As we discuss the factors that lead to the SoccerPlex Stadium renovation project last month, it is only fitting that I adopt an “investigation” theme following last night’s season premier of 2 of my favorite television crime dramas.
Certainly it did not take the extensive type of special investigating skills that are possessed by NYC’s finest detectives to lead us to the factors for renovation: 1) 4″ organic layer build up & 2) the large poa annua infestation. But the problems caused by the organic layer factor were not as obvious as the lime green poa annua.
But by following the clues, the 3 major challenges with the field from a maintenance and playability all manifested as clues leading back to the perpetrator: the 4″ organic layer.
Those 3 clues were:
1) An initial severe black layer issue
2) Surface hardness when dry
3) Lack of root depth
Let’s explore the clues and how they pointed back to the organic layer:
1) An initial severe black layer issue: When I inherited the field in the spring of 2009, a thick black anaerobic layer topped the field. Black layer is caused by the lack of soil gas exchange due to excessive moisture/ lack of aeration in the top layer of the field. Upon my arrival in February we started topdressing immediately to prepare the field for the exhibition season in early March. Even with 1/4″ of sand across the top of the layer, during the initial few matches on the field, players were slipping and sliding from the black layer.
Aggressive aeration and continued topdressing solved the problem of the black layer. Initially however, the cause of the layer was blamed on the lack of and improper aeration techniques during the field’s first 8 seasons: not the 4″ organic layer. The sand based field w/ turf grid stability fibers had only been aerated 2 times a year for the previous 5 years- 1 time in the spring, 1 time in the fall at 4″ with coring tines. The sand below that 4″ had hardened off completely, especially with turf grids (sand w/ re-inforced gets very hard over time if not aerated deep). So the reason for the black layer originally seemed that it must be from the 4″ aerations had created a top “layer” that was holding all the water because the sand below was sealed off and water could not soak in.
And yes, that was part of the problem Once the field was deep tined multiple times over the next month, core aeration took place at multiple depths, and topdressing sand was applied… the black layer was broken down. But the clues towards a bigger issue started to become more glaring as the anaerobic conditions continued in the top layer.
2) Surface hardness when dry: The clue for the organic layer being problem was the surface hardness of the field. The field would go from soft to extreme hard as soon as it dried down. Athletes were complaining about the surface hardness on their legs and balls that were played long in the air bounced off the field like it was concrete. To negate the problem, aggressive aeration continued to be implemented in conjunction with heavy watering prior to high level events to insure the surface was soft and playable for the athletes. The cultivation and watering helped… but more water starts to lead back to the the black layer issues. More clues that there was a bigger issue.
3) Lack of root depth: The last clue towards a larger issue with the SoccerPlex Stadium field was the lack of root depth that could be created. Even with aggressive aeration, proper nutrient management, and a bio-stimulant program designed to drive roots… the roots still did not want to leave the top 4″. They would push down through the sand channels with aeration holes, but the major root mass would not push past.
At the point of connecting all the evidence from the challenges of the 4″ organic layer, it became even more evident that a micro soil environment was present and we were not going to be able to overcome it with aggressive aeration and topdressing alone. The fines in the organic were locking up too quickly to allow water to pass through consistently (causing black layer). The fines locked up and then drying out then created the rock hard surface when dry (making the surface hard for playability) and were holding all of the nutrients from fertilizers and not allowing them down into the sand. With all the nutrients in the top layer, the plant roots had no desire to go into the sand because there was no food there.
The evidence showed that the only answer was to cut out the 4″ organic layer and get back down to the original sand w/ turf grids for stability fibers as the growing media for the grass. Especially with seeding, all of the negatives from the old field would be eliminated: 1) no black layer because the native sand to the field drains at over 20″ per hour; 2) no surface hardness because the sand is firm but soft; and 3) the roots can grow down through the entire 12″ consistent profile.
Now that the renovation as been completed and the seed is growing in, already it is clear that all those factors have been eliminated. The organic layer gone, along with the poa annua removed, has reduced the amount of water require for irrigation, the amount of fertilizer used, and will slash the amount of fungicide needed. Already, just 26 days later, the evidence is clear the renovation was a success.