稻田不同灌溉模式的节水减污效应分析——以浙江平湖为例

【目的】研究不同灌溉模式下水稻的节水及减污效应,探寻适合平原河网区的水稻节水灌溉模式。【方法】在浙江平湖灌溉试验站设定常规灌溉、薄露灌溉和适雨灌溉3种模式,测定了灌溉量以及排水和渗漏水样中的TN、TP、NH_4~+-N、NO_3~--N和COD等。【结果】适雨灌溉灌水量相较于常规灌溉和薄露灌溉分别减少了67.4%和43.4%,节水效果最好;适雨灌溉排水量最少,相较于常规灌溉和薄露灌溉,适雨灌溉TN排放量分别减少了86.9%和90.7%,NH_4~+-N排放量减少了96.7%和98.3%,COD排放量减少了61.5%和62.5%,TP和NO_3~--N的减排效果不明显。【结论】在本研究条件下,适雨灌溉的节水减污效果更好。

Efficacy of Different Irrigation Methods in Saving Water and Ameliorating Pollution in Paddy Field: Take Pinghu as an Example

【Objective】Improving water use efficiency and ameliorating pollution is a challenge facing agriculture and this paper aimed to present an experimental study on efficacy of different irrigation methods in saving water and reducing pollution in paddy field in attempts to provide a suitable management for paddy field in plain regions.【Method】We examined three irrigation methods: flooding irrigation, shallow-water irrigation and rain-collecting irrigation in Pinghu, Zhejiang province. For each irrigation, we measured TN, TP, NH_4~+, NH_3~- and COD in both irrigation water and drainage water.【Result】Compared with flooding and shallow-water irrigation, rain-collecting irrigation reduced the amount of irrigation water by 67.4% and 43.4%, TN loss by 86.9% and 90.7%,emission of NH_4~+ by 96.7% and 98.3% and COD emissions by 61.5% and 62.5% respectively. The difference in change of TP and NH_3~- between all three irrigation methods was not significant.【Conclusion】For the areas we studied, the rain-collecting irrigation is most effective in saving water and reducing pollution.