title: [Runoff Pollution Experiments of Paddy Fields Under Different Irrigation Patterns].
abstract: To study runoff and non-point source pollution of paddy fields and to provide a scientific basis for agricultural water management of paddy fields, paddy plots in the Jintan City and the Liyang City were chosen for experiments on non-point source pollution, and flood irrigation and intermittent irrigation patterns were adopted in this research. The surface water level and rainfall were observed during the growing season of paddies, and the runoff amount from paddy plots and loads of total nitrogen (TN) and total phosphorus (TP) were calculated by different methods. The results showed that only five rain events of totally 27 rainfalls and one artificially drainage formed non-point source pollution from flood irrigated paddy plot, which resulted in a TN export coefficient of 49.4 kg · hm⁻² and a TP export coefficient of 1.0 kg · hm⁻². No any runoff event occurred from the paddy plot with intermittent irrigation even in the case of maximum rainfall of 95.1 mm. Runoff from paddy fields was affected by water demands of paddies and irrigation or drainage management, which was directly correlated to surface water level, rainfall amount and the lowest ridge height of outlets. Compared with the flood irrigation, intermittent irrigation could significantly reduce non-point source pollution caused by rainfall or artificial drainage.
authors.forename: Jing-wen
authors.initials: JW
authors.lastname: Zhou
authors.forename: Bao-lin
authors.initials: BL
authors.lastname: Su
authors.forename: Ning-bo
authors.initials: NB
authors.lastname: Huang
authors.forename: Yu-tang
authors.initials: YT
authors.lastname: Guan
authors.forename: Kun
authors.initials: K
authors.lastname: Zhao
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D055868:Floods; D005618:Fresh Water / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis; D012275:Oryza; D010758:Phosphorus / Q000032:analysis; D011891:Rain; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen