NUTRIENT CONCENTRATIONS OF TURFGRASS AND SOIL TEST LEVELS AS AFFECTED BY SOIL MEDIA AND FERTILIZER RATE AND PLACEMENT

There has been a trend toward using sandier growing media on highly trafficked turf areas to combat the detrimental effects of compaction on soil physical properties. Use of sand to modify, or even replace, existing soil also affects the nutrient status of these turf areas and could lead to both macronutrient and micronutrient deficiencies. Greenhouse experiments were conducted to determine the effects of natural organic fertilizer (Milorganite) or micronutrient supplement (Esmigran) applied to the surface or incorporated at several rates on the nutrient concentration of 'Pennfine' perennial ryegrass (Lolium perenne L.) grown on quartz sand, a sand-peat topdressing mix, and a silt loam soil. Effects of Milorganite rate were most apparent on sand and topdressing, and, with at least one soil for one harvest period, increased rates of Milorganite resulted in increased tissue concentration for phosphorus (P), potassium (K), calcium (Ca), sulfur (S), manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn). With Esmigran, increases in tissue concentration due to rate were found for Mn, boron (B), and Zn. Interactions among soil, rate, and application method made it difficult to generalize concerning nutrient availability from these fertilizers. Effects tended to be most obvious with sand and were more apparent with surface applications in some cases and with incorporation in others. Tissue analysis was superior to soil testing for assessing the nutrient status of a turfgrass stand.