Topdressing plays a vital role in turfgrass to maintain wears under suboptimal growing conditions and to alleviate soil compaction and increase hydraulic conductivity, and improve soil physical properties. The objective of this research was to mainly investigate the effects of olivine as new topsoil on turfgrass growth and soil property. Four topsoils containing 100: 0, 70: 30, 50: 50 and 0: 100 of sand: olivine (v/v) were topdressed on green and fairway in 2001. As results, the turf quality, root length and dry weight were considerably improved in all olivine treatments of green and fairway compared with only sand treatment. Especially, 30% (v/v) or 50% (v/v) olivine was commonly optimal in turfgrass. The unique and main chemical components in soil after topdressing with olivine were Mg and Si, which might finally enhance turfgrass growth. These observations suggest that olivine as a primary component of topdressing helps vigorous turfgrass growth by providing necessary nutrients such as Mg and Si. However, soil physical properties as bulk density, hydraulic conductivity and water retention, were not changed in all treatments of both green and fairway, indicating that olivine is useful to maintain soil physical stability in turfgrass areas as much as those by sand.
The study was conducted to know whether turfgrass growth could be influenced by silicate. Turf responses to silicate were evaluated by several factors such as, turf visual quality, root length, shoot density, and dry weight under the field environment. Creeping bentgrass rooting seemed to be rather sensitive to a spray of silica. The root length was enhanced by an increase of potassium silicate application rates up to 10ml/m2. However, turf visual quality, shoot density, and dry weight were not significantly differed between treated and untreated turfgrass. Under the traffic stress condition, Silicate application was considerably higher than none application in turf visual quality as well as root length.