| 王静,郭熙盛,王允青,吕国安.秸秆还田条件下稻田田面水不同形态氮动态变化特征研究[J].水利学报,2014,45(4): |
| 秸秆还田条件下稻田田面水不同形态氮动态变化特征研究 |
| Study on dynamics of Nitrogen in different forms in surface water of paddy field under straw return |
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| DOI： |
| 中文关键词: 农业面源污染 氮素 秸秆还田 水体富营养化 |
| 英文关键词: agriculture non-point source pollution nitrogen straw return eutrophication |
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| 中文摘要: |
| 为探索巢湖流域稻麦（油）轮作区水稻季减少农田氮素流失的有效耕作措施，降低其对湖区水质的威胁，采用野外定位观测试验并结合室内实验分析， 研究了连续两年秸秆还田条件下稻田田面水总氮（TN）、溶解态氮（DN）、溶解态有机氮（DON）、铵态氮（NH4+-N）和硝态氮（NO3--N）浓度的动态变化特征。结果表明，稻田施用尿素后第2天或第4天田面水的TN、DN、DON 和NH4+-N 浓度达到峰值，然后随着时间的推移迅速降低，至8~10 d后趋于稳定；在整个水稻生育期内，NO3--N 浓度普遍较低；尿素施用后8~10 d之内是控制稻田氮素流失的关键时期，秸秆还田降低这一时期TN、DN、NH4+-N 浓度的效果显著，而DON 浓度差异未达显著水平。DN 是稻田田面水氮素存在的主要形态，所占TN 比例达63.2 ％~88.8 ％，尿素施用后6 d 内DN 又以NH4+-N 为主，NH4+-N 所占TN 的比例为33.8 ％~69.9 %。DON 是稻田田面水氮素的重要组成部分，其生态环境效应不容忽视。秸秆还田还有利于水稻产量的提高，增产幅度分别为12.25 ％和7.68 ％，平均为9.96 ％。在保证水稻产量的前提下，秸秆还田可以作为控制稻田氮素流失的措施在巢湖流域使用。 |
| 英文摘要: |
| In order to explore the effective tillage for reducing nitrogen losse and improving lake water quality， field experiments were conducted to study the dynamics of TN （total nitrogen）， DN （dissolved nitrogen），DON （dissolved organic nitrogen），ammonia nitrogen（NH4+-N） and nitrate nitrogen（NO3--N） concentrations in surface water of paddy field in the Chaohu Lake region in two consecutive years. The results show that the concentrations of TN、DN、DON and NH4 +-N in surface water reached the maximums after 2 or 4 days of urea application， then declined rapidly， and finally leveled off after 8~10 days. The NO3--N concentration remained at a low level during the whole rice growing seasons， although it showed a little raise after 4 or 6 days of urea application. Obviously， it is the critical period for controlling N loss from paddy field within 8~10 days after urea application. Straw return could effectively decrease the higher concentrations of TN， DN and NH4 +-N in surface water during the earlier stage， whereas the differences in DON concentration was not so significant. Therefore， straw return is beneficial for lowering the potential risk of N loss. Furthermore， DN was the predominant form of TN in surface water， which accounted for 63.2 % ~88.8 % of the TN. Within 8 days after urea application， the proportion of NH4 +-N to TN was 33.8 ％~69.9 %. DON was a significant component of TN in surface water，which suggested that its ecological and environmental effects should not be neglected. The results also show that the rice yields of CTS increased significantly by 12.25 % and 7.68 % compared with CT，which indicated that straw return could increase the rice yields. The findings indicate that assuring the production of rice yields， straw return appeared to be an effective measure for the source control of the nitrogen loss from paddy field in the Chaohu Lake region. |
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