Ronald Strahan, Koske, Thomas J. | 10/6/2005 11:50:12 PM
The turfgrass cover on playing fields definitely affects the play of the game. Field speed, ball roll and safety are all very much related to the turf condition. An attractive field is inspirational to the team and a pleasure to watch it play on. Everything will break when it hits it's limit, but we can grow grass in most situations if money is no object. That may be a tough proposition, however, for low-budget fields where you are not irrigating playing surfaces.
Even modestly budgeted fields can have well-grassed playing surfaces. You simply need to have good soil fertility, irrigate as needed and mow properly; nature does the rest.
If you irrigate, use the system as needed for infrequent but deep (4"-5") irrigation when the root zone is first dry. Water in cycles, if necessary, to get the best percolation and efficiency for your irrigation dollar yet still have deep wetting. Deep wetting improves rooting depth, and roots are what sustain the turf during periods of high wear.
Soil fertility is step number one and something you can control. Athletic fields should be fertilized at least 4 times per season. Bermudagrass is most productive in a soil pH of 6 to 7. A pH below 5.8 makes bermudagrass less competitive and encourages weeds and lesser grasses to come in. Lime as needed during the cooler months to maintain a pH of 6. A $7 LSU AgCenter routine soil test will tell you the pH and levels of available Ca, Mg, P and K and some idea about soil salts. A fertilizer program should be based on these test values to ensure adequate levels and avoid expensive excess levels. If you need lime, the soil test results will tell you how much to put out for a given response.
Sampling the native-soil field or amended soil field is usually more useful than sampling a high-sand field. Sample at least every other year to keep up with the seasonal differences and to keep your field's fertility from getting way out of line. This saves half the cost of annual soil testing, which is still a good idea.
Your choice of lime is calcitic lime (high calcium) or dolomitic lime (high magnesium). Check the levels of Ca and Mg; they should be about 10-to-1 in ratio. If they are skewed, choose the more-suitable form of lime. Topdressing lime over grass at more than 1 ton per acre is risky unless you are in the cold, dormant season. Consider split applications or delay until mid winter; although if you need lime now, you need it now (during the current growing season). Hold off liming from June through September.
Follow the test recommendations for P2O5 and K2O application. You may apply
complete fertilizer that will meet your soil test recommendations. However, most soils can get away with one spring application of phosphorus (P) unless soil P is very low. This is not true for very sandy fields; they need more spoon feeding throughout the season. Split phosphorus applications if readings are low to very low.
Potassium (K) may better be applied as a split application, especially in sandy soils. Apply K in spring, then in mid-to-late summer. Go into the fall with higher levels of K. Potassium toughens turf to moderate stress and freezing.
Apply N at a rate of 40-45 pounds per acre four to five times during the growing season for common bermuda fields. Over this amount may be wasteful or may hurt the turf. If you have a hybrid Tifway 419, it needs about 25% to 50% more fertility; you may fertilize it lightly every month from April to September if you can.
Don't worry about soil micronutrient levels; just get your soil pH right and it should all work out well.
If soil salt (salinity) levels are high, you must try for high soil calcium levels and increased irrigation. Figure out where that salt is coming from. Have your irrigation water analyzed at our soil test lab. If your soil pH is acceptable and you need the Ca, add gypsum for the Ca with no effect on raising soil pH. If the pH is below 6, use calcitic lime to raise it and add the calcium.
Some managers will have fertilizer custom blended and bulk spread by a co-op. That's great, but you can use combinations of an N source, muriate of potash and maybe a 13-13-13 to meet the soil's need just as well. It just takes some strategy and knowledge of what your soils need. At less than 2 acres, athletic fields are not that big.
Mowing should be done properly whether you have a moderate or higher fertility program. Common bermudagrass is cut at about 1 to 1.5 inch for best sustainability, but hybrids must be cut lower. A ¾- to 1-inch cut on hybrids is a sustainable range but will require reel mowers and extra cutting for best health and appearance.
Because of the 1/3 rule of cut (never remove more than the top third), shorter-cut turf requires more frequent mowings (shorter interval between mowings). Always try to mow when your turf has grown back 50% from its cutting height. This will minimize mowing stress and maintain stand density no matter what grass or mowing height you choose. Mowing heights should be raised slightly during the late fall to prepare the grass for the dormant winter period.
Keep your mower blades reasonably sharp to avoid ragged cuts. These bad cuts will create more stress in the plant and can contribute to greater disease susceptibility.
Watch for pest problems, and remember they are most easily controlled if caught early. That is especially true of weeds. With early attention, you may get by with using the less high-tech materials and equipment for adequate control.