不同施肥條件下蛇紋石土壤中重金屬之溶出特性與水稻吸收量

Soluble heavy metal and rice uptake from a serpentine soil with different fertilizer treatments

吳景翰(Wu Jing-Han)

指導教授 ： 許正一

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00186

摘要

台灣地區蛇紋岩土壤分佈於花東地區，而蛇紋岩土壤富含Cr、Ni、Co等重金屬，可能對作物生長與環境生態造成危害。本論文以一池上地區由蛇紋岩所風化之膨轉土，使用油粕堆肥與化學肥料，設計不同施肥處理，包括對照組(空白)、化肥推薦量、一半化肥推薦量+一半堆肥施用量(2.5 ton/ha)、堆肥施用量(5.0 ton/ha)及2倍堆肥施用量(10 ton/ha)，以盆栽試驗方式種植水稻(高雄45號)，並使用六種單一萃取化學法(H2O、HCl、NaNO3、CaCl2、EDTA及DTPA)，探討不同施肥處理之可溶性重金屬濃度，以了解稻米不同部位重金屬(Fe、Mn、Cr、Ni、Co)之吸收量。實驗結果顯示，鉻、鎳等重金屬大部分累積於根部，唯錳累積於莖葉比根部高。受到蛇紋岩土壤母質特性之影響，植體中重金屬濃度較一般植物(1~2 mg/kg)高，穀粒中Cr累積達4.48 mg/kg，Ni為累積6.71 mg/kg，但與台灣地區一般水稻比較並無特別高。供試土壤之不同單一萃取法中，經不同肥料處理後，所能萃取出土壤重金屬濃度皆比實驗前土壤來得高，說明蛇紋岩土壤經種植水稻後會增加重金屬可溶性。油粕堆肥屬酸性，故本論文各種堆肥處理中土壤與植體重金屬累積濃度較高。在不同肥料處理時之pH值可明顯以兩倍油粕堆肥處理者最低，而其他的處理之pH變化不大。另外，不同肥料處理之土壤溶液中重金屬元素變化量差距不大。

關鍵字

蛇紋岩土壤 ； 水稻 ； 重金屬 ； 施肥

並列摘要

Serpentinitic soils are concentrated in the eastern areas of Taiwan, which are rich in heavy metal such as Cr, Ni, and Co with potential risk to crop growth and the eco-environment. This study used a serpentinitic Vertisol for the pot experiment by paddy rice (Kaohsiung No. 45) amended with different fertilizer treatments in the open field. All treatments were: unfertilized control (Blank), full recommended dose of chemical fertilizer (CF), half recommended dose of chemical fertilizer + 2.5 ton ha-1 oilseed compost (1/2 CF + 2.5 OC), 5.0 ton ha-1 oilseed compost (5.0 OC), and 10 ton ha-1 oilseed compost (10 OC), respectively. Six single extractions, including H2O, HCl, NaNO3, CaCl2, EDTA, and DTPA, were performed for the treated soils. The experimental results indicated that Cr and Ni were concentrated in the root of rice, and Mn was in the stalk parts. The concentration of all metals in the rice tissues were higher than those in general plants (1~2 mg/kg), and thus the Cr and Ni levels in the brown rice were up to 4.48 mg/kg and 6.71 mg/kg. However, the Cr and Ni levels in this study were within the normal ranges of rice grain in Taiwan. The amounts of heavy metal using the single extraction were always higher in the soils with fertilizer treatments than the initial soils, suggesting the solubility of heavy metal increased with the planting rice in the soils. In the oilseed compost treatments, the metal contents in soil and plant were high, due to the strong acidity of the compost in reducing soil pH. Additionally, no difference was found in heavy metal levels of soil solution between all treatments.

並列關鍵字

serpentinitic soil ； rice ； heavy metal ； fertilizeration

參考文獻

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