Advancing natural turf to meet tomorrow’s Dr Iain James challenges Senior Lecturer
Centre for Sports Surface Technology
Cranfield University What do we think of when we think ‘natural turf’? Golf
The Wisley Golf Club, Surrey, UK Football
Melbourne Cricket Ground, Melbourne Tennis
All England Lawn Tennis Club, Wimbledon, London Natural turf in the news...
The Guardian, 7 November 2009 Wembley
Attendance: 47,106
Average attendance in Guinness Premiership on same weekend: 10,262 ± 1140
The Sun, 19 April 2010 Not just elite sport Natural Turf Performance
• Ambience and aesthetic quality • Sport performance • ball-surface interactions • player-surface interactions • Durability
• Environmental and financial sustainability (increasingly) Delivering quality
Level Elite Quality Resource consumption Revenue generation Attention
Quantity, Participation, Environmental benefit Rec. Challenges for natural turf
• Deliver quality surfaces in poor environments • Deliver flexibility for stadia • Deliver safe, high quality surfaces with insufficient resources • Deliver quality surfaces with reduced resources • Deliver surfaces that look good on HD TV The natural turf system
Understanding the system enables delivery of quality...
(...or an explanation of why quality isn’t delivered) The natural turf system (simplified)
CO2/O2 O2/CO2
Light
H2O
Structural support
O2 H2O
CO2 Plant nutrients Soil matrix
20-30% ‘Air’
45% Mineral
30-20% ‘Water’
5% Organic Matter Compaction and porosity Dry Bulk Density
1.40 g/cm3 1.65 g/cm3 1.80 g/cm3
30% t n e t n o C e r u t s i o M
20%
Source: Shipton and James (2009) ECB Cranfield Guidelines for Rolling in Cricket. www.cranfield.ac.uk/sas/sst/rolling Soil particle size
Clay
Silt
Fine Sand
Medium Sand Coarse Sand Soil types
Cricket Pitch, Eden Park, Auckland3
Cricket Pitch, WACA, Perth1 Cricket Pitch, AMI Stadium (Lancaster Park), Christchurch3 Cricket Pitch, SCG, Sydney2
Cranfield University Football Pitch
Uttoxeter Racecourse, UK5 Cricket Pitch, Port of Spain, Trinidad4
Fairway, Woburn Golf Course6
Fairway, Wisley Golf Cricket Pitch, Lord’s, London Course
Stadium sand-construction Lingfield Park Racecourse, football pitches UK5 e.g. Wembley, Arsenal
USGA Specification Golf Green7
Outfield, Lord’s Cricket Ground, London Leicester Racecourse, UK5 8 Sandown Park Racecourse, UK5 Tennis Court, Wimbledon, London Rugby Pitch, Eden Park, Auckland Construction materials
So why construct from sand? Hydraulic conductivity / Infiltration Soil type Saturated hydraulic rate conductivity Beach sand 360 mm/h Very sandy soil 180 mm/h Field (agricultural) soil 18 mm/h Irrigation water Compacted clay soil < 3.6 x 10-4 mm/h Source: Brady & Weil, Nature and Properties of Soil 13th ed. USGA Specification golf green: >150 mm/h
Standard Infiltration rate FIFA 1* or 2* >180 mm/h DIN 18035/4 for >60 mm/h natural turf FA Performance >5 mm/h Quality Standard Typical CEC values for sports turf soils Fertiliser quantity
Soil texture Cation exchange capacity (cmol kg-1) Sand (1-2% OM) 1-3 Sand (2-4% OM) 3-5 Sandy loam 3-10 Loam 7-16 Silt loam 10-25 Clay (2:1 mineralogy) 20-50 Clay (1:1 mineralogy) 4-6
Source: Carrow et al., 2001. Turfgrass Soil Fertility and Chemical Problems The natural turf system (simplified)
CO2/O2 O2/CO2
Light
H2O
Irrigation quantity
Structural support
O2 H2O
CO2 Plant Fertiliser quantity nutrients Mechanical testing of sports soils Mechanical testing of sports soils
Sand(a) Clay(b) Loam 800 800 2 2 - - C1 m m
N N C2 k 600 k 600 , ,
) ) C3 q q ( ( s s s s
e 400 e 400 r r t t s s c c i i
r S1 r
o 200 o 200 t t
a S2 a i i v v
e S3 e D 0 D 0 0 5 10 15 20 25 0 5 10 15 20 25
Axial strain (a),% Axial strain (a),%
Guisasola IN, James IT, Llewellyn CA, Stiles VH, Dixon SJ (2010a). Quasi-static mechanical behaviour of soils used for natural turf sports surfaces. Sports Engineering 12:99-109 Sensitivity of shear strength to water content
300 2 ) - s s
m 250 e r N t k s s g s 200 n e i r n t i s f n d
l 150 o e c i
y Sand a c P i k r 100 o 0 Clay Loam t 0 a i 1 v e
@ 50 ( D
0 0.1 0.3 0.5 0.7 0.9
Saturation ratio
Guisasola IN, James IT, Llewellyn CA, Stiles VH, Dixon SJ (2010a). Quasi-static mechanical behaviour of soils used for natural turf sports surfaces. Sports Engineering 12:99-109 Tracking movement
Courtesy of Vicky Stiles and Sharon Dixon at University of Exeter Stiles VH, Dixon SJ, James IT (2006). An initial investigation of Human-Natural Turf Interaction in the Laboratory Running on natural turf
Fy, BW -1.5 -1.0 -0.5 0 0.5 1.0 1.5 3.0 0 B F 2.5 z A -0.5 Fy 2.0 -1.0 W W B 1.5 , B
e -1.5 , c z r
1.0 F o C F -2.0 0.5 A
0 C -2.5 B -0.5 -3.0 0 0.1 0.2 0.3 Time, s
0.00 s 0.00 s 0.00 s
0.10 s 0.10 s 0.10 s
0.20 s 0.20 s 0.20 s
50 mm 50 mm 50 mm
A(c) (d)B (e)C Cyclic dynamic loading
2 N k
, 1 z F
0 0 1 2 3 4 5 6 7 8 9 10 Axial displacement (z), mm Visco elastic behaviour – rate dependent S2 0.63 kN s-1 S2 5.87 kN s-1 500 500
2 First cycle 2 - - m 400 Last cycle m 400 N N k k , ,
s 300 s 300 s s e e r r t t s 200 s 200 l l a a i i x 100 x 100 A A 0 0 0 0.01 0.02 0.03 0.04 0.05 0 0.01 0.02 0.03 0.04 0.05 Axial strain Axial strain C2 0.61 kN s-1 C2 5.72 kN s-1 500 500 2 2 - - m 400 m 400 N N k k , ,
s 300 s 300 s s e e r r t t s 200 s 200 l l a a i i x 100 x 100 A A 0 0 0 0.01 0.02 0.03 0.04 0.05 0 0.01 0.02 0.03 0.04 0.05 Axial strain Axial strain C1 0.62 kN s-1 C1 5.70 kN s-1 500 500 2 2 - - m 400 m 400 N N k k , ,
s 300 s 300 s s e e r r t t Guisasola IN, James IT, Stiles VH, s 200 s 200 l l a a i i
Dixon SJ (2010b). Dynamic x x 100 100 behaviour of soils used for natural A A 0 0 turf sports surfaces. Sports 0 0.01 0.02 0.03 0.04 0.05 0 0.01 0.02 0.03 0.04 0.05 Engineering 12:111-112 Axial strain Axial strain
Effect of mowing on root volume m m 0 5 The natural turf system (simplified)
CO2/O2 O2/CO2
Light
H2O
Irrigation quantity
Structural support
O2 H2O
CO2 Compromised Plant Fertiliser quantity root system nutrients Managing turf in stadia
Can we really finish the system off?
The natural turf system (simplified)
CO2/O2 O2/CO2 Air quality Light
Light quality/quantity H2O
Irrigation quantity
Structural support
O2 H2O
CO2 Compromised Plant Fertiliser quantity root system nutrients Shade problems
July 2008, Docklands Stadium, Melbourne Shade problems Emirates stadium by night Plant breeding
Penn State Turfgrass Breeding Trial, Pennsylvania USA Courtesy of Mark Bartlett Reinforcing rootzones
Fibresand (e.g. Lord’s, Wembley)
Netlon / StrathAyr Reinforcing rootzones
Desso GrassMaster (Arsenal, MK Dons etc)
Motz TS11 (Eden Park, MCG)
Aim: to provide flexibility for venues Recreational sport facilities
Challenges... Limited carrying capacity
Standard soil pitch with pipe drainage = 1-3 h/week
Sand slitted pitch = 3-5 h/week
Baker SW, Gibbs RJ, Adams WA (1991). Making the most of natural turf pitches. Final results of a case studies approach. II. Playing quality. Natural Turf Pitches Prototypes Advisory Panel Report No. 7. Sports Council, London, UK. Challenges for recreational level sport
• Limited maintenance budgets • Sand slit system: £30-40 k /pitch • Topdressing: £3k /pitch /year
• Restricted resource use • Water restrictions in San Diego metropolitan area 12 min of irrigation per week & $2 ft2 tax rebate for synthetic turf
• Nitrogen fertiliser application: 1% N2O emission (N2O= 298 CO2e) • Reduction of pesticide exposure Concerns of safety and liability A L L E T A Surgery & consultations £ 4950 P
Post-op physiotherapy £ 1050
Work time lost pre-op £ 2400
Work time lost post-op £ 3200
Sundries £ 57
Lost future earnings £ 0 from playing rugby
Total £ 11,657 Synthetic turf solution
• Synthetic turf is part of the solution, but not all of it:
• Natural turf remains the only viable surface for some sports due to £/ha of synthetic turf
• Playing requirements for some sports dictate natural turf? Challenges for the future... Challenges for the future (1)
• Need to increase hours of use whilst reducing resource consumption for natural turf (improved sustainability) • Water footprint of 1m3 per round of golf in Spain
• Carbon footprint of 400 g CO2e per round in UK
• Solution: • Improved water use efficiency • Grass breeding (drought, wear and pest resistance + reduced mowing) • Soil amendment • Rootzone design (less sand, less water, less fertiliser) Challenges for the future (2)
• Need improved understanding of injury on natural turf
• Solution: • Further study of player-surface interaction • Epidemiology studies • Improved (relevant) characterisation of surfaces Challenges for the future (3)
• Improved resilience to a changing climate
• Solution: • Research into mitigation and to improve resilience • Understanding the role of sports surfaces in flood prevention • Improved facilities strategies at national level • Improved education Conclusion
• The modern sports surface is a huge improvement on those of 20-30 years ago.
• Unsustainable solution for all but a small percentage of sports facilities in the future
• The modern natural turf surface is vulnerable and not the final answer – further work required (plenty of evidence to support this). Thank you for listening
www.cranfield.ac.uk/sas/sst [email protected]