U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
March 1996
Abstract
Harvest frequency and burning can affect forage yield of monocultures of switchgrass (Panicurn virgutum L.), big bluestem (Andropogon gerurdii Vitman), and Indian grass [Sorghastrum nutuns (L.) Nash]. Current information is based largely on results from mixed stands. A field experiment was established in 1986, and from 1988 to 1991 treatments were applied with burning in March, April, or May plus an unburned control. Growing season yield was measured by harvesting 1 (June), 2 (June and July), or 3 (June, July, and August) times with unharvested control plots included. End-of-season standing crop from all plots was determined after plants became dormant. Treatments were applied to the same plots annually and were arranged in a split-split plot, randomized complete block design. The main plot was species, subplot was burn date, and sub-subplot was harvest frequency. Burning reduced yields (P<0.0l), and yields were lowest in plots burned in May. Burning reduced yields of Indian grass most (57%) and big bluestem least (15%). In 1989, plots harvested three times produced yields similar to plots harvested once for all species. By 1991, yields of plots harvested 3 times per growing- season were reduced (P=0.08) below those of plots harvested once. Yield response of species also varied across the study. Growing-season yields in 1991 were 113, 67, and 89% of 1989 yields for switch grass, big bluestem, and Indian grass, respectively. Regardless of burning and harvest frequency combination, switch grass produced as much or more herbage than the other species.
Comments
Published in J. Range Manage. 49:157-l 62.