黄土高原草地植被恢复与土壤抗冲性形成过程──Ⅲ.植被恢复对土壤腐殖质物质及水稳性团聚体的影响

Vegetation Restoration and Improvement Process of Soil Anti-scourability in Loess Plateau──Ⅲ. Effect of Vegetation Restoration on Soil Humus and Aggregations

植被恢复对于抗冲性土体构型形成具有重要意义。随着植被演替，土壤腐殖质物质含量得到提高，但C／N基本保持恒定。植被恢复可改善水稳性团聚体质量，增加团聚体平均重量直径。沙打旺草地改善水稳性团聚体作用于同期自然恢复草地，胡敏酸和植物0．1～0．4mm毛根对于＞1mm水稳性团聚体形成都具显著作用。

Vegetation restoring had a important contribution on improving soil structure. The substance of humus were improved as vegetation succession, however there was no significant change on C/N. The mean weight of aggregation was increased during vegetation succession. The artificial grassland showed the better affect on improving aggregation than natural vegetation succession. Both humus acid and plant fiber root with the diameter of 0. 1 -- 0. 4mm could improve the formation of soil aggregation.