Grower reports of reduced stands of orchardgrass led to research examining how mowing height and fertility may affect stand persistence, points out Ray Smith, University of Kentucky Extension forage specialist.

The conclusion: Growers may need to adjust their mowers to higher cutting heights.

Smith and graduate student Leah Saylor used a four-year-old stand of Benchmark+ orchardgrass, which had been managed for hay. They harvested crop four times during the 2011 growing season and once in December, taking readings on cutting heights of ½”, 2” and 4” with four replications.

Sixty-pound nitrogen and 100-lb potassium applications were made after each of three cuttings – the first, second and fourth. Regrowth was measured one and two weeks after each clipping.

At the end of the growing season, the ½” mowing height showed less than 25% cover; the 2” height, 50% cover; and the 4” treatment, close to 100% cover.

It’s not hard to adjust mower height. If needed, most disc mower manufacturers offer cutting-height adjustment kits, Smith says.