Fall Management Effects on ‘Grasslands Matua’ Prairie Grass Production and Sward Characteristics
- Gerald A. Jung ,
- John A. Shaffer and
- John R. Everhart
Ruminant animal production costs in the northeastern USA can be lowered by extending the fall grazing season. Two field experiments were initiated with prairie grass [Bromus unioloides (Willd.) H.B.K. cv. Grasslands Matua; syn. B. willdenowii Kunth] to determine effects of fall management (i.e., clipping) on forage production and winter survival. Plantings were made in May 1986 for Exp. 1 and June 1990 for Exp. 2. Experiment 1 addressed date of fall harvest and residual stubble height effects on fall yields and tiller density, winter survival, and spring yields and tiller density. Experiment 2 addressed the interaction of harvest frequency and residual stubble height on the same parameters as for Exp. 1. Fall yields of Matua peaked at 4.0 Mg ha−1 in late October to early November (Exp. 1 and 2). Mean fall yields were reduced 20, 40, and 60% as residual stubble height was increased from 7.5 cm to 12.5, 20.0, or 25.0 cm, respectively (Exp. 1). Spring yields were high from plots clipped to a 7.5-cm stubble in September and decreased as fall harvest was delayed to November (Exp. 1). Spring yields from plots clipped to a 7.5-cm stubble in late November were only 20 to 25% of yields from plots clipped in September. Leaving a higher residual stubble in fall compensated considerably for the deleterious effect of harvesting in late fall. Clipping to a 20.0-, 12.5- or 7.5-cm stubble in fall resulted in linear decreases in spring yields as fall harvest was delayed from September to November, and clipping to 25.0 cm gave a quadratic response, with a peak at mid-October. Matua plots that were harvested once in late fall or not at all (check) recovered very slowly in spring and had a lower yield potential than plots that had been harvested two, three, or four times in fall. To optimize production of Matua in fall and spring it is recommended that one summer rest period be extended to allow natural reseeding and that two or three fall harvests or grazings be taken to increase stand density and winter survival.
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