Short-season forages planted in late summer can be sources of highly digestible fiber in ruminant livestock rations. There are several excellent forage options that can be considered for no-till or conventional tillage plantings in the late summer or early fall planting window. These forages can be a planned component of the overall forage production plan. They can be utilized on land that would otherwise sit idle until next spring, such as following wheat or an early corn silage harvest.
Oat or Spring Triticale silage
These cereal forages can be planted for silage beginning the last week of July and into early September. Dry matter yields of 1.5 to 3 tons per acre (about 5 to 5.5 tons at 30 to 35% DM) of chopped silage or Baleage are possible if planted in late July to early August. Harvesting between late boot, or early heading, will optimize quality. Yields will be lower for plantings made in early September, in which case late autumn grazing would be a more viable option. Our research utilizing oats planted on September 1st versus September 15th showed about a one-ton difference in yield.
Liquid manures, if available, can make a very economical source of nitrogen for these late-planted oats. While earlier planting dates of oats have seen yields plateau with about 100 pounds of nitrogen, our later planting in September has seen significant yield increases at the 138- and 184-pound nitrogen treatments. These September plantings are often not ready for harvest until after a killing frost.
The potential feed value of oat silage can be similar to mid-bloom alfalfa. As a grass, maximum inclusion rates in diets for animals with high nutritional demand (e.g. lactating cows) are less than those for alfalfa, but it is a very acceptable feed.
Spring triticale is a biotype of the hybrid cross between cereal rye and wheat (there is also a winter biotype that acts like winter wheat). In our research, oat averaged slightly higher fall yields than spring triticale, but this varied across years. If cut at the proper maturity, spring triticale forage has a higher feed value than oat, similar to early-bloom alfalfa. Seed cost for spring triticale is usually higher than oat, but it is later maturing than oat or barley and will maintain its forage quality for an extended harvest window.
About 50 pounds of nitrogen per acre will be needed to optimize yield potential of these cereal forages following wheat when planted in late July early August. Following corn silage harvest, and especially if manure is applied before planting the short-season forage, there likely will be no need for additional nitrogen application.
Check herbicide rotation restrictions from the previously planted crop. Other potential challenges include rust infection, especially with oat. Rust could impact yield and feed quality, depending on when during the growing season infection occurs. Our research has shown a significant yield and quality advantage to treating July and early August planted oat with a fungicide to control rust.
Oat or Spring Triticale and Winter Cereal Mixed Silage
Planting mixtures of oat or spring triticale with cereal rye, winter wheat, or winter triticale will allow a fall harvest or grazing as well as a harvest or grazing of the winter cereal next spring. Keep in mind that the window for harvesting rye silage in the spring to obtain high quality forage is usually very early and very short. Winter wheat and winter triticale mature later and more slowly in the spring than winter rye. Forage yields in the spring will be 2.5 to 3 tons of DM per acre of high quality forage when harvested in boot stage. In the fall, the oat/winter cereal or spring triticale/winter cereal mix should yield slightly more than oat or spring triticale alone, with the potential for the spring cereal harvest. Corn silage or soybean can be then planted after the winter cereal harvest in the spring.
Italian Ryegrass Silage
This grass emerges as fast as oats and could produce up to a ton of dry matter per acre in the fall if planted in August, and less yield if planted into September (it should be planted by mid-September at the latest). This crop would also be available for additional cuttings next year, starting in late April or early May and then every 25-30 days into June or early July.
In our research, a fall harvest and three additional harvests the following year have shown total yields between 3 to 5 tons of dry matter across all the harvests, when improved varieties of Italian ryegrass are planted and winter survival is good. Italian ryegrass can winterkill in severe winters. It is important to not allow a lot of growth going into the winter to avoid mold growth that damages the stand. To avoid this, make a late fall cutting or graze to a height of 3 inches late in the year. This crop will shut down by mid- to late-summer the year after a fall establishment. It would fit best in a rotation with sorghum-sudangrass or forage sorghum planted in early July.
Harvesting Italian ryegrass before heading optimizes quality, as with all grasses. When planted in September and harvested in late fall, the quality will be superb (NDF around 48% and NDF digestibility about 80%). August plantings harvested in late fall will be slightly lower in quality with crude protein in the mid-teens and NDF in the mid-50s. Next year, the crop will head out quickly at each harvest, and will be a medium quality forage. But with proper diet formulation, it can be used in even in lactating cow rations.
Sorghum, Sorgumsudan, and Pearl Millet
Compared to oats or spring triticale the warm season grasses like sorghum, sudan grass, sorghum sudan and pearl millet need to be planted sooner and carry more risks. These crops should be planted as early in July as possible to maximize growth. Some producers even prefer to just grow more corn silage on the ground with research from Wisconsin suggesting August’s first planted corn silage can yield 1.5-2 tons of dry matter. In that study, Mid July planted corn silage yielded 4-5 tons of dry matter. The benefit of corn silage is that it is familiar and has more weed control options. Sorghum and sorghum sudan have yielded between 2-6 tons of dry matter but usually contain less energy than corn silage. One advantage to sorghum and sorghum sudan is that it can be made as baleage.
Utilizing short-season forages can provide excellent quality forage to supplement other forages such as corn silage and alfalfa or perennial grasses, while also increasing land use efficiency. Maintaining forage cover year-round protects the soil from erosion and contributes to building soil organic matter over the long-term.