By Eric Watkins
For years, I, along with others at the University of Minnesota and elsewhere, have touted fine fescues as “low input” turfgrasses that needed less water, fewer pesticides, less nitrogen fertilizer, and less mowing than other grasses. Our observations were the basis for this claim; however, this wasn't clearly backed up by research. To address this, a research team led by Drs. Aaron Patton at Purdue University and Ross Braun, now at Kansas State University, set up a field trial at our research facility in St. Paul and at Purdue in West Lafayette, Indiana. The idea was fairly straightforward--compare a number of cool-season turfgrasses for how many inputs they needed. We decided to focus on two inputs--herbicides and fertilizer. On a regular basis, data was collected on each plot to determine whether it needed to be fertilized (based on visual quality attributes falling below a certain threshold) or sprayed with a broadleaf herbicide (based on weed coverage exceeding 10% of the plots area). Individual plots were then fertilized and/or sprayed with herbicide as determined by the assessment, and we kept track of all these input events for each plot. Then, at the end of the study, we tallied up the total amount of inputs that were needed for each plot. In Figure 1 below, you can see how each of the varieties we tested performed in terms of the number of inputs applied per year. Results from Indiana and Minnesota were quite similar--you can see that fine fescues did really well, showing up in the upper left quadrant of each graph, indicating that they had higher quality, with fewer inputs.
The final data analysis showed a few things:
- Newer cultivars outperformed the older cultivars
- Fine fescues needed fewer inputs than the other turfgrasses
- Kentucky bluegrass and perennial ryegrass need quite a bit more (over 50% more) fertilizer and pesticide inputs than fine fescues
Although this study didn’t address differences in drought tolerance, we have accumulated good evidence that the fine fescues also fare better than Kentucky bluegrass and perennial ryegrass under short term droughts of 60 days or less.
If you want to read more about this study, the results were published in the Crop Science article “Assessing the fertilizer and pesticide input needs of cool-season turfgrass species."