鲁西平原毛白杨造林地土壤速效磷和速效钾空间变异性研究

Study on the Spatial Variability of Soil Available Phosphorus and Available Potassium in Populus Tomentosa Planted Land in Western Plain of Shandong Province

研究了位于鲁西平原冠县苗圃毛白杨6.0ha造林地的速效养分分布, 为毛白杨造林试验地布设、养分精准管理、确定合理采样数提供依据。试验将土壤在水平方向大约按50m×50m分为24块样地,每块样地分为0~20㎝,20~40㎝,40~60㎝三层取样,进行三维空间采样和室内分析。结果表明速效养分含量属于较低水平,且随土层加深逐渐降低。土壤速效磷含量是1.32~1.89mg？kg-1,总体均值为1.51±0.09mg？kg-1,三个层次含量分别为1.66±0.15mg？kg-1、1.44±0.07mg？kg-1、1.44±0.06mg？kg-1。速效钾含量是23~78mg？kg-1,总体均值46.95±8.33mg？kg-1, 三个层次的含量分别为63.29±9.69mg？kg-1、43.38±8.35mg？kg-1、34.17±6.96mg？kg-1。三个层次速效磷变异系数分别为9%、5%、4%,属于弱变异水平,速效钾变异系数分别为15%、19%、20%,属于中等变异水平,变异水平和取样精度直接影响合理采样数。土壤速效磷含量在水平和垂直方向上变化不大,土壤速效钾含量自西向东先增后减,自北向南升降交替、变化复杂。

Analyze of the soil available phosphorus and available potassium in a 6.0 hectare Populus tomentosa planted land in Guanxian county of Shandong province was aimed to benefit test arrangement of Populus tomen- tosa planted land, the site specific nutrient management and determining rational sampling number. To have a better understanding the available phosphorus and available potassium status grid sampling method with grid size （50 m×50 m） was used. Each grid was subdivided into three layers （0-20 cm, 20~40em, 40-60 cm）. The re- sults showed： available nutrient content was a lower level , which was decreased with the soil depth, and the range of available phosphorus was 1.32-1.89 mg/kg, the population mean was （1.51±0.09） mg/kg, and the con- tents Of three layers were （1.66±0.15）mg/kg, （1.44±0.07）mg/kg, （1.44±0.06）mg/kg, respectively. The ranges of available potassium was 23-78 mg/kg, the population mean was （46.95±8.33）mg/kg, and the contents of three layers was （63.29±9.69）mg/kg, （43.38± 8.35）mg/kg, （34.17±6.96）mg/kg, respectively. The Coefficient of Vari- ance of the available phosphorus was 9%, 5%, 4% in three layers, respectively, which were weak variability. And available potassium was 15%, 19%, 20% in three layers, respectively, which were moderate variability. Ra- tional sampling number was related to coefficient of variation and sampling precision. The value of available phosphorus changed little both in the horizontal direction and vertical direction, and the coefficient of variance of available potassium increased at first and then decreased from west to east, but ascended and descended, var- ied complicatedly from north to south.