SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/43432
an overall plan are noted in the table. The primary turfgrass characteristics that influence plant wear tolerance are: a) degree of living shoot biomass, i.e., verdure and shoot density; b) turfgrass growth rate; c) nature of the thatch or mat layer where both include living and dead organic mat- ter; d) presence of high plant succulence or low cell turgidity; and e) nature of turfgrass rooting, stolon, and rhizome development. Turfgrass species and cultivars within a species that exhibit superior wear tolerance inherently have characteristics that foster better tolerance to wear. Studies on turfgrass species or cultivar wear tolerance consistently demonstrate that greater wear tolerance is associated with high verdure and shoot density at the normal mowing height for a particular use. The first line of defense against wear injury is a dense, healthy turfgrass stand that provides a cush- ioning effect and ability to rapidly regenerate leaves and shoots. Attention should also be given to any factor that may limit growth rate or cause a decline in shoot density since slow growth and low density not only foster greater wear but delay recovery. Sometimes the active growing period can be extended somewhat in the fall or early spring by Fe and N applications. Important factors affecting turfgrass growth rate are: a) nutrient limitations or de- ficiencies retarding growth—most common on sand-based fields would be low N, P, Mn and Mg (K will be discussed later), where soil tests and plant analysis will aid in deter- mining needs; b) climatic conditions can limit growth and those that cannot be dealt with by direct management should be con- sidered in traffic control measures (common are drought, cool/cold or excessively warm weather); c) saline conditions from saline ir- rigation water acts as a plant growth regula- tor; d) surface soil compaction inducing low soil oxygen and high mechanical strength can reduce shoot growth by 30-50 % which significantly increases potential for wear in- jury; e) sand fields where the organic matter accumulates to above approximately 4-5 % by dry weight in the surface 1-2 inches can result in low soil oxygen if the sod receives moisture daily by irrigation or rainy periods which in turn limits shoot and root growth; f ) any pest limiting growth or reducing shoot density; g) scalping or mowing too close even if not a scalp condition; h) shaded grass has more fragile and spindly shoot tis- sues that are more susceptible to wear injury and the lower light limits recovery; and i) ap- plication of a PGR that excessively reduces plant growth rate during high traffic periods. PGRs often are used to "tightened up" the canopy which can aid in wear tolerance but delay recovery if wear injury occurs. Thatch is a layer of live and dead plant tissues overlying the soil surface, while mat is a layer of living and dead organic matter with appreciable sand or soil intermixed. A "good" mat should have > 85 % sand by weight so as not to be dominated by the or- ganic matter component. Mat layers that do not contain sufficient sand can result in a compacted organic layer that holds excessive moisture during wet periods and can result in poor rooting. Moderate thatch/mat (0.25 www.stma.org SportsTurf 13