Abstract:
The province of Gansu is an important agricultural product supplier in China, with
Codonopsis pilosula, cauliflower (a typical plateau summer vegetable), potato, and corn (seed crop) being the advantageous crops. To investigate soil pesticide residues of these crops, chromatography and mass spectrometry were employed to analyze the residues of organic pesticides in cropland soil. Additionally, a non-metric multidimensional scale method was used to examine the spatial variations in soil pesticide residues among the different crops. The environmental risks posed by pesticide residues to soil organisms were assessed using the risk-quotient method. The results show that acetochlor, atrazine, and glyphosate were detected in the soil at concentrations of 8.280-52.418, 33.693-40.088, and 1.022-18.421 μg·kg
-1, respectively. Thus, the levels of the three herbicides in the soil were found to be relatively low. However, different crop types exhibited variations in the predominant pesticide residues in the analyzed soil samples. Acetochlor was predominantly detected in
Codonopsis pilosula planting areas, atrazine was exclusively identified within corn cultivation zones, and glyphosate showed a higher prevalence across the cauliflower, corn, and potato planting regions. In total, thirty-two organophosphate pesticides were detected, with concentrations ranging from 0.369-3 845.028 μg·kg
-1. These pesticides were widely detected in
Codonopsis pilosula growing areas but were only occasionally detected in cauliflower, corn, and potato growing areas. The risk of most organophosphorus pesticide residues to soil biological environment were within the acceptable range (
RQ value ≤1). The analysis detected nine pyrethroid pesticides, with deltamethrin being present at a concentration range of 2.904-59.514 μg·kg
-1. These residues were found primarily in the planting soils of potato P2 and cauliflower V3. Compared to the other pyrethroid pesticides, deltamethrin exhibited a higher
RQ value; however, the risk remained within an acceptable range based on the results of the soil bioenvironmental risk assessment. Two organochlorine pesticides were also detected; however, the overall concentrations were low, and the soil bioenvironmental risks fell within an acceptable range. The study area contained a diverse range of pesticide residues, however, the overall levels were relatively low. Consequently, the soil bioenvironmental risk remains within acceptable limits, facilitating the sustainable development of advantageous crop cultivation and promoting a healthy soil ecological environment in Gansu.