Spring Annual Forages
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With spring not far off, it is time to start planning and thinking about any spring annual forages that we might plant. Part of the process may be anticipating a need for extra feed or booking seed early.
Species and Varieties
Spring-planted small grain cereals commonly yield about 2.5 – 4.0 tons/acre. There can be some year-to-year variability in yield depending on the spring growing conditions. For spring or cool-season annual forages, the planting period is typically late March to early April, or when soil temperatures are in the 42-to-45-degree Fahrenheit range. Oats is probably the most common cool-season annual forage planted in Nebraska. However, spring triticale or spring barley are two other small grain options that have been found to perform similarly to oats in terms of forage yield and quality. Also similar is the number of days until ready to begin grazing or hay; so, the different species could be mixed if desired. One could look at seed cost of the different species before deciding.
For the small grain cereals, there are varieties that have been developed specifically for forage use. For these varieties, some of the characteristics might include plant height, leaf width, days to maturity, and overall forage yield and quality. Don’t forget to consider the herbicides that may have been used on a field the previous year. Some herbicides have long residuals that could hinder establishment even into this spring.
Tables 1 and 2 present yield and quality results of several spring-planted oat, triticale, and barley varieties grown at North Platte. Test plots were planted on March 30 and received 70 lb. nitrogen/acre at planting.
If grazing is a primary goal, Italian ryegrass could be included in a mix with the small grain cereals and this will result in a longer grazing period. Italian ryegrass regrows well after grazing and will continue growth well into the summer if there is adequate moisture. In an oats-Italian ryegrass mixture, the seeding rate would be about 60 to 80 lbs. oats/acre and 15 to 20 lbs. ryegrass/acre.
Field peas are another species that could be included to enhance forage quality and provide some nitrogen fixation. In an irrigated trial at North Platte, it was found that a mixture of 52 lb./acre oats and 17 lb./acre field peas resulted in a forage crude protein (CP) content of 14% compared to 8% CP for oats alone. In that oat-peas mixture, the peas accounted for 25% of the total forage.
Seeding Rates and Fertilization
Seeding rate recommendations when planting small grains for forage can vary widely depending on the source. For oats, 2 to 3 bushels (76 to 114 lb.) per acre is common. Similarly for spring barley, 2 to 2.5 bushels (96 to 120 lb.) per acre and spring triticale at 2 bushels (about 116 lb.) per acre.
Recent University of Nebraska-Lincoln trials evaluated 4 oats seeding rates (25, 50, 75, or 100 lbs. per acre) and found total forage yield to be similar at the 50, 75, and 100 lb rates, and greater than the 25 lb. per acre rate. Seeding rate did not influence forage quality.
Annual forages usually need nitrogen (N) fertilizer to reach their yield potential. As with all crops, N fertilizer application should be according to soil test recommendations. With the spring-planted small grain cereals, N is usually the limiting nutrient. For irrigated fields, 50 to 70 lb. of N per acre can be applied at planting or within the first month. For dryland fields, nitrogen rates can be similar if there is adequate precipitation. Nitrogen fertilization has also been shown to increase forage crude protein.
With the early spring planting date of the small grain cereals, grazing can typically begin around the 3rd or 4th week of May and last into early July. The starting date will vary depending on the spring growing conditions. However, be ready to start grazing when plant height reaches 6 to 8 inches. Once it is at that height, growth will occur quickly, and it can shoot up to 12 inches in almost no time. The early grazing will stimulate the formation of new tillers.
Ideally, one should graze to keep the growth between 6 and 12 inches. This might require an initial lighter stocking rate, about one cow-calf pair for every two acres, then adjust animal numbers upward as oat growth changes. In general, a good stand of cereal small grains could support up to 2 cow-calf pairs per acre for about a 6-week period.
The small cereal grains are usually ready for hay harvest around the 3rd week of June. This can vary depending on the desired forage quality. Early harvests, such as when the crop is in a late-boot stage will result in forage with a crude protein content of 12 to 14%. When harvested at a later growth stage, such as milk to soft-dough, yield will be greater and crude protein content may range from 7 to 10%.
Haylage and Silage
While maturity remains important to maintain quality of small grains, moisture at ensiling is another factor to consider. Wilting is needed in most cases when ensiling grass forages as haylage and silage. At harvest, small grains in the boot stage may be at or above 80% moisture or 20% dry matter (DM). The goal is to produce a low-moisture silage more commonly referred to as haylage, baleage, or wilted silage. When ensiling, grasses should be 40 to 60% DM prior to ensiling. Forages should not be ensiled with more than 70% moisture (or less than 30% dry matter concentration) due to potential seepage losses and growth of undesirable bacteria, which can result in undesirable fermentation. Generally, small grains harvested from boot stage to soft dough require wilting of 24 hours or more to achieve the targeted range of 40 to 60% DM.
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