Research On Determination Methods And Distribution Of Three Pesticide Residues In Xinjiang Cotton Soil

This study is based on the cotton field of Xinjiang Kuitun region, with the three kinds of commonly used herbicide, atrazine, acetochlor, trifluralin as the research object, combining with the actual situation, considering factors such as management style, continuous cropping years and pesticide use, to choose typical cotton to make soil sample collection, to make survey to related management measures at the same time of sampling. After pretreatment of collected soil samples, pesticide ingredients contained in the sample is extracted, separated and purified. High performance liquid chromatography is used to determined atrazine, acetochlor, trifluralin three kinds of pesticide residue levels, based on the three levels of pesticide residue in different time and space this paper reveals the status quo of the residue, analyzes the laws of its formation. The main results were as follows:1. The analysis method of determining: ultrasonic assisted extraction, Florisil solid phase extraction small column purification, high performance liquid chromatography(HPLC) method were established through research to detect three kinds of pesticide residues in the soil at the same time.2. By HPLC detection, to determine the pesticide residues ranges of the three kinds of atrazine and acetochlor and triflurali in soil. Test results as follows: atrazine residue in the soil at each sampling point is in 0.0070-0.1465 mg/kg; Acetochlor residue in the soil at each sampling point is in 0.0122 mg/kg to 1.1575 mg/kg; Trifluralin in every sampling point in the soil residues is 0-0.1531 mg/kg.3. On the time scale, along with the increasing length of continuous cropping, three kinds of pesticide residues levels increase trend overally, among which: atrazine in soil tillage 10 years reached the highest amount of residue and acetochlor residue level fluctuation is bigger; trifluralin residues in 30 years of farming soil did not check out, but in farming 50 years of soil, detection quantity is higher, which may be associated with farming commune in the process of disturbance; Comparing three kinds of pesticide residues in soil and tillage farming 50 years and 2 years soil residues, it is found that its residues are in multiple growth. Multiples of acetochlor reached 6 times, the highest pesticide residues is 1.1575 mg/kg, if it is transferred to the water, can cause some aquatic organisms die directly, so the application of acetochlor should strengthen management and standardization.4. On the different space, from the point of vertical space variability, three kinds of pesticide residues is obviously accumulated in 20-40 cm, with the time accumulation of acetochlor and atrazine application, 20-40 cm residues in soil were higher than 0 to 20 cm soil layer. Because trifluralin itself characteristic, and application level, it was not detected in the soil, its regularity is not strong, but also was in line with the law of that with the increasing cultivation age, 20-40 cm residues in soil is higher than the 0 ~ 20 cm soil layer. This shows that in the management mode of current agricultural macroscopic control, the characteristics of pesticide use and management concentration is obvious.5. From the point of residue levels, pesticide residue in the farmland soil in Xinjiang belongs to low levels across the country, plus that the cotton did not enter the food chain, it is relatively safe. But pesticide residues make the negative effects on soil therefore also need proper control. Through the study, it is showed that in order to protect the local ecological environment and soil security, in the process of crop cultivation, it is necessary to reduce the use of atrazine, appropriately control the use of trifluralin, avoid acetochlor using in cotton fields.To sum up, the study result can provide some basic data for cotton production safety, to provide technical support for guiding farmers to reasonably use pesticides. Reasonable and correct use of pesticides can also reduce farmer’s production input, reduce the production cost, and improve the farmers’ income, promote sustainable development in Xinjiang cotton industry.