Cutting height effects on wetland meadow forage yield and quality

Research was conducted to determine the effect of clipping height on forage yield and quality of 3 wetland meadow plant associations. Bluegrass-clover (Poa spp. and Trifolium spp.), grass-sedge (Poa spp., Deschampsia caespitosa, and Carer spp.), and sedge (Carer spp.) associations were cut to stubble heights of 5, 10, or 15 cm in 1988, 1989, and 1990. Forage yield, herbage residue, crude protein (CP), and acid detergent fiber (ADF) were determined for forage harvested in June, July, and August. Forage yields of all associations increased as clipping height decreased. The majority of total forage produced for all associations was harvested in the June clipping. Herbage residue exceeded 1.4 Mg ha(-1) for all clipping heights, dates, and associations. Average CP concentration of the bluegrass-clover, grass-sedge, and sedge associations was 12.1, 13.3, and 10.8%, respectively. The CP concentration of the 2 grass-dominated associations increased with decreasing clipping height, but clipping height effect on sedge association CP was not consistent across the growing season. Clipping date had a greater effect on forage CP concentration than did clipping height. Crude protein concentration of all associations increased from the June clipping date to the July clipping date and declined in August. Clipping height did not significantly affect ADF of the bluegrass-clover or grass-sedge associations. Sedge ADF decreased with increasing clipping height in the first clipping, but increased with increasing clipping height in the second and third clippings. Bluegrass-clover ADF increased in a linear fashion from 30.9% at the June clipping date to 36.1% at the August clipping date. In contrast, both the grass-sedge and sedge associations showed curvilinear responses to clipping date, increasing from June to July and then declining in August.