毛乌素沙地风沙土粒径和矿物组成对固定态铵含量的影响  

Effects of particle size and mineral composition on fixed ammonium of aeolian sandy soil in the Mu Us Sandy Land

作　　者：刘娜 佘维维[1,2] 秦树高[1,2] 乔艳桂 刘靓 张宇清[1,2] Liu Na;She Weiwei;Qin Shugao;Qiao Yangui;Liu Liang;Zhang Yuqing(Yanchi Research Station of the Mu Us Desert,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of National Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,宁夏盐池毛乌素沙地生态系统国家定位观测研究站,北京100083 [2]北京林业大学水土保持国家林业与草原局重点实验室,北京100083

出　　处：《农业工程学报》2020年第23期131-138,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划课题(2016YFC0500905);中央高校基本科研业务费专项(2015ZCQ-SB-02)。

摘　　要：固定态铵是土壤氮素的一种重要形态,对植物生长具有十分重要的作用;然而,风沙土中固定态铵的含量及其影响因素目前并不清楚,限制着对沙地土壤肥力来源及其维持机制的认识。该研究测定了毛乌素沙地裸沙地、沙柳(Salix psammophila)和油蒿(Artemisia ordosica)林地风沙土固定态铵的含量,并分析了土壤粒径及矿物组成对其的影响。结果显示,1)研究区土壤固定态铵平均含量为18.63 mg/kg,占土壤氮库的8.77%,不同植被下土壤中固定态铵含量存在明显差别,油蒿林地土壤固定态铵含量(23.03±1.88 mg/kg)显著高于裸沙地(16.63±0.61 mg/kg)和沙柳林地(16.82±1.25 mg/kg);2)风沙土粒径组成与固定态铵含量显著相关,粒径越细,固定态铵含量越高,粒径越粗,含量越低;3)风沙土矿物组成与固定态铵含量间无显著关系。研究表明,毛乌素沙地风沙土中固定态铵含量取决于土壤物理构成而非矿物化学组成,植被主要通过影响粒径组成而影响其含量。固定态铵是荒漠土壤肥力的重要组成部分,通过合理的植被建设增加土壤细粒物质,有利于提高固定态铵含量,对土地荒漠化治理和生物生产力的提高具有十分重要的意义。Fixed ammonium is commonly defined as the ammonium ion not replaced by neutral salts,particularly between the layers of 2:1 clay mineral.It is also an important component of soil nitrogen pool,and plays a significant role in plant growth.However,the content of fixed ammonium in aeolian sandy soil and its influencing factors are largely unexplored,which limit understanding of the formation of soil fertility and nitrogen cycle in sandy lands.In this study,soil fixed ammonium was determined in three sampling plots(bare sandy land,Salix psammophila land,and Artemisia ordosica land)in the Mu Us Sandy Land,and further to examine the effects of soil particle size and mineral composition on fixed ammonium.In June 2019,ten 5 m×5 m subplots were randomly selected in each sampling plot.In each subplot,ten soil cores at 0~20 cm depths were randomly collected,and mixed to create one composite sample.All soil samples were air-dried and divided into three fractions(>0.25 mm,0.1-0.25 mm,<0.1 mm).The contents of fixed ammonium in all soil fractions were measured by the Silva-Bremner method.Soil total nitrogen was analyzed using a vario EL III elemental analyzer(Elementar,Germany).The soil mineral composition was determined by the X-ray diffraction(D8 Advance,Bruker Biospin,Germany).The results showed that the average content of soil fixed ammonium in the research site was 18.63 mg/kg,accounting for 8.77% of the soil nitrogen pool,where the soil fixed ammonium and total nitrogen content were most distributed in the Artemisia ordosica land(23.03±1.88 mg/kg and 274.71±8.38 mg/kg,respectively),followed by the Salix psammophila land(16.82±1.25 mg/kg and 197.15±6.74 mg/kg,respectively),and the least in the bare sandy land(16.63±0.61 mg/kg and 145.99±9.45 mg/kg,respectively).The composition of soil particle significantly differed among three different plots,with more fine-textured soils in Artemisia ordosica land than that in Salix psammophila land and bare sandy land.In addition,the content of fine-textured soils in Salix psammo

关 键 词：植被 粒径 风沙土 固定态铵 矿物组成 毛乌素沙地 

分 类 号：S151.93[农业科学—土壤学]