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NO3--N的形式存在,各类生境土壤NH4＋-N平均含量比NO3--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2.7mg.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。
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： （1）The NO3--N accounted for larger proportion of mineral N in sandy land. The average NH4＋-N concentration was lower from 58. 2 % to 79.7 % than that of NO3--N across all habitats. （2）Soil 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 2.7mg·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 and3.4 mg·m^-2·d^-1. （3）From 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. （4）Nitrified N accounted for 100% of mineralized N in all the five habitats. This indicated that the sandy land was prone to losing inorganic N.
出处
《中国沙漠》
CSCD
北大核心
2009年第3期438-444,共7页
Journal of Desert Research
基金
中国科学院西部之光西部博士项目(O828881002)
国家重点基础研究发展计划专题项目(2009CB421303-4)
国家自然科学基金项目(40601008
40471004)共同资助
关键词
土壤氮素
矿化/硝化作用
科尔沁沙地
soil nitrogen
net N mineralization/nitrification
Horqin sandy land
