OSTMA NEWSLETTERS U M M E R 2 0 2 0

FROM YOUR PRESIDENTJoel Thornton

Hello fellow turf managers! We continue to hope that you are all doing well! Normally this time of year I would ask how your seasons were going and wish you all the luck against Mother Nature, league scheduling, and the “equipment gods” that you could possibly get. But this year is like nothing any of us have ever seen. The phrase “uncertain times” is heard multiple times a day on television, in print, and on the internet, and it continues to be a “PC” way to try to relate to the current situation involving Covid-19. And it continues to be an understatement. Many of us find ourselves stuck at home, bored, fearful, laid off or furloughed, in many cases, terminated, and in the worst cases, sick ourselves. Nothing that I can say in a quarterly “Presidents Message” can change anyone’s current circumstances or the daily uncertainty that a large portion of us are experiencing. All I can say to you is that we have been and continue to sympathize with all of you. OSTMA is here for all of you to do whatever we can to help. Don’t hesitate to reach out with any questions you might have that we could potentially assist you with. We have some of the best minds in the industry that are willing to offer help in anyway they can.

With that being said, the OSTMA board is working hard to offer our services to our members as best we can. We have begun a webinar series that all members are invited to participate in to continue to try to share as much information, experiences, and ideas related to operating under the current Governor’s Stay-At-Home Order related to social distancing. I encourage you all to follow our social media pages and website for updates on these events. We will continue to share job opportunities on our website should you find yourself in need of alternative or temporary employment as well during this global pandemic. Should you be an employer looking for employee assistance at this time. Please do not hesitate to reach out as well.

We seem to have begun trending in the right direction but we are also being told that this event may continue to have an effect on us for a while. There is no manual for this. All we can do is try to remain positive, vigilant, and prepared for changes that may occur in the near future.

We’re a hard-working, resilient group of people and we WILL get through this! Whether it is next month or next year, we will carry on! Stay positive, safe, and motivated and we will come out of this experience better, stronger, and more prepared than ever. Good luck to all of you, and I look forward to seeing you all in person when the storm passes.

Sincerely,

Joel ThorntonPresident Ohio Sports Turf Managers Association

This has truly turned out to be a chal lenging year. As the State of Ohio has gradually re-opened its economy, the COVID-19 pandemic continues to have a significant impact on everyday l ife.

As the virus took hold in the United States, OSTMA was in the midst of forming an advocacy coalit ion with the Ohio Lawn Care Association (OLCA) and the Ohio Turfgrass Foundation (OTF) to strengthen the voice of turfgrass industry at the Ohio Statehouse. Chad Hawley and Troy Judy of The Batchelder Company have been retained to represent the dai ly interests of turfgrass professionals in the Ohio General Assembly. Additional ly, OSTMA continues to be a strong partner in the Ohio Professional Applicators for Responsible Regulation.

Days before the stay-at-home executive order was enacted, OSTMA, along with OLCA and OTF, lobbied the Governor to al low the green industries to be considered essential businesses as they benefit the publ ic by reducing pests and treating noxious weeds. Advocacy, something many members may not think about on a dai ly basis, is a crit ical member benefit that may make the difference as to whether turfgrass professionals can continue to work unimpeded.

The Governor’s init ial order created some confusion as to whether green industry business were considered essential. The coalit ion worked hard for clarity to make sure that sport turf, lawn care and golf course maintenance could continue. We ultimately did get the confirmation that those maintaining sports fields could continue to do so for the day when they are able to be used again.

OSTMA had to cancel its May field day, but has been holding a series of town hal l meetings, free to members, to discuss how everyone is handling the dai ly chal lenges you have al l faced.

This crisis has upended our entire world – from how we conduct business to how to shop for groceries to how we vote. Sporting events, concerts and festivals have been cancelled across the board. Business as usual wi l l change and change dramatical ly. But it wi l l also create opportunities. We wil l get through this and we wil l be better. Thank you continued support of OSTMA and we wil l continue to advocate for your interests.

6 1 4 . 6 1 0 . 4 6 2 4 E x t . 1 0 1 | m a r k @ b e n n e t t - m a n a g e m e n t - l l c . c o m .

OSTMA EXECUTIVE DIRECTOR MESSAGEMark Bennett

LET’S CONNECT

2ND EDITION OF ROUTE TO RECOVERY GUIDE IN PROGRESS

Sports Field Management 2nd Edition to the Route to Recovery Guide is being digitized and wil l be released the week of June 8. Included in this guide is the Playing Conditions Index (PCI), which is recommended to be used to gather information on field surface safety and playabil ity as athletes are brought back for play. It also contains a media advisory that wi l l help you communicate the information to your employers and your media departments. A detai led article on Crisis Field Management and l inks to short videos from our 5-week series are also included.

2021 ELECTION SLATE IS UNDERWAY

Shortly, you wil l receive a l ink to the form to indicate your interest in board service for 2021. The Nominating Committee encourages al l members to consider board service. The requirements are few, but candidates must have a passion for the industry and be dedicated to serving STMA. Prior committee service or serving on other organizations’ boards is highly recommended. The positions that are open include:

• Secretary/Treasurer

• Schools K-12 Director

• Director At Large (elected)

• Director representing Professional Faci l it ies

• Commercial Director

Board service usual ly involves four in-person board meetings yearly, participation in the annual STMA conference and chair ing one or more committees. This year STMA has held two of its board meetings virtual ly. The 2021 slate of candidates wil l be presented to the membership in November with electronic voting closing in mid-December.

UPDATE FROMNATIONAL STMA

How did you get your start as a turf manager?

"Took care of the field" during high school baseball . I put air quotes there because I can't cal l what I did actual ly productive work. But my heart was in the r ight place. Drifted aimlessly post high school for a couple semesters unti l I discovered that Sports Turf Management was an actual career! Owens CC 2010 graduate and I proudly hang it in my home office.

1

Tell us a little about your facility: the challenges and things you love

Fremont City Schools athletic faci l it ies consist of the standard sport al lotment for NorthWest Ohio. Most of our athletic areas are 30 years old or younger. A lot of our athletic space has been impacted in some way by our new bui lding construction. We are very fortunate to be upgrading our school districts elementary schools, as well as our High School over the next few years. I don't l ike to toot my own horn but we are a 2019 Pioneer Athletic Field of Excel lence winner and a 2017 OSTMA Field of the Year award winner.

2

What are you doing during the COVID pandemic? Share your experience with us.

Not much, we were sent home with pay the second week of March. For the most part I stayed busy restoring a Jeep and dreaming of going to work. I 'm not sure what the overal l consensus for the COVID experience is supposed to be, but mine sure felt l ike I was in 'retirement stage'.

3

You have a Twitter account to communicate with your user groups. Has it been effective?

Actually, I haven't been very active on the FR Grounds twitter recently. I would chalk that up to not being very proud of the athletic areas at the moment. Two months of work was lost over the pandemic. Now I feel l ike I 'm playing catch up. My second ferti l izer app was supposed to be down last week of May.. .boy I should spray those weeds down along the fences and bleachers.. .crap the area mower is down again. (so much to do when you are a one man operation)

4

Q&A CORY HULLGroundskeeper for Fremont City Schools

What’s the coolest thing you’ve been involved with during your career so far?

The coolest thing I have been involved with at Fremont Schools was tackl ing a softbal l field renovation. It 's one thing to discuss it, see it on a diagram, study the data or information. But to actual ly start the project was absolutely amazing. We converted a 1990s era l imestone screenings infield to MarMix infield mix. Getting to play in the dirt is always fun, but chal lenging with a small budget and l imited access to proper equipment. That being said, I 've got a lot of work to do left.

5

Q&A

What is the most important tool or piece of equipment in your shop?

The absolutely most versati le piece of equipment I use is our 2008 John Deere 4x2 Gator. I have adapted many attachments; ferti l izer spreader, snow plow, pesticide sprayer, nai l drag, etc etc. Anyone, in a single man operation should outfit themselves with a uti l ity vehicle of some kind.

6

What is the most satisfying part of your job?

I was just thinking about this whi le r iding around on our area mower last week, and it has to be the constant fulfi l lment in my job. Everything I do has an impact in some way. Over the last seven years I have been employed here, I have had former athletes tel l me anecdotes of small detai ls or moments for them. Seeing the progress we've made since 2013 has been absolutely amazing. Just thinking about that progress makes this whole thing satisfying. But don't let me fool you, the majority of students at Fremont City Schools know me as the "landscaping guy".

7

What do you do outside of turf?

Outside of turf, I "play army man in the woods". That's what my boss cal ls it, I cal l it reenacting. It's fun to camp once a month and hang out with some real ly great people. I 've been tinkering away at our 1995 Jeep Wrangler in the garage over the last 6 months, and I real ly love to hang out with my son Martin. He's real ly into Hot Wheels Monster Trucks r ight now, so if anyone would l ike to debate how awesome they are with a 4 year old.. .he's game.

8

• Share your favorite joke: "My wife and I were happy for 10 years, and then we met." -R. Dangerfield

• What 3 famous people, living or dead, would you want at your fantasy dinner party?

Gene Wilder, Christoph Waltz, Ian Flemming

• What’s your favorite sports movie? The Big Green

• If your life was a movie, what song would be on the soundtrack? "Slave to Love"- Bryan Ferry

• What food combination do you want to ban? Obviously we al l can agree, Pineapple and Pizza

Quick-fire round (one answer, have fun)

CORY HULLGroundskeeper for Fremont City Schools

David Gardner, The Ohio State University

An entire article can be written just about nitrogen ferti l ization for good reason. Not only is nitrogen a crit ical part of many components of the plant but it is also one of the only nutrients that, when applied, causes an obviously visible agronomic response (the grasses gets greener and grows faster). But nitrogen is just one of the elements that are essential to the growth and development of plants, including your athletic turf. In this month’s article I ’ l l discuss each element, what it does for the plant, and how and when to apply it.

If you look at the mineral composition of a grass plant, about 90% by weight is just three elements – carbon, hydrogen and oxygen . These three elements make up both the structural carbohydrates (cel l wal ls, etc) and nonstructural carbohydrates (sugars, starches). But, despite the fact that they are such a large percentage of the plant, we don’t apply these elements as a ferti l izer. Instead, the plant takes them up mainly from carbon dioxide and water. As seen in Table 1 , appl ied ferti l izer sources that supply nitrogen, sulfur and other elements can contribute, but it’s a fair ly small contribution. The rest of the essential elements are minerals found in the soi l that are absorbed mainly by plant roots but also through the leaves if certain fol iar ferti l izers are used.

The first step in developing a ferti l ity program is to take a soi l test. How to do this and al l of the information a soi l test provides could be the subject of a whole article. But, briefly, a soi l test wil l tel l you what levels of each nutrient are present and provide recommendations for additions, if necessary. The soi l test gives information about the pH of the soi l . Soi l pH should ideal ly be close to 7.0 (neutral). When the soi l pH is too low or too high, a nutrient can be present in adequate amounts, yet be chemical ly unavai lable for uptake by the plant roots. The most common example of this is an iron or manganese deficiency due to chemical unavailabi l ity when the soi l pH is too high.

Another important number on the soi l test is cation exchange capacity (CEC). Note from Table 1that, with a couple of exceptions, the mineral nutrients are taken up by plants in the univalent (1+) or divalent cation (2+) form, which is why the measure of a soi ls cation exchange capacity is important to understand. CEC is also an important measure for it wi l l guide how you apply ferti l izer. If you have a low CEC soi l (tends to be high in sand) then the soi l holds less nutrients. To compensate you should apply less ferti l izer but more frequently. On high CEC soi ls (tend to also be high in clay or organic matter) the soi l holds more nutrients and so you can ferti l ize less often but with higher amounts.

FERTILIZATION &ATHLETIC FIELDS

The Primary Macro Nutrients

The six macro nutrients are nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. They are cal led macro nutrients because they are present in the plant in relatively larger amounts compared to the micronutrients. The macronutrients are further divided into the primary macro nutrients (nitrogen, phosphorus, and potassium) and the secondary macronutrients (calcium, magnesium, and sulfur). The distinction is that the primary macro nutrients tend to be added as ferti l izer with regularity whereas the secondary macronutrients tend to be supplied only when a soi l test indicates a need.

Phosphorus is very important to plant survival. When a plant harvests energy from sunl ight, the energy transfer system in the plant uses a molecule cal led ATP. The P stands for phosphate. Phosphorus is also present in nucleic acids and phospholipids. Despite these important roles, a typical ferti l izer bag contains much less phosphorus than nitrogen and potassium. There are three reasons for this. One is that, examining Table 1, we see that phosphorus plays a crit ical role in the plant but is present in much smaller quantities compared to nitrogen and potassium. A second reason is that phosphorus is relatively immobile in a soi l system so supplemental applications are not needed as often. An exception is at establ ishment time. A newly germinating seedling does not have an extensive root system and cannot “mine” the phosphorus is needs from the soi l , thus the reason for higher phosphorus containing starter ferti l izers. Mature turf has the extensive roots system and can more effectively supply its phosphorus needs. The third reason phosphorus is applied in smaller quantities is because it is implicated in causing eutrophication of surface waters such as lakes and streams. Eutrophication is the phenomenon where a species of blue-green algae (actual ly bacteria) multiply rapidly in phosphorus enriched water and result in oxygen depletion and water qual ity degradation.

You may now be thinking “how can a nutrient that is not mobile in the soi l move into the water and cause eutrophication?” Two l ikely avenues are movement of soi l sediment into water ways and runoff losses of applied ferti l izer phosphorus. Except at construction time, movement of soi l sediment is minimal. You can do a lot to help prevent runoff losses of phosphorus by doing two things: 1) only apply it if a soi l test indicates that it is needed and 2) prior to the application, perform core aerification, vertical mow, or conduct another practice that wi l l increase infi ltration into the soi l , rather than runoff, of the phosphorus after application. We also know that phosphorus should not be applied to frozen soi l , as this greatly increases runoff losses. Also, it’s not just turfgrass seedlings that use extra applied phosphorus. Weed seedlings do as well . So you should avoid applying phosphorus when weeds are germinating. Thus an application for the purpose of supplementing mature turfgrass should be made sometime during the summer.

Potassium is the other primary macronutrient. Unl ike the other elements mentioned thus far, it is not part of any structure or component of the plant. Rather, potassium plays a role in regulating water balance in plant cel ls as well as the correct functioning of certain enzymes. Because of the way the potassium works in the plant, it is implicated in improving a plant’s abi l ity to deal with environmental stresses such as heat and drought. Synergistic relationships between nitrogen, phosphorus, and potassium in turfgrass were found in the late 1970’s. However, research to conclusively quantify the abi l ity of potassium to improve, for example, drought tolerance, has been difficult to conduct. Over the years the trend in ferti l izer analysis has changed. In 1980 a typical ferti l izer analysis for use in turf might have been 32-2-4. When the use of high amounts of potassium became “trendy” (around the early 1990’s or so) the typical analysis might have been 22-2-22. Today there tends to be a mix of phi losophies about the merits of higher potassium ferti l ity. I have seen cases where high potassium levels make a difference and others where it did not. If trying higher potassium levels in order to improves stress tolerance, leave a check plot so you can document the benefit.

The two most commonly used ferti l izer sources of potassium are potassium chloride and potassium sulfate. Potassium chloride is a less expensive source. However, it has a much higher potential to cause physiological burn (chlorosis to the leaf tissue caused by contact of the ferti l izer with the leaf – Table 2). A standard practice when ferti l iz ing is to wash the ferti l izer into the soi l by l ightly

i rr igating fol lowing application. If this practice is not fol lowed then the use of ferti l izer materials that have high physiological burn, especial ly when applied on hot or dry days can result in some unwanted yel lowing of the leaves.

The Secondary Macronutrients

The secondary macronutrients are used by the plant in relatively larger quantities, but in most cases are present in adequate amounts to satisfy plant growth needs. These nutrients tend to be added based on the results of a soi l test. Several sources of these elements are avai lable for use as a ferti l izer (Table 3) . These elements are also commonly added to ferti l izers designed to supply micronutrients to turf.

Calcium is constituent of cel l wal ls. It is required for the growth of meristems and for cel l division. Calcium deficiencies are most l ikely to occur in lower pH soi ls or on constructed athletic fields in which the sand used is si l ica based. When a grass plant is deficient in calcium one of the signs in reddish brown younger leaves. Magnesium is the atom in the center of the chlorophyl l molecule. It is also required for protein synthesis, phosphorylation and enzyme activation. Deficiency symptoms include yel low leaves with a reddish tint at the edges. As with calcium, magnesium deficiency is not common. Sulfur is a component of some of the amino acids. In parts of the United States sulfur deficiencies are rare because the burning of high sulfur coal results in acid rain that supplies an adequate amount of sulfur for plant growth. Also, sulfur is found in many ferti l izers (think sulfur coated urea). Sulfur deficiencies manifest as a yel lowing of the younger leaf tissue.

The Micronutrients

The “micro” part of the term sometimes leads my students to bel ieve that these are less important elements. Each of the micronutrients is just as important as the macronutrients and without any of them the plant can’t survive. Most of them function either in the production of chlorophyl l or the formation of carbohydrates. Micronutrients are present in the plant in much smaller quantities. Actual ly, the focus of some of the research in micronutrient management for turfgrass has been on potential toxicity if over-applied or in the soi l at too high of a concentration. There were concerns about zinc and chlorine toxicity however research shows this to not be an issue. Boron , however, can occasional ly reach toxic levels if irr igating with effluent water. Copper toxicity has been reported but this is rare. Molybdenum and Nickel , as you can see in Table 1 , are the two elements found in the lowest concentration in the plant. I have not heard of a documented case of a deficiency of either of these elements. Manganese deficiency, on the other hand, is somewhat more common and manifests as a yel lowing of the leaf but the leaf veins and tips remain green.

Testing labs do test for micronutrients and can identify potential nutrient deficiencies. Some of the elements are natural ly more or less l ikely to be deficient. Many of the micronutrients tend to be avai lable in sufficient quantities in the soi l or are del ivered as “contaminates” of N-P-K ferti l izers. If deficient, many of these elements can be supplied by way of a “micro nutrient package” sold by ferti l izer vendors. Micronutrient deficiencies are more frequently observed on sandy soi ls with lower cation exchange capacities.

The most frequently seen micro nutrient deficiency is with Iron. Not because there is not enough of it ( iron is a very common element in earth’s crust). Rather, the chemistry of iron in the soi l is what causes the issue. Depending on the pH of the soi l and the parent material of the soi l , iron tends to be present in sparingly soluble salts. Plant roots excrete substance cal led chelating agents that solubi l ize the iron so it can be taken up. So, to ferti l ize with iron you can purchase inorganic sources (Table 3) , but this should only be done to correct an iron deficiency in the soi l (somewhat rare). Also, at higher pH levels (above 7.5) the issue isn’t amount of iron present, but rather chemical avai labi l ity.

A more common use of ferti l izer iron for turfgrass is to cause a rapid greening of the turf for aesthetic reasons. Iron is not a component of chlorophyl l but it is a cofactor in its production and ferti l iz ing with iron result in rapid increase in chlorophyl l leading to darker green leaves. In fact, over application causes a blackening of the turf ( it’s actual ly ultra-dark green). This is temporary because iron is not mobile in the plant and one the blackened leaves are mowed off the symptom disappears. So to get the benefit of the rapid darkening of the leaf tissue (for a big game or event) chelated forms are typical ly applied. These are more expensive but usual ly necessary in order to del iver the intended response.

Other elements play a role in certain plant species but are not essential to al l species. Or, they may partial ly substitute the role of another element (vanadium for molybdenum, for example). Of these elements, the one that has received the most attention it si l icon, because it is thought that it may play a role in strengthening cel l wal ls. This would of course have ramifications for sports field traffic tolerance. Research into the potential benefits of si l icon applications is ongoing.

An understanding of the role that each element plays in growth and development is useful when designing a ferti l ity management program. Applying the most appropriate ferti l izer at the r ight time, based on the results of a soi l test is one of the primary practices in order to achieve successful field management.

Table 1. Essential Elements for Turfgrass Growth and Development

Table 2. Ferti l izer materials vary in their potential to cause physiological burn: The salt index value is a measure of the effect of a ferti l izer on the osmotic potential of the soi l solution compared to sodium nitrate. Fol iar burn potential is high if high-salt-index materials are used on sal ine soi ls or during periods of high heat or moisture stress.

Material Salt Index Value

Potassium chloride 114Ammonium nitrate 105Urea 75Ammonium sulfate 69Potassium sulfate 46Ureaformaldehyde 10Superphosphate 8IBDU 5

Table 3. Sources of different macronutrients (and iron, which is a micronutrient) commonly used as ferti l izer materials in turfgrass.

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Depending on which plant physiology textbook you read, there are about 18 elements that have been classified as essential to plant growth. Al l of them are equally important for, by definition, without them the l ife cycle of the plant could not be completed. However, many of these 18 elements are not applied as a part of our routine ferti l ization programs on athletic fields. Some of them are not minerals (carbon, hydrogen and oxygen). Many of them in native soi l are assumed to, in most cases, be present in adequate quantities such that applying them is only justified if a soi l test indicates. These include the macronutrients calcium, magnesium and sulfur plus the micronutrients boron, chlorine, copper, iron manganese, molybdenum, nickel, sodium, zinc. Even phosphorus and potassium should technical ly be applied only when a soi l test indicates need. Al l of these are the subject of next month’s article “Ferti l ization and Athletic Fields.” Al l of the attention this month is given to nitrogen, and for good reason. 1) It is one of only two elements whose application results in an obvious visible agronomic response from the grass ( iron is the other). 2) There are some concerns about nitrogen in the environment and applications to turfgrass have been implicated as potential ly contributing to this problem. 3) We don’t have a soi l test for nitrogen thus we make applications based on some sort of “schedule” which is affected by many different factors.

NITROGEN &TURFGRASS

Why is Nitrogen Important?

If we look at the composition of a typical plant we see that a majority of its weight ( just under 90%) is composed of the atoms carbon, hydrogen and oxygen. These elements are parts of both structural ( i .e. cel l wal ls) and nonstructural ( i .e. sugars) carbohydrates. That means that the other 15 elements deemed essential comprise the remaining just over 10% of the weight of the plant. By far the next most abundant is nitrogen at about 4.6%. It is a component of amino acids, proteins, chlorophyl l , nucleic acids, and co-enzymes. Thus it serves many biological functions within the plant. Because of this the level of nitrogen affects many things including: root growth, shoot growth, turfgrass stand density, color, recuperative potential and disease proneness.

Why is Nitrogen a Potential Problem?

By the 1990’s most folks in the industry were keenly aware of the controversies associated with the use of some of our pesticides for turfgrass management. At that time though, not as much attention was paid to whether our ferti l ity management practices might contribute to unwanted environmental contamination. But, that was then. In the present we know that over application or misapplication of certain nutrients can and does lead to unwanted environmental contamination. The extent of the contribution by turfgrass management practices is debated. Nonetheless, turfgrass management is implicated. At first, al l of the attention was on phosphorus, due to its contribution to eutrophication of lakes (more on this in next month’s issue).

Turfgrass scientists have also studied whether there could be unwanted movement of nitrogen from a turfgrass system. This work became very complex because the fate of nitrogen in a plant-soi l system is very complicated, with nitrogen existing in many different forms (Figure 1). There was some concern about the potential for ferti l izer nitrogen to leach out of turfgrass in the form of nitrate nitrogen. But, at that time many turfgrass researchers were interested in the fate of applied nitrogen in order to understand and make nitrogen use more efficient in turf. For example, they wanted to understand if

gaseous loss of nitrogen occurred and if it did, to what extent. Many of the init ial studies that were done during the 1980’s and early 1990’s were encouraging from an environmental standpoint. What was found was that if nitrogen was properly applied to turfgrass then it was immobil ized very quickly and very l ittle of it was detected in water that leached out of the soi l profi le. As a result of these studies, it was thought that turfgrass was not a significant contributor to nitrate leaching.

What many of these studies shared in common was that they were conducted on newly established turfgrass. In newly established turfgrass much of the nitrate nitrogen is quickly converted into organic forms via immobil ization. If the nitrogen is immobil ized then it can’t leach. These conversions between different nitrogen forms are governed by microbial populations in the soi l . Over time, however, the balance of the different forms of nitrogen in the soi l shifts and on older turfgrass systems, it was found that ferti l izer nitrogen can in fact leach out of the system. One of the first projects that shed l ight on this was a very long term project conducted at Michigan State University. Using the same lysimeter plots where it was first concluded that nitrate leaching might not be an issue, researchers began to find excessive levels of nitrate in the leachate after about a 10 year period. The good news from this project is that it was also found that the level of nitrate detected in the leachate could be significantly reduced simply by applying less nitrogen. Therefore, it is recommended that on older turfgrass stands the amount of nitrogen applied should be reduced in order to reduce leaching potential. This should not result in a decrease in turfgrass qual ity because the rest of the nitrogen is supplied from the nitrogen that had been tied up in organic forms becoming avai lable again through a process cal led mineral ization (essential ly the reverse of immobil ization).

Gaseous loss of nitrogen through volati l ization can be substantial. However, this is not as much of an environmental concern since the end product of this avenue of loss is nitrogen gas and most of the atmosphere is nitrogen. Gaseous loss of nitrogen is more of an economic consideration. Indeed there is research that shows that gaseous loss of nitrogen can be as high as 25% of what was applied. Form of nitrogen had a significant impact on the amount of gaseous loss. Runoff losses of nitrate and ammonia can also be substantial. What happens is nitrate or ammoniacal nitrogen dissolved in water moves off the field during an excessive rainfal l . Practices that improve the infi ltration capacity of the soi l , such as core cultivation and vertical mowing can reduce runoff losses substantial ly. The goal is to get the nitrogen to the roots (not above them to be lost to runoff or below them to be lost to leaching).

The main culprit for environmental contamination with nitrogen is nitrate leaching. Several states have placed restrictions on the application of nitrogen in order to reduce leaching losses. Some of these laws have produced positive results. The law in New Jersey, for example, requires a higher percentage of slow release forms of nitrogen be applied and this has significantly improved turfgrass qual ity. The reason is that on New Jersey’s predominately sandy soi ls, appl ication of slow release nitrogen results in more uptake by the turf and less loss to leaching. If you l ive in a state that regulates applications of nitrogen, then these laws wil l no doubt have an effect on how you apply ferti l ize. However, if you don’t l ive in one of these areas you are probably applying nitrogen to your fields according to some sort of “schedule” that’s based on research data. The difficulty with determining how much nitrogen to apply and when is that there is no practical soi l test to measure nitrogen status in the soi l . You can test for ammoniacal nitrogen and nitrate nitrogen but studies have shown that these concentrations can vary l iteral ly over a period of days. In other words, by the time the soi l test lab tel ls you the amount of nitrate or ammonium in the soi l it has probably changed. Knowledge of these soi l test values is not useful for predicating your turfgrass nitrogen needs.

Apply Nitrogen to Your Athletic Turf, not to the EnvironmentNitrogen is important for plant growth. It is also a potential problem if it is not applied correctly. Thus, the goal of your nitrogen ferti l ity program should be to supply the turf with exactly the amount of nitrogen it needs, in timely manner, whi le avoiding excess that is both costly and potential ly harmful to the environment.

Kentucky bluegrass, perennial ryegrass, and bermudagrass require more annual nitrogen than tal l fescue. In addition, the requirements can vary significantly among cultivars of the same species. Improved cultivars wi l l require more ferti l izer compared to the common varieties. Mowing and irr igation management also have a big impact on nitrogen needs. Turf that is mowed shorter (your game day field) wi l l require more nitrogen compared to the surrounding areas or fields that are mowed higher. Similarly, if irr igation is optimized the ferti l ity requirements wil l be higher. Turf that is subject to more traffic stress wi l l also require more nitrogen. The point to consider here is that if you have a large faci l ity the nitrogen needs of the game day fields, the practice fields and the surrounding areas are al l a bit different.

You should test your soi l in order to determine ferti l ity needs. As I ’ve said, the test wi l l not give information about nitrogen requirements but it wi l l help to determine how you should apply nitrogen. The number of interest is the cation exchange capacity or CEC. This is a measure of the number of exchange sites or the nutrient carrying capacity of your soi l . Another way to think of it is as a measure of potential ferti l ity. If you CEC is low, such as the case if you have a sandy soi l , then you wil l want to apply less nitrogen but more often. If your CEC is high, typical of a clay soi l , then you can apply more nitrogen less often.On a high maintenance soi l based field with Kentucky bluegrass or perennial ryegrass where leaching of nitrate is not of concern, a generic application schedule is:

This is a very generic schedule, however. On a sand based field that is mowed shorter you would want to apply less nitrogen but more often. If it is a low maintenance soi l-based field then you might only make two applications per year. These applications would typical ly be in May to promote spring green up and in August to help the turf recover from summer stress.

Other adjustments to this generic schedule should take into account your location, not only because of differences in grass growth during the year (the season and thus the ferti l ity needs of the turf are different in warmer areas) but also if there are any laws or restrictions on ferti l izer applications at any given time of the year.

This brings us to the topic of late season ferti l ization. Much research has been done that concludes that this application is both the most beneficial to the turf and yet the most potential ly harmful to the environment from nitrate leaching and runoff. The recommendation

for late season nitrogen applications had typical ly been to use a 100% water soluble source applied at about 1-1.5 lbs N / 1000 ft2 after top growth ceases but the grass is sti l l green and before the soi l freezes. This has been shown to provide many benefits to the turf including more production of root tissue (either in the fal l or in early spring) and less potential for excessive shoot growth in the spring. As a result, carbohydrate reserves are not depleted in the plant and it is more resistant to summer time stress. In response to environmental concerns, more recent research has shown that this late fal l appl ication, where permitted and recommended, can include slow release nitrogen, which is much less l ikely to leach or runoff. In locations where late fal l ferti l ization is either not recommended (for example, on a sand based field) or not permitted, you may want to consider applying 0.5 lbs N/1000 ft2 of a water soluble nitrogen source in mid-October instead. The bottom l ine is that late fal l ferti l ity recommendations vary considerably by state and you should consult your state Turfgrass extension special ist who can provide recommendations for your location.

In a recent issue (May, 2015) I discussed in more detai l the different sources of nitrogen ferti l izers and the agronomic advantages and disadvantages of them. As important as nitrogen is to the health of the athletic field, it is also important that nitrogen be applied correctly. In this way you help to protect the environment. Another upside of making your nitrogen use more efficient is that you wil l also help protect your budget in the process.

Figure 1 . The nitrogen cycle in turfgrass is very complicated and the conversions between different forms are governed by microbial activity. Because of this, a soi l test for nitrogen status is not practical. However, understanding the dynamics that affect the nitrogen cycle can help us to prevent loss of nitrate nitrogen into the environment.

HERBICIDE RESISTANT WEEDSDavid Gardner, The Ohio State University

Herbicides are an effective tool for the control of most weeds on athletic fields. But, the turfgrass management environment is unique compared to row crop agriculture in that our goal is to maintain a high qual ity aesthetical ly pleasing and functional surface over a period of many years. This being the case, some of the tools used in row crop agriculture to control weeds are not practical or possible for athletic field management, for example regular ti l lage. Given the way that turfgrass is managed, herbicides are our primary and usual ly only option. Herbicide resistance, long a problem in production agriculture, is an issue that is becoming more frequently reported in turfgrass. While not widespread at this time, it has the potential to become one of the significant chal lenges athletic field managers wi l l face in coming years.

Some of the herbicides that we use today have been around since the mid 1940’s. At this time there are relatively few new herbicide chemistries being developed for the turfgrass market. The development of resistance to herbicides by weeds is not at al l a new phenomenon, with cases being reported as early as 1970. The severity of this issue in turfgrass seems to vary depending on the target weed species, and it seems, location. Herbicide resistance issues in turfgrass were first reported in the southern United States. It has relatively more recently been reported in cool season turfgrass and is not yet as serious of a problem. By taking steps now to understand the issue we can perhaps help to prevent and/or delay herbicide resistance becoming a serious issue in cool season turfgrass.What weeds are Resistant and where is this Observed?

The first reported instance of herbicide resistance was in 1970 when it was observed that the herbicide simazine was no longer control l ing groundsel when used in nurseries in the state of Washington. By the first part of this decade the number of weed species that have been found to be resistant to at least one family of herbicides exceeded 200 and a few of these species are important weeds in athletic field management (Figure 1) . Goosegrass (Eleusine indica) was one of the first turfgrass weeds in which herbicide resistance was documented when it was found that the dinitroanaline herbicides were no longer providing control. Annual bluegrass has shown resistance to the warm season turf herbicides foramsulfuron, trif loxysulfuron, imazaquin, simazine, atrazine; the non-selective herbicide glyphosate; and the cool season turf herbicides bispyribac, benefin, pendimethalin and prodiamine. Resistance in these species has been known for a long time and management recommendations for herbicides have been altered accordingly. For example, oxadiazon is now more often recommended as a preemergence control for goosegrass. Aaron Patton, a weed scientist at Purdue University, has documented or is studying resistance development in the fol lowing weeds: smooth crabgrass (to quinclorac), buckhorn plantain (to 2,4-D), ground ivy (to synthetic auxin herbicides). Again, it is important to note that these occurrences are not yet widespread but we are seeing cases of suspected weed resistance reported with increasing frequency.

A common misconception is that weeds acquire resistance to a particular herbicide. This is not the right way of describing the phenomenon. As with al l l iv ing things there is genetic :

variabi l ity within a population. Some species have more genetic variabi l ity than others but al l have it. Because of this, a population that is normally susceptible to a particular type of herbicide wil l have individuals that have the abi l ity to tolerate and therefore not be ki l led by the herbicide. If this resistant individual is al lowed to complete its l ife cycle and reproduce then its offspring wil l also have the trait that al lows it to resist that particular type of herbicide. If the same herbicide that is no longer effective is used over and over again then the population of resistant weeds wil l grow and can eventual ly become the majority. The resistant weeds can then be spread by wind, equipment and al l of the other normal ways that weeds are spread.

How to Reduce the Risk of Herbicide Resistance

First and foremost, in cases of documented resistance to herbicides, rate very quickly becomes a non-factor. In other words, if you have a weed that is resistant, doubl ing or tr ipl ing the rate of the product and reapplying wil l tend to not be effective. Indeed where resistance is documented, resistance to up to 80x rates has been reported by turfgrass scientists.

The best and most effective method to reduce the r isk of a weed population acquir ing resistance to a class of herbicides is to not use the same product year after year but rather to rotate among the different herbicidal modes of action that are avai lable. The reason for this is that if a weed population develops resistance to a particular type of herbicide, there is a good chance that it wi l l resist al l other herbicides that work the same way. This presents some practical chal lenges for athletic field managers who maintain cools season turfgrass fields. One of the chal lenges is mental. That is, many turfgrass managers use “this” herbicide in order to control “that” weed because they know that it works (or that it has been working). Since most turfgrass managers are paid to, among other things, produce a high qual ity aesthetical ly pleasing playing surface, rotating away from a product that is desirable, either because of its economics or its performance to another product in order to help reduce the potential development of a problem that is real but may not be obvious yet can be a hard argument. But, just l ike with fungicides, athletic field managers are going to need to learn and pay attention to the different modes of action of the herbicides.

There is an excel lent extension bul letin avai lable from the University of Florida that categorizes al l herbicides avai lable for both cool and warm season turfgrass. The bul letin is SS-AGR-394 and it can be found at http://edis. ifas.ufl .edu. Another chal lenge for cool season turfgrass managers is that, compared to production agriculture or even warm season turfgrass, there are not a lot of practical rotation options avai lable for cool season turfgrass managers. Table 1 l ists only the preemergence herbicides avai lable for cool season turfgrass managers. Table 2 l ists herbicides for postemergence control of grassy weeds and sedges and Table 3 l ists the herbicides avai lable for cool season turfgrass managers for postemergence control of broadleaf weeds.

The tables are organized according to how the herbicides work to control weeds, often referred to as their Mode of Action (or MOA). Two different classification systems have been developed to categorize herbicides by their modes of action. One of these was developed by the Herbicide Resistance Action Committee (HRAC) and the other by the Weed Science Society of America (WSSA). The tables report the :

modes of action of the herbicides according to both of these classification systems. So, for example, the herbicide siduron at the top of table 1 was categorized as a C2 herbicide by the HRAC and as a category 7 herbicide by the WSSA. That there are two different classification systems being widely used may cause some confusion. However, the important thing is that with both systems there is general agreement on how the herbicides should be categorized according to their modes of action. So, for example, siduron is a substituted urea class herbicide that works in plants by inhibiting photosystem I I . It has a different mode of action than the dinitroanaline herbicide benefin, which inhibits mitosis. For ease of interpretation, herbicides with the same mode of action within a table have the same colored background on the table. Most pesticide manufacturers now include at the top of their label a box with the WSSA code in order help turfgrass managers easi ly identify what type of herbicide they are using.

Proper rotation involves using herbicides with a different MOA (or colored background on the table) for each application. For example, if the objective is to avoid resistance development in crabgrass then rotating between benefin and prodiamine is not effective because both are dinitroanaline herbicides. It is also not effective to rotate between a dinitroanaline herbicide and the herbicide dithiopyr. Dithiopyr is in a different chemical class ( it’s a pyridine) but both the pyridines and the dinitroanalines have the same mode of action. Looking at the other preemergence herbicides in Table 1 that are effective for crabgrass control reveals that our options for an herbicide to rotate with the mitosis inhibitors include just siduron (which is used more at seeding time) or bensul ide.

A strategy to help deal with this is to incorporate the use of postemergence herbicides into the management plan and to also rotate among these chemistries. So, for example, the use of fenoxaprop one year fol lowed by quinclorac in year 2 and then either topramazone or mesotrione (different chemical classes but same mode of action) for year 3.

I mentioned that if a weed population acquires resistance to one herbicide then it probably wi l l resist al l herbicides that work the same. With goosegrass there is an exception in that dimethenamid-p is label led for control, even though it is a mitosis inhibitor. However, dimethenamid-p is a different type of mitosis inhibitor according to both classification systems.

For the broadleaf herbicides, if the target is an annual weed then a preemergence herbicide may be useful. Pendimethalin or prodiamine or dithiopyr in year 1 fol lowed by bensul ide in year 2 may effectively control many of our summer annual broadleaf weeds. Another option may be to rotate to isoxaben, depending on the target weed. When rotating, of course you need to make sure that the target weed is on the label. For perennial broadleaf weeds, if you examine Table 3 , knowing that weed resistance is becoming a serious issue, you could say we have been very fortunate in turfgrass because for a very long time our postemergence herbicides were al l synthetic auxins. The registrations (al l since the year 2000) of the PPO inhibitors and the ALS inhibitors have provided cool season turfgrass managers with some important options for herbicide rotation programs to control broadleaf weeds.

Some closing thoughts

After reading this article you may be thinking that I ’m being melodramatic or just looking for a different tangent to write about. However, whi le the overal l problem of herbicide resistance in cool season

turfgrass is sti l l relatively minor this does have the potential to become one of the more significant management issues that turfgrass managers wi l l face in the future. So, you should do your part and adopt a proper herbicide rotation program. The other thing that you should do is to remain observant. Whenever an herbicide application fai ls it has historical ly been acceptable or even easy to just rational ize the fai lure – “It must have been mixed wrong” or “The product was applied incorrectly” or “The weather must have been bad after I appl ied it”. These things can and unfortunately do happen. But, when noticing a herbicide fai lure, if the herbicide targets more than one weed, observe whether al l the weeds kept growing or is it just one species that didn’t seem l ike it was control led adequately. If this is the case then certainly fol low up. It could also be that you have found an herbicide resistant population. Report suspected cases to your state extension special ist. They may be able to do tests to verify the resistance and then alter management recommendations for control of that weed.

Figure 1. Herbicide resistance is either suspected or confirmed with these weeds that are common on cool season turfgrass athletic fields.

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GreenVelvetSod has been helping the local Grove City Titans Baseball team make the most of the COVID situation by bui lding a new practice field for their summer league team. #ifyoubul idittheywil lcome

A Galloway Baseball team the Grove City Titans 14U team was forced to find a new home to practice for their summer league activit ies. Because of the COVID restrictions, the team has been forced out of the local high school faci l it ies where they have traditional ly held practices. To make the best of the situation, the team has taken it upon themselves to bui ld their own field to practice. The league president contacted Greenvelvet Sod asking for any products to help with their summer bal l field. The team has taken a plot of land previously used as a horse pasture and is quickly making it home.

The Team manager’s Tricia May-Woods said, “I ’m sure it feels l ike business as usual but please know you have twelve, 14 year old boys working hard and are THE MOST excited about this dirt.”

Bel ieve it or not, this team is not alone in requesting help for these kinds of projects. Kudos to al l these sports teams and potential turfgrass experts on their init iative in finding ways to work around a pretty tough situation!

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