Abstract: The effects of simulated trampling on turf physical characteristics and quality, turfgrass growth, root morphology, root spatial distribution, were measured for two consecutive years in a field experiment, using the nationally registered Bermudagrass variety ‘Yangjiang’ with different turf bed ratios [river sand∶yellow sand] of 0∶100, 20∶80, 40∶60, 60∶40, 80∶20, 100∶0 (control). It was found that simulated trampling increased soil bulk density, soil compaction and soil shear strength, and decreased soil total porosity. The compaction-related changes in physical properties of the experimental turf-beds caused a change in root morphology reflected in deeper expansion of the root system, but reduced above-ground growth of ‘Yangjiang’ Bermudagrass, including decreased dry weight of clippings and verdure, a decline in turf quality score, but increased above-ground density of turf. Compared with a pure river sand turf-bed, inclusion of yellow-sand in the turf-bed decreased soil compaction, promoted root growth and rooting depth, increased turf density, dry weight of turf clippings and turf verdure, and enhanced the traffic resistance of the turf. The beneficial effects of including yellow sand in the turf-bed were optimized with a 60%∶40% ratio of river sand∶yellow sand. Therefore, 60% river sand and 40% yellow-sand is the recommended optimum ratio for construction of turf-beds.

Key words: sport turf, simulated trampling, turf-bed ratio, sand, root