放牧对草地土壤含水量与容重及地下生物量的影响

Effects of Grazing on Soil Moisture,Bulk and Pasture Underground Biomass

探究不同放牧压下,滇东北人工草地土壤含水量、土壤容重和地下生物量的变化规律。用土钻分层取样以烘干法测定土壤含水量,环刀法测定土壤容重,土钻取样以对角线法测定草地植物地下生物量。放牧对土壤表层(0～5cm)含水量和土壤容重的影响较大,表层土壤含水量随牧压增大而减小,轻牧下土壤容重的波动较小;草地植被地下生物量主要分布在0～10cm土层,占0～30cm土层植物地下生物量的64%～74%。适度放牧能在一定程度上稳定土壤结构,草地植物地下生物量随牧压增加而减少。

The study on changes of soil moisture,soil bulk and pasture underground biomass under different grazing pressure in northeast Yunnan Province of China were conducted.Soil moisture,bulk and plant belowground biomass were measured by soil drill layered drying,ring shear testing and diagonal process methods.Grazing mainly affected soil moisture and bulk of top soil （0-5 cm）,the surface soil moisture decreased as grazing pressure increased,changes on soil bulk were less under light-grazing pressure;underground biomass of pasture vegetation mainly focused on 0-10 cm soil,which consisted of 64%-74% of total belowground biomass across 0-30 cm soil.Moderate grazing would make soil structures stable in some extents and pasture belowground biomass decreased as grazing pressures increased.