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Crops

Some Grasses May be a Better Choice than Alfalfa

Written by Blaine Horn
    The Johnson County office of the University of Wyoming Cooperative Extension Service has been conducting a cool-season perennial grass hay trial at two area ranches since 2004.
    The purpose is to evaluate the long-term hay production potential of Luna and Mandan pubescent wheatgrass, NewHy hybrid wheatgrass, Rosana western wheatgrass, Critana thickspike wheatgrass, Hycrest crested wheatgrass, Bozoisky Russian wildrye, Manchar smooth bromegrass, and Regar meadow bromegrass and determine if production costs associated with these grasses might be lower than that for alfalfa.
    Alfalfa provides good hay yields its first few years of production, but, as stands age, yields decline and weed problems increase. For alfalfa fields to remain productive, they have to be periodically farmed. This usually entails plowing the alfalfa and planting an annual forage crop such as oats or millet for a couple of years before the field is planted back to alfalfa. If cool-season perennial grasses are able to produce hay yields comparable to alfalfa but for more years, overall costs for hay production could be lowered. In addition, grass hay fields could also be grazed without fear of bloat providing more management flexibility to livestock producers.
    Plots of the above grasses were established in irrigated fields, previously in alfalfa, at two ranches in 2003 with harvests occurring in late June 2004 to 2007. The trials were on Larry Vignaroli’s ranch along Lower Clear Creek northeast of Buffalo and on a ranch on Lower Piney Creek northeast of Buffalo near the Johnson-Sheridan County line that is leased by Ray Daly.
    Spring precipitation in 2005 and 2007 was sufficient to forego irrigation at both locations, but, due to the dry conditions in 2004 and 2006, irrigation water was applied in late May 2004 and early June 2006 at Daly’s and in late May 2006 at Vignaroli’s. Because the surrounding field at Vignaroli’s was to be planted to millet in 2004, irrigation did not occur until July.
    For cool-season grasses to produce comparable yields to alfalfa, application of a nitrogen fertilizer is needed. At Daly’s, 100 pounds of nitrogen per acre was applied on April 19, 2005, May 19, 2006, and May 9, 2007, and, at Vignaroli’s, 30 and 100 pounds per acre on May 12, 2006, and May 1, 2007, respectively.
    Grass hay yields at Daly’s averaged 2.1, 3.6, 2.4, and 3.0 tons per acre in 2004, 2005, 2006, and 2007, respectively, and, at Vignaroli’s, 1.7, 2.1, 2.0, and 3.6 tons per acre. The lower yields at Vignaroli’s, except in 2007, was probably due to no irrigation prior to harvest in 2004, no nitrogen fertilizer in 2005, and 70 pounds per acre less nitrogen in 2006. The higher yields in 2007 at Vignaroli’s may have been due to nitrogen fertilizer being applied a week earlier.
    Weekly harvests of the grasses at Daly’s in 2005, 2006, and 2007 beginning the end of April for a grazing simulation study has shown these grasses enter their fast growth phase in mid-May. If adequate soil moisture is not present at that time, growth of the grasses and resultant hay yields will be reduced. The lower average hay yields of the grasses in 2006 compared to 2005 and 2007 at Daly’s supports this. In addition, if nitrogen fertilizer is to be applied, it probably needs to occur by early May for the grasses to take full advantage of it.
    June 2004-2007 hay yields of Luna and Mandan pubescent wheatgrass, Hycrest crested wheatgrass, NewHy hybrid wheatgrass, Manchar smooth bromegrass, and Regar meadow bromegrass averaged 2.9 tons per acre for the two locations, and 1.9 tons per acre for Bozoisky Russian wildrye, Rosana western wheatgrass, and Critana thickspike wheatgrass.
    If 2007 yields are not included, the averages are 2.6 and 1.6 tons per acre, respectively. Alfalfa hay yields for 2004, 2005, and 2006 for Johnson and Sheridan counties averaged 2.5 tons per acre.
    The potential for some of these grasses to be used for hay production in lieu of alfalfa looks promising; however, costs of production and price per ton received needs to be calculated to make a final determination. The study will continue for another six years, possibly more, to document any decline in stand of any of the grasses as stand longevity impacts establishment costs.
    At this time, I would recommend a meadow bromegrass for hay production because they provide good hay yields and regrowth if used for grazing and more flexibility with regard to harvesting hay with respect to palatability. The pubescent wheatgrasses may yield as much as the meadow bromes but, if harvested at maturity, they do not seem to be as palatable.
Research results should be applicable to eastern Wyoming and possibly the state as a whole but definitely the northeast.
    Additional study results can be accessed via http://ces.uwyo.edu. Horn is a UW CES educator specializing in forages and rangeland and livestock management serving Johnson and Sheridan counties. He is based in Buffalo.