420
420 GYPSUM CONTENT
By Special Request
Estimated value of the amount of gypsum present in soils.
Summary: The procedure is based on the measurement of the loss of crystal water associated with the hydrated form of gypsum. The precise determination of gypsum is difficult because of sources of Ca and SO4 other than from gypsum. The method has a detection limit of approximately 0.1meq 100 gm-1 and is reproducible within 20%.
Klute, A. 1986. Water retention: laboratory methods. p. 635-662. In: A. Klute (ed.) Methods of soil analysis: Part 1. Physical and mineralogical methods. ASA Monograph Number 9.