Annual cereal forages serve an integral role in integrated crop/livestock production systems across the West. Recently, producers have realized the values of annual cereal forages in rotational systems when renovating alfalfa, integrating them into systems to supplement perennial forages, and in cover crop mixes. Cool-season annual cereal forages most widely used in Montana and across the West include barley, wheat, oats, and triticale.
There are many advantages of growing annual cereal forages including adaptation to cool climates and higher elevations, they are easy to grow with no special equipment required beyond a grain drill, they are productive in dryland and irrigated systems, they provide good nutritional quality to livestock, and they are effective at disrupting weed and disease pest cycles and rodent problems. With the myriad benefits of using cool-season annual cereal forages, there are also disadvantages. Primary disadvantages include being annual crops that require yearly planting and the potential for nitrate accumulation.
Nitrates in cereal forages have the potential to cause nitrite poisoning in livestock, which, depending on the severity, can lead to economic losses due to weight loss, abortion, reduced breeding rates, weak calves, reduced milk production, and animal death. Nitrate content of cereal forages can be assessed both qualitatively and quantitatively. Montana State University Extension developed the Nitrate “QuickTest” protocol for qualitatively evaluating nitrate presence with a diphenylamine/sulfuric acid solution. Additionally, growers send samples to a laboratory to obtain quantitative analyses of nitrate content of cereal forage hay.
Livestock producers have inquired frequently in the fall with Montana State University Extension offices regarding the nitrate content of cereal grain regrowth, often referred to as volunteer growth. These producers, wishing to capitalize on the new growth, want to better understand the potential for nitrates, but many have little experience grazing it and approach the situation with caution.
Research regarding the potential for nitrate accumulation in fall regrowth of cereal forages is unavailable and nutrient quality of the feed is limited. Producers have largely relied on Nitrate QuikTests to evaluate the safety of using this feed resource due to its convenience. Additionally, comparisons of the Nitrate QuikTest and quantitative laboratory analyses do not exist for fall cereal growth. Therefore, the purpose of this study is to evaluate the nitrate content of cereal growth in the fall, 2) evaluate the forage quality of the available growth, and 3) evaluate how environmental conditions and crop management strategies impact nitrates and forage quality, and 4) evaluate the accuracy of the Nitrate QuikTest on fall cereal growth.
This participatory research project will allow participating producers to run their operations as they normally would, while allowing access to fields for data collection. Production practice information will be shared, data will be synthesized to obtain results, and solutions and actions will be formulated. These solutions and actions can then be shared locally, statewide, regionally, and nationally.
- Evaluate nitrate content and forage quality of fall growth of annual cereal forages on five to ten fields per year.
- Compare results of Nitrate QuikTest and laboratory analyses.
- Evaluate effect of soil moisture on nitrate content of forage.
- Evaluate the effect of frost on nitrate content of forage.
- Evaluate the effect of annual nitrogen fertilizer application on nitrate content of forage.
- Educate producers, Extension faculty, and others regarding the potential for nitrates and forage quality of cereal forage fall growth, accuracy of the Nitrate QuikTest, environmental conditions and management actions impacting nitrate levels, strategies for minimizing risk of economic loss by grazing forages with
- Evaluate change in knowledge, behaviors, and attitudes; producer adoptions of recommended strategies; changes in management by producers as a result of this information, including the WSARE Program Outreach Survey in the process.
Fields with annual cereal forage fall growth were sampled in October and November. Eight fields were sampled, including four that contained alfalfa with a hay barley cover crop; one with only hay barley; one with alfalfa, hay barley, oats, and peas; one with hay barley and peas; and one with hay barley, oats, turnips, peas, and radishes.
In each field, 10 locations were chosen randomly to sample forage and to take soil moisture and soil temperature readings. Information was obtained from the ranchers about annual fertilization regimes, frost events, and irrigation practices for each field.
The Nitrate QuikTest and an additional nitrate test developed at the University of Georgia were each performed on each forage sample. Samples were also sent to a laboratory for forage quality and nitrate analyses.
Educational & Outreach Activities
To date, education and outreach activities have been limited to one-on-one consultations with ranchers that initially agreed to participate and additional discussions with those who had fields that met the project criteria. These interactions provided an opportunity to engage with the ranchers and discuss their operations, how annual cereal forages fit into their grazing regimes, and how various factors have the potential to affect nitrate quantity in that forage.