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通过田间试验测定坡面径流进入稻田生态系统后,面积约200m2的垄作稻田对径流中氮、磷的消纳效果。径流灌入水田后24h,径流中TN和颗粒态氮浓度分别下降了60.1%～88.0%和91.2%～98.7%,且各处理之间没有显著差异。大雨产生的径流中TN浓度显著高于中雨和小雨,径流进入水田后田面水中TN浓度高于小雨和中雨径流进入水田后田面水中TN浓度,但是这种差异仅仅体现在前3h。径流样品刚刚加入后,水田田面水中颗粒态氮占较高的比例,颗粒态氮占TN的43.5%～87.7%。随着时间的推移,颗粒态氮占TN的比例逐渐下降,其他形态氮素所占的比例逐渐上升,径流样品加入后24h,颗粒态氮占TN的比例下降至10.2%～22.7%,其他形态氮素所占比例升至77.3%～89.8%;可溶态的无机氮和有机氮成为TN的主要组成部分。水田生态系统对坡面径流中磷的控制同样表现出较高的效率,径流灌入水田后24h,6次降雨过程产生的径流中TP和颗粒态磷浓度分别下降了60.6%～86.0%和82.9%～93.0%,且各处理之间没有显著差异。径流样品刚刚加入水田后,水田田面水中颗粒态磷占较高的比例,颗粒态磷占TP的89.7%～97.7%。随着时间的推移,颗粒态磷占TP的比例逐渐下降,径流加入后24h,颗粒态磷占TP的比例下降至37.4%～45.7%。水田生态系统对坡面径流中氮、磷消纳体现出较高的效率,主要得益于其能够较快地消纳颗粒态的氮、磷。
Field experiments were conducted to determine the effect of nitrogen and phosphorus in runoff on ridge-paddy fields with an area of about 200 m 2 after the runoff was measured in paddy fields. The runoff TN and particulate nitrogen concentrations dropped 60.1% -88.0% and 91.2% -98.7%, respectively, after runoff infiltration into paddy fields, and there was no significant difference among treatments. The TN concentration in runoff produced by heavy rain was significantly higher than that in moderate and light rains. The TN concentration in surface water after runoff into paddy field was higher than TN concentration in surface water after rainfall and moderate rainfall runoff entered paddy field, but the difference was only reflected in the first 3 h. Immediately after runoff samples were added, the proportion of particulate nitrogen in surface water of paddy fields accounted for a high proportion, and the particulate nitrogen accounted for 43.5% to 87.7% of TN. With the passage of time, the proportion of particulate nitrogen to TN gradually decreased, and the proportion of other forms of nitrogen gradually increased. The proportion of particulate nitrogen to TN decreased to 10.2% to 22.7% after 24 hours of addition of runoff samples. The proportion of nitrogen rose to 77.3% ~ 89.8%. Soluble inorganic nitrogen and organic nitrogen became the main components of TN. The paddy field ecosystem also showed high efficiency in controlling phosphorus in runoff. The runoff TP and particulate phosphorus concentrations in runoff decreased by 60.6% ~ 86.0% and 82.9% respectively % ~ 93.0%, there is no significant difference between the treatments. Immediately after runoff samples were added to the paddy field, the proportion of particulate phosphorus in paddy field water accounted for a relatively high proportion. Particulate phosphorus accounted for 89.7% -97.7% of TP. With the passage of time, the proportion of particulate phosphorus to TP decreased gradually, and the proportion of particulate phosphorus to TP decreased to 37.4% -45.7% at 24 h after runoff addition. The paddy field ecosystem shows high efficiency for nitrogen and phosphorus consumption in slope runoff, mainly due to its ability to quickly absorb particulate nitrogen and phosphorus.