中国农业科学2011，Vol.44Issue(24)：5021-5030,10.DOI:10.3864/j.issn.0578-1752.2011.24.007
黄土高原典型土壤有机氮组分剖面分布的变化特征
The Changing Characteristics of Profile Distribution of Soil Organic Nitrogen Component of the Typical Soil Types on the Loess Plateau
摘要
Abstract
[Objective] In order to evaluate the effects of location, soil depth and land use on the contents of soil organic nitrogen (N), the size and composition of soil organic N pool were studied using a large variety of soil profiles sampled on the Loess Plateau. [Method] Based on different soil types and land-use patterns, 96 soil samples in 8 depth classes(0-10,10-20,20-40,40-60, 60-80, 80-100, 100-120 and 120-140 cm) were collected from different regions on the Loess Plateau. The method of Bremner was used to test the soil organic N content. [Result] Even with the same land use pattern, the content of soil depth-specific total soil hydrolysable N and its components increased from north to south on the Loess Plateau. The proportion of organic N components within total hydrolysable N was stable. However, the proportion of total hydrolysable N in total soil N significantly decreased within 0-40 cm layers and remained stable below 40 cm. The content of four components significantly decreased within 0-40 cm, slightly decreased within 40-80 cm and remained stable below 80 cm. The percentage of organic N components in total hydrolysable N differed among soil types: amino acid-N (39.5%) > ammonia N(32.3%)>HUN fraction(25.7%) > amino sugar-N(2.5%) in Ust-Sandiic Entisols; amino acid-N (36.0%) > ammonia N (35.6%) > HUN fraction (25.3%) > amino sugar-N (3.1%) in Los-Orthic-Entisol; and ammonia N (50.6%)>amino acid-N (29.0%)>HUN fraction (17.5%)>amino sugar-N (2.8%) in Eum-Orthic Anthrosol. Except ammo sugar-N, all the soil organic N components within 0-40 cm in grassland were more than those in cropland; however, the inter-layer variation became smaller with the profiles. [Conclusion] From north to south of the Loess Plateau, the content of organic N and its different forms increased, the proportion of organic N component in total hydrolysable N was stable in the same layer under the same land-use patterns. However, the proportion of total hydrolysable N in total soil N decreased. Amino acid-N and ammonia N were the major forms of the soil organic N on the Loess Plateau. Land-use pattern had a great effect on the content and distribution of N. Both organic N and its components in grassland was more than that in cropland.关键词
有机氮组分/剖面/黄土高原/分布特征Key words
organic nitrogen components/profile/the Loess Plateau/distribution characteristics引用本文复制引用
党亚爱,王国栋,李世清..黄土高原典型土壤有机氮组分剖面分布的变化特征[J].中国农业科学,2011,44(24):5021-5030,10.基金项目
公益性行业科研专项(201103003)、中央高校2009基本科研业务费专项资金资助(QN2009051)、2008校内博士科研启动费(z1110020833) （201103003）
