Impacts of Turf Care Products on Soil Biological Health
Wendy Griffin, Mussie Habteselassie, Viktor Tishchenko (University of Georgia, Griffin)
Due to the need for aesthetics, the maintenance of golf courses entails extensive use of turf care products (e.g., pesticides, wetting agents, plant growth regulators, biostimulants). Biostimulants that contain microbial inoculants and/or organic products are often marketed as being more sustainable and cheaper alternatives than the other products. This assumes that biostimulants are better in enhancing the beneficial services of soil microorganisms. However, there is lack of research in evaluating how effective biostimulants are, and how they affect the health of the turfgrass system and turf quality. A field study is currently underway at two locations in Georgia to evaluate the effects of select biostimulants on soil biological health and turf quality.
A unique delivery system for applying biostimulants directly in the root zone is also being tested to evaluate its efficacy in improving the survival of microbial inoculants in the soil. Soil biological health will be evaluated by determining microbial abundance and function. Abundance of different microbial groups (total bacteria and fungi, ammonia-oxidizers, nitrogen-fixing bacteria, and arbuscular mycorrhizal fungi) was quantified with quantitative polymerase chain reaction. Microbial function will be evaluated by assaying for different enzyme activities that relate to carbon, nitrogen and phosphorous cycling. Turf quality will be measured using a lightbox and camera to photograph plots. Images will then be analyzed using Turf Analyzer software to calculate the Normalized Difference Vegetation Index and percent green cover. The relationship between turf quality and soil biological health will be determined using multivariate statistical analysis to identify soil biological health indicators that best predict turf quality.