土壤2：1型黏土礦物之電荷分布在銨固定化作用中的角色
Other Title
The Influence of Layer Charge Distribution of 2:1 Clay Mineral on Ammonium Fixation
Journal
土壤與環境
Journal Volume
12
Journal Issue
1&2
Start Page
41
End Page
55
ISSN
1029-2950
Date Issued
2009
Author(s)
Abstract
氮（N）是植物生長的必需元素，而土壤2：1型層狀矽酸鹽礦物對銨離子（NH(下標 4 上標 +))的固定作用能夠影響土壤中氮的有效性。銨固定作用是由於NH(下標 4 上標 +)受到層狀矽酸鹽礦物之負電荷的庫倫靜電力吸引而固定於礦物的層間。此層狀矽酸鹽礦物的負電荷是源自於四面體層或八面體層發生同構取代作用產生。本研究探討十四種層狀矽酸鹽礦物的電荷分佈對其銨固定作用的影響。根據Greene-Kelly法，層狀矽酸鹽礦物的八面體層電荷能經由鋰飽和、300°C加熱處理中和之，因此實驗針對有無鋰飽和處理的層狀矽酸鹽礦物對NH(下標 4 上標 +)的固定作用進行討論。從結果發現，四面體同構取代為主的礦物其總NH(下標 4 上標 + 下標 ex）固定量與四面體層電荷NH(下標 4 上標 + 下標 ex）固定量的相關性較佳（R^2=0.8978）；八面體同構取代為主的礦物其總NH(下標 4 上標 + 下標 ex）固定量則是與八面體層電荷NH(下標 4 上標 + 下標 ex）固定量的相關性較佳（R^2=0.8581）；而所有2：1型礦物的總NH(下標 4 上標 + 下標 ex）固定量與八面體層電荷NH(下標 4 上標 + 下標 ex）固定量之相關性(R^2= 0.5383)高於四面體層電荷NH(下標 4 上標 + 下標 ex）固定量（R^2=0.0608）。此結果顯示層狀矽酸鹽礦物的八面體層電荷在銨固定作用中扮演了一個較重要的角色。
Nitrogen (N) is essential for plant growth. One of the predominant soil reactions controlling nitrogen availability is ammonium (NH(subscript 4 superscript +)) fixation on 2 : 1 phyllosilicate minerals. The fixation of NH(subscript 4 superscript +) ions in the interlayers of these minerals occurs in response to Coulombic attraction between NH4(superscript +) ions and negative charge sites in the phyllosilicate layers. The negative charges originated from isomorphic substitution in tetrahedral and/or octahedral layers. This study investigated the effects of layer charge distribution in fourteen 2:1 phyllosilicate minerals on their NH(subscript 4 superscript +) fixation. Based on the Greene-Kelly test, the minerals were saturated with Li(superscript +) and heated at 300°C to neutralize the octahedral layer charges. The experiment of NH(subscript 4 superscript + subscript ex) fixation was then conducted for the minerals before and after Li treatment. The results indicated that the amount of NH(subscript 4 superscript + subscript ex) fixation was highly correlated to the tetrahedral layer charge and octahedral layer charge in the minerals whose isomorphic substitution predominately occur in the tetrahedral sheet (R^2 = 0.8978) and octahedral sheet (R^2 = 0.8581), respectively. The correlation of the total NH(subscript 4 superscript + subscript ex) fixation in all the minerals to the NH4(superscript +)(subscript ex) fixation attributed to the octahedral layer charge (R^2 = 0.5383) was better than that to the tetrahedral layer charge (R^2 = 0.0608). This suggests that the role of the octahedral layer charge in the NH(subscript 4 superscript + subscript ex) fixation of the minerals is more important than that of the tetrahedral layer charge.
Subjects
銨固定
黏土礦物
Greene-Kelly法
四面體和八面體層電荷
Ammonium fixation
clay minerals
Greene-Kelly test
octahedral and tetrahedral layer charges
Type
journal article