Four years of research at the Sheridan Research and Extension Center suggests grass-legume mixtures with alfalfa are the most productive and profitable, overriding changes in weather conditions and management.
Based on the research, the most recommended forages for Wyoming is a 50-50 percent mixture of meadow bromegrass with alfalfa, a 50-25-25 percent mixture of meadow bromegrass, alfalfa, and birdsfoot trefoil, and 70-30 percent mixture of meadow bromegrass with alfalfa. Although mixtures purely of meadow bromegrass and sainfoin had relatively lower gross margins, this crop may have more value considering sainfoin enhances forage palatability and prevents bloat.
Numerous studies indicate grass-legume mixtures can improve forage yields, nutritive value, and net economic benefits. Meadow bromegrass is a popular cool-season grass found suitable. This species can grow upright and allows legumes to thrive in mixtures (Figure 1). Different combinations of meadow bromegrass and legumes including alfalfa, birdsfoot trefoil, and sainfoin can help alleviate challenges of producing monocrops that include costs of nitrogen (N) fertilizers required to optimize yield, comparatively low nutritive value of grasses, and bloat disorder in livestock caused by alfalfa.
Alfalfa hay has higher market prices compared to other hay crops. High forage nutritive value has been used as a benchmark for setting alfalfa and grass hay prices. Alfalfa hay with crude protein (CP) values of less than 16, 16-18,
July 2018
B-1327
Meadow bromegrass-legume
18-20, 20-22, and greater than 22 percent is rated as utility, fair, good, premium, and supreme quality, respectively.
On the other hand, grass hay with CP concentrations less than 5, 5-9, 9-13, and greater than 13 percent is ranked as low, fair, good, and premium quality hay, respectively.
There are no clear price standards for sainfoin, birdsfoot trefoil, and grass-legume mixtures per se. According to USDA NASS report for 2018, alfalfa hay prices increased by $33 and $35 following change from fair to good and good to premium quality, respectively.
In contrast, grass hay price increased by $44 and $80 corresponding to a change from fair to good and good to premium quality.
Nutritive value of hay fed to cattle determines the net income from livestock farming. According to USDA NASS report, livestock feed accounts for about 12 percent of the total farm operating cost. High-quality hay enhances productivity of beef and dairy cattle.
Experiments from 2013-2017 at the Sheridan Research and Extension Center (ShREC) determined forage yield, nutritive value, and gross margin (GM) for meadow bromegrass, alfalfa, sainfoin, and birdsfoot trefoil mixtures and monocultures.
There were 50-50 percent and 70-30 percent mixtures of meadow bromegrass with each legume, 50-25-25 percent mixture of meadow bromegrass with alfalfa and birdsfoot trefoil, and similar mixture with meadow bromegrass, alfalfa and sainfoin.
The last crop combination was 50-16.7-16.7-16.7 percent mixture of meadow bromegrass, alfalfa, sainfoin, and birdsfoot trefoil.
Grass monocultures received 0, 50, and 100 pounds of N per acre as urea. Seed rates and ratios were estimated by dividing recommended seeding rates with pure live seed (PLS). PLS is the amount of live seed in bulk seed
Figure 1. Meadow bromegrass-legume mixtures improve forage performance at the University of Wyoming Sheridan Research and Extension Center.
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and is calculated by multiplying the percentage of seed purity by percentage of seed germination.
The recommended seeding rates based on PLS for mea-dow bromegrass, alfalfa, sainfoin and birdsfoot trefoil were 20, 20, 35, and 10 pounds per acre, respectively.
Planting was September 4, 2013, and plots were harvested in mid-June, August, and October each year from 2014 to 2017. Harvested samples were used to estimate forage dry matter (DM) yield per acre and nutritive value using the near infrared reflectance spectroscopy (NIRS) (Figure 2).
Economic analysis was based on expenses involved in producing each crop (Table 1) according to different treatment and cumulative forage dry matter yields. Each treatments was treated as an enterprise. Gross margins (GM) were calculated each year according to Equation 1.
GM = CI - VOC
Where CI is the cash inflow (U.S. dollars) and VOC is the variable operational cost ($).
Variations were observed among treatments for the total forage DM yield. Total forage yield from mixtures was consistently higher compared to legume and grass monocultures 2015-2017 (Table 2). This was particularly evident in the 50-50 percent and 70-30 percent mixtures
of meadow bromegrass with alfalfa and 70-30 percent mixture of meadow bromegrass with birdsfoot trefoil.
The same applied to a 50-25-25 percent mixture of meadow bromegrass, alfalfa, and sainfoin; 50-25-25 percent mixture of meadow bromegrass, alfalfa, and birdsfoot trefoil; and 50-16.7-16.7-16.7 percent mixture of meadow bromegrass, alfalfa, birdsfoot trefoil, and sainfoin.
Sainfoin monoculture had the lowest forage yield in all the years.
Alfalfa monocrop CP varied from supreme (28 percent), good (17.7 percent), to supreme (23.9 percent) in 2015, 2016, and 2017, respectively, based on USDA guidelines. Although these guidelines apply only to alfalfa, they were used to evaluate birdsfoot trefoil and sainfoin.
The CP concentration for birdsfoot trefoil was rated as supreme in 2015 and 2017 (22 percent) and good in 2016 (18.1 percent). CP concentration for sainfoin was rated as good in 2015 (18.2 percent) and premium in 2017 (21.9 percent).
Some of the grass-legume mixtures containing alfalfa and birdsfoot trefoil improved forage nutritive value (particularly CP concentration) to levels equivalent to good quality alfalfa in 2015 and 2017. These include 50-50 percent mixture of meadow bromegrass with alfalfa (19.7 percent), 70-30 percent mixture of meadow bromegrass with alfalfa (19.3 percent), and 70-25-
Figure 2. Hay baling at the Sheridan Research and Extension Center in June 2016 (left); forage nutritive value analysis using near infrared spectophotometer at the University of Wyoming forage laboratory (right), December 2016.
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25 percent mixture of meadow bromegrass, alfalfa and birdsfoot trefoil (19.1 percent).
Variations were observed among years and treatments for GM (Table 3). The 50-50 percent mixture of meadow bromegrass with alfalfa (Figure 3) had the highest four-year total GM of $1,497 per acre. This was similar to GM for 50-25-25 percent mixture of meadow bromegrass, alfalfa, and birdsfoot trefoil (Figure 3) ($1,440 per acre) and 70-30 percent mixture of meadow bromegrass with alfalfa ($1,368 per acre).
Sainfoin monoculture earned the lowest total GM of $62.
All treatments had a significant increase in GM in the year 2015 compared to 2014 when no enterprise had profits. In subsequent years, some mixtures maintained a consistent increase in profits. These were the 50-50 percent mixture of meadow bromegrass with alfalfa ($241 to 802 per acre) and 70-30 percent mixture of meadow bromegrass with alfalfa ($313 to 753 per acre).
The other crops that maintained an increase in GM during the similar period were the 70-30 percent mixture of meadow bromegrass with birdsfoot trefoil ($324 to 676 per acre) and 50-16.7-16.7-16.7 percent mixture of meadow bromegrass, alfalfa, sainfoin, and birdsfoot trefoil ($290 to 636 per acre).
There were no significant gains in profits for meadow bromegrass monoculture with or without fertilizer between 2015 and 2017. It is evident alfalfa and birdsfoot trefoil tended to add value to hay when included in mixtures with grass. Mixtures helped compensate
for low sainfoin monocrop yields associated with high temperatures and weed infestation (Figure 4).
In particular, the 50-16.7-16.7-16.7 percent mixture of meadow bromegrass, alfalfa, sainfoin, and birdsfoot trefoil showed potential to sustain yields and increase profit margin compared to the consistently low economic benefits from sainfoin monocrop.
Overall, grass-legume mixtures, which include alfalfa and birdsfoot trefoil, have potential market value comparable to good quality, pure alfalfa hay. Investments in grass-legume mixtures can be recouped resulting in profits.
Figure 3. The 50-50 percent mixture of meadow bromegrass with alfalfa (left); the 50-25-25 percent mixture of meadow bromegrass, alfalfa, and birdsfoot trefoil (right) at the Sheridan Research and Extension Center, June 2016.
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Figure 4. Benefits of grass-legume mixtures. Left, a 50-50 percent mixture of meadow bromegrass and sainfoin without weed problems. Right, sainfoin monoculture infested by weeds at the Sheridan Research and Extension Center, June 2017.
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Adjesiwor, A.T., M.A. Islam, V.D. Zheljazkov, J.P. Ritten, and A. Garcia y Garcia. 2017. Grass-legume seed mass ratios and nitrogen rates affect forage accumulation, nutritive value, and profitability. Crop Science. 57:2852-2864. doi:10:2135/cropsci2016.09.0776.
Cosgrove, D.R., and M. Collins. 2003. Forage establishment. In R.F. Barnes et al., editors, Forages: An introduction to grassland agriculture. Blackwell Publishing, Ames, IA. p. 239 -256.
Dhakal, D. 2015. Forage grass-legume mixtures for improved forage yield, forage quality, stand persistence, soil properties and economics. Ph.D. Dissertation, University of Wyoming, Laramie.
Holzworth, L., J. Mosley, D. Cash, D. Koch, and K. Crane. 2003. Dryland pastures in Montana and Wyoming: Species and cultivars seeding techniques and grazing management. Montana State University: 10, 11, 24.
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Patterson, P.E. 2015. Alfalfa hay production. University of Idaho. https://www.uidaho.edu/-/media/UIdaho-Responsive/Files/cals/programs/idaho-agbiz/crop-budgets/Southeastern-irrigated/Alfalfa-hay-2015.ashx?la=en&hash=007C6986954CF66A957B2F4C04543D71DE856BD0 (Accessed 16 March 2017).
USDA. 2017. Farm production expenditures 2016 summary. http://usda.mannlib.cornell.edu/usda/current/FarmProdEx/FarmProdEx-08-03-2017.pdf (Accessed 16 April 2018).
USDA NASS (United States Development Agency National Agricultural Statistics Service). 2018. 2016 State agriculture overview, Wyoming. https://www.nass.usda.gov/Quick_Stats/Ag_Overview/stateOverview.php?state=WYOMING (Accessed 3 Jan. 2018).
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