Decreasing contamination of runoff: Experimental considerations

Within 15 minutes of collecting a sample, a colourimeter can determine the phosphorous content of the water, though the total volume of runoff at that concentration is much more time-consuming to determine. Shown here are various water samples mixed with reagent that causes a colour change proportional to the amount of phosphorous in the sample. Photo courtesy Kayla Snyder

By Christopher Murray, PhD

An ideal study would be one where stands of various turfgrasses were monitored over long periods, some with fertilizer applied and some without, and with data collected regarding the amount of pollutants in runoff. This is easier written than done, of course, and many obstacles stand in the way of obtaining these ideal results.

First, a study that is perfectly realistic and controlled is difficult to achieve, and often one of these goals is sacrificed in favour of the other. Second, there is a logistical obstacle associated with measuring a wide variety of experiments probing different conditions, especially when long-term measurements are concerned. For example, to grow two different types of turf under three different fertilization regimes and two different watering regimes amounts to 12 individual tests that need to be monitored; the costs of researchers and automatic samplers can escalate very quickly as more variables are added to the experimental design.

Considering no studies are completely controlled, totally realistic, and performed with unlimited resources, one must make conclusions based on existing studies carefully—some experimental shortcomings are more likely to influence one’s interpretation than others. When considering the benefit to water quality associated with turfgrass, it is clear measuring the amount of runoff is at least as important as measuring the concentration of pollution in that runoff. However, the former is much more difficult to characterize than the latter.

Read the full article: Turf Fertilization: Decreasing contamination of runoff

Comments are closed.