摘要
为了探究平原圩区稻田氮磷流失机制,以江西省芳溪湖流域作为典型研究区,开展不同尺度稻田排水氮磷浓度时空变化特征研究。结果表明:在时间尺度上,排水总氮、氨氮平均浓度最高值出现在5月和7月;硝氮变化趋势为先降低后升高,最低浓度出现在8月份;总磷浓度变化趋势为先上升后下降,最高值出现于8月;排水中氨氮/硝氮比例随时间总体表现出先升高后降低的特征,最大比例出现在8月份。在空间尺度上,排水总氮、氨氮和总磷浓度的中位值表现为干沟尺度>田间尺度>流域尺度>斗沟尺度。农田排水氮磷浓度的时空变化过程复杂,在水稻不同生育阶段和不同空间尺度上存在较大差异,施肥和降雨过程对流域氮磷浓度有较大影响,因此需要在种植过程中加强田间养分和水分管理,合理控制排水时间,建议在施肥16 d后排水;降雨过程整体呈现“降-升-降”的变化趋势,建议稻田涝水在2~4 d内排出。
In order to investigate the mechanism of nitrogen and phosphorus loss from paddy fields in plain polder areas,this study took the Fangxi Lake watershed in Jiangxi Province as a typical study area and carried out a study on the spatial and temporal variation of nitrogen and phosphorus concentrations in paddy drainage at different scales.The results showed that the highest mean concentrations of total nitrogen and ammonia nitrogen were found in May and July;the change trend of nitrate nitrogen was first decreased and then increased,with the lowest concentration occurring in August;the change trend of total phosphorus concentration was first increased and then decreased,with the highest value occurring in August;the ratio of ammonia nitrogen/nitrate nitrogen in drainage showed a general increase and then decrease over time,with the largest ratio occurring in August.On the spatial scale,the median values of total nitrogen,ammonia and phosphorus concentrations in drainage water were as follows:dry ditch scale>field scale>watershed scale>bucket ditch scale.The spatial and temporal variation of nitrogen and phosphorus concentrations in farmland drainage was complex and varies greatly at different stages of rice fertility and at different spatial scales.Therefore,it is necessary to strengthen nutrient and water management in the field during the planting process and reasonably control the drainage time.It is recommended to drain water after 16 days of fertilization.The overall rainfall process presents a change trend of"down-up-down".It is suggested that the flood water in the paddy field should be discharged within 2~4 days.
作者
姜佩华
池泽涌
熊玉江
徐保坤
袁念念
JIANG Pei-hua;CHI Ze-yong;XIONG Yu-jiang;XU Bao-kun;YUAN Nian-nian(School of Resources and Environment,Yangtze University,Wuhan 430100,China;Agricultural Water Conservancy Department,Changjiang River Scientific Research Institute,Wuhan 430010,China)
出处
《节水灌溉》
北大核心
2023年第5期39-45,共7页
Water Saving Irrigation
基金
国家自然科学基金委员会—中华人民共和国水利部—中国长江三峡集团有限公司长江水科学研究联合基金项目(U2040213)。
关键词
平原圩区
芳溪湖流域
不同尺度
变化特征
氮磷浓度
plain polder area
Fangxi lake basin
different scales
variation characteristics
nitrogen and phosphorus concentrations
