<0.05). The total amount of pesticide followed the trend: lemon planting area > prickly ash planting area > cabbage planting area > citrus planting area. The types and levels of pesticide residues varied significantly among crop types and seasons. Ecological risk assessment results indicated that carbendazim posed a high ecological risk. The high-risk crop plots were located in lemon planting areas, with 6 sites in winter and 8 sites in summer. The acute risk of pesticides in the surveyed economic crop soils to earthworms was generally low. For high-risk pesticides, their soil residue concentrations should be monitored, providing a basis for further identification of pesticide pollution problems and risks in the soils of economic crop areas in the Sichuan Basin. This study has important practical guiding significance for ensuring soil environment monitoring and agricultural product quantity safety in important cash crop producing areas in the Sichuan Basin.

Key words: cash crop, soil, pesticide residue, distribution characteristics, ecological risk