Severe drought conditions in the Nebraska Panhandle mean forage for grazing or hay will be in short supply. Irrigated ground growing a winter wheat crop harvested in July can be utilized to produce a high-quality forage for fall and winter grazing or hay. To examine this option, a two-year study was conducted in 2012 and 2013 at the High Plains Ag Lab.
Three different forages were planted. Sorghum-sudangrass hybrid, oats, and foxtail millet were evaluated at two irrigation levels following irrigated wheat. Dry matter production, total digestible nutrients, crude protein, and nitrates (NO3) were measured.
In 2012, it was an extremely hot and dry year, not unlike the conditions being experienced in 2026. Although it was intended to have minimal irrigation levels, researchers thought it was important to have one level unrestricted. As a result of the heat and drought, the two levels were 4 and 8 inches. In 2012, when forage production was averaged over both planting date and irrigation level, the sorghum-sudangrass hybrid produced more dry matter tons than oats and millet (2.0 vs. 1.3 and 1.2, respectively). In the second year, 2013, there was late summer rain, and the irrigation levels were 4 and 5 inches. The sorghum-sudangrass hybrid and oats produced more dry matter tons than millet (1.0 and 1.1 vs. 0.64, respectively).
The earlier the forages were planted, the more total dry matter tons were produced before frost. Oats may have an advantage over sorghum-sudangrass and millet if planted after August 1, because they will continue to grow after a light freeze until temperatures drop into the low 20s Fahrenheit. Due to the dry conditions in 2012, the wheat was harvested early in July, so the two planting dates for the annual forages were 7/18/2012 and 8/02/2012. In 2013, a more typical year for moisture and temperature, the annual forages were not planted until 8/05/2013 and 8/20/2013.
Forages were harvested on 9/26/2012 and 10/08/2013. All forage quality was acceptable, with the lowest crude protein being over 10 percent on a dry matter basis and the total digestible nutrients (energy) being at least 60 percent on a dry matter basis, regardless of planting date and irrigation level.
In 2012, all forages had NO3 (nitrate) levels between 2,600 to 4,400 ppm. This would have been a concern if the forages were harvested for hay because safe levels are below 1,500 ppm. However, forages were left standing, and samples were collected the following March of both years, and the NO3 level had dissipated to below the safe level of 1,500 ppm in all three forages. Due to the dry, cool conditions that usually occur in the fall and winter for this region, forage quality changed very little over the winter and would have made these forages a good option for grazing as a standing hay crop.
In western Nebraska, the window for planting forages after wheat harvest and growing significant fall forage is narrow. The last two weeks of July and the first two weeks of August appear to be optimum. After this time, the forage has a very limited time to grow. The forage quality in this study would have provided acceptable gains for weaned calves or bred replacement heifers, whether harvested as hay or left as standing forage for winter grazing.
