Extraction of aluminium from acid, strongly weathered fijian soils using M KCI: A comparison of methods of extraction and determination

Abstract

A B S T R A C TA comparison was made of methods for the extraction and determination of exchangeable aluminium (A13 + ) in acid, strongly weathered soils. The results showed large dgferences in the amounts of A13+ in each soil, depending on the method of extraction and determination. This observation has important implications for the liming of acid soils because in recent years there has been an increasing tendency to base application rates on the amounts of exchangeable A13+ in soils. It appears that the most suitable method of extracting A13 @om acid, strongly weathered Fijian soils involves shaking the soils with M KCI for 2 x 1-h periods, followed by the determination of A13 + using the oxine colorimetric procedure.