稻田中扑草净的消解规律及最终残留量研究

Degradation and final residue of prometryn in paddy field

为评价扑草净的环境安全性，以制定安全、合理的使用准则，选择吉林、黑龙江和湖南的三个试验区域，研究了稻田中扑草净的消解规律及最终残留量．结果表明，扑草净在稻田水和水稻植株中的降解速率较快，半衰期相对较短（稻田水中扑草净半衰期为0．7～1．9d，水稻植株为2．O～2．2d）；而在土壤中的降解速率较慢，半衰期较长（4．9～17．4d）．收获期，对土壤、植株、糙米及稻壳样品进行了最终残留量的测定，均未检出扑草净．由此可见，扑草净较易降解，在推荐施用剂量（259／6扑草净（WP），2．250kg／hm2）下，环境和水稻中残留量较低，对环境和作物安全．

In order to evaluate the environmental safety of prometryn and standardize its reasonable application, three fields （Jilin, Heilongjiang and Hunan） were chosen to carry out the related experiments including prometryn degradation and final residue determination in paddy field and rice. The results showed that ,as for the three selected fields, the degradation rates in water and rice plant were relatively faster and the half lives of prometryn in water were 0.7- 1.9 d,while for the rice p the half lives were 2.0-2.2 d. The degradation rates in soil were relatively slower and the half 1 ant yes were long （4.9~17.4 d）. In the harvest time,the final residue of prometryn in soil,rice plant,brown rice and rice hull were determined and the values were all below the limit of quantity, indicating that prometryn was easy to degrade. It was safe for both environment and crop to use prometryn under the recommended application dose （25% prometryn WP 2. 250 kg/hm2） because the residue of prometryn in environment and paddy were very low.