Effect of Crumb Rubber Topdressing on Golf Course Traffic Areas 1999

D.K. Tompkins, J.B. Ross and D. L. Moroz

Executive Summary

During the summer of 1999, a crumb rubber topdressing experiment was established on two golf courses: one in Calgary and one in Edmonton. The goal was to determine the impact of the crumb rubber topdressing on turfgrass quality in high traffic areas. Potential benefits of the crumb rubber topdressing are improved wear tolerance, turf resiliency, water infiltration and overall quality. However, it is important that there be no negative impact on turf quality. In particular, zinc levels in soil and tissue were monitored to ensure these levels are not a problem for plant growth.

The experiment was established on high traffic areas at two golf courses: McCall Lake Golf Course in Calgary and Victoria Golf Course in Edmonton. The experiment was set up in a split plot design with four replications. Main plot treatments included four different crumb rubber mesh sizes: less than 20, 10-20, 7-10 and 6-16. Subplot treatments included four depths of crumb rubber topdressing: 0, 6, 12 and 18 mm.

Crumb rubber topdressing improved turf resiliency (Figure 1), but the different mesh sizes had no significant impact. Increased resiliency, is indicated by a lower number.

Figure 1. Effect of crumb rubber depth on turf resiliency

Neither crumb rubber mesh size, nor crumb rubber depth had a significant effect on water infiltration. However, there was a trend towards increased water infiltration with larger mesh size (Figure 2) and increase depth (Figure 3). There is a lot of variability in water infiltration readings, and larger data sets (i.e. combined years) may well provide data that is statistically significant if these trends continue.

Figure 2. Effect of crumb rubber mesh size on water infiltration

(average of 2 sites).

Figure 3. Effect of crumb rubber depth on water infiltration

(average of 2 sites).

The crumb rubber mesh size (Figure 4) and the crumb rubber depth (Figure 5) had no effect on turf quality.

Figure 4. Effect of crumb rubber mesh size on turf quality (average of 2 sites).

Figure 5. Effect of crumb rubber depth on turf quality (average of 2 sites).

Higher levels of soil zinc were associated with increased crumb rubber depth on the October 15 sampling period (Figure 6), but mesh size had no significant impact. However, this increase in soil zinc levels was relatively minor.

Figure 6. Effect of crumb rubber depth on soil zinc (ppm) (average of 2 sites).

Therefore, during the establishment year of this trial, the use of crumb rubber topdressing improved turf resiliency without negatively impacting turf quality. The impact of crumb rubber on wear tolerance is yet to be determined.

Introduction

A preliminary study was established three years ago on two athletic fields in Edmonton to determine the impact of crumb rubber topdressing on the turf. These sites were set up with a one time application of crumb rubber. The crumb rubber improved both turf resiliency and wear tolerance. For example, the first spring following application, there was a significant improvement in area cover in areas with the crumb rubber topdressing. However, the second spring, all of the turf with and without crumb rubber topdressing was dead from over use. This had been a very mild winter and the two fields had been in constant use.

Based on this preliminary study, it was felt that the crumb rubber topdressing might have a beneficial impact on golf course high traffic areas.

Over time, the crumb rubber may improve wear tolerance by cushioning the growing point of the plants from damage. Also, the crumb rubber should improve turf resiliency and possibly water infiltration. However, it is important to demonstrate that there is no negative impact on turf quality. Since the crumb rubber contains high levels of zinc, soil and tissue zinc was monitored to ensure that it doesn’t rise to levels that reduce turf quality.

Materials and Methods

This experiment was established on two golf courses: McCall Lake in Calgary and Victoria in Edmonton. Plots were established in high traffic areas near the teeing areas.

The experiment was established in a split plot design with four replications. Main plot treatments included four different crumb rubber mesh sizes: less than 20, 10-20, 7-10 and 6-16. Subplot treatments included four depths of crumb rubber topdressing: 0, 6, 12 and 18 mm. Replications included two different holes on each golf course. On each hole, a rep was located in the rough and one was located in the fairway.

Turf colour, density, area cover and quality (average of colour, density and area cover) were monitored using a 1-9 scale. Turf resiliency, water infiltration, soil water content, grass clipping dry weight, zinc tissue content and soil zinc content were also measured.

Results and Discussion

Turf Resiliency

The use of crumb rubber improved turf resiliency (Table 1). Improved turf resiliency, is indicated by a reduction in the Clegg Impact Unit. Therefore, turf resiliency increased with increased depth of crumb rubber, but the mesh size had no impact. Also, improved resiliency was associated with the McCall site.

Table 1. Treatment effects on turf resiliency (CIU).

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Water Infiltration and Water Content

Water infiltration was not significantly influenced by either mesh size, or depth (Table 2). However, there was s distinct trend towards increased water infiltration with larger mesh size and increased depth. There was increased water infiltration at the Victoria site.

Table 2. Treatment effects on water infiltration.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Crumb rubber mesh size and crumb rubber depth had no significant influence on soil water content (Table 3). An increased soil water content was associated with the Victoria site.

Table 3. Treatment effects on soil water content.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Turf Quality (Area Cover, Density, Colour and Quality)

Turf area cover (Table 4), density (Table 5), and quality (Table 6) were not significantly influenced by either crumb rubber mesh size or crumb rubber depth. Turf colour (Table 7) was significantly influenced by mesh size only at the October 15 rating period. In this case, slightly improved colour was associated with the smaller mesh size.

When significant differences in turf quality was present between sites, the McCall site had higher ratings.

Table 4. Treatment effects on turf area cover.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Table 5. Treatment effects on turf density.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Table 6. Treatment effects on turf quality.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Table 7. Treatment effects on turf colour

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Grass Clipping Dry Weight

Neither crumb rubber mesh size nor depth had a significant impact on grass clipping dry weight (Table 8).

Table 8. Treatment effects on grass clipping dry weight.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Tissue Zinc and Soil Zinc

Higher tissue zinc concentrations were associated with the smaller mesh size and increased depth of crumb rubber (Table 9). Higher tissue zinc was associated with the Victoria site.

Table 9. Treatment effects on tissue zinc concentration.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Higher soil zinc concentration was associated with increased crumb rubber depth (Table 10). However, mesh size had no significant impact. In this first year, the elevated zinc concentration in both tissue and soil had no significant impact on turf quality or growth.

Table 10. Treatment effects on soil zinc concentration.

¹Within a column, for each source of variation, numbers followed by the same letter are not significantly different at p=0.05.

Summary

Improved turf resiliency was associated with increased crumb rubber depth, but mesh size had no impact. There was a trend towards increased water infiltration with larger mesh size and increased depth. Turf quality and grass clipping dry weight, were not impacted by mesh size or depth. Both the tissue and soil zinc concentrations increased with increased depth. Also, an elevated tissue zinc concentration was associated with the smaller mesh size.

This was only an establishment year, but these results are positive for using crumb rubber as a topdressing treatment on turf. However, the impact of the crumb rubber on wear tolerance over time has not yet been evaluated.