模拟氮沉降对油松土壤水溶性碳氮及其光谱特征的影响  

Effects of Simulated Nitrogen Deposition on Soil Water-Soluble Carbon and Nitrogen Fractions and Their Spectral Characteristics in the Land of Pinus tabuliformis

作　　者：翟珈莹 何俐蓉 吴阳 王国梁 薛萐[1,5] ZHAI Jiaying;HE Lirong;WU Yang;WANG Guoliang;XUE Sha(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;Shaanxi Institute of Land Engineering Technology,Xi′an 710016,China;College of Forestry,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]中国科学院大学,北京100049 [3]陕西地建土地工程技术研究院,西安710016 [4]西北农林科技大学林学院,陕西杨凌712100 [5]西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《水土保持研究》2020年第2期136-141,148,共7页Research of Soil and Water Conservation

基　　金：十三五国家重点研发计划(2016YFC0501707);国家自然科学基金(41771557);中科院西部青年学者项目(XAB2015A05).

摘　　要：大气氮沉降对土壤水溶性碳氮含量变化的影响目前还没有一致的结论,为研究氮沉降对黄土高原林地土壤水溶性碳氮的影响,以人工油松林为研究对象,采用氮添加的方式模拟氮沉降,设置3个氮添加梯度,分别为N3[3 g/(m2·a)],N6[6 g(/m2·a)],N9[9 g/(m2·a)],并选不施氮[CK,0 g/(m2·a)]作为对照处理,对土壤水溶性碳、氮组分及其光谱学特征进行了研究。结果表明:氮添加增加了水溶性总氮(WSN)和水溶性硝态氮(WNO-3-N)含量,随着氮添加水平增加均呈增长趋势,水溶性有机氮(WSON)、水溶性铵态氮(WNH+4-N)和WSON/WSN含量先降低后升高;对土壤水溶性有机碳(WSOC)没有显著影响。氮添加对土壤水溶性有机物质光谱特性影响不显著,三维荧光光谱分析表明土壤水溶性有机质主要由类富里酸物质、芳香族蛋白质物质组成,类富里酸物质随氮添加水平先降低后升高,类芳香族蛋白质物质在土壤表层呈升高趋势。氮沉降通过微生物的转化固定作用使C和N在土壤中积累,对土壤水溶性有机质产生了一定的影响,但微生物及组分分配、元素转化各过程的耦合及对氮沉降的响应机制还不清楚。There is no consistent conclusion about the effect of atmospheric nitrogen deposition on the change of soil water-soluble carbon and nitrogen fractions.In order to study the effect of nitrogen deposition on soil water-soluble carbon and nitrogen fractions of forestland on the Loess Plateau,the simulated nitrogen deposition was conducted with the method of nitrogen addition into the Pine tabuliformis community.The four nitrogen addition gradients are CK[0 g/(m2·a)],N3[3 g/(m2·a)],N6[6(g/m2·a)],N9[9 g/(m2·a)].The results showed that nitrogen addition increased soil water-soluble total nitrogen(WSN),water soluble nitrate nitrogen(WNO-3-N)content,which indicated the increasing trend with the increase of nitrogen addition level;content of water-soluble organic nitrogen(WSON)and water-soluble ammonium nitrogen(WNH+4-N),WSON/WSN decreased at first and then increased with nitrogen addition level;nitrogen addition had no significant effect on the contents of WSOC and the spectral characteristics of soil water-soluble organic matter;the fluorescence emission spectrum showed that the main humus types of soil water soluble organic matter were fulliacid-like substances and aromatic protein substances,fulliacid-like substances decreased at first and then increased with nitrogen addition level,and aromatic protein substances presented the increasing trend in the surface soil.Nitrogen deposition accumulates C and N in the soil through microbial transformation and fixation,and has impact on soil water-soluble organic matter.However,the mechanism of microbial and component distribution,coupling of various processes of element transformation and response to nitrogen deposition are still unclear.

关 键 词：氮沉降 水溶性碳氮 三维荧光光谱 

分 类 号：S714[农业科学—林学]