Submitted to: Grass and Forage Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2011
Publication Date: 6/18/2011
Citation: Bartholomew, P.W., Schneider, J.M., Williams, R.D. 2011. Pasture residue amount and sowing method effects on establishment of overseeded cool-season grasses and on total annual production of herbage. Grass and Forage Science. 66(4):560–568.
Interpretive Summary: In the Southern Plains overseeding warm-season pasture with cool-season grasses in fall offers the possibility of extending the grazing season and increasing year-round forage production. As a method of pasture improvement it is relatively low-cost and low-input and should be of interest to small and resource-limited farmers. However, small farmers may face problems in taking advantage of this practice, because access to a specialized no-till seeder may be difficult. Even if equipment is available lack of time for land preparation, particularly removal of residues of unevenly grazed warm-season pasture, may present problems for effective drill function. We tested the effects of different amounts of warm season pasture residue on establishment and production of cool-season grasses oversown in fall using a no-till seeder or by surface broadcasting. The effectiveness of establishment by no-till drilling was reduced as the amount of residue at sowing increased. On average, broadcast sowing was less effective than no-till drilling, but it was not affected by the amount of residue present at sowing. Production of cool-season forage was slightly greater with no-till sowing than with broadcasting, but warm-season grass production in the following season was reduced when cool-season grasses were no-till drilled. The net effect of sowing method on year-round forage production favored use of broadcast sowing. Overall, increased residue at sowing did not affect cool-season grass production. The main effect of increased residue in fall was to increase warm-season grass production in the following growing season. However, we concluded that year-round forage production would be increased if surplus residues were completely utilized in fall, rather than retained to increase grass yield in the following year.
Technical Abstract: Warm-season pasture residue may create problems for no-till overseeding with cool-season grasses in the USA Southern Plains. Removal of residue to facilitate overseeding, however, represents additional cost and requires labor that may not be available on small livestock enterprises. Field experiments were undertaken to assess the effects of warm-season pasture residues averaging 1.62, 2.48 or 3.36 t DM ha-1 on establishment and herbage production of Italian ryegrass (Lolium multiflorum Lam.) or tall fescue (Festuca arundinacea Schreb.) overseeded by broadcasting or by no-till drilling into dormant warm-season pasture. On average no-till drilling was more effective than broadcasting in establishing both grass species, but it was no more effective than broadcasting when used with the greatest amount of residue. Cool-season grass production was increased by 0.16 when no-till drilled, but combined yearly total herbage production of cool- and warm-season grasses was increased by 0.07 when cool-season grasses were established by broadcasting. Amount of residue at sowing did not significantly (P > 0.05) affect herbage yield of cool-season grass, but increased residue in fall resulted in a 0.16 increase in total herbage production in the year following sowing. Depending on year, increased residue either increased minimum temperatures in the surface layer of soil or had no significant effect on soil temperature. There was no evidence that residue amount affected over-winter survival of grass seedlings and any productivity benefits of increased residue are small compared with livestock feed losses arising from underutilization of warm-season pasture residue in fall.