Basic Cation Soil Testing Methods for Sand Based Greens. (4501)
Authors:
R.A. St. John* - Iowa State University N.E. Christians - Iowa State University H.G. Taber - Iowa State University
Abstract:
Frequent soil testing is a tool used by golf course superintendents to maintain high quality greens. Results for samples taken from sand-based rootzones may not be accurate, because the soil test methods used for analysis were generally developed for agronomic soils that have large clay and silt fractions. This can particularly be a problem on calcareous sand samples, because many soil test reagents react with and dissolve calcium carbonate. The objectives of this research are to evaluate and modify several different methods for measuring exchangeable basic cations and the cation exchange capacity, and to determine the best methods for sand-based
turfgrass rootzones. Several different extraction methods are being studied to determine which one is most influenced by the presence of calcium carbonate.
Cation exchange resins are also being used to help determine which tests give more reliable results. In a second study, ‘Penncross’ creeping bentgrass has been
established in the greenhouse on both silica and calcareous sand to better
understand the limits of the Basic Cation Saturation Ratio (BCSR) theory. Initial results with calcareous sand samples indicate that increasing the pH of the
ammonium acetate method from 7.0 to 8.1 decreases the measured exchangeable calcium concentration by an average of 33%.
Speaker Information: Rodney St. John, Iowa State University, 106 Horticulture Hall, Ames, IA 50010; Phone: 515-294-1653; E-mail: [email protected]
Session Information: Monday, November 1, 2004, 7:25 AM-11:50 AM Presentation Start: 9:45 AM
Keywords: Turfgrass; calcareous; soil testing; cation exchange capacity CEC
