Song Ya-Hui, Zhang Jiao-Yang, Liu Hong-Fei, Xue Sha, Li Yang-Yang
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Huan Jing Ke Xue. 2020 Feb 8;41(2):905-913. doi: 10.13227/j.hjkx.201907085.
The plantation on the Loess Plateau was selected as the research site to study the changes of soil water-soluble carbon and nitrogen content and components of soil dissolved organic matter (SDOM) under different management measures (litter removal, young forest, shrubs, grassland). The uncleared plantation was used as the control. Results show that the soil water-soluble organic carbon content of shrubs and young forests was significantly higher than that in other management measures. The content of soil water-soluble organic carbon decreased with an increase in soil depth, whereas soil water-soluble organic carbon/soil organic carbon (WSOC/SOC) increased. The change of soil water-soluble nitrogen content corresponded to that of water-soluble carbon. The content of soil water-soluble nitrogen content in the young forest was higher than that of other management measures, and generally decreased with an increase in depth. Different management measures have significant effects on SDOM components. Based on three-dimensional fluorescence spectroscopy combined with parallel factor (EEM-PARAFAC) analysis, four components of SDOM are identified, which are mainly divided into categories, humus, protein-like, and soluble microbial metabolites in three major categories, among which the main component of the SDOM is the rich acid humus, and the highest content in the soil of the young forest of is rich acid. The results suggested that management measures had certain effects on soil water-soluble carbon and nitrogen content as well as SDOM components, especially in young forests and shrubs. The young forest and shrubs increased the content of soil water-soluble organic carbon and water-soluble nitrogen, enhanced their ability to migrate and transform in the soil, and changed the structural composition of soil organic matter, hence enhancing the degree of humification and further improving soil quality.
以黄土高原人工林为研究地点，研究不同管理措施（去除凋落物、幼林、灌木、草地）下土壤水溶性碳氮含量及土壤溶解有机质（SDOM）组分的变化。以未清理的人工林作为对照。结果表明，灌木和幼林的土壤水溶性有机碳含量显著高于其他管理措施。土壤水溶性有机碳含量随土壤深度增加而降低，而土壤水溶性有机碳/土壤有机碳（WSOC/SOC）升高。土壤水溶性氮含量的变化与水溶性碳的变化一致。幼林土壤水溶性氮含量高于其他管理措施，且一般随深度增加而降低。不同管理措施对SDOM组分有显著影响。基于三维荧光光谱结合平行因子（EEM-PARAFAC）分析，鉴定出SDOM的四个组分，主要分为腐殖质、类蛋白质和可溶性微生物代谢产物三大类，其中SDOM的主要成分为富里酸腐殖质，幼林土壤中富里酸含量最高。结果表明，管理措施对土壤水溶性碳氮含量及SDOM组分有一定影响，尤其是在幼林和灌木林中。幼林和灌木林增加了土壤水溶性有机碳和水溶性氮的含量，增强了它们在土壤中的迁移转化能力，改变了土壤有机质的结构组成，从而提高了腐殖化程度，进一步改善了土壤质量。
