Simulated Traffic on Turfgrass Topdressed with Crumb RubberJohn N. Rogers III, J. Timothy Vanini, and James R. CrumAgron. J. 90:215-221(1998)

Topdressing(Beard1973 )

Fig. 3. Electron microscope scan of sand-sized soil particles at 9400X magnification.

Fig. 4. Electron microscope scan of sand-sized crum rubber particles at 9400X magnification.

1.2.3.

:RCBD 1.() 0.017.134.244.1 and 88.2 t/ha 2.: 6.0-2.0 mm 2.0-0.25mm

Table 1. Particle size distribution of the soil rootzone mix and of large (26 mm)and small (2.00.05 mm) crumb rubber topdressing at East Lansing, MI. 79.3

:1-yr-old Kentucky bluegrass-perennial ryegrass (Poa pratensis L.-Lolium perenne L.)

Topdressing ()19932911538mmSimulated traffic:

Simulated trafficBrinkman traffic simulator3361993261419945158-1096

peak deceleration(Gmax) time to peak deceleration(Tp) impact duration(Tt)Ball bounceShear resistanceClipping yieldTurf cover

peak deceleration(Gmax)time to peak deceleration(Tp)impact duration(Tt)GmaxGmax gGmax1280g 260g

Clegg impact soil testerhammer (0.46m)Impact value (IV) IVhammer2.25kg

*,** Significant at the 0.05 and 0.01 probability levels,respectively.Table 2.1 Mean squares for treatment effects of crumb rubber topdressing on peak deceleration (Gmax), in a trafficked Kentucky bluegrassperennial ryegrass stand at East Lansing, MI.

Mean squares Gmax Source ofvariation 1993 1994 df 20 Sept. 22 Oct. 3 Dec. 15 Sept. 17 Oct. 10 Nov. 30 Dec. Replication28.732.263.6616.3220.7216.83699.45Crumb rubber rate (R)476.78**246.87**164.13**24.9815.4315.0611545.07** Crumb rubbersize (S) 156.91*0.093.333.821.3723.94271.80R x S 417.1920.9315.3319.1228.6418.07501.04 Error 187.617.7415.829.6012.2210.54226.29

* Significant at the 0.05 probability level. On 20 Sept. 1993, crumb rubber rates were 0.67 times the listed rate. Table 3. Effects of crumb rubber particle size and topdressing rate on peak deceleration (Gmax) on a trafficked Kentucky bluegrassperennial ryegrass stand at East Lansing, MI.

Gmax 19931994Treatment20 Sept.22 Oct.3 Dec.15 Sept.17 Oct. 10 Nov.30 Dec.Rate, t ha-1 g071696766675819317.170727268706016034.272717367716213644.168667067696111488.263566063686278LSD (0.05) 335NSNSNS18Particle size Large 676768666960139Small 706769676962133Soil water, kg kg 10.1740.2180.2020.1630.1210.1230.132

*,** Significant at the 0.05 and 0.01 probability levels, respectively.Table 2.2 Mean squares for treatment effects of crumb rubber topdressing on time to peak deceleration (Tp),and impact duration (Tt) in a trafficked Kentucky bluegrassperennia ryegrass stand at East Lansing, MI.

Mean squares Source ofvariation Tp (1994)Tt (1994) df 15 Sept. 17 Oct. 10 Nov.15 Sept. 17 Oct. 10 Nov. Replication20.040.150.510.070.070.72Crumb rubber rate (R)41.05**0.60**0.33*4.65**4.33**1.88* Crumb rubbersize (S) 10.090.030.210.250.260.03R x S 40.30**0.20*0.270.64*1.03 **0.76 Error 180.060.070.100.210.130.62

Table4. Time to peak deceleration (Tp) and impact duration (Tt) as affected by crumb rubber topdressing rate and large (26 mm) or small (2.00.05 mm) particle size in a Kentucky bluegrassperennial ryegrass stand at East Lansing, MI (1994). * Significant at the 0.05 probability level.

TtTp15 Sept. 7 Oct.10 Nov.15 Sept.17 Oct.10 Nov.TreatmentLargeSmallLargeSmallLargeSmallLargeSmallmsRate, t /ha 05.15.45.24.85.69.29.59.28.610.117.15.35.05.15.06.19.59.19.08.89.734.25.55.25.25.15.510.09.59.69.19.444.15.35.45.25.55.79.610.19.310.210.588.25.86.65.56.15.810.912.010.311.611.1LSD (0.05) 0.40.40.40.80.61.0Particle size Large 5.7*10.3*Small 5.810.2

Ball bounce331990FIFA

Table 5.2 Mean squares for treatment effects on ball bounce (% rebound) in a trafficked Kentucky bluegrassperennial ryegrass stand at East Lansing, MI. *,** Significant at the 0.05 and 0.01 probability levels, respectively.

Mean squares Ball bounce Source ofvariation 1993 1994 df 20 Sept.15 Sept. 10 Oct.. Replication214.769.250.01Crumb rubber rate (R)430.52*19.76*43.55*Particle size (S) 12.2620.97*2.56R x S 47.3018.45*6.55 Error 187.444.6410.11

* Significant at the 0.05 probability level.Table6.1 Ball bounce as affected by crumb rubber topdressing rate and large (26 mm) or small (2.00.05 mm)particle size in a Kentucky bluegrassperennial ryegrass stand at East Lansing, MI.

Ball bounce 199320 Sept. 199415 Sept. 10 Nov. TreatmentLargeSmall % rebound Rate, t ha-1036.838.842.941.117.136.440.438.741.734.234.239.136.142.044.136.438.836.638.688.231.538.833.535.6LSD (0.05) 3.34.03.9Particle size Large 34.840.1Small 35.339.5

Shear resistance

Table 5.1 Mean squares for treatment effects on shear resistance (Nm) in a trafficked Kentucky bluegrassperennial ryegrass stand at East Lansing, MI. *,** Significant at the 0.05 and 0.01 probability levels, respectively.

Mean squares Shear resistance Source ofvariation 1993 1994 df 20 Sept. 22 Oct. 5 Nov. 15 Sept. 27 Oct. 10 Nov. Replication26.686.1127.990.6712.678.54Crumb rubber rate (R)498.05**79.05**55.58**10.90**24.88**16.72**Particle size (S) 18.1515.67*20.8223.07*23.13*1.79R x S 44.223.760.605.669.226.09 Error 183.563.385.473.254.573.00

* Significant at the 0.05 probability level. On 20 Sept. 1993, crumb rubber rates were 0.67 times the listed rate.Table6.2 Sheer resistance as affected by crumb rubber topdressing rate and large (26 mm) or small (2.00.05 mm)particle size in a Kentucky bluegrassperennial ryegrass stand at East Lansing, MI.

Shear resistance 19931994Treatment20 Sept. 22 Oct.5 Nov.15 Sept27 Oct.10 Nov.NmRate, t ha-1025.620.717.617.616.211.917.123.720.217.019.716.315.334.222.515.316.218.419.113.744.122.115.313.318.820.716.088.215.012.210.316.119.615.4LSD (0.05) 2.32.22.82.22.62.1Particle size Large 21.416.0*14.017.2*17.5*14.2Small 22.317.515.719.019.214.7

Clipping yield

Table 5.3 Mean squares for treatment effects on clipping yield (g m -2 ) in a trafficked Kentucky bluegrassperennial ryegrass stand at East Lansing, MI. *,** Significant at the 0.05 and 0.01 probability levels, respectively.

Mean squares Clipping yield Source ofvariation 1993 1994 df 2 Oct.15 Apr. 10 Aug. 20 Oct.Replication20.341.7133.99*1.95**Crumb rubber rate (R)40.7832.74**31.56*0.47Particle size (S) 10.945.2925.580.10R x S 41.907.43*12.950.43 Error 180.551.927.920.19

Table 7.1 Clipping yield estimates as affected by crumb rubber topdressing rate and large (26 mm) or small (2.00.05mm) particle size in a Kentucky bluegrassperennial ryegrass stand at East Lansing, MI. On 2 Oct. 1993, crumb rubber rates were 0.67 times listed rates.

Clipping yield 2 Oct. 1993199420 Apr.9 Aug.20 Oct.TreatmentLarge Small LargeSmallg m-2Rate, t ha-100.90.70.60.37.00.417.10.90.70.80.67.10.434.20.80.71.00.45.20.544.10.61.31.02.12.90.788.20.71.62.34.54.30.7LSD (0.05) 0.71.21.8NSParticle size Large 6.40.5Small 5.40.5

Turf cover

Table 5.4 Mean squares for treatment effects on turf cover(%) in a trafficked Kentucky bluegrassperennial ryegrass stand at East Lansing, MI. *,** Significant at the 0.05 and 0.01 probability levels, respectively.

Mean squares Turf cover Source ofvariation 1993 1994 df 1 Oct. 25 Oct. 30 Sept. 27 Oct. 30 Dec. Replication2120.00230.8363.33*184.30167.50Crumb rubber rate (R)4316.671461.67**55.211111.97*1872.08*Particle size (S) 13.333.334.80149.63120.00R x S 4570.00**495.00**1.8867.9772.08 Error 18108.8997.58.8682.82138.80

Table 7. Turf cover estimates as affected by crumb rubber topdressing rate and large (26 mm) or small (2.00.05mm) particle size in a Kentucky bluegrassperennial ryegrass stand at East Lansing, MI. On 2 Oct. 1993, crumb rubber rates were 0.67 times listed rates.

Turf cover 19931994 1 Oct. 25 Oct.TreatmentLargeSmallLargeSmall30 Sept.. 27 Oct4 Dec.%Rate, t ha-105340272785534217.16047503089625134.26347634787726344.14760475790736688.253805780938988LSD (0.05) 18 1741114Particle size Large 886860Small 897264

a.b.

44.1 88.2 t/ha