In regions where wheat fields dominate the agricultural landscape, farmers often use fall and spring growth as a source of forage — weather permitting. What seemed like a questionable year to use wheat and other small grains as dual-purpose crops looks to be shaping up as a productive one, albeit a bit behind schedule.
In last week's Cow-Calf Corner newsletter from Oklahoma State University Extension, Paul Beck says August rainfall gave farmers in Oklahoma and neighboring states hope for a suitable wheat grazing season. That hope was quickly shaken when a nearly 60-day dry spell settled in for the duration of September and October.
Luckily, precipitation returned at the end of October, and since then, a large portion of the Southern Great Plains has received roughly 8 to 10 inches of rain. Despite the extended stretch of dry weather, Beck says the much needed moisture has many farmers once again wondering when wheat pastures will be ready for grazing.
The beef cattle nutrition specialist explains a general rule for stocking wheat pastures is to ensure steers have at least 4 to 5 pounds of forage dry matter per pound of body weight to maximize performance during fall and winter. For a 500-pound backgrounder calf, that would be roughly 2,500 pounds of forage dry matter throughout the grazing season.
“At a stocking rate of 2 acres per steer, we need 1,200 to 1,300 pounds of forage growth per acre,” Beck states. “If you estimate 200 pounds of forage per inch of forage height at the main mass of tillers in a good, thick stand of wheat pasture, the wheat should be 6 to 7 inches tall on average across the field.”
Beck continues to note that wheat and other small grains can produce about 3.3 pounds of forage dry matter per growing degree day. Using the growing degree day equation below, Beck enters 42ºF as the critical temperature for wheat, whereas rye and triticale warrant a critical temperature of 38ºF.
Growing degree days = average daily temperature – critical temperature
“The slightly lower critical temperature for rye and triticale seems like very little difference, but it can have a large impact on growth potential as we get into cooler conditions,” Beck writes.
According to crop growth in central Oklahoma, Beck says forage has recently taken advantage of optimal growing conditions with yields rapidly progressing during November. For example, in a triticale and ryegrass field that emerged around November 12, he estimated the stand would have accumulated 850 to 900 additional pounds of forage growth per acre by the end of last week. The long-term forecast looks promising as well.
“Based on projected temperatures for the next month with average daily temperatures around 44ºF, we should expect 15 to 20 pounds of additional forage growth per day, reaching 1,200 pounds of forage accumulated by December 20,” Beck adds.
Even though forage growth may have been set back by a dry start to fall, he encourages farmers to proceed with grazing small grain fields when yields are adequate. With that said, waiting a few extra days will be even more beneficial to stand condition and animal performance.
