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对桉树人工林间种象草(Pennisetum americanum×P.purpureum)×(Pennisetum purpureum)复合经营模式的土壤物理性质及养分含量进行研究。结果表明:对比桉树纯林,桉-草经营模式的土壤容重降低了14.75%~22.12%,土壤总空隙度和毛管孔隙度分别提高了3.57%~16.51%和15.39%~18.67%,土壤饱和持水量和田间持水量分别提高了6.01%~34.14%和16.95%~43.99%,林地土壤物理性质得到改善。桉-草模式下林地土壤pH值降低了9.2%~10.5%,土壤有机质含量提高87.5%~24.2%;土壤全量N、P和速效N、P的含量提高7.06%~89.99%,提高幅度的大小排列顺序为速效N>全量P>全量N>速效P,全量K和速效K含量减少,单位面积蓄积量提高14.14%。A层土壤理化性状改善幅度大于B层。桉树人工林间种象草复合经营模式,有助于改善林地土壤结构,提高林地养分含量,促进林木生长,是比较适宜推广发展的桉树复合经营模式。
The soil physical properties and nutrient contents of the Pennisetum americanum × P. purpureum × Pennisetum purpureum compound management model were studied. The results showed that the soil bulk density decreased by 14.75% -22.12% compared with the eucalyptus-pure forest and eucalyptus-grasses management system, and the total soil porosity and capillary porosity increased by 3.57% -16.51% and 15.39% -18.67%, respectively. The water quantity and field water capacity increased by 6.01% -34.14% and 16.95% -43.99% respectively, and the physical properties of forest soil were improved. The soil pH value decreased by 9.2% -10.5% and soil organic matter content increased by 87.5% -24.2% under the eucalyptus-grazing mode. The contents of total N, P and available N, P in soil increased by 7.06% -89.99% The order was available N> total amount P> total amount N> available P, total amount K and available K decreased, and the volume per unit area increased by 14.14%. The improvement of soil physical and chemical properties in layer A was greater than that in layer B. Eucalyptus planted as a grass plant species of mixed management mode, contribute to improving the soil structure of forest land, raising the nutrient content of forest land, and promote the growth of trees, it is more appropriate to promote the development of eucalyptus composite business model.