植物根系与土壤抗冲性

Plant Roots and Soil Anti-scourability

植物根系在改善土壤生态环境方面有两大显著特点:一是根系改善土壤物理性质,增加土壤非毛管孔隙度,强化降水就地入渗的水文生态功能;二是根系尤其是≤1mm径级的须根稳定土层结构,增加土壤>2mm粒级水稳性团粒及有机质含量,创造抗冲性土体构型的生物动力学性质。该文从描述黄土高原土壤抗冲性的成因入手,综述了近年来植物根系提高土壤抗冲性研究的新成果,重点讨论了有效根密度的剖面分布与土壤抗冲性及其他物理性质改善效应的关系。

Plant roots have two significant characteristics in improving soil eco-environment:one is the ecological function of roots to retain water and infiltrate rainfall into soil by enhancing nocapillary poresity of soil: the other is bio-dynamic role of fibrous roots less than lmm in diameter to construct the soil profile with anti-scourability by increasing water-stable aggregates of >2mm in diameter and organic matter of soil. From the descriptions of forming causes of soil anti-scourability on Loess Plateau, a recent progress in researches of soil anti-scourability intensified by plant roots has been summarized, and the interrelation of the distribution of effective root density in soil profile with the effects of roots on soil anti-scourability and other physical properties is emphatically discussed.