Using Herbicide and No-Till Planting to Establish Garrison Creeping Foxtail in Wet Meadows

Garrison creeping foxtail can increase the forage yield of wet meadows. However, tillage can be problematic on heavy-textured soils and thick sod mats often associated with wet meadows. This study examined the potential of establishing Garrison with the use of herbicides and no-till planting. Garrison was no-till drilled into a wet meadow using herbicide control of existing vegetation in the entire plot, herbicide application in bands with seed planted in the resulting strips, and no herbicide control of vegetation. Garrison establishment, forage yield and quality, and percent of forage yield comprised of Garrison were evaluated. Overall forage yield and Garrison establishment were highest when the entire plot was treated with herbicide; however, frequency of Garrison was negatively correlated (r = -0.86) with crude protein. Direct seeding resulted in very little Garrison establishment and was considered a failure. This study indicates that inexpensive herbicides can improve establishment of Garrison creeping foxtail and that Garrison can increase the productivity of wet meadows. Garrison Creeping Foxtail Wet meadows are a valuable source of grazing and forage for livestock and wildlife in the western U.S. (5,11). Wet meadows in the Intermountain West are often characterized by high elevation, short growing season, and heavy clay soils deficient in nitrogen. They are commonly managed for early spring and late autumn grazing or a single hay harvest followed by late autumn grazing. Intensive grazing pressure, high water tables, spring flooding, summer drought, and excess soil salinity often result in reduced productivity of grasses and forbs on these sites (4). Productivity can be enhanced with water management, weed control, fertilization, prescribed burning, and seeding improved forages (11). Garrison creeping foxtail (Alopecurus arundinaceus Poir.) was released in 1963 by the USDA-NRCS (formerly SCS) and recommended for improving the productivity and palatability of wet meadows in the northern and central Great Plains (2,10). Garrison is a long-lived perennial with vigorous rhizomes. It is adapted to a broad range of wetland soils and has high flooding tolerance. Garrison is one of the earliest maturing forage grasses, producing high yields that are comparable with other pasture grass species. There is limited information available about Garrison's comparative yield, quality, and effect on species composition in meadows by dominated wet grass, rush (Juncus spp.), and sedge (Carex spp.) (5). Establishment of Garrison can be difficult and costly due to the associated problems of using tillage on the heavy textured, frequently saturated meadow soils. Holzworth et al. (3) found that using glyphosate to control existing vegetation and no-till drilling were more successful than cultivation in establishing Garrison on a wet meadow. However, Reece et al. (5) reported that herbicide control of existing sedge-dominated vegetation prior to planting of Garrison was not economically feasible. Some producers in Utah have opted to feed Garrison hay and use livestock trampling of dispersed seed to get small patches of Garrison established. This takes many years to establish a stand, and has been only marginally successful. 5 July 2004 Forage and Grazinglands The overall purpose of this study was to show that the productivity of wet meadows can be increased by establishing Garrison creeping foxtail with lowcost chemical fallow methods. Specific objectives were (i) to evaluate establishment of Garrison creeping foxtail using combinations of herbicide treatments and no-till planting; and (ii) to evaluate the effect of Garrison creeping foxtail on forage yield and quality. Wet Meadow Research Site The experiment was conducted on a wet meadow 2 miles west of Hyde Park, Utah (41°47'N, 111°51'W, 4,442 ft above sea level). Average annual precipitation of three locations within a 10-mile radius of the site for 183 years is 18.2 inches with most received during the autumn, winter, and early spring (Utah Climate Center). The soil was a Salt Lake silty clay characterized by being deep with low permeability, high water table, and water holding capacity of 10 inches per 5 feet. The site was located in a low valley area of an ancient lake terrace with mild alkalinity, and dominated by excess subsoil water in the spring and dry conditions in the later part of the growing season. The meadow usually received two subsurface irrigation events in midto late-summer. Vegetation at the site was dominated by Kentucky bluegrass (Poa pratensis L.), foxtail barley (Hordeum jubatum L.), and sedge (Carex spp.). Complete species composition in the experimental area at the time the study was started is presented in Table 1. Table 1. Plant species composition in a wet meadow located near Hyde Park, Utah in 1998 prior to planting Garrison creeping foxtail. Treatments All herbicide applications, as part of the three treatments described below, were tank mixes of 1 qt/acre of glyphosate (41%, 3 lb acid equivalent per gallon) combined with 1 qt/acre of 2,4-D amine (3.8 lb acid equivalent per gallon). Herbicides were applied early-May 1998 when all vegetation was actively growing and a follow up application was made late June 1998 to control surviving plants (escapes) and new flushes of annual and perennial weeds. Garrison creeping foxtail was no-till drilled in early November of 1998 into three treatments with a John Deere Flexiplanter equipped with depth bands set at 0.5 inches deep. The three treatments were as follows: (i) herbicide control of vegetation on the entire plot area and seeded at a rate of 6 lbs pure live seed (PLS) (not coated) per acre on 12-inch row spacing; (ii) band-spraying herbicides to control existing vegetation in strips 12 inches wide on 32-inch centers and seeded at a rate of 2 lbs PLS per acre into the center of the sprayed strips; and (iii) seeding Garrison directly, without any herbicide control of existing vegetation, at a rate of 6 lbs PLS per acre using 12-inch row spacing. Throughout this paper, the three treatments described above may be referred to as complete-herbicide, banded-herbicide, and direct-seeded, respectively. Treatments were laid out in a randomized complete block design with three replications. Plots were 25 ft wide and 150 ft long. Common Name Latin Name Composition (%) Kentucky bluegrass Poa pratensis L. 30 Foxtail barley Hordeum jubatum L. 25 Nutsedge Carex spp. 18 Red top Agrostis alba L. 10 Rushes Juncus spp. 5 Reed canarygrass Phalaris arundinacea L. 5 Quackgrass Elytrigia repens (L.) Nevski 3 Tall fescue Festuca arundiacea Schreb. 3 Curly dock Rumex crispus L. 1 5 July 2004 Forage and Grazinglands During the establishment year (1999), grazing and deferred-grazing treatments were applied by dividing plots into two equal strips. Cattle were allowed to freely graze in the grazing strip during September and October of 1999. Cattle were excluded from grazing in the deferred-grazing treatment during this same period. Fences were removed and the entire experimental area was grazed after forage harvests in 2000 and 2001. Data Collection and Analysis Forage yield was determined by harvesting a 4-ft-wide strip the length of the plot with a flail harvester when Garrison reached anthesis and when the site was dry enough for equipment operation. Harvests were made on 7 June 2000 and 5 July 2001. Additionally, in 2001, the yield and quality of a one-time hay harvest were compared to utilization of Garrison at an earlier growth stage by harvesting a separate 4-ft wide strip on 30 May and again on 5 July. For all harvests, green weight was measured and subsamples were taken to determine dry matter yield and forage quality. Samples were dried at 140°F in a forced-air oven to constant weight, then weighed and double ground through a 0.0394-inch screen for quality analysis. The sample dry weight was used to convert green weights to dry weights. Forage nitrogen content was measured using the combustion method (1) with a LECO CNH-2000 Elemental Analyzer (LECO Corp., St. Joseph, MI). Crude protein was estimated by multiplying nitrogen content by the coefficient 6.25. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) were determined with an ANKOM-200 Fiber Analyzer (ANKOM Technol. Corp., Fairport, NY). The percent of harvested biomass comprised by Garrison creeping foxtail was determined by hand harvesting two sub-samples, 2 ft wide × 3 ft long, directly in the path of the flail harvester from each plot, each year. Garrison was separated from the rest of the sample and the resulting dry weights were determined. Establishment success or frequency of Garrison in the stand was evaluated just prior to harvest each year using the frequency grid described by Vogel et al. (12). A 30-×-30-inch quadrat containing 25 6-×-6-inch grids was placed on the plot directly in the path of the flail harvester. Each grid was scored for the absence or presence of Garrison and used to calculate the frequency at which Garrison was found in the stand. Four quadrats were scored in each plot. Dry matter yield, forage quality, percent Garrison composition, and Garrison frequency were analyzed across years, using the GLM procedure (6) as a stripplot analysis. Years were treated as repeated measures using the split-block in time analysis described by Steele and Torrie (9). Thus all main effects and interactions were tested using their respective interaction with replication as the error term. Treatment and grazing management were considered fixed effects. Mean separations were made using Fisher's protected least significant difference at the 0.05 level of probability. Correlations among forage yield, forage quality, percent Garrison composition, and Garrison frequency were estimated using the