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/714252
FIELD SCIENCE 12 SportsTurf | September 2016 www.sportsturfonline.com certain types of cement, so its presence in high concentrations in turf paint can damage grass. Paint is often mixed with water before use. If that occurs and then the paint sits for a long time, the calcium carbonate will separate and harden. This is similar to how it works in the soil. If applied often enough to the same area, it will eventually migrate several inches into the soil and harden; choking off grass plants at their roots, and potentially affecting the chemistry of the soil as well as water infi ltration. Additionally, paints contain a binder or polymer that acts as the adhesion component for bonding to the surface. This level of the binder (resin) will determine how long the paint persists. Common binders used in turf paints are acrylic and latex. This study began by comparing different rates of a white, water-based acrylic paint from a major supplier of athletic fi eld paint. The objective was to determine the amount of paint that would remain in the soil after a long period of time. Tests were then conducted using three different green-pigmented paints from Sensient Technologies. These paints include acrylic, polysaccharide resin number one (PSR #1) and polysaccharide resin number two (PSR #2). The acrylic paint from Sensient has similarities to water-based acrylic athletic fi eld paints available from other companies with regard to the four basic elements; however, the Sensient product uses less acrylic binder. The objectives of this study were to determine the effects of green acrylic polymer paint and two green paints with polysaccharide resin technology on the chemical and physical parameters of a sand-based sports fi eld media, and to see if one of the three paints broke down quicker than the other two. MATERIALS AND METHODS The study was performed over 6 months in the horticulture greenhouse at Iowa State University. Large trays of sand were placed on greenhouse benches. Trays were arranged in order on the bench and measurements were taken monthly. The soil and paint mixtures in the trays were watered regularly to encourage microbial activity. The amount of paint mixed with soil was determined from preliminary chemical tests. Several different rates of water- based acrylic paint were uniformly mixed with sand and chemically tested along with a sample containing accumulated paint over the past 8 years from Jack Trice Stadium at Iowa State. The results were used to compare and estimate how much paint should be used in the study. After determining similar results between the mixed samples and the Jack Trice Stadium sample, additional chemical tests were performed on test batches of soil with the Sensient paints to determine the best rate for this study. Chemical tests were performed monthly on subsamples from each tray, and the samples were submitted to the soil-testing laboratory for soil chemical testing. Samples were collected in small plastic bags and immediately driven to the testing lab so there was no variability among treatments over the 6 months. The lab performed tests for phosphorus (P), sulfur (S), potassium (K), zinc (Zn), sodium (Na), magnesium (Mg), calcium (Ca), pH, buffered pH, cation exchange capacity (CEC), base saturation potassium (K_BSat), base saturation magnesium (Mg_BSat), base saturation calcium (Ca_BSat), base saturation sodium (Na_BSat), and organic matter (OM). A saturated hydraulic conductivity (Ks) test was completed on additional subsamples taken from the trays monthly. Samples were collected in metal cylinders. The metal cylinders were sealed across the bottom with cheesecloth and taped with electrical tape around the sides. The soil and paint mixture was added to each cylinder by spooning small amounts of sand at a time, leaving about two to three centimeters on top for water to pond. Samples were carefully packed the same way to avoid circumstances that would skew results. Once all cylinders were fi lled, the 12 samples were put in a large tub of water and left for 10 minutes until completely saturated. When samples were saturated, they were removed one at a time and placed on a ring and clamp stand. Water was ponded in the top of the cylinder using a Mariotte bottle. The outfl ow rate was measured with a graduated cylinder and a stopwatch at three different time increments for each replication. Once those measurements were taken, each measurement was recorded along with the ponded depth and the length of the soil sample. These data were used to solve for the Ks in Darcy's equation. All measurements were taken in centimeters/second. The study was conducted as a split plot in time. RESULTS Levels of CEC, K, Zn, Na, Ca, P, and S were affected by the presence of paint in the media. Cation Exchange Capacity. There were no differences in CEC among paint treatments at any time during the study. However, there were differences in CEC of the media among dates (Figure 1). There was a decrease in CEC as compared to the untreated control in months two and three. By month fi ve, 6 4 2 0 -2 -4 -6 Average CEC Month 1 4 5 6 2 3 0 1 2 Figure 1. CEC in the soil adjusted for the control. 0=acrylic, 1=PSR#1, 2=PSR#2.