Effects of short-period grazing on soil light fraction and particulate carbon and nitrogen in Zhaosu meadow steppe

摘要

Compared with rangeland vegetation, the response of soil organic matter to grazing was relatively slow, and ermerged a certain hysteretic nature, but the response of soil active organic fractions to changing of external enviroment, including soil microbial mass, readily oxidizable carbon, light fraction organic matter, particulate organic matter, ect., was more sensitive than that of soil organic matter.In order to better reveal the response mechnism of rangleland soil organic matter to grazing in early stage, the influence on soil carbon and nitrogen content of light fraction component, particulate component, the light fraction, the particulate under no grazing (0 cattle/ha), light grazing (0.38 cattle/ha), moderate grazing (0.64 cattle/ha) and heavy grazing (0.94 cattle/ha) condition in Zhaosu meadow steppe by field-controlled grazing experiment and laboratory analysis was studied.