桉树纯林和桉—珍混交林造林前后土壤理化性质的比较

Comparison of soil physical and chemical properties before and after the afforestation of Eucalyptus gradis pure plantation and mixed plantation of E. gradis with precious hardwood

为了探讨桉树纯林和桉树-珍贵树种混交林造林前后土壤理化性质的变化趋势。在广西南宁市郊南面的马尾松林采伐迹地上,分别营造桉树纯林(EP)和桉树-珍贵树种混交林(EM)两种人工林模式,进行造林前后土壤(0~60 cm土层)理化性质的比较研究。结果表明:1)EP和EM土壤容重为1.097~1.433 g/cm3;总孔隙度为47.32%~59.64%,其中非毛管孔隙度为7.76%~17.67%;通气度为11.33%~19.62%;饱和、毛管和田间持水量依次为23.58%~42.16%、21.11%~39.76%和9.19%~37.77%。2)土壤p H值为4.28~4.75;有机质为4.12~29.01 g/kg;全N、水解N分别为0.18~0.72 g/kg、27.96~87.61 mg/kg;全P、有效P分别为0.16~0.30 g/kg、0.45~3.29 mg/kg;全K、速效K分别为1.11~2.76 g/kg、0.16~0.29mg/kg。3)3年生桉树纯林和桉树-珍贵树种混交林两种人工林模式,在造林前后的各项土壤理化指标差异微弱,统计分析结果均无显著差异。

In order tfo discuss the changed trend of soil physical and chemical properties before and after the afforestation of Eucalyptus gradis pure plantation （EP） and mixed plantation of E. grad/s with precious hardwood （EM）. Both of two plantation models were afforested in the Pinus massoniana cutting blank in the south of Nanning, Guangxi Autonomous Region, then the soil （0-60 cm）physical and chemical properties before and after the afforestation were studied. The results showed that： （1） There was 1.097-1.433 g/cm^3 of soil bulk density of （EP） and （EM） before and after afforestation. There was 47.32%-59.64% of soil total porosity and then 7.76%-17.67% of non-capillary porosity, 11.33%-19.62% of venting quality. There was 23.58%-42.16%, 21.11%-39.76%, 9.19%-37.77% of saturation moisture capacity, capillary moisture capacity and field moisture capacity, respectively. （2） 4.28-4.75 of soil pH value; 4.12-29.01 g/kg of organic matter; 0.18-0.72 g/kg of total N, 27.96-87.61 mg/kg of hydrolytic N; 0.16-0.30 g/kg of total P, 0.45-3.29 mg/kg of available P, 1.11-2.76 g/kg of total K, 0.16-0.29 mg/kg of available K. （3）There was no significant difference in the physical and chemical properties of soil before and after afforestation between 3 year-old E. gradis pure forests and 3 year-old mixed plantation of E grad/s and precious hardwood.