中文摘要：

为探究荒漠土壤有机氮组分对封育年限的响应规律,研究了不同封育年限（封育时间为0、1、4和11a）对中度退化伊犁绢蒿（Seriphidium transiliense）荒漠草地土壤全氮（total nitrogen,TN）、轻组氮（light fraction organic nitrogen,LFON）、颗粒氮（particulate organic nitrogen,PON）、微生物量氮（soil microbial biomass nitrogen,SMBN）及其分配比例的影响。结果表明,与封育0a相比,其它封育年限5-10、10-20、30-50cm土层的TN含量均显著降低（P〈0.05）,且0-50cm土层TN含量随封育年限延长呈“降-升”趋势;封育11a,0-5cm土层PON含量达到最高,而封育4a,5-10和20-30cm土层PON分配比例显著增加;0-20cm土层LFON含量增加显著,且0-5cm土层含量最高。0-50cm土层SMBN随封育年限增加呈“降-升”趋势,而封育4a,5-10和20-30cm土层SMBN分配比例显著高于封育0a和封育1a（P〈0.05）;0-10cm土层LFON和0-50cm土层LFONR与封育年限呈显著正相关。总之,短期封育（1～11a）下,中度退化伊犁绢蒿荒漠土壤全氮含量仍未得到恢复,但促进了LFON、PON、SMBN及其分配比例的增加。

英文摘要：

To explore the effects of different grazing exclusion lengths on soil organic nitrogen, we soil nitrogen, particulate organic nitrogen, light fraction organic nitrogen, soil microbial their distribution ratios in a moderately degraded Seriphidium transiliense desert. The grazing exclusion lengths on the percentage of soil organic nitrogen was researched using a exclusion year, four grazing-exclusion years and eleven grazing-exclusion years. Compared biomass influence control, studied total nitrogen and of different one grazing- with the control, the content of total soil nitrogen significantly decreased in 5--10, 10--20 and 30--50 cm of soil depth and the con- tent of total nitrogen in 0--50 cm of soil depth appeared first to decrease then increased with the increase in grazing-exclusion years. The particulate organic nitrogen was highest in 0--5 cm of soil depth after eleven graz- ing-exclusion years, with a significant increase in the accumulation of particulate organic nitrogen distribution ratios in soil depths of 5--10 and 20--30 cm. Light fraction organic nitrogen significantly increased in 0--20 and 0--5 cm of soil depth, while it reached the highest after four grazing-exclusion years. The soil microbial bio- mass nitrogen appeared first to decrease then increased in 0--50 cm of soil depth. Comparing four grazing-ex- clusion years with the control and one grazing-exclusion year, soil microbial biomass nitrogen distribution ratio significantly increased in 5--10 cm and 20--30 cm of soil depth. Correlation among grazing-exclusion years with light fraction organic nitrogen in 0--10 cm of soil depth and light fraction organic nitrogen distribution ratio in 0--50 cm of soil depth was significantly positive. In conclusion, the content of total soil nitrogen was not recov- ered, but light fraction organic nitrogen, particulate organic nitrogen, soil microbial biomass nitrogen and their distribution ratios increased after short-term grazing exclusion （1~11 a） in moderately degraded S. transiliense desert.