摘要
选择湖南省长沙县典型中亚热带双季稻田长期定位试验小区,通过田间观测明确不同施肥、水分管理、秸秆还田、生物质炭农艺管理措施对氮磷径流流失的影响,采用冗余分析方法(RDA)探明稻田氮磷径流流失的主控因子。研究结果表明:早晚稻各处理田面水总氮浓度在施肥后(基肥、分蘖肥和穗肥)第1 d达到峰值,并在10 d后逐步恢复到平稳水平;早稻田面水总磷浓度在施基肥后第1 d迅速达到最高,晚稻在施肥后第5 d才达到峰值。早晚稻田面水氮磷浓度受农艺管理措施影响明显,在间歇灌溉条件下,施有机肥、秸秆还田与生物质炭比常规化肥处理分别降低总氮浓度34.05%、15.34%~19.76%和15.46%~17.47%;秸秆还田与生物质炭相对常规化肥处理分别降低田面水总磷浓度6.33%~8.76%和9.09%~13.66%。铵态氮和颗粒态磷是氮磷径流流失的主要化学形态,施肥后10 d内是氮磷径流流失风险窗口期,该期间总氮和总磷径流流失分别占稻季总流失量的82.53%~97.66%和6.73%~47.02%。冗余分析结果表明配施有机肥促进氮磷径流流失,施用生物质炭主要促进稻田氮素径流流失,秸秆还田主要减少稻田氮素径流流失。综合考虑氮磷径流流失防控潜力、实际效果和实施可行性,中亚热带双季稻田采取高效水分管理(尤其是流失风险窗口期)加秸秆还田是减少稻田氮磷径流流失的可行方式。
The typical central subtropical double-cropping rice ecosystem was observed in the Changsha County,Hunan Province,to determine the effects of different agronomic measures(e.g.fertilization,water management,straw returning,and bio-charcoal application)on nitrogen(N)and phosphorus(P)runoff losses,and to identify the key determinants of the NP runoff losses through the redundancy analysis method(RDA).The results suggested that:The total-N(TN)concentrations in surface ponding water peaked one day after fertilization(base fertilizer,tiller fertilizer,and heading fertilizer)under different agronomic measures in the paddy fields,and then decreased to a stable level 10 days after fertilization;the total-P(TP)concentrations peaked one day after base fertilization during the early rice season,while peaked five days after base fertilization during the late rice season.The NP concentrations in surface ponding water were strongly affected by the agronomic measures.Under the intermittent irrigation condition,organic fertilizer application,straw returning,and bio-charcoal application reduced the TN concentrations by 34.05%,15.34%~19.76%,and 15.46%~17.47%,respectively,and straw returning and bio-charcoal application decreased TP concentrations by 6.33%~8.76%and 9.09%~13.66%,respectively,compared with the conventional chemical fertilizer application.The TP and TN were lost mainly in chemical forms of ammonium-N and particle-P in surface runoff of paddy fields,and the period within 10 days after fertilization was the window period for the NP runoff losses,when occurred 82.53%~97.66%and 6.73%~47.02%of TN and TP runoff losses during the whole cropping season,respectively.The RDA indicated that application of organic fertilizer promoted the TN and TP runoff losses,application of bio-charcoal increased the TN runoff loss,and straw returning reduced the TN runoff loss,in the paddy fields.Based on the comprehensive consideration on the potential and actual effects,and practice feasibility of agronomic measures,implementing efficient wat
作者
杨坤宇
王美慧
王毅
尹黎明
李勇
吴金水
YANG Kun-yu;WANG Mei-hui;WANG Yi;YIN Li-ming;LI Yong;WU Jin-shui(Key Laboratory of Agro-ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China;University of China Academy of Sciences,Beijing 100049,China;Hunan Institute of Water Resources and Hydropower Research,Changsha 410007,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2019年第8期1723-1734,共12页
Journal of Agro-Environment Science
基金
国家重点研发计划项目(2017YFD0800104)
湖南省重点研发计划项目(2017NK2150)~~
关键词
氮
磷
径流流失
稻田
农艺管理措施
nitrogen
phosphorus
runoff loss
paddy fields
agronomic management factors
