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
FieldScience materials that can serve as an energy source for the populations of various microorgan- isms in the zone immediately around the root, the rhizosphere. Many of these mi- crobes have the capacity to mineralize or- ganic matter, that is, break down organic matter into compounds that can provide for some of the nutritional needs of the plant. The amount of root exudates can highly in- fluence soil microbial communities. When grass growth is suppressed by high tempera- ture stress, as may happen with cool-season grasses, the production of root exudates has been shown to decline. This decline is likely the result of the lack of initiation of new roots in combination with root mortality. HOW CAN YOU ENHANCE ROOT GROWTH? root growth, and manage so as to minimize their negative effects. Excessive wear and compaction, shade, incorrect watering prac- tices including excessive or inadequate irri- gation, drought, temperatures not conducive to root development, and exces- sive or inadequate fertility will all lead to re- duced rooting. Pay attention. Make regular inspection Know the factors that will compromise >> AERATION IS AN IMPORTANT TOOL for en- hancing root growth. This single plant was taken near the side of an aeration hole on a grass ten- nis court in early spring. Note the improved root- ing that is beginning as a result of aeration. sive root systems are less likely to divot and slip. Plants with deep and extensive roots provide a more stable and safer playing sur- face. Roots encourage microbial activity. Healthy functioning roots exude organic 18 SportsTurf | May 2012 ergy. This energy comes from respiration: the breakdown of carbohydrates in the pres- ence of oxygen with a subsequent release of energy. When carbohydrate reserves are low or not available, roots will not have the en- ergy needed to absorb nutrients. Deep, extensive root systems are able to access more nutrients and more water from a larger volume of soil than can weaker, shallower root systems. Roots anchor plants. Plants with exten- of the root system a habit. Note its depth and distribution. How does its condition relate to time of year, climate and your management? Increased depth and breadth of rooting allow the roots to harvest from a greater volume of soil, thus requiring less need for irrigation and applied nutrients, particularly nitrogen. Making good roots makes good environmental sense. Maintain a well aerated rootzone. The depth and extent of roots as well as root branching increase when the rootzone is kept well aerated. Roots expend less energy as they bore through the soil. Roots in poorly aerated soil tend to be thicker in di- ameter and less branched than roots grow- ing in well aerated soil. These roots are inefficient at water and nutrient uptake. Good drainage, both surface and subsur- face, management of thatch, relief of com- paction and appropriate topdressing in conjunction with aeration practices will en- sure a well aerated soil. Manage thatch. While a small amount of thatch can be beneficial to the perform- ance of a sports field, excess thatch can cause problems. In addition to interfering with proper water and air movement, thatch provides a harbor for insects and dis- ease organisms. Excess thatch will result in reduced rooting with a subsequent reduc- tion in water and nutrient uptake. Roots that do develop within the thatch layer will find little nutrients to absorb there, and will have difficulty absorbing water. The sports field management plan should provide steps that keep thatch in check. Manage traffic. Wear can lead to a sig- nificant reduction in rooting. Using agro- nomic and field scheduling strategies that minimize wear and encourage shoot density can result in increased root biomass and depth. The greater the mass and the deeper the roots, the more nutrients and water the plant can access to support the shoot sys- tem. Irrigate intelligently. Irrigation events should be spaced as far apart as possible without sacrificing turf quality. Frequency and duration of irrigation will be deter- mined by type of rootzone, environmental conditions, amount and intensity of traffic, and many other factors. Turf watered deeply and infrequently, using a wilt-based irriga- tion strategy, has been shown to have a deeper, more extensive and efficient root system than turf watered frequently and shallowly. New seedings should be watered so as to provide adequate moisture for the germi- nating and developing seedlings. Keeping the seedbed moist and gradually decreasing the frequency and increasing the duration of irrigation events as the seedlings grow are critical to encouraging rapid and deep root- ing and successful establishment. Overwatering results in reduced rooting. As water fills the spaces in the soil, less oxy- gen is available for respiration, and the re- sult is less energy available for the grass roots to take up and absorb not only water but also nutrients. Fertilize judiciously. Provide adequate nutrients at the proper time for balanced turfgrass shoot and root growth, with par- ticular emphasis on prudent use of nitro- gen. As the levels of N applied to turfgrasses increase, the amount of shoots increases www.sportsturfonline.com