广西国有钦廉林场桉树人工林土壤肥力评价

Evaluation of Eucalypt Plantation Soil Fertility in Guangxi State-owned Qinlian Forest Farm by Nemerow Method

为了解广西国有钦廉林场桉树(Eucalyptus spp.)人工林的肥力状况,选取pH、有机质、全氮(N)、全磷(P)、全钾(K)、速效N、速效P、速效K、有效硼(B)、有效铜(Cu)、有效锌(Zn)和有效铁(Fe)12个因子作为评价指标,采用改进的内梅罗指数法对不同层次土壤肥力质量进行评价。结果表明,总体(混合层)、0~20 cm土层和20~40 cm土层的pH值均为4.47,属较强酸性土壤;除pH值变异系数低于5%外,其他养分的变异系数均较大。总体、0~20 cm和20~40 cm土层的有效Fe处于富有水平;除0~20 cm土层的速效N、速效K处于中下水平外,其他养分均处于贫或极贫水平。总体、0~20 cm和20~40 cm土层土壤综合肥力指数分别为0.63、0.69和0.56,肥力等级均属于Ⅲ级,土壤贫瘠。钦廉林场在桉树人工林营建过程中,通过配方施肥对土壤进行补充,避免养分缺乏造成桉树生长不良的现象。

In order to understand fertility status of eucalypt plantation in Guangxi state-owned Qinlian forest farm, 12 soil nutrient factors including pH, organic matter, total N, total P, total K, available N, available P,available K, available B, available Cu, available Zn and available Fe were selected as evaluation indexes, and soil fertility qualities of different soil layers were evaluated by improved Nemerow method. Results showed that pH values of total, 0-20 cm and 20-40 cm soil layers were 4.47, which were more acidic soils. Coefficients of variation of other nutrients were larger except for pH, which had a coefficient of variation of less than 5%.Available Fe was rich in total, 0-20 cm and 20-40 cm soil layers. Except available N and available K in0-20 cm soil layer were in middle and lower level, other nutrients were in poor or extremely poor level. Comprehensive fertility indexes of soil in total, 0-20 cm and 20-40 cm soil layers were 0.63, 0.69 and 0.56, respectively, and all fertility grades belonged to grade III and soil was barren. To minimize eucalypt growth problems caused by nutrient inadequacy, Qilian forest farm might provide formula fertilizer to the soil.