Pamela Rice, Research Chemist and Adjunct Professor, USDA-Agricultural Research Service and Department of Soil, Water and Climate
Brian Horgan, Professor, Department of Horticultural Sciences
Strategies used to maintain managed biological systems, including golf course turf, often involve application of fertilizer and pesticides to optimize plant health and protection. The transport of applied fertilizers and pesticides with runoff to surrounding surface waters has been shown to result in enhanced algal blooms, promotion of eutrophication or negative impacts on sensitive aquatic organisms or ecosystems. In previous research we demonstrated that changes in cultivation practices (e.g. type and timing of core cultivation) reduced the volume of runoff and the percentage of applied pesticides and nutrients that moved off-site with runoff from creeping bentgrass turf. In the current study we evaluate the influence of turfgrass species on runoff quantity and quality.
Experiments are underway to compare the volume of runoff and measure the amount of pesticides and nutrients in runoff from conventional versus low input turfgrasses. Plots (20ft x 80ft) maintained as a golf course fairway (0.5 inch height of cut) were seeded with bentgrass (Dominant Xtreme 7: a 7:3 mixture of ‘007’ creeping bentgrass and ‘SR 1150’ creeping bentgrass) or a fine fescue mixture (equal parts ‘Chariot’ hard fescue, ‘Seabreeze GT’ slender creeping red fescue and ‘Cardinal’ strong creeping red fescue and ‘Longfellow II’ chewing fescue). Each plot is equipped with runoff gutters, a flume, an automated sampler, and a flow meter to measure flow rates, calculate runoff volumes and collect subsamples of the snowmelt and rainfall runoff. Studies will be performed with fertilizer and pesticides applied at label rates to both the traditional and low input turf, as well as additional studies with pesticides applied at label rate for bentgrass turf and 2/3 label rate for the low input fine fescue turf.
To date we have observed the fine fescue mixture produces greater quantities of snowmelt and rainfall runoff than bentgrass (Figure 1). Collected runoff samples have been processed and are being stored frozen until completion of chemical analysis. In our previous studies with creeping bentgrass turf we found that runoff volume was more influential than chemical concentration to the overall mass of chemicals transported off-site with runoff. We are curious to learn if this trend continues with the low input fine fescue mixture or if other influencing factors are of greater importance. Data collected from this study will guide strategies to manage low input fine fescue mixtures in order to provide optimal results for golf course managers, golfers and the environment.
Figure 1. Comparing runoff from bentgrass and fine fescue turf. Examples of hydrographs collected in June 2014.