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/701691
www.stma.org August 2016 | SportsTurf 37 infl uenced by the amount of polymer in the soil; the type of polymer used and soil characteristics, such as salt content. As the concentration of ions increases in water, the amount of hydration by the polymer decreases. The lifespan of polymers is thought to range from 2 to 10 years, depending on the type of polymer and soil conditions. The literature reports that the time between irrigation events can be extended with the use of polymers, but the actual water savings with use of these products is dependent on application rates and soil conditions. Cost of these products may be a limit- ing factor for effective application rates. Initially, polymers were used to help manage water in potted plants, ornamental beds and in planting trees and shrubs. Over the years, soil-applied polymer use has expanded to turf ap- plications. They are used in the establishment of sod and sprigs, improving seed germination and in general turf use. The chal- lenge in using polymers on established turfgrass is delivering the polymer crystal to the rootzone. Some turf managers will aerate the turf and drag the crystal into the holes. In addition to this practice, there are now machines that will inject or "plant" the polymer crystals into the soil. Surfactants/wetting agents. Surfactants or wetting agents are probably the most common products used to manage soil moisture. These materials are used for a number of applications in turf and plant management, including relief from localized dry spots, improved drainage, assist the effi ciency of various pesticides, reduced dew and frost accumulation, improved seed germination, reduced fairy ring damage, alliviation of soil compaction, improved irrigation effi ciency, diminished dust on dirt paths, enhanced fi rmness of golf course bunker sand and more. Surfactants stand for SURFace ACTive AgeNTS (SURFACTANTS). These are agents that affect the surface of a liquid or solid. As previously stated, the formation of waxy, non-polar coatings on soil particles is the cause of hydrophobic conditions. The non-polar soil particle surface will not attract, and may actually repel, the polar water molecule, which prevents irrigation water or rainfall from infi ltrating soils to hydrate plants. Creating a polar surface allows water molecules to enter and fi ll the soil. The surfactant has a non-polar and a polar end on the molecule. The non-polar end of the surfactant molecule aligns with the non-polar surface of the organic soil coating, leaving the polar end exposed outward from the soil particle. This allows the polar water molecules to be attracted to the polar surfactant molecules therefore overcoming the hydrophobic condition. There are many different kinds of surfactants, most of which fall into these four basic categories: Anionic – Form negatively-charged ions in water Cationic – Form positively-charged ions in water Nonionic – Does not ionize in water Amphoteric – Take on the ionization of the water Non-ionic surfactants are the most common products used in the turf industry due to their safety, compatibility with other products and ease of use. As technology has improved, a number of categories of non-ionic surfactants have been developed. These include: Polyoxyethylene (POE). This is older technology originally developed to treat localized dry spots. They can be phytotoxic. Block Co-Polymer Surfactants. These are the most com- monly used turfgrass surfactants. They are safer and are effective in treating soil water repellency, improving soil water content and plant available water. This category has two sub-categories: Straight Block Co-Polymers and Reverse Co-Polymers. Alkyl Polyglucoside Surfactants. These are made from sugar molecules reacted with a fatty acid and are considered as naturally derived. When blended with a block co-polymer the performance appears to be better than either technology alone. These blended technologies appear to increase water infi ltration, improve water availability and enhance irrigation effi ciencies. Modifi ed Methyl Capped Block Co-Polymer. This is a class of surfactant that is a modifi cation of the co-polymer class. This technology forms a thinner, more continuous fi lm around the soil particle. Humic Substance Redistribution Molecules. These molecules allow water penetration through the soil profi le by Accessories & Materials Sideline Protectors Track Protectors Goal Post Pads Chains and Down Markers Field Marketing System Football Machines 800.837.8062 www.safdirt.com @DIRTGottaLoveIt Like Southern Athletic Fields on Continued on page 41