摘要
为明确鄱阳湖平原双季稻区稻田氮磷流失的季节性分布及污染风险,于2015—2019年对位于江西省南昌市南昌县向塘镇国控监测点的“冬闲-双季稻”种植模式进行了原位监测。结果表明:监测期早稻季径流量占全年总量的比例最高,为39.11%~61.50%,其次是冬闲季,占23.31%~54.30%,而晚稻季的径流量最小;氮磷养分流失量与径流量的季节分配规律相似,也大体表现为早稻季>冬闲季>晚稻季。然而,监测期多数年份(除2016年外)防控关键期(施肥后10 d)的径流量及氮磷流失量占全年总量的比例均低于13%,表明双季稻田防控关键期的污染风险可能被夸大。但极端降水条件下,径流量、氮流失量和磷流失量在全年的占比分别为27.34%~52.19%、14.21%~54.06%和25.38%~45.95%,远高于防控关键期,表明极端降水可能导致较大的双季稻田面源污染风险。因此,对于鄱阳湖平原双季稻区,早稻季和冬闲季均是稻田氮磷流失防控的重要时期。由于降水事件具有偶然性,仅靠降低“防控关键期”的氮磷流失来防控面源污染具有较大风险,极端降水条件下的氮磷流失防控可能是未来消减双季稻区面源污染的重点研究方向。
To better understand the seasonal distribution and pollution risk of nitrogen and phosphorus losses in double-cropping rice fields in the Poyang Lake Plain,in-situ monitoring was carried out on the"winter fallow double-cropping rice"planting pattern at the state-controlled monitoring site of Xiangtang Town,Nanchang County,Jiangxi Province,China during 2015—2019.According to the results,the runoff volume in the early rice season showed the highest proportion(39.11%–61.50%)of the annual total during the monitoring period,followed by the winter fallow season(23.31%–54.30%)and the late rice season.The seasonal distribution of nitrogen and phosphorus losses was similar to that of the runoff volume,with a higher proportion in the early rice season than in the winter fallow season.In most monitoring years(except 2016),however,both the runoff volume and nitrogen and phosphorus losses accounted for less than 13%of the annual total in the critical period of prevention and control(10 days after fertilization),revealing a possibly exaggerated pollution risk in the critical period of prevention and control in double-cropping rice fields.In contrast,under extreme precipitation conditions,the proportions of runoff volume,nitrogen loss,and phosphorus loss were as high as 27.34%–52.19%,14.21%–54.06%,and 25.38%–45.95%of the annual total,respectively,much higher than those in the critical period of prevention and control.This indicates that extreme precipitation may bring a higher risk of non-point source pollution in double-cropping rice fields.Hence,both the early rice season and the winter fallow season are important periods for the prevention and control of nitrogen and phosphorus losses in the doublecropping rice fields in the Poyang Lake Plain.Given the unpredictability of precipitation events,it may lead to risks when the prevention and control of non-point source pollution is achieved only by reducing the nitrogen and phosphorus losses in"the critical period of prevention and control".Thus,the prevention and control of nitrogen and phosphorus losses in extreme precipitation conditions is a potential key research direction for relieving non-point source pollution in double-cropping rice fields.
作者
杨涛
王玉清
吴火亮
俞莹
陈静蕊
陈晓芬
秦文婧
刘佳
徐昌旭
YANG Tao;WANG Yuqing;WU Huoliang;YU Ying;CHEN Jingrui;CHEN Xiaofen;QIN Wenjing;LIU Jia;XU Changxu(Soil and Fertilizer&Resources and Environmental Institute,Jiangxi Academy of Agricultural Sciences,National Engineering and Technology Research Center for Red Soil Improvement,Nanchang 330200,China;Agriculture and Rural Bureau of Nanchang County,Nanchang 330200,China;Jiangxi Agricultural Ecology and Resource Protection Station,Nanchang 330046,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2023年第4期852-860,共9页
Journal of Agro-Environment Science
基金
国家重点研发计划项目(2021YFD1700203)
江西省现代农业科研协同创新专项(JXXTCXQN 202209,JXXTCXQN202008)
国家现代农业产业技术体系建设专项(绿肥,CARS-22-Z-06)。
关键词
鄱阳湖平原
双季稻
氮磷流失
季节分布
污染风险
Poyang Lake Plain
double-cropping rice
nitrogen and phosphorus loss
seasonal distribution
pollution risk
