US - Farmers across the US are being advised to set disc mowers higher when cutting orchardgrass to halt hayfields “thinning out”.
Disc cutting removes the lower leaves of the plant and the base of the tillers, resulting in “disasterous” consequences for some grasses, warns a Kentucky forage specialist.
Unlike alfalfa, which regrows from energy stored below ground in a taproot, orchardgrass has a “more upright growth habit”, meaning low cutting reduces photosynthetic ability.
This is according to Ray Smith, University of Kentucky, who recommends a cutting height of three to four inches.
“Most disc mower manufacturers sell skid shoes to insure higher cutting heights,” said Ray. “These are well worth the price.”
While disc mowers can easily cut at one to two inches, he said higher settings can still ensure thick, weed free stands.
A survey of US forage experts found several reasons for hayfield deterioration, including: lower fertility, severe weather, insects and other disease factors.
“They felt that the number one reason for shorter stand life was low cutting heights,” he added. “And low cutting heights were mainly attributable to disc mowers.”
He outlined one study determining that low cutting reduced stand longevity, regardless of additional fertilizer treatments.
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