摘要
在江汉平原地区,因水肥管理粗放,特别是人为排放刚施肥泡田水,水稻种植引发的氮磷面源污染问题比较严重,迫切需要掌握稻田氮、磷动态特征,并据此进行科学的肥水管理。采用大田试验的方法,设置不同氮磷梯度,研究了江汉平原稻田田面水氮磷形态与浓度动态变化特征及施肥的影响。结果表明:施尿素后,田面水可溶性总氮(DTN)、可溶性有机氮(DON)和铵态氮(NH4^+-N)占总氮(TN)的比例分别在88.0%、44.7%和31.6%以上,且随施氮量增加而增大;施磷肥后,田面水中颗粒态磷(PP)占总磷(TP)的比例为76%~93%,且随施磷量的增加而降低。田面水中氮素浓度与施氮量之间呈分段线性相关关系,当施氮量分别超过287.8、289.9、231.5和336.7kg·hm^-2后,TN、DTN、NH4^+-N和DON的浓度会跃增;田面水中各形态磷素浓度均随施磷量的增加而线性增加。施氮肥后,田面水中TN和DTN浓度均在施肥后1d达到峰值,在基肥和分蘖肥后5d、穗肥后2d降低至与不施氮肥基本接近;NH4+-N浓度在基肥和分蘖肥后2d、穗肥后1d达到峰值,基肥和分蘖肥后5d、穗肥后2d后降低至与不施氮肥趋同。施磷肥后TP、PP和可溶性总磷(DTP)的浓度均在施肥后1d达到峰值,3d后急剧降低,降幅均在79.0%以上。可见,在江汉平原地区,施尿素后田面水中氮素以DTN为主,尤其是DON和NH4^+-N,施磷肥后以PP为主。减少氮、磷肥用量可降低稻田氮、磷损失,且氮肥施用量应尽可能控制在231.5kg·hm^-2以内。施基肥和分蘖肥后5d内、施穗肥后2d内是江汉平原稻田氮素损失的关键控制期,施磷肥后3d内是磷素流失的关键控制期。
【Objective】Because of extensive management of water and nutrients in rice cultivation, especially artificial drainage of just fertilized paddy fields for mechanized rice transplanting and direct rice seeding, non-point source N and P pollution turned out to be very serious in Jianghan Plain, posing a great threat to the safety of agricultural water and drinking water. N and P in paddy field surface water are the direct sources of non-point source N and P pollution. It is, therefore, essential to master rules of the changes in N and P in paddy field surface water to preventing and controlling the non-point source N and P pollution from paddy fields. However, at present, it is still unclear how N and P changes in paddy fields surface water and how fertilizer application affects the changes in the Jianghan Plain. This is a topic that calls for further studies.【Method】In this study, a field experiment, designed to have a number of treatments varying in N and P application rate along a gradient, was carried out to explore how N and P changes in paddy field surface water and how fertilizer application affects the changes. Samples of paddy field surface water were collected for 8 consecutive days after each fertilizer application for analysis of total N (TN), total soluble N (DTN), soluble organic N (DON), NH4 ^+-N and NO3 ^--N, total P (TP), total soluble P (DTP), and particulate P (PP).【Result】Results show that total soluble N (DTN), soluble organic N (DON) and NH4 ^+-N accounted for 88.0%, 44.7% and 31.6%, respectively, of the total N (TN) in surface water, after application of urea, and increased with increasing N application rate, while particulate P (PP) made up 76%~93% of the total P (TP) after application of superphosphate, but decreased with increasing P application rate. A piecewise linear correlation was observed between N concentration in surface water and N application rate. With increasing N application rate, N in surface water would increase in concentrations, and when N application rate excee
作者
张富林
吴茂前
夏颖
翟丽梅
段小丽
范先鹏
熊桂云
刘冬碧
高立
ZHANG Fulin;WU Maoqian;XIA Ying;ZHAI Limei;DUAN Xiaoli;FAN Xianpeng;XIONG Guiyun;LIU Dongbi;GAO Li(Institute of Plant Protection and Soil Fertilizer,Hubei Academy of Agricultural Sciences,Hubei Engineering Research Center for Agricultural Non-point Source Pollution Control,QianJiang Scientific Observing and Experimental Station of Agro-Environment and Arable Land Conservation,Ministry of Agriculture and Rural Affairs,P. R. China,Key Laboratory of Fertilization from Agricultural Wastes,Ministry of Agriculture and Rural Affairs,P. R. China,Hubei Engineering Research Center for Agricultural Environmental Control,Wuhan 430064,China;Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081, China;Agricultural Environment Protection Station of Xishui County,Xishui,Hubei 438200,China)
出处
《土壤学报》
CAS
CSCD
北大核心
2019年第5期1190-1200,共11页
Acta Pedologica Sinica
基金
国家重点研发计划项目（2016YFD0800500）
公益性行业（农业）科研专项（201003014）
农业部长江中游平原农业环境重点实验室开放基金项目共同资助~~
关键词
江汉平原
田面水
形态
动态变化
关键控制期
Jianghan Plain
Surface water
Forms
Dynamic change
Key controlling period
