Winter kill and recovery at Nihzny Novogorod
Charles Henderson, Managing Director at Professional Sportsturf Design (PSD), writes about the Nihzny Novogorod Stadium in Russia.
Following England’s victory at the World Cup, they head to the second of Football Technology’s pitches constructed for the World Cup under STG.
Konstantin Chamilovich of STG were responsible for the stadium build. I first visited Nihzny Novogorod in June 2017 and was struck back by the scale of this city’s car manufacturing. The drive into the city is accompanied by a 2.5km car assembly line of an impressive scale constructed for the manufacture of the famous Lada.
An earlier pitch construction was targeted at Novgorod due to a colder climate than Volgograd and a much longer winter. This early start proved to be invaluable to delivery of the pitch for the World Cup.
As per Volgograd, Football Technology assisted by PSD went about selecting a supply chain for the construction of the pitch, these included:
- DESSO Grassmaster reinforcement systems
- SGL lighting systems
- Sub-air ventilation system
- Oleg Bow and Rehau undersoil heating system and pipe works.
- Rain Bird pitch irrigation system
Pitch construction was commenced and delivered on schedule which allowed a near full grow-in to be achieved prior to the onset of dormant conditions.
Due to regional restrictions on the use of heating, under which the pitch heating fell, from the outset use of the heating was heavily restricted. We as turf managers had to accept an element of social responsibility on this matter, the heating of family homes had to be considered, more important. This meant having to let the pitch freeze on numerous occasions through November which we had not wanted to occur.
In December after only having access to undersoil heating for a couple of weeks, a technical decision was made to shut the heating and let the pitch freeze.
Due to the success of the initial establishment, Nihzny Novgorod was selected for the opening test games of the Government stadia placing a spotlight on the stadium. It was at this point the realisation of Winter Kill came to fruition.
Novgorod from the outset was considered at very high risk of winter kill, this combined with test fixtures in April 2018 presented a difficult agronomic situation. A winter extending well into spring and the night to day temperature swings of 15-20 degrees centigrade this was ideal for crown hydration and left an extremely difficult decision to be made.
Crown hydration damage continues to be one of the most destructive yet least preventable forms of winter kill. It is a problem generally associated with turf growing in plants with high water content whose saturated cells rupture and die following extreme fluctuations in freezing and thawing temperatures. The vast majority of crown hydration kill occurs in the period of snow melt which in our case was man-made through the use of heating. Ryegrass due to the exposure of the crown is susceptible to crown hydration. This combined with a need to bring the pitch out of snow melt early made the pitch vulnerable.
Prevention of Crown Hydration
- Hardening of the plants going into winter was attempted during autumn but given the age and need to establish turf cover pre winter in the short window was complex. Nitrogen applications were ceased 3-4 weeks prior to winter heating and lighting shut down. Potassium applications were increased to harden the plants and make it more durable against crown hydration.
- Daily discussions took place throughout late February and early March including reviews of forecasted weather. Day-night temperature swings in this period were relentless. So in early March the decision was made to remove the snow cover, start undersoil heating and use pitch covers. Night temperature swings were such that some level of crown hydration would inevitably occur.
- A decision was made to assume winter kill had occurred since obvious visual symptoms can take days/weeks to discover. Overseeding was implemented and the process of recover undertaken.
Practical Factors
From the outset of this project, the prevention of crown hydration was pivotal but a critical choice existed:
- Bring the pitch out of dormancy earlier with the presence of high temperature swings increasing the risk of crown hydration, however this allowed more time to establish and grow-in the turf for early fixtures.
- Delay bringing the pitch out of dormancy to reduce the chance of crown hydration, gamble that temperature swings would reduce and eliminate / reduce winter kill experienced. If we were wrong, this left little to no time to establish new turf cover.
A technical decision was to select option 1. This was a decision which paid dividends as Novgorod continued to experience -10 to -15 degrees at night all the way through to early April. If option two had been implemented, we would have likely still experienced a level of crown hydration and had insufficient time to recover the pitch to any extent for the test fixtures.
The prolonged night time low temperatures that continued well into what was technically meant to be spring This presented the next challenge, taking a pitch from 50% cover to 85% cover in 5 weeks with an average atmospheric temperature of 5 degrees and night time lows of between -5 to -10 degrees centigrade.
Heating, Sub-Air, Covers and Lights
As a new pitch with juvenile turf cover, inherent stability is low, pushing turf cover establishment and grow-in as quickly as possible was pivotal. Football Technology’ commitment to an arduous daily routine consisted of:
7am – Check undersoil heating temperatures (set at 16 degrees)
8-9am – Moving lighting rigs
9-10am – Pull pitch covers off and turf lighting rigs back on
12pm – Irrigate pitch and move lighting rigs to accommodate irrigation.
5pm – Moving lighting rigs and replace pitch covers
6-7pm – Move lighting rigs back over covers
The above routine was implemented for nearly 6-weeks with the introduction of mowing, fertiliser and other refinement practices being included as turf cover progressed.
The opening test fixture took place on April 14th 2018 which presented a steep learning curve. As the city’s first new stadium, local pressure was extremely high for the opening to be successful and stories of turf being flown-in started to surface. It was at this point, ensuring all stakeholder held their intended path became critical. Readiness of the pitch for the World Cup was never in doubt but keeping stadium and tournament organisers on board with this was critical.
Even with climate change, it was inevitable that temperatures would start to increase, however this didn’t occur with temperatures running nearly 3-4 weeks behind norms. This limited turf development that could be achieved for the opening game in April.
Recovering and Establishing New Turf Cover During a Cold Spring
Recovery of existing plants – The priority in these situations is always to recover existing surviving plants. Immediate applications of light and frequent nitrogen and potassium commences along with magnesium and low levels of phosphorus to make sure of availability. This was kept light and frequent to ensure newly establishing root systems had access to vital nutrients in the upper profile. Mowing and physical treatments were kept to a minimum through the first 2-3 weeks.
Establishment of new plants – Overseeding was undertaken immediately on snow melt on the assumption it was required. This was implemented at high rate.
Managing plants at varying stages – Perhaps the most complex and irritating activity turf managers have to implement is establishing new turf cover amongst mature turf cover. With surviving plants at 4-5 leaf stage and newly germinating turf in amongst it, the two have very different requirements. However programmes must be oriented around the newly stabling turf cover through the first 2-4 weeks to ensure weak and thin areas are established.
Creating density – pushing density was pivotal to a successful pitch at Nihzny as this would bind the upper 0-10mm of the surface. Early use of growth regular Modus at light rates was implemented as soon as ryegrass hit three leaf stage. As soon as full plant development had occurred, full rates were commenced to forced lateral plant development and close up the surface.
All is well that ends well
On completion of the two test fixtures a period of 3.5 weeks was available to prepare the pitch for the World Cup. Eventually temperatures started to increase which made finishing of the turf cover easier. Management during this period became easier and more conventional as overseeding had worked and was at full maturity and visual uniformity throughout.
Focus then moved towards surface performance refinement to facilitate ideal firmness and tractions levels through implantation of shallow spiking.
Nihzny Novgorod was always going to be a tougher venue due to climate, the decision to commence early pitch construction proved pivotal and without this would have required us to turf the pitch reducing end quality.
A number of pre-emptive decisions based simply on risk management allowed earlier recovery and establishment of full turf cover in late spring and subsequently focus on refinement prior to World Cup.
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