The NFL in Mexico City: last year will not be repeated!
$45 million gone.
Adios. That was the economic impact to Mexico for previous NFL matches. Not only was the cancellation of the 2018
Rams v. Chiefs game a black eye for all parties involved, but also it resulted
in an unprecedented joint “statement” from the NFL’s Commissioner Roger Goodell
and Mexico’s President-Elect Andrés Manuel López Obrador.
Earlier this year, at
the recommendation from the NFL’s consultants, Azteca Stadium brought in World
Sports Solutions International (World Sports) to serve as technical advisors
and make recommendations relating renovating the field. World Sport’s resume includes, construction,
renovation and/or maintenance of 9 of the 12 stadiums used during the 2014
World Cup – Brazil.
Many in the sports
turf industry watched the scene unfolding at Azteca Stadium in November 2018 in
disbelief. There were many questions and not many answers. It’s human nature to
try to blame a disaster on a single cause, the simpler the better. It would be
wrong to point blame at a single cause. The reality is that decades of history,
intense traffic, Mother Nature and technology all transpired to cancel the 2018
NFL Mexico City game.
Based on interviews
with the grounds crew, reviews of reports and inspection of the playing field,
World Sport’s agronomist, Renato Luis Lauretti, concluded that four factors all
contributed to the field not being in playing condition: inadequate soil and
drainage; installation of a hybrid system that hampered remediation efforts;
weather; and high traffic.
Soil and drainage
When Azteca Stadium
was built in 1968, the architects and engineers had a different understanding
of sports fields than today. Fast forward to 2017 and 2018, and the Azteca soil
had developed into almost entirely organic matter. Black, mucky soil that was
easily compacted and easily became anaerobic when wet conditions persisted.
This 40+-year-old soil, that by all accounts was the original soil when the
stadium was first constructed, was of more interest to archeologist than sports
To compound the
problem, the drainage system that was originally installed when the stadium was
built had been rendered ineffective over the years, filled with muck and of no
practical impact. Water could not effectively penetrate the high organic matter
soil and would remain trapped far above the drainage system.
While the field could
look great, it simply could not handle any appreciable amounts of water and be
playable. Moreover, once the rain fell the soil would become anaerobic,
depriving the kikuyugrass of oxygen and adding unnecessary stress.
In the spring of
2018, the PlayMaster hybrid grass system from Tarkett Sports was installed at
Azteca. The key advantage to hybrid systems is the added soil stability, which
is lost over a short period of time once the warm-season grasses, such as
bermudagrass and kikuyugrass, mature because the stolons and rhizomes provide
the necessary horizontal reinforcement.
Azteca now had a PlayMaster,
installed over easily compacted, high organic matter, mucky soil, with no
effective drainage. The roots of the kikuyugrass faced a challenge, to stay
above the carpet layer where ample oxygen was present or venture downward into
compacted oxygen deprived environment to quickly wither and die.
The installation of
the hybrid system created a major challenge for Azteca’s ground crew. To create
the right environment for the roots to penetrate through the carpet layer into
the subsoil, the subsoil needed to be decompacted and its composition changed
by introducing sand to mitigate anaerobic conditions.
With the newly
installed hybrid system, pulling cores was now off the table, as was the use of
a deep rotary aerator. The PlayMaster became an impediment to fixing the
underlying soil conditions that were allowed to exist prior to installation of
the hybrid system. As a result, the hybrid system created a barrier to the
implementation of cultural practices needed to promote a healthy sod by
remediating the poor soil conditions and traffic events.
The summer and fall
of 2018 was wetter than anticipated. The historical average rainfall over a
30-day period in Mexico City from June to September is between 4.4 inches to
6.3 inches per month. October sees about 2 inches and November sees about .50
inch. In 2018, October received more than its average amount of rain and 5 days
before the game, November 14, the Stadium received close to .7 inches, bringing
November’s total to over 1.1 inches.
With no effective
drainage, the mucky soil stayed very wet contributing to the anaerobic
conditions and the kikuyugrass remained in a weakened condition with its root
system predominately above the hybrid carpet layers.
The stadium is home
to two professional soccer teams and the Mexican National team and hosts events
almost every weekend. In 2018, Shakira played back-to-back concerts over the
October 11 weekend, followed by multiple professional soccer games. The pitch
was left in shambles after the Shakira concert, with dead and dying grass on a
hybrid system installed over very poor soil that hampered cultural practices
necessary to create a strong turf stand that could recover.
World Sports was
brought in by Azteca Stadium to assess existing conditions and make
recommendations in the capacity of technical consultants and eventual project
managers if renovation was decided. World Sports’ agronomist Renato Luis
Lauretti was brought in to oversee the project, supported by Breno Cuoto to
oversee the sod farm and installation, and Fabio Camara, our engineer
agronomist, to oversee the installation of the drainage system and sub base.
On March 20, 2019,
the sod farm was far from ready. This singular challenge could spell disaster
for the project. World Sports designed a fertility program and recommended
immediate changes to the cultural practices designed to push the grass so that
it could be harvested in early June. With roughly 2½ months, the grass would
need to make dramatic progress to be harvested.
On May 10, 2019,
World Sport performed its final inspection of the sod. Over the course of 50
days, the grass had formed a reasonably dense stand and was looking ready. The
true test would be rolling a sod sample to visually inspect and understand the
maturity of the root structure. Two test rolls were taken, with the conclusion
being that the sod was still immature, but very close to being harvested.
After assessing the
existing conditions and the likelihood that another failure was probable if the
underlying soil conditions were not rectified, and based on World Sports’
recommendation that the sod would be ready by June, a decision was made by the
Azteca Stadium ownership group to move forward with the renovation of the field
by installing a working drainage system, replacing the high organic matter soil
with 12 inches of sports sand (90/10% mix) and sodding the field using
stadium’s existing kikuyugrass sod.
Once the green light
for the project occurred, local contractors removed the hybrid system,
irrigation and high organic matter soil. An attempt was made to locate and move
the old drainage system, but it was deeper than anticipated and left in place
to prevent delays to the project.
Fabio Camera arrived
in Mexico City on May 31 to provide technical advice and oversee the
installation of the sub base, drainage system, irrigation and soil base. The local contractors and engineers worked
quickly to maintain the tight schedule.
The sub base was
graded with a 1-degree slope from the crown to the side of the pitch. The drainage
system consists of 27 feeder drains on each side of the pitch that flow into a
6-inch collector drain on both sides of the field. The collector drains were
previously installed by Azteca as part of a remediation effort earlier in the
year. The feeder drains maintain the slope of the sub base and are supported
with geotextile and gravel.
An irrigation system
was installed, with new pump, clock and control using Toro elements, 24 heads
with an extra valve and four heads at the south end due to its being a larger
The topsoil now
consists of a 90/10 high quality sand to peat moss mix. The peat moss arrived a
few days late, having traveled from Canada, which caused a 2-3 day delay. The
slope from center to side of the field was reduced to .8%.
On June 11, the sod
began to be installed; while the root systems could have been more mature, the
initial rolls are all looking good and installation proceeded with few
At the time of this
article, sod harvest and installation are proceeding. In the coming months we
hope to update the STMA members on the results of sod installation and
maintenance practices in preparation for the numerous soccer games and the
eventual NFL game between the Chargers and Chiefs in November 2019.
Michael Newcomb is
COO, World Sports Solutions International. World Sports Solutions International
has offices is Brazil, California, Florida and Nevada, providing sports field
construction, renovation, maintenance and consulting services for all levels.