Dr. Mark Sulc, OSU Extension Forage Specialist, The Ohio State University
Dr. Bill Weiss, Dairy Nutrionist, The Ohio State University
Many forage stands were damaged this past winter, and the wet spring has further deteriorated stands that appeared they might recover. It is now too risky to try to establish perennial forages, with the warmer summer weather at our doorstep. We should wait until August to establish perennial stands. Meanwhile, what options can we consider for growing forage this year?
We are also well past the time when cool-season species like oats, triticale, Italian ryegrass, spring barley can be planted. As we move into late May and early June, we must switch to planting warm-season species.
Corn silage is still the top choice for an annual forage in terms of overall greatest dry matter yield and nutritive value compared with the other summer annual options. Even if planted so late as to prevent grain formation, the feeding value of corn is at least equal to that of the other summer annual grasses, and forage yields are likely to be higher. However, corn silage won’t be an option for every situation.
Sudangrass, sorghum x sudangrass hybrids, pearl millet, and forage sorghum
These forages grow rapidly in summer and yield 3.5 to 5 tons of dry matter with good nutritive value, especially if selecting sorghum varieties with the brown-midrib (BMR) trait that produces forage almost as good as regular corn silage (although lower in starch) with very good fiber digestibility. Soil temperatures should be at least 60-65 F before planting. These species can be planted up to late June in northern Ohio and mid-July in central and southern Ohio. Forage can be ready for harvest in as little as 40 to 50 days. See image above for Sorghum x sudangrass and teff growth 40 days after planting on June 12. Forage sorghum can produce up to 8 tons dry matter per acre in a single cut. Pearl millet is essentially free of prussic acid poisoning potential, but the sorghum species have the potential for prussic acid poisoning that occurs primarily after frost events. Nitrate toxicity is possible with all summer annual grasses and management steps should be taken to reduce that risk.
Mixtures of summer-annual grasses and legumes such as field peas and soybeans are marketed by some seed dealers. The legumes can increase protein content but only in the first harvest because they don’t regrow after cutting. Legumes increase the seed cost, so consider the benefit of including legumes vs. supplementing with other protein sources.
Teff is a warm-season grass that can be used for hay, silage, or pasture. Soils should be at least 60-65 F before planting Teff. The first crop should be ready in 40 to 50 days. It produces 3 to 4 tons of dry matter per acre over several cuttings and can tolerate both drought-stressed and waterlogged soils. More details on managing this forage can be found in a factsheet from Cornell University.
Brassica species can be planted in May to early June for late summer grazing or fall grazing by cattle or sheep. These species contain high moisture content, so they should be used for grazing only. Brassicas have very low fiber and high energy and should be treated more like a concentrate than as forage in diets. For more information on brassicas for forage, see the Penn State factsheet.
Seeding Rates and Mixtures
Plant high quality seed of a known variety, which will ensure high germination rate and avoid unpleasant surprises regarding varietal identity and crop characteristics.
Chopping and ensiling or wet wrapping are the best mechanical harvest alternatives for the summer annual grasses, while grazing is really the only option for the brassicas. With the exception of Teff, dry baling the summer annual grasses is a challenge.
Table 1. Guidelines for seeding various annual forages. Yield and nutritive value ranges are for silage, which vary greatly with maturity stage at harvest. Generally, for hay, expect lower CP and higher NDF concentrations.
|Forage crop||Seeding rate (lb/acre)||Planting dates1||Dry matter yield (ton/acre)||CP(%)||NDF(%)|
|Corn silage||28-34k2||4/20 – 6/15||5.0 – 9.0||6 – 9||38 – 50|
1 Planting date range for Ohio. In southern Ohio, the spring dates should be in the early range, and in the fall, they can be in the later range.
2 28,000 to 34,000 seeds per acre; seed companies provide hybrid specific planting rates.