CLINOPTILOLITIC ZEOLITE AS AN AMENDMENT FOR ESTABLISHMENT OF CREEPING BENTGRASS ON SANDY MEDIA

In a field experiment, clinoptilolitic zeolite was compared to sphagnum peat and sawdust as sand amendments at 5%, 10%, and 20% (v/v) to enhance 'Penncross' creeping bentgrass (Agrostis palustris Huds.) establishment and to compare their gravimetric and volumetric cation exchange capacities and their effects on moisture retention and cation exchange capacities of the resultant mixes. In addition, cation exchange capacities and exchangeable K+ and NH4+ were analyzed from clinoptilolitic zeolite of particle sizes ranging from < 0.25 mm to > 5.0 mm. All amendments, except 10% and 20% sawdust, resulted in superior establishment compared to unamended sand. Peat-amended sand retained significantly more moisture than sawdust- or zeolite-amended sand at -6, -10, -33, and -250 kPa soil matric potentials. Zeolite exhibited a much higher volumetric cation exchange capacity than either sawdust or sphagnum peat. Cation exchange capacity and exchangeable potassium of clinoptilolitic zeolite was greatest when particle size was < 0.5 mm; however, little exchangeable ammonium nitrogen was detected.