农药杀虫单的稻田流失规律研究

通过测坑、人工降雨等手段，对水溶性农药杀虫单的稻田消解动态、渗漏流失和径流流失等进行了研究。结果表明，(1)无水稻时，杀虫单在稻田水中消解的半衰期为0．76d；分蘖初期，杀虫单在稻田水中降解的半衰期为1．02d；平均为0．89d。(2)杀虫单的渗漏流失量在用药后8d内可达总用药量的7％—10％，平均为8．48％。(3)极端情况下，用药当天如果遇暴雨(50mm雨量)，杀虫单的径流流失量将达到用药量的30％左右。杀虫单的渗漏损失不可避免，故其流失控制应从径流损失着手，尽量避免在可能有暴雨的当天或雨前1—2d用药。

Study on the Rule of Loss of Molosultap in Rice Field

Based on some experimental means, such as testing-hole, man-made raining, etc., to study the degradation process, leakage loss, runoff loss, etc. of molosultap in rice field water have been conducted. The study results showed that the half-life of molosultap in rice fields waters was 0.76 day with no rice, and 1.02 days in tillering period, and 0.89 day; in average; the leakage quantity of molosultap 8 days in after applying accounted 7% - 10% of the total application in the field; in extreme condition, if it encounter rainstorm (50mm) in the day of applying molosultap, the percentage of runoff loss will be about 30%, which will result in serious pollution. The leakage loss of molosultap is unavoidable, so control of molosultap pollution should focus on runoff loss. Averting to apply pesticides when there is probable rainstorm, and some proposals to prevent non-point pollution caused by water soluble pesticides were also put forward.