超基性岩類在高壓下與水進行蛇紋岩化作用,而後產生蛇紋岩等礦物,其廣泛分布於板塊交界處,鉻、鎳重金屬濃度有偏高現象。本論文選取東部板塊交界處的(A)、(B)及(C)等50處農地進行蛇紋岩母質風化後土壤基本性質、生物有效性探討及鉻、鎳濃度偏高對其50個作物的影響分析,結果顯示調查範圍部分鉻、鎳濃度含量偏高並且超出土壤污染管制標準(鉻:250mg/kg、鎳:200mg/kg),再以0.1N HCl及0.005M DTPA萃取法評估其生物有效性,鎳萃取濃度較鉻濃度高,推估鎳移動性大於鉻,可能對作物存在較高風險,另外探討土壤及作物食用部位其相關性,不具明顯相關性。
Ultramafic rocks are derived from hot sea water under high pressure for serpentinization, and then transform as serpentinite, which are widely distributed in the intersection of tectonic plates. Heavy metals are enriched in these rocks including chromium and nickel. This study selected 50 soil samples from (A), (B), and (C) in eastern Taiwan to explore the soil basic properties related to bioavailability of Cr and Ni. Results show that the total chromium and nickel were higher than the soil pollution control levels (Cr: 250 mg/kg, Ni: 200 mg/kg) in some soil samples. By using 0.1N HCl and 0.005M DTPA extraction methods, the Ni extracted concentration was higher than Cr. Therefore, the mobility of Ni was higher than that of Cr. In addition, this study found no significant correlation of the metals between soil and crop.