博白林场桉树人工林土壤肥力内梅罗指数法评价分析

Assessment of Eucalypt Plantation Soil Fertility in Bobai Forest Farm by Nemerow Method

为了解广西国有博白林场桉树(Eucalyptus spp.)人工林林地的肥力状况,以pH值、有机质、全氮、全磷、全钾、碱解氮、速效磷、速效钾、有效铜、有效锌、有效硼和有效铁等指标为基础,采用内梅罗指数评价法对不同层次土壤肥力质量进行评价分析。结果显示,总体土壤养分变异系数为4.90%~105.84%,A层土壤养分变异系数为5.88%~141.85%,B层土壤养分变异系数为4.36%~98.49%,除pH值变异系数较小外,其他指标的变异系数均较大。总体上,土壤的有机质、全氮、全磷、速效磷和速效钾平均含量分别为18.38 g/kg、0.89 g/kg、0.27 g/kg、2.07 mg/kg和36.63 mg/kg,均处于贫或极贫水平;微量元素中,有效铁的平均含量为130.32mg/kg,达到极富水平,有效铜、有效锌和有效硼的平均含量分别为0.27、0.55和0.21 mg/kg,均处于贫或极贫状态;土壤综合肥力指数为0.73,肥力等级为Ⅲ级。

In order to understand soil fertility of eucalypt plantation in Guangxi state-owned Bobai forest farm,based on indexes of pH value,organic matter,total nitrogen,total phosphorus,total potassium,alkali-hydrolyz⁃able nitrogen,available phosphorus,available potassium,available copper,available zinc,available boron and available iron,soil fertility qualities of different levels were evaluated and analyzed by Nemerow method.Re⁃sults showed that variation coefficients of total soil nutrients were 4.90%-105.84%.Variation coefficients of soil nutrients in layer A were 5.88%-141.85%,which of layer B were 4.36%-98.49%.Except for pH values,variation coefficients of others were high.In total,average contents of soil organic matter,total nitrogen,total phosphorus,available phosphorus and available potassium were 18.38 g/kg,0.89 g/kg,0.27 g/kg,2.07 mg/kg and 36.63 mg/kg,respectively,which were in poor level.In microelements,average content of available iron was 130.32 mg/kg reaching extremely rich level,and average contents of available copper,available zinc and avail⁃able boron were 0.27,0.55,0.21 mg/kg,which were in poor or extremely poor level.The comprehensive fertility index of soil was 0.73 with grade Ⅲ.