施氮对荒漠化草原土壤理化性质及酶活性的影响  

Effects of nitrogen addition on soil physico-chemical properties and enzyme activities in desertified steppe

作　　者：苏洁琼[1] 李新荣[1] 鲍婧婷[1,2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所沙坡头沙漠研究试验站,兰州730000 [2]中国科学院大学,北京100049

出　　处：《应用生态学报》2014年第3期664-670,共7页Chinese Journal of Applied Ecology

基　　金：中国科学院知识创新工程重要方向性项目(KZCX2-EW-301);国家自然科学基金项目(40930636)资助

摘　　要：以腾格里沙漠东南缘的荒漠化草原为对象，设置添加0、1．75、3．5、7和14gN·m^-2·a^-15个氮素水平，研究了施氮对该地区土壤理化性质和土壤酶活性的影响．结果表明：施氮导致表层（0—10cm）和下层（10～20cm）土壤中总氮、NO3^--N、NH4＋-N和有效氮的累积，土壤pH下降，对土壤有一定的酸化作用．施氮明显抑制了土壤酶活性，且不同酶活性在氮素投加水平、土层深度和年际间有所差异．土壤酶活性与土壤氮素水平、土壤pH及土壤水分之间存在显著相关关系．To investigate the impacts of nitrogen （N） enrichment on soil physico-chemical property and soil enzyme activities in desert ecosystems, a field experiment by adding N at 0, 1.75, 3.5, 7, or 14 g N . m^-2 . a^-1 was conducted in a temperate desert steppe in the southeastern fringe of the Tengger Desert. The results showed that N addition led to accumulations of total N, NO3--N, NHa＋-N, and available N in the upper soil （0-10 em） and subsoil （10-20 cm）, however, reduc- tions in soil pH were observed, causing soil acidification to some extent. N addition pronouncedly inhibited soil enzyme activities, which were different among N addition levels, soil depths, and years, respectively. Soil enzyme activities were significantly correlated with the soil N level, soil pH, and soil moisture content, respectively.

关 键 词：氮素 土壤酶活性 荒漠化草原 

分 类 号：S812.2[农业科学—草业科学]