Institute of Environmental Science and Technology, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou, 310058, China.
Environ Sci Pollut Res Int. 2013 Oct;20(10):6980-91. doi: 10.1007/s11356-012-1391-1. Epub 2013 Jan 4.
Resource-conserving irrigation and fertilizer management practices have been developed for rice systems which may help address water quality concerns by reducing N and P losses via surface runoff. Field experiments under three treatments, i.e., farmers' conventional practice (FCP), alternate wetting and drying (AWD), and AWD integrated with site-specific nutrient management (AWD + SSNM) were carried out during two rice seasons at two sites in the southwest Yangtze River delta region. Across site years, results indicated that under AWD irrigation (i.e., AWD and AWD + SSNM), water inputs were reduced by 13.427.5 % and surface runoff was reduced by 30.236.7 % compared to FCP. When AWD was implemented alone, total N and P loss masses via surface runoff were reduced by 23.330.4 % and 26.931.7 %, respectively, compared to FCP. However, nutrient concentrations of surface runoff did not decrease under AWD alone. Under AWD + SSNM, total N and P loss masses via surface runoff were reduced to a greater extent than AWD alone (39.447.6 % and 46.148.3 % compared to FCP, respectively), while fertilizer inputs and N surpluses significantly decreased and rice grain yields increased relative to FCP. Therefore, by more closely matching nutrient supply with crop demand and reducing both surface runoff and nutrient concentrations of surface runoff, our results demonstrate that integration of AWD and SSNM practices can mitigate N and P losses via surface runoff from rice fields while maintaining high yields.
在西南长江三角洲地区的两个地点,在两个水稻季节进行了三种处理(即农民传统做法(FCP)、交替湿润和干燥(AWD)以及 AWD 与特定地点养分管理相结合(AWD + SSNM))的田间试验。跨站点年份的结果表明,与 FCP 相比,AWD 灌溉(即 AWD 和 AWD + SSNM)减少了 13.4%至 27.5%的水输入和 30.2%至 36.7%的地表径流。当单独实施 AWD 时,与 FCP 相比,通过地表径流的总氮和磷损失质量分别减少了 23.3%至 30.4%和 26.9%至 31.7%。然而,单独实施 AWD 时,地表径流的养分浓度并没有降低。在 AWD + SSNM 下,通过地表径流的总氮和磷损失质量比单独实施 AWD 时减少了更多(与 FCP 相比,分别减少了 39.4%至 47.6%和 46.1%至 48.3%),同时肥料投入和氮盈余显著减少,与 FCP 相比,水稻产量增加。因此,通过更密切地匹配养分供应与作物需求,减少地表径流和地表径流养分浓度,我们的结果表明,将 AWD 和 SSNM 实践相结合可以减轻稻田通过地表径流的氮和磷损失,同时保持高产。