title: [Effects of nitrogen addition on soil physico-chemical properties and enzyme activities in desertified steppe].
abstract: 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 x 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, NO(3-)-N, NH(4+)-N, and available N in the upper soil (0-10 cm) and subsoil (10-20 cm), however, reductions 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.
authors.forename: Jie-Qiong
authors.initials: JQ
authors.lastname: Su
authors.forename: Xin-Rong
authors.initials: XR
authors.lastname: Li
authors.forename: Jing-Ting
authors.initials: JT
authors.lastname: Bao
mesh_terms: D055598:Chemical Phenomena; D003889:Desert Climate; D004798:Enzymes / Q000737:chemistry*; D065948:Grassland; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D014867:Water
chemical_list: D004798:Enzymes; D012987:Soil; D014867:Water; D009584:Nitrogen