贵阳花溪石灰岩、石灰土与定居植物化学元素含量特征

Chemical Element Concentration in Calcite,Calcareous Soil and Plants on the Rocky Desertification Area in Huaxi,Guiyang

对贵州花溪区石灰岩、石灰土及定居植物中化学元素含量进行研究。结果表明:石灰岩的pH值为9.38,全P和全K含量低,全Ca和全Mg含量较高,微量元素含量表现为Fe>Pb>Ni>Mn>Co>Cu>Zn>Cd;石灰土的pH值为7.53～7.98,有林地的有机质、全N及全P含量高于无林地,N素和P素有效率很低,速效N仅占全N含量的0.47%～1.18%,速效P仅占全P的0.8%～1.5%,全K含量亦不高,但有林地速效K含量(251.81mg·kg-1)超过土壤速效K含量对应的富K(>155mg·kg-1)水平等级,属富K型土壤,无林地全Ca及全Mg含量高于有林地,微量元素含量表现为Fe>Mn>Pb>Zn>Ni>Cu>Co>Cd,全Pb,全Zn及全Cu含量均未超过国家规定的3级标准;定居植物体内不同元素含量的差异很大,同一元素在不同植物体内含量的变化范围亦很大。

This study investigated chemical element concentrations in calcite, calcareous soil and restored plants in a limestone rocky desertification area in Huaxi, Guizhou Province. Results showed that pH value was 9.38, concentrations of total P and K were low while that of total Ca and Mg were high, and the microelement concentrations was ranked in the order of Fe 〉 Pb 〉 Ni 〉 Mn 〉 Co 〉 Cu 〉 Zn 〉 Cd in calcite. In calcareous soil, the pH value was around 7.53 - 7.98. The concentrations of organic matter, total N and P were higher in forestland than in bare land. The concentrations of available N and P were very low with the value of 0.47% - 1.18% and 0.8% -1.5% respectively. Total K concentration in calcareous soil was also lower, but available K concentration （251.81mg· kg^-1 ） in forest soil was higher than that K-rich soils （ 〉 155 mg· kg^-1 ）, so the limestone soil is classified as a K rich soil. The concentrations of total Ca and Mg were higher in bare land than in forestland. The microelement concentrations in limestone soil was ranked in the order of Fe 〉 Mn 〉 Pb 〉 Zn 〉 Ni 〉 Cu 〉 Co 〉 Cd. The concentrations of total Pb, Zn and Cu were not higher the third State standards so that vegetation restoration was feasible in calcareous soil. The concentrations of different elements in the plants grew in calcareous soil had great difference, so were the changes of the same element concentrations in different plants.