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中国沙漠 ›› 2009, Vol. 29 ›› Issue (3): 438-444.

• 生物土壤与生态 • 上一篇    下一篇

科尔沁沙地不同生境土壤氮矿化/硝化作用研究

李玉强, 赵哈林, 李玉霖, 崔建垣, 左小安   

  1. 中国科学院寒区旱区环境与工程研究所, 甘肃 兰州 730000
  • 收稿日期:2008-01-21 修回日期:2008-03-19 出版日期:2009-05-20 发布日期:2009-05-20

Soil Nitrogen Mineralization and Nitrification in Different Habitats, Horqin Sandy Land

LI Yu-qiang, ZHAO Ha-lin, LI Yu-lin, CUI Jian-yuan, ZUO Xiao-an   

  1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2008-01-21 Revised:2008-03-19 Online:2009-05-20 Published:2009-05-20

摘要: 利用顶盖埋管原位培育法测定了科尔沁沙地不同生境(丘间低地、固定、半固定、半流动和流动沙丘)土壤氮素矿化/硝化速率的月际动态及净矿化/硝化量。结果表明:①沙地土壤无机氮主要以NO-3-N的形式存在,各类生境土壤NH+4-N平均含量比NO-3-N低58.2%~79.7%;②土壤氮素矿化/硝化速率随植被与土壤条件的恶化呈现递减的趋势,从丘间低地到流动沙丘,净矿化速率分别为61.0、43.4、29.1、5.3 mg·m-2·d-1和2.7 mg·m-2·d-1,净硝化速率分别为61.8、46.2、30.1、6.2 mg·m-2·d-1和3.4 mg·m-2·d-1;③从丘间低地到固定、半固定、半流动和流动沙丘,矿化氮总量分别减少28.8%、52.3%、91.4%和95.5%,硝化总量分别减少25.3%、51.3%、90.0%和94.5%;④不同类型生境土壤净硝化氮占净矿化氮的比例都为100%,表明沙地土壤中植物可利用氮素易于淋溶或氨挥发损失。

关键词: 土壤氮素, 矿化/硝化作用, 科尔沁沙地

Abstract: Soil net N mineralization and nitrification were determined using the PVC tube closed-top in situ incubation method in different habitats (interdunal lowland, fixed, semi-fixed, semi-moving and moving sand dune) in Horqin sandy land. The results showed that: ①The NO-3-N accounted for larger proportion of mineral N in sandy land. The average NH+4-N concentration was lower from 58.2% to 79.7% than that of NO-3-N across all habitats. ②Soil net N mineralization and nitrification rates decreased along the degenerating of plant and soil. Net N mineralization rate was 61.0, 43.4, 29.1, 5.3 mg·m-2·d-1 and 2.7 mg·m-2·d-1 in interdunal lowland, fixed, semi-fixed, semi-moving and moving sand dune, respectively, whereas N nitrification rate was 61.8, 46.2, 30.1, 6.2 mg·m-2·d-1 and 3.4 mg·m-2·d-1. ③From interdunal lowland to fixed, semi-fixed, semi-moving and moving sand dune, the total net N mineralization was decreased by 28.8%,52.3%, 91.4% and 95.5%, and total net N nitrification by 25.3%, 51.3%, 90.0% and 94.5%, respectively. ④Nitrified N accounted for 100% of mineralized N in all the five habitats. This indicated that the sandy land was prone to losing inorganic N.

Key words: soil nitrogen, net N mineralization/nitrification, Horqin sandy land

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