pH、鈣離子和鍶離子對強酸性土壤中鉀行為之影響

The Impacts of pH, Ca and Sr on Potassium Behaviors in Strongly Acid Soils

陳仁炫(Jen-Hshuan Chen) ； 洪建民(Chien-Min Hung) ； 王怡雯(Yi-Wen Wang)

《土壤與環境》 6卷3期 (2003/09) Pp. 133-143

https://doi.org/10.30058/SE.200309.0003

摘要

石灰質材的添加為改善強酸性土壤生產力的主要對策。CaCO3本身具有提昇土壤pH及提供鈣的雙重效果，而pH及鈣兩者已知均會對土壤鉀之行為有所影響。本試驗的目的為分辨pH、鈣離子和鍶離子對強酸性土壤中鉀行為之相對影響效應。選用兩種不同風化程度的強酸性土壤(關西和北溝土壤)，分別加入不同量的CaCO3和SrCO3並於25˚C下培育30天。另於關西土壤添加與CaCO3提供相同鈣量之CaCl2．2H2O。結果顯示CaCO3的添加，除能提昇土壤pH值外，亦能使土壤中三種型態鉀(溶液性鉀，交換性鉀，非交換性鉀)有顯著的改變，且改變程度及趨勢均甚為相似，而CaCl2．2H2O的添加不會造成土壤pH的改變，且三種型態鉀並不隨CaCl2．2H2O用量的增加而有顯著改變的現象。藉由本試驗的結果，可推知在強酸性土壤施用CaCO3所造成土壤中鉀型態及鉀有效性的改變，pH的影響效應實大於鈣離子，而在提昇相同pH的狀況下，鈣離子對土壤鉀行為的影響又比鍶離子大。

關鍵字

強酸性土壤 ； 鉀行為 ； 鉀有效性

並列摘要

Liming is one of the main strategies improving soil productivity in strongly acid soils. As CaCO3 liming could raise pH and supplement Ca ions into soil, the potassium behaviors would be influenced by CaCO3 addition. This study is to investigate and discern the relative effect among pH, Ca and Sr on potassium behaviors in strongly acid soils. Two acid soils (Kuan-Si and Bei-Go) of different degree of weathering were involved and with various amount of CaCO3 and SrCO3 added to present soil pH about 5.5, 6.5 and 7.5 after incubation at 25˚C for 30 days. Besides, CaCl2．2H2O were also applied in Kuan-Si soil containing equal amount of Ca as that of CaCO3 added. Items of pH, soil solution K, exchangeable k, nonexchangeable K and potassium fixation index were all determined after incubation.
The results indicated similar extent and trends of transformation among three K forms, that is, decreasing content of soil solution K and exchangeable K but increasing nonexchangeable K level were observed in both CaCO3 and SrCO3 treatments of two soils. As to CaCl2．2H2O addition, pH increase was not found and the change of three K forms was not significant when application rate raised. It may suggest that pH effect (neutralizing) takes a more effective role than Ca ion influencing change of K forms and soil potassium availability when liming in acid soil. Furthermore, adjusting to the same soil pH, Ca ion exerts more powerful effect than Sr ion on potassium behaviors in strongly acid soils.

並列關鍵字

strongly acid soil ； K behavior ； K availability