川西北高寒沙化草地有机氮组分特征

发布时间：2018-07-04 20:02

本文选题：川西北 + 高寒草地　；参考：《中国沙漠》2017年03期

【摘要】：通过野外调查,结合土样采集及室内分析(Bremner法),研究了川西北不同程度沙化草地(未沙化、轻度沙化、中度沙化、重度沙化、极重度沙化)不同土层(0~20、20~40、40~60、60~80、80~100 cm)的有机氮组分特征。结果表明:随着草地沙化程度的提高,不同土层的土壤有机氮组分含量均呈下降趋势,其中0~20 cm土层变化最明显,土壤酸解全氮(TAHN)、非酸解氮(NAHN)、酸解氨态氮(AN)、氨基酸态氮(AAN)、氨基糖态氮(ASN)、未知态氮(HUN)含量降低幅度分别为90.58%、69.28%、91.44%、91.01%、87.77%、88.99%;与未沙化草地相比,极重度沙化草地有机氮组分含量显著降低,且下降幅度呈现出AANANHUNASNNAHN特征,表明AN、AAN较ASN、HUN、NAHN对生态环境变化更为敏感;不同沙化阶段土壤有机氮组分含量降低幅度存在较大差异,但均呈现出沙化前期降幅相对较大,沙化后期降幅相对较小的变化特征,表明草地沙化前期土壤有机氮素流失更为严重。因此,及时对沙化草地的治理,对于防治沙化草地氮素流失具有重要意义。
[Abstract]:Based on field investigation, soil sample collection and indoor analysis (Bremner method), the organic nitrogen fractions of different soil layers (0 ~ 20 ~ 20 ~ 20 ~ (20) ~ (40) C ~ (40) C ~ (60) C ~ (60) C ~ (60) C ~ (60) ~ 0 ~ (80) ~ (100 cm) of sandy grassland (non-desertification, light desertification, moderate desertification, heavy desertification, very heavy desertification) in northwest Sichuan were studied. The results showed that with the increase of grassland desertification, the content of soil organic nitrogen components in different soil layers showed a decreasing trend, and the change of soil organic nitrogen content in 0 ~ 20 cm soil layer was the most obvious. Soil total nitrogen (TAHN), non-acidolysis nitrogen (NAHN), acidolysis ammonia nitrogen (an), amino acid nitrogen (AAN), aminosaccharide nitrogen (ASN), unknown nitrogen (Hun) were decreased by 90.5889.2891.4491.0177.777.7788.999.The organic nitrogen fractions of extremely heavy sandy grassland decreased significantly compared with non-sandy grassland. The decrease range showed the characteristics of AANANHUNASNNAHN, which indicated that ANNNAAN was more sensitive to ecological and environmental changes than ASNN HUNNAHN, and that the decrease of soil organic nitrogen content in different desertification stages was different, but the decrease of soil organic nitrogen content was relatively large in the early stage of desertification. The change of soil organic nitrogen loss in the early stage of grassland desertification was more serious than that in the later stage of desertification. Therefore, it is of great significance to control the nitrogen loss of sandy grassland in time.
【作者单位】：四川农业大学资源学院;开江县国土资源局;
【基金】：国家科技支撑计划项目(2008BAK51B02) 四川省科技支撑计划项目(2013SZ0110)
【分类号】：S812.2

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