滇西北亚高山不同土地利用类型土壤容重与根系生物量的比较研究

调查了滇西北亚高山5种土地利用类型表层土壤(0～15 cm)的含水量、容重、剖面特征以及地下根系生物量。就0～15 cm土壤层的平均含水量而言,刈草草地>放牧草地>种植草地>青稞地>荒山灌丛,说明耕种(青稞地)使土壤干燥,荒山灌丛土壤含水量较低,与其所处的微地形有关。青稞地由于人为翻耕的原因,表层土壤中植物根系很少,土壤容重最大,其他4种不同土地利用类型表层土壤的容重均≤1.00 g/cm3,可能是土壤层中有大量植物根系的原因。种植草地经过1次翻耕,其土壤容重小于经过多次翻耕的青稞地,大于其他3种土地利用类型,说明土壤植物根系含量的多少直接影响着土壤容重的大小。在土壤容重计算过程中,应考虑植物根系的作用。

Comparative Studies on Soil Bulk Density and Underground Roots Biomass under Different Land Use Types in Northwestern Yunnan Province

The soil bulk density,soil moisture and soil section,and underground roots biomass under different land use types in northwestern Yunnan Province were investigated.The average soil moisture in 0~15 cm was forage meadows>grazing pastures>cultivated meadows> barley terra>deserted-hill boscages.It was resulted that culture could make the soil dry and the lowest soil moisture of deserted-hill boscages was related to the altitude of the hill.Being man-made culture,there was a little roots underground barley terra,which made the soil bulk density was the biggest.For the roots of the soil,the soil bulk density of the other 4 kinds of meadows were less than or equal to 1.00 g/cm3.The soil bulk density of cultivated meadows was less than barley terra and more than the other 3 kinds of meadows.It was said that the roots biomass could affect the soil bulk density.So the effect of plant roots should be considered in the calculation of soil bulk density.