中国生态农业学报2017，Vol.25Issue(5)：625-633,9.DOI:10.13930/j.cnki.cjea.161024
山西省太原市旱作农区大气活性氮干湿沉降年度变化特征
Temporal variation of atmospheric wet/dry reactive nitrogen deposition in Taiyuan rainfed farming area of Shanxi Province
摘要
Abstract
Nitrogen (N) deposition has a series of negative effects on ecosystem, therefore the atmospheric reactive N (Nr) pollution and deposition induced by excessive anthropogenic Nr have become a global environmental concern. Until recent years, researches on Nr deposition and precipitation were conducted at different scales, but still there are few continuous monitoring data about N deposition in rainfed farming areas. Here, the temporal variation of atmospheric wet and dry N depo-sition was quantified using the DELTA system, passive samplers and rain gauge at Hecun Village (which is Yangqu County, Taiyuan City, Shanxi Province) in a four-year period spanning from April 2011 to March 2015. The results showed the average deposition rates of NH3, HNO3, NO2, particle form of NO3-(pNO3-) and particle fore of NH4+ (pNH4+) in the four-year period were 4.50 kg(N)·hm-2·a-1, 3.54 kg(N)·hm-2·a-1, 2.56 kg(N)·hm-2·a-1, 1.62 kg(N)·hm-2·a-1and 2.75 kg(N)·hm-2·a-1, respectively. This led to total dry deposition value of 12.38–18.95 kg(N)·hm-2·a-1, with N dry deposition flux being the highest in 2011, and the lowest in 2014. From April 2011 to March 2015, there was a positive linear correlation between monthly dry N deposition and ammonia deposition (with a correlation coefficient range of 0.8098–0.9371), indicating that ammonia had a significant influence on N deposition of the study area. Total wet N precipitation range was 11.67–41.31 kg(N)·hm-2·a-1 in the region and the average concentrations of NO3--N and NH4+-N in rainfall were 3.20 mg(N)·L-1 and 2.43 mg(N)·L-1, respectively. There were con-siderable differences in annual wet N deposition fluxes in the four-year period, of which it was the highest in 2012 and the lowest in 2014. Moreover, wet N deposition accounted for over 50% of total N deposition. Furthermore, there was a positive linear cor-relation between NO3--N and NH4+-N concentrations in rainwater in the four-year period, and there was also a positive linear cor-relation between NO3--N concentration and rainfall and then a quadratic correlation was also observed between NH4+-N concentra-tion and rainfall. This indicated that rainfall had a significant impact on wet depositions of NO3--N and NH4+-N. Such high deposi-tion rates of Nr in Taiyuan showed a severe Nr pollution from anthropogenic sources and a significant atmospheric N input in croplands. Overall, there were bigger differences in annual wet N deposition than annual dry N deposition for the investigated four-year period in Taiyuan area. Although tested in dry land, the rate of dry deposition was lower than that of wet precipita-tion. This study was important for N management referring to Nr deposition in farmlands and for monitoring N cycle in the farmland ecosystem.关键词
活性氮/干沉降/湿沉降/年度变化/旱作农区Key words
Reactive nitrogen/Dry deposition/Wet deposition/Annual variation/Rainfed farming area分类
资源环境引用本文复制引用
刘平,刘学军,刘恩科,韩彦龙,李丽君,白光洁,许稳,吕薇,张强..山西省太原市旱作农区大气活性氮干湿沉降年度变化特征[J].中国生态农业学报,2017,25(5):625-633,9.基金项目
山西省财政支农项目(2016ZZCX-13)、山西省回国留学人员科研资助项目(2016-133)和2016年度人力资源和社会保障部留学人员科技活动项目择优资助 The study was supported by the Shanxi Financial Project (2016ZZCX-13), the Research Project of Shanxi Scholarship Council of China (2016-133) and the Science and Technology Project for Visiting Scholar of Human Resources and Social Security Ministry of China. （2016ZZCX-13）
