刚果12号桉人工林下土壤微生物与土壤养分研究初报

Characteristics of Soil Microorganisms in a Eucalyptus ABL12 Plantation

以海南省儋州林场刚果12号桉(Eucalyptus ABL12)人工林土壤为对象,研究了刚果12号桉人工林地土壤微生物类群的分布规律及土壤养分的变化。结果表明:在土壤剖面上,土壤微生物具有一定的垂直变化,并随着土层深度的增加而减少,主要集中在0～20 cm的土层中;土壤微生物3大类菌中,细菌所占比例最大,其次为放线菌、真菌;土壤微生物数量还具有一定的季节变化,最大值一般出现在9、10月份;各样地中土壤微生物类群及土壤养分总体表现为:桉-豆科牧草>桉-禾本科牧草>纯桉林,且土壤微生物类群与土壤养分之间存在一定的相关性。本研究结果也表明,经过桉树-牧草间种后,桉树人工林土壤的微生物性质得到了很大改善。

The distribution pattern of soil microorganisms and soil nutrient status in a Eucalyptus ABL12 plantation with different undergrowth were determined in Danzhou, west of Hainan Province. The soil microorganisms showed a tendency of vertical variation, decreasing with the increase of soil depth, and they were manly distributed in 0 -20 cm soil layer. Bacteria were found to be the most abundant, followed by actinomycetes and fungi. Seasonal variation was also observed in the numbers of soil microorganism which were found in September and October at large. The soil microorganisms and soil nutrients in the Eucalyptus stand were lower than those in the controls： the vegetable field and the rubber tree stand. The numbers of soil microorganisms were recorded highest in the vegetable field, followed in a decreasing order by the rubber tree plantation, legume-intercropped plot, herbage-intercropped plot and monoculture plot. These results demonstrated that intercropping E. ABL12 with tropical legumes has improved largely the soil environment for the soil microorganisms to live in, indicative of the better soil microbiological properties and soil nutrient levels.