Improving High School Sports Fields

By Andrew S. McNitt, Ph.D.

Looking to upgrade or rehab your natural turfgrass fields this growing season? While every situation is different and I can’t cover all contingencies, I’m going to share my general experience in working with high schools in Pennsylvania.

The most important thing to start with is an assessment of drainage, especially considering the precipitation we had in most parts of the state during 2018. If the crown of the field is worn out and you are playing in a soup bowl (Figure 1), there is no sense throwing any additional resources at this field until the crown is reestablished.

Figure 1: Field with no crown. This field is leaned from one side to the other.

I’m not naïve. I understand that asking for the addition of good quality compost, a regrade, and sod is a big ask and difficult to get approved. The point is that you must keep asking because that is the factor limiting the quality of the field. I advise against trying to create band-aid solutions. Money will be wasted and the opportunity to get the larger project approved may be compromised. At least ask to get some bids on the larger resod project.

I understand a little about the bidding process inside a school district and the complaints that are lodged if a bid goes to a contractor outside the district. My advice is to divide the project into pieces, maybe for both the construction and the design. An architect or project manager is not always needed on a job of this size but sometimes it’s money well spent. Allow your local architect to do any permitting required, etc. and ask if the architect would then accept a sub who specializes in the finish specifications for athletic fields. Similarly, ask that the trucking for the compost and maybe application tilling and rough grading be bid to local contractors but bid the finish work to a sport construction specialist. Keep asking/explaining in a respectful manner. I often tell my students: “it’s not necessarily the best grass growers who rise to the top of this industry, it’s usually the best communicators, because they can effectively communicate the issues to the administrators who control the purse strings and are able to garner the resources needed to create a quality turfgrass surface.”

Last season the ground stayed wet regardless of a crown. Creating a nearly all-weather playing surface using sand is beyond the scope of this article but you can get some great information by googling ‘Michigan State Sand Cap System’ or by using this link: https://bit.ly/2X4l4Z1. Let’s say you have a crown and the field drains adequately during ‘normal precip years.’ Now what is the most important item you can spend your money on?

The answer: PEOPLE. Again, a tough sell, but that is the correct answer. There is no magic potion you can spray on the field to suddenly make it hold up to wear better. It’s really just doing the basics really well like in the Karate Kid. It’s wax on, wax off. If you do basic maintenance really well, you’re 85% of the way there. So again, you have to communicate the need. Numbers help. How long does it take to trailer the mowers to a grade school campus, mow, trim, clean up and return? Show the administrators, on paper, where all the man-hours are going. If adequate drainage is in place, you will need additional labor to improve the quality of the fields, pure and simple.

It would be a great help if in the summer you could hire a few retired folks to do some mowing in the common areas, but often the labor structure in school districts won’t allow that. You need butts on mower seats because almost everything I talk about from here on requires you to make the grass grow faster and if the grass is growing faster, you will have to mow more often. Golf course fairways are mowed pretty much every other day. Penn State’s Beaver Stadium is mowed about 3 times per week during much of the year. Figure 2 shows two plots with exactly the same care. Simulated soccer-type wear was applied evenly to both. The one on the left was mowed once per week while the one on the right was mowed 3 times per week. Nothing else differed. Mow often with a high-quality mower. It can be a rotary, but it should be adjusted with a sharp blade to aid in turf health.

Figure 2: Both areas received the same maintenance and the same traffic. This plot was mowed once per week.

Figure 2: Both areas received the same maintenance and the same traffic. This plot on right was mowed 3 times per week.

A trick I learned from Dr. Dave Minner at Iowa State: Don’t spread your resources out evenly among all your fields. Create a showcase field and give it the resources it needs perhaps at the expense of some other fields. Why? Because if you spread out meager resources equally, the fields will all be average and maybe the administrator’s view of your sports field management abilities will also be average. When you ask for more resources to improve fields, the administrator imagines the result and figures the fields will just be a little more average.

But if you have one field where you demonstrate your abilities, several things happen. One, everyone sees, first hand, what you can create. Next, you will begin to get lobbying allies. Coaches who don’t use that field will ask: “Hey, why doesn’t my field look like that?” Answer: “We need more people.” Soon they are lobbying for you to get additional labor.

A couple other points on mowing. On multi-use fields, mow as high as you can, within reason. Obviously, you may need to keep the soccer field a bit lower than the football field, and perhaps the field hockey field a bit lower. The turf can better withstand the abrasion and grinding of many feet if the height is higher. I don’t see much reason to have your effective height much higher than 3 inches. Remember, this isn’t the bench setting measured in the shop but the effective height of the grass after mowing (Figure 3).

Figure 3: The effect of mowing height on wear resistance. This plot was mowed at 1.25 inches.

Figure 3: The effect of mowing height on wear resistance. This plot was mowed at 3 in.

Let’s address another mowing issue that needs to be corrected in many cases. Quit raising and lowering the height of cut during summer, especially for fields that will receive fall use. This is not helpful and likely weakens the turfgrass. For instance, we’ve all heard that in the summer, it is less stress for the grass if it is mowed higher. The roots are deeper and the plant can withstand drought to a greater degree, etc. That’s all true, but here’s the issue. When will you be bringing the height of cut back down to playing height? Preseason football begins early to mid-August. Will you be lowering the height of cut then? August is typically among the most stressful months for our cool-season turfgrasses. So, the grass is stressed by weather and you are going to put a second stress on it by lowering the height of cut at this time? And shortly after that second stress, you are going to let 80 athletes begin running around on the grass with cleats. It’s the triple whammy! The turfgrass will suffer.

Pick an appropriate height of cut and stick with it. Just mow more often.

Next is fertilizer, especially nitrogen. For very high-traffic multi-use fields, you need nitrogen so that the grass is growing quickly and can recover from the wear. If I’m invited to a school by an administrator and I don’t know the sports turf manager, when I ask how much nitrogen is being applied to a field I typically get: “3-4 lbs. of actual nitrogen per 100 square feet per year, sir.” See, you know the amount that should be applied. Later, in the bar, after I’ve gained your confidence, you explain: “Andy, we can’t apply any more than 2 lbs. per year because we can’t keep up with the mowing. Currently, if it rains for 2 days, we are on a 10-day rotation at best.” See, it’s butts in seats. You’ve got to have the mowing in place before you can apply the appropriate nitrogen. Go to the upper end of the recommended scale on these high use fields. If you are confident in your calibration and application techniques, a fast release nitrogen source like urea is the best bang for the buck! But you must be calibrated or you’ll burn the grass. Next, spend money on good quality seed. Stop buying overseed mixes with small amounts of Kentucky bluegrass in them. The blue is expensive and doesn’t come up unless the field is rested for a season (Figure 4). Perennial ryegrass is the only cool season grass that has a chance to establish on high-use fields during play.

Figure 4: Results of overseeding with equal weight of seed while surface is exposed to traffic. Ryegrass.

Figure 4: Results of overseeding with equal weight of seed while surface is exposed to traffic. Tall Fescue.

Figure 4: Results of overseeding with equal weight of seed while surface is exposed to traffic. Kentucky Bluegrass.

Next, seed a lot. Typical p. rye overseeding rates are maybe around 8 lbs. per 1000 square feet on the high end. Those rates were created for establishing turfgrass when no wear was applied. If you are seeding and playing on the surface simultaneously, you’ll need more. Lots more.

The series of photos shown in Figures 5 and 6 demonstrate that with nothing else altered, the application of more seed to fields being trafficked, resulted in greater turf cover.

Figure 5: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. 5lbs Seed per 1000 sq. ft

Figure 5: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. 15lbs Seed per 1000 sq. ft

Figure 5: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. 25lbs Seed per 1000 sq. ft

Figure 5: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. 35lbs Seed per 1000 sq. ft

Data collected by Dr. Minner indicated that percent turf cover continued to increase up to 200 lbs. per 1000 feet squared. It may continue to increase at rates above 200 lbs. but Dr. Minner stopped at 200. From both Dr. Minner’s data and data collected at Penn State, it appears that the law of diminishing return kicks in right around 30 or 35 lbs. per 1000 square feet as indicated in Figure 6.

Figure 6: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. 50lbs Seed per 1000 sq. ft

Figure 6: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. 90lbs Seed per 1000 sq. ft

Figure 6: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. Economic Threshold !!! 35lbs Seed per 1000 sq. ft

Figure 6: Turf cover resulting from varying rates of perennial ryegrass overseeding during simulated wear. Economic Threshold !!! 90lbs Seed per 1000 sq. ft

Figure 7: Eighty percent of a football game is played on the area from just outside the numbers and between the 20-yard lines.

Thirty pounds per 1000 seems like a lot of seed because it is. Remember though, you may not need to apply that much to the entire field. Maybe just apply 35 lbs. per 1000 to the field within the field (Figure 7).

On 15,800 square feet, 30 lbs. of good quality perennial ryegrass seed per thousand should cost around $1000. I know you want to purchase through your local Agway or other local seed dealer. That’s fine, but ask them to special order some decent quality seed. Use ntep.org. Don’t go crazy though and require what is listed at the top of the NTEP listing. Pretty much the top 50% are about equal. That’s a stretch, but I suggest selecting the cheapest cultivar you can get from the top 30–50% of those listed in NTEP. As long as you stay away from the poor cultivars, the quantity in this case is more important than the difference in quality among the cultivars in the top 30%. Remember, you are almost growing this grass as an annual, constantly reseeding.

Dr. Minner and I went back and forth on a seeding schedule. We both agree that if you can afford it, seed all the time. Early, mid, and late spring, all fall, late fall, etc. However, considering a limited budget on a stadium field with fall use, we suggest the following. Dr. Minner emphasized that applying the seed early was more advantageous than waiting. He suggested starting to seed in the late summer/early fall even before wear was evident. He reasoned, what good is it to hold back some seed until mid-October? It’s not doing you much good when it’s still in the bag on a shelf. I agreed with this philosophy except that I thought if you applied all the seed early, some of the seed would be displaced by divots and those areas would not have as much chance to recover. So, after some discussion we compromised. Apply 20–25 lbs. at the beginning of the season and apply 2 lbs. per 1000 square feet to high wear areas after the each of the first five home varsity football games. The JV team will cleat-in the seed on Monday.

I’m out of space for this issue. Again, every situation is unique, but I would follow the need for seed with good quality aerification then topdressing. I’ve written about topdressing of sports fields in a previous issue. See the Summer 2013 issue: http://www.thepaginator.com/preview.php?ID=1106

Of course, irrigation is very important during some nonflood years. I look at irrigation like I look at recrowning. It’s a capital expense and falls under a different budget. If you are asking for an irrigation system, break it into parts. Perhaps in year one you just have the main water line extended. Year two you put in the system and use manual valves. Year three you install the controller. Biting off three small chunks may be more palatable to the administrators.

Lots more detail is required to custom fit a program to your particular needs, but I hope this begins to set a blueprint for improvement. Remember, the answer is always no if you don’t ask. Be smart, be respectful, do your homework, document it, and tactfully keep reminding everyone what is needed for field improvement and safety. It has been said that after the façade of the school building, the stadium sports field is the most viewed item in the school district.