TURF BASICS
By Tom Samples, Ph.D., and John Sorochan, Ph.D., The University of Tennessee; and Brad Jakubowski, Ph.D., The University of Nebraska
E
arlier in our three-part series on turfgrass nutrition, we introduced 16 essential plant elements and described the function of macronutrients and micronutrients in turfgrass systems, the consequences of too little of (or unavailable) plant nutrients and common commercial sources of plant nutrients.
In this issue of Tennessee Turfgrass, we discuss strategies for integrating turfgrass nutrition into a Best Management Plan for Tennessee’s managed turf. We detail the value of soil testing and turf-tissue testing, and we discuss how several turfgrass types and environmental factors can influence turf and landscape management decisions.
Considerations when developing a fertilization plan
Soil-test and tissue-test results Phosphorus (P) and potassium (K) are relatively immobile nutrients, moving downward very, very slowly in most native 30
TENNESSEE TURFGRASS
DECEMBER/JANUARY 2008
soils. The amounts of these two primary macronutrients available for uptake by turfgrasses can be determined by soil testing. If soiltest results indicate low levels of P and K, these nutrients can be applied to turfs at rates greater than the turfgrass requirement for each. This will result in increased amounts of P and K in the soil. Technology is also available in many soil-testing laboratories to determine the amounts of calcium (Ca), magnesium (Mg) and sulfur (S), as well as micronutrients such as boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn) in the soil. These tests are especially beneficial when managing turfgrasses in soils with a limited nutrient-holding capacity (such as those containing large amounts of sand) or soils that have a relatively high leaching potential. Dry clippings may also be submitted for nutrient analysis. Such a tissue test serves as a snapshot of the nutrient content of the turfgrass at the time the sample was taken. In addition to reporting the test results, both soil- and tissue-test reports usually contain specific fertilizer recommendations.
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