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Forage Options for Unseeded Fields

Unseeded fields provide an opportunity to boost forage inventories with annual crops. These forage crops have a bonus of suppressing weeds and protecting the soil from erosion.
 
When selecting a forage crop consider the livestock’s dietary needs, the type and quality of forage in inventory, herbicide or fertilizer previously applied, and resources that are readily available. However, during wet conditions producers should strive to make the best quality forage possible. It is easy to dilute high-quality feeds with poorer quality ingredients, but it is not always possible to buy quality forage to make up for a low-quality crop.
 
Nitrogen requirements may be partially or wholly met by manure applications where appropriate. None of the annual forage options dry well enough to make hay; they are best preserved as silage or baleage.
 
If protein is needed:
 
Cereal/pea mix
 
Peas do not work well on their own, as they tend to lodge which makes harvest difficult. Ideally the chosen varieties of cereal crop and peas should have the same number of days until flowering. However, if there is a difference in maturity (due to variety or weather), harvest when the cereal is at or prior to the boot stage to maximize quality. When planting in August seed the cereal crop at 80-100 kg/ha (70-90 lbs/acre) plus peas at 50-75 kg/ha (45-70 lbs/acre). Target a uniform depth of 2.5 cm (1 in.) depth. Apply 20-30 kg N/ha (18-27 lbs N/acre). Harvest is typically 45-50 days after planting. Set cut height to 7-10 cm (3-4 in.).
 
Red clover
 
Red clover seed can be relatively inexpensive. Plant in early August at 11 kg/ha (10 lbs/acre) at 6-12 mm (0.25-0.5 in.) depth in clay or loam soils, 12-18 mm (0.5-0.75 in.) in sandy soils. First cut is typically 60-70 days after planting, with maximum quality before 20% bloom, and maximum yield after that. Subsequent cuts are typically around 30- to 35-day intervals. Set cut height to 5 cm (2 in.). Note that red clover silage is often darker in colour than alfalfa; the dark colour is not automatically an indicator of spoilage.
 
Annual clovers
 
Berseem clover is better suited to wet soils. Plant in August at 20-22 kg/ha (18-20 lbs/acre) at 6 mm (0.25 in.) depth. First cut is typically 60 days after planting, subsequent cuts on a 25- to 30-day interval. Set cut height to 7-10 cm (3-4 in.).
 
Crimson clover prefers well-drained soils. Plant in August at 10-22 kg/ha (9-20 lbs/acre) at 6 mm (0.25 in.) depth in clay soils, 12-18 mm (0.5-0.75 in.) in sandy soils. Ideal harvest time is 4-6 weeks before seed set. Set cut height to 7-10 cm (3-4 in.).
 
Soybeans
 
Soybeans are one of the most difficult crops to ensile. Their high oil/low sugar content buffers against the pH drop that allows proper fermentation to occur. They are also difficult to pack, which makes excluding oxygen from the silo very challenging. Feed value is best if harvested at R3-R4. Producers in the U.S. have had some success growing soybeans in a 50:50 mixture with grasses to increase the sugar content of the silage, which improves fermentation. Alternatively, silage corn could be chopped and layered or mixed into the beans as the silo is filled. Moisture content at harvest must be ideal for the type of silo being used and packing and sealing must be perfect to preserve soybeans as forage.
 
Read crop protection product labels carefully before use to ensure they have been tested on and determined to be safe for use on forage crops. Not all herbicides and fungicides are safe for use on crops consumed by animals, and many have not been tested for this purpose. While soybeans are commonly grown as an oilseed crop in Ontario, the management for forage soybeans is very different. Since it is so difficult to ensile soybeans, they are a high-risk forage for someone who has never made them before – it only takes a small mistake during harvest and storing to result in a rotten, inedible soybean crop when the silo is opened.
 
If energy or digestible fibre is needed:
 
Cereal silage
 
Plant in early August at 80-100 kg/ha (70-90 lbs/acre) and 2.5 cm (1 in.) depth. Apply 45-55 kg N/ha (40-50 lbs N/acre). Cereals provide options. Maximum fibre digestibility occurs before boot stage. Harvest for this as a grassy crop is typically 45-50 days after planting. Producers looking for more yield and starch content could wait until soft dough stage and ensile the crop to get something that feeds out more like corn silage than haylage. This is typically around 60 days after planting. Set cut height to 7-10 cm (3-4 in.).
 
“Annual” ryegrass
 
Both Westerwold (a true annual) and Italian (a biennial) ryegrass are commonly called “annual” ryegrass in Ontario. Plant in August at 39-45 kg/ha (35-40 lbs/acre) and 6-12 mm (0.25-0.5 in.) depth. Apply 55 kg N/ha (50 lbs N/acre). Maximum quality is before boot stage; head emerges 55-60 days after planting. Set cut height at 10 cm (4 in.). Harvest subsequent cuts on 30-day intervals. After each cut, apply 50 kg N/ha (45 lbs/acre) to improve regrowth.
 
Italian ryegrass may overwinter, so growers should have a plan to terminate this crop. Adequate nitrogen fertility and late season harvest delays dormancy and reduces winter survival. More consistent control of Italian ryegrass has been achieved in research trials by Dr. Peter Sikkema (University of Guelph, Ridgetown campus) with glyphosate applied at 1800 g ae/ha (e.g. Roundup Transorb at 1.34 L/acre). Adequate control can be achieved when lower rates of glyphosate are used (900 g ae/ha) provided it is tank-mixed with the labelled rate of group 2 corn herbicides (i.e. Accent, Option or Ultim). Tank-mixing any atrazine-based product with glyphosate will reduce control of Italian ryegrass and should be avoided.
 
If yield is needed:
 
Silage corn
 
While yield potential declines with delayed planting date, corn is still a big sub-tropical grass that has been bred to grow well in Ontario’s climate. Even if it does not reach the half- to three-quarters milk line maturity growers typically aim for, immature corn plants contain enough sugar in their leaves and stems to ferment well.
 
Warm-season annual grasses…if the summer is expected to be hot/dry
Options include: forage sorghum, sudangrass, sorghum-sudangrass (a hybrid), and any of several millet species. Normally these crops are planted in early June; but planting into moisture once soil temperatures exceed 12°C is most important for good germination.
 
Sorghums, sudangrasses, and their hybrids should be planted at 15-30 kg/ha (14-27 lbs/acre) and 2-4 cm (0.75-1.5 in.) depth. Apply 55 kg N/ha (50 lbs N/acre) up front. They have a reputation for being low-quality, but this is generally a result of using a one-cut system that delays harvest until the crop is mature; yield and quality are maximized in a two-cut system. First cut is typically 60 days after planting, but the crop must be at least 65 cm (26 in.) tall before harvesting. Set cut height to at least 10 cm (4 in.) to encourage regrowth and apply 50 kg N/ha (45 lbs/acre) after first cut. The crop is ready to be harvested again when it is over 65 cm (26 in.) tall. Quality is best before boot stage, but yield is highest when heads emerge. Growth rates will slow as the temperature drops, and warm-season annuals will be killed by frost. It is possible that only one-cut will be realized this late in the year. Be aware that these crops produce prussic acid when stressed. To reduce the risk of prussic acid poisoning in livestock:
  • Do not pasture or green chop stands less than 45–60 cm (18–24 in.) tall.
  • Do not ensile or green chop sorghum over 76 cm (30 in.) tall for 3–5 days after a killing frost. Silage should be completely fermented before feeding (6–8 weeks).
  • Immediately after a frost, remove the livestock from the pasture until it has dried out (usually 6–7 days). If new shoots develop, harvest the field as silage rather than pasture.
  • After a drought ending rain, do not graze animals on new growth.
There are several species of millet. The ones most commonly used for forage are pearl, Japanese, foxtail, and proso. Seed at 9-20 kg/ha (8-18 lbs/acre) at 6-12 mm (0.25-0.5 in.). For single-cut millets, apply 100 kg N/ha (90 lbs N/acre) up front, while two-cut crops need 50 kg N/ha (45 lbs/acre) as starter fertilizer. All types are typically ready to harvest 55-60 days after planting, with maximum quality at boot stage, and maximum yield at heads-emerged. Pearl and Japanese millets will usually regrow to enable a second cut, although growth rates will slow as the temperature drops, and warm-season annuals will be killed by frost. It is possible that only one-cut will be realized this late in the year. Cut pearl and Japanese millets at 10 cm (4 in.) height to encourage regrowth and apply 50 kg N/ha (45 lbs N/acre); the next cut will likely be 30-35 days later. Since no regrowth is expected from foxtail or proso millets, cut these at 5 cm (2 in.) height.
 
Another option with warm-season grasses is to plant in July, take the first cut as outlined above, then terminate and plant fall rye or winter triticale in August or September as a double crop. Plant at 90 kg/ha (81 lbs/acre). Apply 50-80 kg N/ha (45-72 lbs N/acre) in the spring, then harvest for silage at flag-leaf or boot stage in May. Spring seed a new perennial forage stand or silage corn after the rye is harvested.
 
“Annual” ryegrass…if the summer is expected to be cool/wet
Both Westerwold (a true annual) and Italian (a biennial) ryegrass are commonly called “annual” ryegrass in Ontario. While these grasses typically go dormant during the hot summers in Ontario, they thrive in cool conditions with frequent rainfall. Plant in August at 39-45 kg/ha (35-40 lbs/acre) and 6-12 mm (0.25-0.5 in.) depth. Apply 55 kg N/ha (50 lbs N/acre). Maximum quality is before boot stage; head emerges 55-60 days after planting. Set cut height at 10 cm (4 in.). Harvest subsequent cuts on 28-day intervals. After each cut, apply 50 kg N/ha (45 lbs/acre) to improve regrowth.
 
Italian ryegrass may overwinter, so growers should have a plan to terminate this crop. Adequate nitrogen fertility and late season harvests delay dormancy and reduce winter survival. More consistent control of Italian ryegrass has been achieved in research trials by Dr. Peter Sikkema (University of Guelph, Ridgetown campus) with glyphosate applied at 1800 g ae/ha (e.g. Roundup Transorb at 1.34 L/acre). Adequate control can be achieved when lower rates of glyphosate are used (900 g ae/ha) provided it is tank-mixed with the labelled rate of group 2 corn herbicides (i.e. Accent, Option or Ultim). Tank-mixing any atrazine-based product with glyphosate will reduce control of Italian ryegrass and should be avoided.
 
If all that is needed is a new alfalfa stand:
 
Alfalfa is auto-toxic, which means mature plants produce chemicals that prevent new alfalfa plants from establishing. Stands that were summer-seeded last year will not have this auto-toxic effect, but older stands cannot be patched with or followed by alfalfa. 
 
Since alfalfa is a perennial crop, it is vital to seed into good soil conditions that will support the crop for its lifetime over 9-12 cuts. Planting too deep, inadequate seed-to-soil contact, crusting, drowning, or dry conditions can all stress seedlings and reduce germination. These stresses reduce yield potential, life of the stand, or both. This means that producers wishing to replace winterkilled alfalfa should wait until late summer to seed or hold off until the following spring.
 
Summer-seed alfalfa mixtures before the following dates:
  • More than 3100 CHUs: August 10-20
  • 2700 to 3100 CHUs: August 1-10
  • Less than 2700 CHUs: July 20-30
Legumes seeded after early September rarely survive the winter, since the small plants are more susceptible to heaving. A nurse crop is not recommended for summer seeding, as they compete too strongly for moisture.
 
Options for grazing
 
Just about anything can be grazed. In addition to the above crops, consider adding forage brassicas (rape, kale, turnips, radishes, etc.) to a mix to increase the protein content. Seed at 2-6 kg/ha (2-5 lbs/acre) as part of a mixture. Apply 45-70 kg N/ha (40-65 lbs N/acre). The crop is ready to be grazed 10-12 weeks after seeding. Do not graze mixtures containing brassicas for more than eight weeks to avoid goitre-like symptoms in livestock. Brassica leaves do not store well; most producers do not have equipment to harvest roots for storage.
 
Crop residues can provide good grazing for mature animals with maintenance requirements. Avoid hairy vetch, buckwheat, and mustard in mixes to be grazed. These crops can be poisonous (hairy vetch and mustard) or cause skin sensitivity (buckwheat) in livestock.
 
Options for bedding
 
If straw is needed for bedding, any spring cereal can produce straw. Spring triticale or rye will produce more straw than oats while barley will produce slightly less. Spring cereals seeded this late in the season do not tiller well. Seed at 75 to 80 lbs/acre. The crop will need 30 to 50 lbs of actual nitrogen to achieve good growth.  Plan to desiccate ten days after heading to prevent grain formation and aid in baling.
 
Switchgrass is being promoted as an alternative to cereal straw. Keep in mind that this perennial crop can be productive for 20 years or more, and generally does not winterkill.
 
Source : Filed Crop News