论文部分内容阅读
为了解植被恢复对侵蚀红壤可溶性有机质含量及结构特征的影响,以福建省长汀县河田镇植被恢复后的侵蚀红壤及对照裸地为研究对象,对两试验地0–60 cm深土壤中可溶性有机质的含量及光谱学特征进行了比较研究。结果表明:侵蚀红壤植被恢复后,土壤可溶性有机碳含量显著提高,在土表到60 cm深度的6个10 cm土层中,植被恢复土壤可溶性有机碳含量分别提高为对照裸地相应土层的5.6、4.7、4.6、3.1、2.4及2.2倍。可溶性有机氮含量在两试验地之间的差异在各土层中不一致。植被恢复各土层侵蚀红壤可溶性有机质的芳香化指数显著高于对照裸地,荧光发射光谱腐殖化指数略高于对照裸地,植被恢复后的侵蚀红壤与对照裸地间荧光同步光谱腐殖化指数无明显差异。荧光同步光谱图中,两试验地侵蚀红壤可溶性有机质的吸收主要为类蛋白质及芳香性脂肪族荧光基团的吸收。傅里叶红外光谱结果显示,与对照裸地相比,植被恢复后的侵蚀红壤土壤可溶性有机质中官能团种类更多,且含有更多芳香碳及羧基碳。两试验地土壤可溶性有机质均表现为芳香化及腐殖化程度随土层的加深而降低。相关性分析显示,土壤可溶性有机质的芳香化及腐殖化指数与土壤碳氮总量有极显著正相关关系。总之,侵蚀红壤经植被恢复后,土壤可溶性有机碳含量及可溶性有机质的芳香化指数显著提高,可溶性有机质的腐殖化指数略有增大,可溶性有机质结构更复杂,更不易被分解,因此有利于土壤肥力的恢复。
In order to understand the effects of vegetation restoration on dissolved organic matter content and structural characteristics in eroded red soils, the eroded red soils and the control bare land after the restoration of vegetation in Hetian Town, Changting County, Fujian Province were selected as research objects. Organic matter content and spectral characteristics of a comparative study. The results showed that the content of soil dissolved organic carbon increased significantly after vegetation restoration in eroded red soils. In six 10 cm soil layers with the depth of 60 cm, the content of soil dissolved organic carbon in the restored vegetation increased to the corresponding soil layers 4.6, 4.7, 4.6, 3.1, 2.4 and 2.2 times. Differences in soluble organic nitrogen content between the two sites were not consistent across all soils. The aromatics index of soluble organic matter in eroded red soils in the vegetation restoration was significantly higher than that in the control bare land, and the humification index of the fluorescence emission spectrum was slightly higher than that of the bare land. After the vegetation was recovered, the fluorescence synchronous spectroscopic humification No significant difference in the index. In fluorescence synchronous spectroscopy, the absorption of soluble organic matter in eroding red soils mainly absorbed the like proteins and aromatic aliphatic fluorophores. Fourier transform infrared spectroscopy showed that there were more functional groups in soil soluble organic matter in the eroded red soil after vegetation restoration compared with bare land and more aromatic carbon and carboxyl carbon. The contents of soil soluble organic matter in both experimental plots showed that the degree of aromatization and humification decreased with the deepening of soil layers. Correlation analysis showed that soil organic matter aromatization and humification index and soil total carbon and nitrogen has a very significant positive correlation. In conclusion, the soil soluble organic carbon content and soluble organic matter aromatics index increased significantly after the restoration of vegetation in eroded red soils. The humification index of soluble organic matter increased slightly, and the structure of soluble organic matter was more complex and less easily decomposed, Soil fertility restoration.