Infield Water Management

By Larry DiVito, CSFM – Guest Blogger

Growing up in the San Francisco area in the 1970s and ‘80s, we experienced a major drought and some other moderate ones as well. Living in an area where water scarcity is a concern, your role as a Groundskeeper or Sports Field Manager (SFM) becomes heavily scrutinized in a hurry. You start to hear a lot about your irrigation running and are often asked several pointed questions regarding how much water grass really needs. Then there is the angry inquiry: “Why on earth are you watering dirt?!!!” Believe me, I heard that loudly a number of times in my teens and early twenties, when I was tending to fields or working as a baseball coach in California. To the novice, the notion of watering around home plate, on the baselines and the infield skin area is about dust control. For the SFM on a baseball field, watering dirt needs to focus on the soil profile players hit, pitch, run and field on, so it has sufficient moisture not just on the surface, but through the surface. 

As you read along, please retain this: the most important time for you to improve playability on your infield dirt is not when you are watering before the game…it is the water you apply six, twelve, eighteen hours or more before the game. That is when you can thoroughly water the soil profile of the infield skin and saturate the dirt, while still allowing time for the top quarter to half-inch to air out, be firm enough, ready for quality play.

Benefits of Deep Watering

Somewhere along the way spending time on fields, I knew to a degree that deep moisture on infields was a good thing. However, it was not until the 2002 season, when I went to work for the LA Dodgers as Eric Hansen’s assistant, that I really began to appreciate the benefits of deep watering on infield skin areas. 

Southern California is an interesting challenge when it comes to maintaining an infield. The lack of spring and summer rainfall, coupled with the strong sun during the baseball season, means that the quality of the infield skin falls squarely on the lap of the SFM. I spent four seasons working for Eric, and my time there led me to strongly believe that a key to quality infield skin was never letting it completely dry out. Turfgrass cultural practices, such as topdressing, mean there will be days after a home stand when the skin area will not get heavily watered.  Other than days for turf specific work, I don’t want to let the dirt totally crack under a baking sun. In retrospect, I have spent many hours watering infield dirt in professional facilities late in the day or early in the evening, while the team was out of town…wonderful and quiet times in an empty ballpark.  I found that starting a home stand was much smoother for us if the skin areas had been receiving thorough and deep water in the days leading up to our games. 

I am not a soil scientist or someone who looks to quantify everything. I am writing this based on years of experience and observation. How the infield skin looks at the surface to your eye is just one part of the equation.

Photo: Brace Hemmelgarn, Minnesota Twins

Whatever your infield dirt profile depth happens to be, ensuring that the dirt is moist all the way through that profile is a critical part of your success as a Spots Field Manager. The adequate moisture through the skin will act to reduce the hardness of the soil profile and lead to truer bounces and improved playability of the surface. 

Selecting Your Nozzle

The golf industry has really embraced the use of handheld soil moisture meters for turfgrass. If you are new to your field or have multiple fields, perhaps one of these devices can be beneficial to you in keeping track of your infield skin moisture. My situation is unique in that I have always gone to work at a ballpark and had only one field to keep an eye on. During the season I am there so much that between my eyes and a rain gauge, I have an idea of where my infield skin moisture is. For those of you running complexes, or skipping around town to various parks within your area, tracking moisture content is certainly a huge challenge. If you have time to water infield skin areas heavily by hand, or utilize irrigation heads, you have an opportunity to do great things. If automation is an option for you, be sure to use high speed heads that rotate in double the time of a standard turf irrigation head. Those will be less of a problem in windy conditions. 

Our industry has a fine selection of nozzles for you to consider for watering your field. When I water turfgrass, I generally prefer to get as much flow as I possibly can for a deep and efficient application. Syringing or cooling is a different consideration. 

For dirt, the specific area and weather situation will dictate the type of nozzle we use. For instance, watering batter’s boxes and the mound requires a finer mist that is easily controlled at your fingertips. Watering baselines means we like to have a nozzle that has a horizontal flow rather than conical, so that we water the dirt of the baselines but not the grass. Infield skin watering requires different nozzle considerations depending on time of day, weather conditions, and proximity to game time. When doing a deep soak, I like to use a 1” ball valve nozzle. 

The pre-game watering should just be a touch up, to ensure consistency. Prior to the game I use a ¾” ball valve nozzle which also allows me to get a horizontal spray using my thumb along grass edges, keeping the water off the grass. Hopefully in the hours leading up to the game you have adequately watered the skin, so that pre-game is not a time to play catch up on water distribution.  

Weather Tracking

What about the weather? If you did not know, the National Weather Service in your area is staffed twenty-four hours per day and is required to provide some type of Aviation Forecast under their Forecast Discussion tab every six hours. They also update with an Hourly Weather Forecast in graph form every three hours regularly throughout the day. Between those two options, you can get a great picture of what your day can and will be like. The data from the NWS Hourly Graph contains sky cover, wind and dewpoint. Those are critical, in addition to temperature and rainfall monitoring, as you manage your infield turf while also making decisions about using your tarp.

In terms of your infield skin, you must look well beyond the chance of rain and potential amounts of rainfall. In addition to rainfall, the amount of sky cover, wind and dew points all play a big part in infield skin maintenance. 

Last season, I had a very interesting scenario going into a noon game. Reading the hourly weather graph the previous afternoon, I saw that in spite of cloud cover, the wind would be out of the North and the air was dry and cool.  We went into game time at noon the next day with air temperatures in the mid-40s, winds from the North at 5-10 mph, full cloud cover and a dew point of 22F. I felt the field played really well that day, mainly because at 5 pm the previous afternoon I watered the infield skin really heavy to the point where there was standing water. I knew from the forecast that the dry overnight air would lead to a firm surface the next morning while the water slowly percolated down through the dirt profile. A unique situation for April in Minnesota, but just an example of knowing what air and sky conditions can mean to a playing surface. 

Dealing with days and games when rain is an issue is a critical part of our profession. If a day or two prior to a game you expect you’ll need to be ready to handle a rain event, a couple of things are important to remember. 

First, thorough moisture content all the way through your infield skin is a huge factor in having a field play well. When expecting rain, try and get a good, deep watering of the skin done two or three days in advance of the adverse weather. From there, you can work to dry out the upper quarter to half inch of your infield so it can handle some precipitation. 

The second point I want to make is that you want to be firm and tight with your dirt heading into a rain game. This does not mean bone dry and cracking. Instead you are looking to have enough moisture ahead of the game so you can roll the dirt with a lightweight roller to firm it up. From there you can add the calcined clay of your choice to improve traction and playability in the rain. My observations lead me to believe that firm dirt, with adequate but not excessive moisture, will accept light to moderate rain better than dirt that is loose and bone dry. This is particularly important around the bases and in the base runner’s lead off areas.

Clearly, my point is for you to find a way to get out and water your dirt…and enjoy it!

An experience to share: during my four seasons at Dodger Stadium, we rarely played day games on any day but Sunday. It is a bit different in Minnesota, as we move game times around quite a bit depending on the time of year or day of the week. I recall that during warm and sunny Sundays in Los Angeles, we had the potential of really drying out on the skin during the last few innings of those Sunday day games. In spite of that, we found that the ball would still bounce well on the skin…if we had kept up all week with deep post-game soakings of the dirt after night games. The Friday night watering of the dirt at 11 pm was critical for Sunday’s playability. Knowing that post-game Saturday night would not be as heavy a watering going into a day game, we really pushed to apply extra water on Friday night. So, we were considering weather and game times thirty-six or so hours in advance of the next day game.

One last set of thoughts. Aside from those times when absolutely flooding the infield dirt to the point of runoff, there is a technique to daily watering of infield skin areas. Even if you roto till your infield in the off season, once your season gets going, areas where the players’ cleats work in calcined clay will hold more moisture than other areas. For instance, where runners lead off 2nd base tends to hold more water, as do the spots where the shortstop and 2nd baseman creep in to play at double play depth. The areas where the 1st baseman and 3rd baseman play back tend to hold more moisture as well. Also, the first four feet off the inside edges from 1st to 3rd base will be firmer than other areas in the body of the infield dirt. This is partly due to your nail drag not working those spots in different directions, and also due to calcined clay not being worked in as much by cleats. So, observe your dirt and water more thoroughly in the spots that dry out quicker, such as the 1st and 3rd basemen backhand areas along the foul line. Water less in the spots that hold more moisture, like lead off areas and where infielders spend more time. If you have a low spot or two, remember to water around the low spot, not in it, as water will find a way to get there until you are able to address the grade. Most of all, just try and enjoy the onset of spring and the chance to be outside working your fields, knowing that your fine efforts will make players of all ages very happy.