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/64785
while the amount of rooting decreases. Focus on providing the lowest amount of N possible without sacrificing the quality needed for sports field performance and safety. The goal should be a dense, wear and stress tolerant shoot system and a deep, dense, stress tolerant root system. While encouraging rooting, the practice of keeping N levels at the minimum needed has the added benefit of also lowering evap- otranspiration (ET), and so contributes to water use efficiency. Time nitrogen applications so as to maxi- mize root growth; strive to maintain a healthy balance between root and shoot growth. Apply potassium before expected stresses of heat, cold and possible drought may occur. Take care not to overly stimulate shoot growth during periods environmen- tally unsuitable for root growth (i.e. in the summer for cool-season grasses). Maintain soil pH at 6.0 – 6.8. Turfgrass roots grow very poorly at reduced pH, espe- cially at pH less than 5.0. Mow appropriately. Maintain turf- grasses at the highest height of cut (HOC) within their mowing tolerance range to en- courage deeper and more extensive rooting. Select cultivars of turfgrass species that have been selected for their adaptation to the mowing height required of the sport. Warm-season grasses are less dramatically affected by low mowing. Bermudagrass es- pecially will tolerate low mowing without significant reduction in rooting. Mow cool-season grasses as high and as should be chosen. Cultural practices should be adjusted: reduce traffic, irrigation and fertility. Some professional stadia are experi- menting with supplementary lighting to deal with shade. Take care with herbicide applications. infrequently as possible given the use of the turf. This is especially important during times of environmental stress. Low mowing can dramatically reduce the depth and ex- tent of roots of cool-season grasses, though bentgrass is not as severely affected as the others. Maximize available sunlight. Turf- grasses grown in reduced light situations are more prone to have weak, sparser root sys- tems. Where shade can be remedied through tree canopy pruning, it should be done. Where shade cannot be remedied, then shade tolerant species and cultivars Avoid using herbicides when turf is under stress or when root growth is restricted. Bensulide, benefin, oxadiazon, oryzalin, pendimethalin, prodiamine, siduron, DCPA and other herbicides may inhibit root growth. Healthy turf may be able to recover from this quickly. However, a turf stressed by drought, heat, traffic or with a compro- mised root system may be more seriously damaged and take a longer time to recover. Roots are the foundation of a turf. Atten- tion to the growth, development and health of the root system can ensure not only a vig- orous, highly performing sports field, but also result in the conservation of precious environmental resources. ■ Mary Owen is extension educator & turf specialist, University Of Massachusetts, www.stma.org SportsTurf 19