This is a soil fertility test. This method involves the extraction of exchangeable aluminum from soils using 2.0 N KCl. Aluminum is determined by Inductively Coupled Plasma spectrometry (ICP-AES). The method doesn’t quantitatively extract aluminum from mineral structures or bound to organic compounds. Soil aluminum concentrations are generally low in mineral soils. The method detection limit is approximately 0.5 mg/kg and is generally reproducible ± 10%.