為探討嘉磷塞在土壤粘粒表面與磷離子間的競爭關係，以及其在土壤粘粒上的鍵結情形，作為瞭解其在土壤環境中的分佈與轉變的參考。以台灣十二種代表性土壤粘粒進行試驗，結果由嘉磷塞與磷酸根離子的競爭吸附情形，得知十二種代表性土壤粘粒中，嘉磷塞在土壤粘粒表面上的吸附均有明顯促使磷酸根離子吸附減少的現象。以膠結物移除後的土壤粘粒進行試驗結果，顯示其對嘉磷塞的吸附主要來自於雲母類與高嶺石類礦物。由嘉磷塞與磷酸根離子在標準粘土礦物表面上的競爭吸附試驗，也証明了高嶺石與雲母類礦物對嘉磷塞的吸附性較大。有嘉磷塞參予競爭吸附時，膠結物的移除與否當有嘉磷塞參予競爭吸附時，膠結的的移除均使試驗土壤粘粒對磷酸根離子的吸附量明顯增加，顯示膠結對嘉磷塞吸附上的重要性。且此種情形較為明顯之土壤粘粒，其氧化鐵含量均較高些，顯示膠結物質中的氧化鐵對嘉磷塞的吸附很重要。

For understanding the behavior of glyphosate in the soil environment, astudy on the competitive relationships between glyphosate and phosphate and the bonding on the clays was carried out.Twelve clays representing cultivated land in western Taiwan were collected and used in this study. The result indicated that the adsorption of phosphate apparently decreased due to competitive adsorption of glyphosate on the soil clays. The experiment of competitive adsorption between glyphosate and phoshate on the clays free of cemented materials were performed. The results showed that kaolinites and micas play an important role to adsorb the glyphosate. The similar result was found by using the standard clay minerals for the competitive adsorption studies. The increases of phosphate adsorption and decrease of glyphosate adsorption was found in the cemented materials free clays. The higher adsorption rate of glyphosate was found in the clays with higher level of iron oxides in cemented materials. These resuits indicated the importance of iron oxides and cemented materials on the adsorption of glyphosate.