Unbuffered and Buffered Salt Methods for Exchangeable Cations and Effective Cation‐Exchange Capacity

This study was conducted to determine if a single unbuffered salt extractant for exchangeable bases and Al could be used in place of a buffered salt extractant for exchangeable bases and an unbuffered salt extractant for exchangeable Al. Barium chloride and a mixed NH 4 Cl‐BaCl 2 extractant were compared with NH 4 OAc for determining exchangeable bases and with KCl for determining exchangeable Al in soils. In general, BaCl 2 extracted less exchangeable K than either NH 4 OAc or NH 4 CL‐BaCl 2 . The NH 4 CL‐BaCl 2 extractant was equivalent overall to NH 4 OAc for extracting exchangeable bases and to KCl for extracting exchangeable Al, although less K was extracted by NH 4 Cl‐BaCl 2 at low levels of K for some Coastal Plain soils. The NH 4 Cl‐BaCl 2 extractant can be used by soil‐test or soil‐characterization labs as a simple one‐step extractant in place of NH 4 OAc and KCl for the determination of exchangeable cations and effective cation‐exchange capacity of soils.