In this study, we investigated characteristics of T-N (Total nitrogen) and T-P (Total phosphorus)load from paddy fi elds during storm and no-storm period. The fi eld monitoring was conductedduring three crop-years (from May 1, 2004, to September 30. 2007) in a rice cultivation arealocated in Emda-myun, Hampyeong gun, Jeollanam-do, Korea. Drainage water samplewas manually collected biweekly during no-storm periods. During storm periods, drainagewater was sampled, by grab technique, several times in proportion to discharge at the outletof the main drainage canal whenever an event occurred. The samples were stored in 2-Lpolyethylene bottles at the sites. They were placed in containers with ice bags and transportedto the laboratory for chemical analyses. Concentrations of T-N and T-P were analyzedaccording to standard methods. To estimate fl ow rates of the study site, rating curves (stageflow rates relationships) were developed. Load was calculated multiplying concentrations andcorresponding runoff volume. Results showed that T-N load during storm period accountedfor 49 to 77% of total T-N load, and 23 to 51% of total T-N load was exported during no-stormperiod. Also, T-P load during storm period accounted for 56 to 80% of total T-P load, and 20to 44% of total T-P load exported during no-storm period. Signifi cant amount of T-N and T-Pwas exported during no-storm period. Irrigation water was supplied to paddy fi eld for ricegrowth during no-storm period and some of them drained as return fl ow due to poor watermanagement. Therefore, it is important to manage T-N and T-P load from paddy fi elds duringno-storm period by adequate drainage management to improve water quality of stream duringbase fl ow period.
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