机构地区:[1]山西省农业科学院农业环境与资源研究所/山西省土壤环境与养分资源重点实验室,太原030031 [2]中国农业大学资源与环境学院,北京100193 [3]山西省农业科学院旱地农业研究中心,太原030031
出 处:《中国生态农业学报》2017年第5期625-633,共9页Chinese Journal of Eco-Agriculture
基 金: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);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~~
摘 要:鉴于大气氮素沉降对整个生态系统的重要影响,我国近年来陆续开展了不同尺度的大气氮素干、湿沉降的研究,但少有农业区多年连续监测的资料。本研究利用DELTA系统、被动采样器和雨量器在山西省太原市郊区阳曲县河村旱作农业区进行了4年的监测试验,观测大气氮素干、湿沉降的时间变异。结果表明:2011年4月—2015年3月,河村4年大气活性氮NH_3、HNO_3、NO_2、颗粒态NO_3^-(pNO_3^-)、颗粒态NH_4^+(pNH_4^+)平均沉降量分别为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^(-1)、2.75 kg(N)·hm^(-2)·a^(-1),大气氮素干沉降总量为12.38~18.95 kg(N)·hm^(-2)·a^(-1),以2011年的氮干沉降量最高,2014年的最低。2011年4月—2015年3月各月氮干沉降量与氨气沉降量之间存在显著正相关,相关系数在0.809 8~0.937 1,由此可知,该地区活性氮沉降主要受农业氨气排放的影响。河村4年雨水中NO_3^-、NH_4^+平均浓度分别为3.20 mg(N)·L^(-1)和2.43 mg(N)·L^(-1),大气氮素湿沉降11.67~41.31 kg(N)·hm^(-2)·a^(-1)。年度间氮素湿沉降存在很大差异,以2012年氮素年湿沉降量最高,2014年最低,每年大气氮素湿沉降占氮总沉降量的份额超过50%。此外,4年湿沉降中不仅NO_3^--N和NH_4^+-N之间、且二者与降雨量也呈显著线性或二次相关关系,说明降雨量对NO_3^--N和NH_4^+-N的湿沉降影响较大。本研究表明太原市旱作农区不同年份间氮素湿沉降比干沉降差异更大,且总沉降数量较高。虽然是旱作区,该地区氮素干沉降略低于湿沉降。研究结果为该地区农田氮肥施用和氮素循环监测提供了理论依据。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 deposition 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 April2011to March2015.The results showed the averagedeposition rates of NH3,HNO3,NO2,particle form of NO3(pNO3)and particle fore of NH4+(pNH4+)in the four-year periodwere4.50kg(N)·hm2a1,3.54kg(N)·hm2a1,2.56kg(N)·hm2a1,1.62kg(N)·hm2a1and2.75kg(N)·hm21,respectively.This led to total dry deposition value of12.38-18.95kg(N)·hm2a1,with N dry deposition flux being the highest in2011,and the lowest in2014.From April2011to March2015,there was a positive linear correlation between monthly dry N deposition and ammonia deposition(with a correlation coefficient range of0.8098-0.9371),indicating that ammonia had a significant influence on N deposition of the study area.Total wet N precipitation range was11.67-41.31kg(N)·hm2·a1in the region and the average concentrations of NO3-N and NH4+-N in rainfall were3.20mg(N)·L1and2.43mg(N)·L1,respectively.There wereconsiderabledifferences in annual wet N deposition fluxes in the four-year period,of which it was the highest in2012and the lowest in2014.Moreover,wet N deposition accounted for over50%of total N deposition.Furthermore,there was a positive linear correlation between NO3-N and NH4+-N concentrations in rainwater in the four-year period,and there was also a positive linear correlationbetween NO3-N concentration and rainfall and then a quadratic correlation was also observed between NH4+-N concentration and rainfall.This indicate
分 类 号:X53[环境科学与工程—环境工程]
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