Eastern Gamagrass Determining its Feasibility as a Forage Crop for the Northeast

Eastern Gamagrass Determining its Feasibility as a Forage Crop for the Northeast

Summary

Forage quality studies comparing harvest date management practices; and forage quality variation among 7 eastern gamagrass genotypes were completed. Eastern gamagrass has good forage quality, when averaged over all first cutting dates for both years CP, IVTD, NDF, lignin and digNDF was 14.7, 79.2, 73.5, 4.0, 71.9 percent respectively. Eastern gamagrass and legume companion crops were successfully established on eight sites. It appears that perennial legumes interseeded in early August of the first year reduced eastern gamagrass yields and vigor in the second and third year compared to being grown without a companion crop. Yields of only three tons/ac were achieved on the best sites without companion legumes due to the extremely cool summer in 2000.

Objectives
Evaluate the adaptability and yields of eastern gamagrass grown on a variety of soil types.

Evaluate the compatibility of eastern gamagrass grown with several nurse/companion crops.

Evaluate the forage quality of eastern gamagrass grown at the USDA-NRCS Big Flats Plant Materials Center, Corning, New York.

Conduct feeding trials comparing eastern gamagrass with corn silage as a significant portion of a dairy ration.

Assess the on farm economic implications of utilizing eastern gamagrass as a significant component in a dairy ration compared to corn silage.

Methods
Eastern gamagrass is a perennial warm-season grass that can be used for hay, haylage and in managed pasture. It is a highly productive, palatable and digestible forage which may have use on dairy farms. Its use on steeper slopes instead of corn silage will reduce soil erosion with its associated water quality problems. Eastern gamagrass cv. ‘Pete’ was established on 12 different sites including eight farms and four teaching or research facilities within nine counties in New York.

Companion plantings were investigated to reduce erosion during establishment, reduce frost heaving problems, add nitrogen, and improve forage quality. Companion plantings of oats and five legumes were established in subplots at all sites immediately following cultivation at the end of July to early August. The legumes were: white clover, red clover, alfalfa, birdsfoot trefoil, and black medic.

All of the companion crops established well and provided good erosion control in the fall and winter; there were also a lot of annual weeds that provided some erosion control earlier in the season. The companion crops persisted well into the third year with cover in mid June for alfalfa, white clover, red clover and birdsfoot trefoil of 74.5, 95.3, 96.5, and 78.5 percent respectively. In some situations, the cover crops were outcompeted by perennial grasses. When fully established, they competed well against annual weeds. As the covers decline, weed infestation becomes a problem which may need a herbicide application to control.

Of the 12 sites, eight are excellent with dense rows of gamagrass and four are fair-to-good. It appears that initial stand density is extremely important in competing with weeds and companion plants. There was no competition between the companion crops and the gamagrass during the establishment year, but the second year (1999) had above normal competition due to drought. In 2000, we had abnormally cool temperatures that reduced gamagrass yields and increased competition from cool-season legumes. There were significantly higher eastern gamagrass yields in the area outside of the companion crop study areas that had additional weed control—the yields at Cornell, Cobleskill, the Lathrope farm and the Big Flats Plant Materials Center for two cuttings were: 2.11, 2.99, 2.75, 3.75 dry matter tons/ac respectively. The perennial companion crops competed with the eastern gamagrass reducing yields compared to the control, and yields fell. The gamagrass yields when grown with alfalfa, white clover, red clover and birdsfoot trefoil were 71.5, 66.8, 78.0, and 82.5 percent of the control respectively. The oats were not competitive with the gamagrass and provided good winter cover for erosion control and potential frost heaving protection.

In order to determine the value of eastern gamagrass grown in the Northeast a forage quality, study was conducted at the Big Flats Plant Materials Center. Forage quality samples were taken on a mature stand of eastern gamagrass cv. Pete.

The plots were cut at three first cutting dates, starting on May 28 and June 13 of 1998 and taken at three weekly intervals. A second cutting was sampled at 3 intervals of 4, 5 and 6 weeks. The average forage quality for the best first cutting dates for both years for CP, NDF, ADF, lignin, dig. NDF and IVTD were 14.8, 70.7, 32.5, 3.0, 73.6, and 80.7 percent respectively. The quality of the first and second cutting decreased as maturity of the forage increased. A five-week cutting interval is recommended.

The information obtained from this study will be used in a computer model to decide on a gamagrass-based dairy ration to test with animal feeding trials. Feeding trials comparing eastern gamagrass with corn silage were conducted at SUNY Cobleskill, Morrisville, and Cornell. Diets were balanced for fiber, total protein, energy and minerals. There was more grain used in the gamagrass diet. There was no significant differences in dry matter intake, milk production, and milk composition between the diets. This study indicates that gamagrass can be used to replace the fiber coming from corn silage.

Reported April 2001