The Basic Cation Saturation Ratio (BCSR) theory makes fertilizer recommendations based on the percentages of calcium (Ca), magnesium (Mg), and potassium (K) found on the cation exchange (CEC) sites. The objectives of this research are to evaluate the validity of using the BCSR theory for sand-based, creeping bentgrass greens. Greenhouse experiments are being utilized to evaluate a wide range of cation ratios for ‘Penncross' creeping bentgrass established on either calcareous or silica sand. A second objective of this research is to evaluate soil testing methods for sand-based greens. Currently, many soil testing procedures for exchangeable cations and/or cation exchange capacity dissolve calcium/magnesium carbonates and calcium sulfate particles during the extraction process. Many sands used for putting green construction are calcareous and contain appreciable amounts of calcium carbonate. The dissolution of calcium carbonate can lead to misleading values for exchangeable Ca, cation exchange capacity, and basic cation saturation ratios. Several different methods for analysis which utilize different pH, ionic strength and saturating cations are being evaluated to determine which method is best for sand-based turfgrass systems.