Development and verification of a quick test for the diagnosis of aluminium toxicity on the deep yellow earths of Western Australia

A quick test for estimating phytotoxic aluminium (Al) has been developed for the deep yellow earths of Western Australia. The method is based on a visual assessment of Al extracted by 0.005 M potassium chloride, using pyrocatechol violet as a colorimetric reagent, combined with a measure of electrical conductivity (EC). Quick test measurements were compared with wheat yields from 52 sites to determine if the method could distinguish between Al toxic and Al non-toxic subsoils. A ratio of [Al]:EC was a better predictor of grain yield than [Al] alone.