Exposure risk assessment and evaluation of the best management practice for controlling pesticide runoff from paddy fields. Part 1: Paddy watershed monitoring.
Exposure risk assessment and evaluation of the best management practice for controlling pesticide runoff from paddy fields. Part 1: Paddy watershed monitoring.
复制标题
暴露风险评估和控制稻田农药径流最佳管理实践的评价。
DOI：
10.1002/ps.1295
复制
发表时间：
2006
影响因子：
4.1
通讯作者：
Hirozumi Watanabe
中科院分区：
文献类型：
--
作者：
S. Vu;S. Ishihara;Hirozumi Watanabe
从2002年4月起，在日本筑波樱花河流域约100公顷的稻田流域，对地表水中的水稻农药浓度沿着水文平衡和水管理条件进行了为期3年的调查。对从稻田到分水岭等不同水文尺度的监测确定了与降雨事件和循环灌溉相关的水管理对于减少农药排放到水生环境的重要性。地面排水显着增加，作为对降雨量大于约1.5厘米天（-1）的响应。结果表明，在溪流中共检测到16种除草剂，其浓度峰值主要出现在施药后的5月上旬至中旬。定义了影响稻田农药径流的两个水分管理因子：过量蓄水量（EWSC）和蓄水期（WHP）。采用蒙特卡罗模拟（MCS）方法，以3年多的观测数据为基础，对稻田稻田中除草剂达梦隆（daimuron）和咪唑磺隆（imazosulfuron）的农药排放量进行了不确定性分析。建议采用浅水深和高排水闸门的间歇灌溉方案，以保持EWSC > 2 cm，并将WHP从现行日本农药法规的3-4天增加到至少10天，以减少日本季风区稻田的农药径流。田间小区良好的水管理和小规模水循环相结合是控制稻田流域农药排放的最佳管理做法。
Rice pesticide concentrations in surface water along with hydrological balance and water management conditions were investigated in a paddy watershed of about 100 ha at the Sakura river basin in Tsukuba, Japan, for 3 years from April 2002. Monitoring on different hydrological scales ranging from a paddy plot up to a watershed determined the importance of water management associated with rainfall events and the cyclic irrigation for reducing pesticide discharge into aquatic environments. Surface drainage significantly increased as a response to rainfall events greater than about 1.5 cm day(-1). A total of 16 herbicides were detected in the stream water and their peak concentrations mostly occurred from early to mid-May following the pesticide application period. Two water management factors influencing the pesticide runoff from paddy fields were defined: excess water storage capacity (EWSC) and water holding period (WHP). Uncertainty analyses of pesticide discharge from a paddy plot for dymron (daimuron) and imazosulfuron (IMS) were performed using Monte Carlo simulation (MCS) with prescribed probability of rainfall and water management practice from observations over a period of 3 years. Application of an intermittent irrigation scheme with shallow water depth practice and high drainage gate to maintain the EWSC > 2 cm and increasing WHP from the current Japanese Agricultural Chemicals Regulation law of 3-4 days to at least 10 days were recommended for reducing the pesticide runoff from paddy fields in a monsoon region such as in Japan. The combination of good water management in field plots and small-scale water cycling is the best management practice for controlling pesticide discharge from paddy watersheds.