Pastures: Annual Pastures
Excerpt from Publication 19, Pasture Production, Order this publication
Table of Contents
Annual crops can be part of a planned pasture program or an emergency remedy in years when the regular pastures have been winterkilled or are suffering from drought. Table 1-2, Annual Forages Fill the Pasture Season, shows the role that annuals can play in filling the pasture season. While annual crops offer flexibility in pasture programs, their advantages must be weighed against the cost of reseeding each year. For supplementing pastures in the summertime, consider grazing hay aftermath (second growth) or feeding hay
*oats can be seeded throughout the season to provide grazing
6 weeks later
Cereals are annual grasses and are a good choice when extra pasture is needed quickly. Any of the cereals, when grazed early enough (when vegetative), will show some regrowth. In the vegetative stage they are a good source of protein but have very low dry matter and fibre content. Provide dry hay as animals cannot obtain enough energy or fibre from grazing young cereals alone. If you want to avoid having to supplement with hay, delay grazing until the cereals have formed stems.
Cereals tend to be nitrate accumulators. If large amounts of nitrogen fertilizer are applied during cool growing conditions or cloudy periods, the plants may accumulate toxic levels of nitrates. To prevent this, limit nitrogen applications to 30-50 kg of nitrogen/ha. Cereals produce the maximum amount of forage when seeded and fertilized for good grain yields. See Publication 811, Agronomy Guide for Field Crops.
Cereals differ in productivity, palatability and feed value. Oats are more palatable than wheat, barley and rye. Considering everything, oats are the preferred spring cereal for grazing.
Oats are ready to be pastured 6-8 weeks after being seeded, and can be seeded anytime from spring to fall. Early spring seedings can be cut for hay and the aftermath grazed until fall. Seed at 80-100 kg/ha.
Oats grown as a companion to an establishing forage crop can also provide an additional source of early summer pasture. Seed the oats at a low rate, 30-40 kg/ha, and graze when 20 cm tall. This not only provides good pasture, but also helps the establishing forage crop by eliminating competition from the oat crop. This allows the young forage plants to grow more vigorously and consequently establish a thicker, higher yielding stand.
Do not allow animals to graze young forage plants. Remove them from the field as soon as they have grazed off the oats.
Fall rye is a versatile pasture crop. It can be grazed in the fall and, if seeded before mid-August, the following spring as well. The fall growth can be grazed until snow cover is too deep for the animals to dig through. If seeded on land that dries quickly, fall rye can provide very early spring pasture. The land must be firm enough in the spring to carry the livestock.
Fertilize rye that is to be grazed in the spring with 50- 80 kg of nitrogen/ha just when the rye starts to turn green. Rye that is grazed early, and has the animals taken off before it starts to mature, can still produce a grain crop if growing conditions are good. This crop matures extremely rapidly after mid-May. Pay careful attention to the stage the crop is in. Seed at 150 kg/ha and fertilize to soil test recommendations.
Winter triticale is a cross between wheat and rye that provides early spring grazing. It can be grown on a variety of soil types, but like fall rye, should not be sown on poorly drained soils. Seed early enough in the fall to provide time for the crop to establish itself. The date of seeding differs with location. Refer to OMAF Publication 811, Agronomy Guide for Field Crops and use the seeding dates suggested for winter wheat. Seed winter triticale at a rate to of 100-125 kg/ha. In the spring, as the triticale is starting to turn green, fertilize with 80 kg of nitrogen/ ha.
Annual ryegrasses produce top quality forage. There are 2 types of annual ryegrass available - Italian and Westerwold. The Italian type is really a biennial, but so seldom survives the winter that it is regarded as an annual. Italian ryegrasses are leafy, short growing (up to 40 cm) and in the seeding year do not come into head. These factors make Italian ryegrass an ideal pasture crop but an extremely difficult one to mechanically harvest.
Westerwold annual ryegrasses grow taller (40-80 cm), have more stems and will head out if left to mature. Graze or cut Westerwold ryegrasses before they head out to maintain high productivity and feed quality.
For maximum yields and quality, annual ryegrasses require top management. Yields range from 8-12 tonnes of dry matter per hectare when there is adequate rainfall. But its need for a constant water supply limits its use in Ontario. The shallow root system of annual ryegrass makes it ill-equipped to access water reserves when rainfall is scarce. During periods of little or no rain the plants stop growing and may die.
Seed annual ryegrass in early spring, using a cultipacker-type seeder. Use 20-25 kg of seed/ha. Roll the seedbed well to ensure good seedling emergence. High soil fertility levels are needed to support the rapid, high production of forage. Use a soil test to determine the phosphorous and potassium requirements, and apply high rates of nitrogen in split (at least 3) applications. Ryegrass will be ready 6 weeks after seeding and, if enough moisture is available, will remain productive until late fall.
Sorghum-sudan grass hybrids can be used for pasture as well as for stored feed. When pastured, start grazing after the plants have reached a minimum height of 75 cm. This will maintain productivity and eliminate the danger of prussic acid poisoning. All members of the sorghum family contain dhurrin, a glucocide that breaks down to release prussic acid poisoning (also called hydrocyanic acid). Normally the amount is not enough to cause problems. However young plants, plants suffering from drought, or plants that have been frosted, contain a much higher level of prussic acid than normal. Do not graze when it is recovering from drought stress. Wait until the frosted plants have dried out completely.
Never allow horses to graze sorghum-sudan grass hybrids. Horses may develop cystitis, a potentially fatal urinary tract infection. Cystitis looks like colic, with blood in the urine.
Once they have reached a height of 90 cm, sorghum-sudan grasses grow very rapidly. Good management is necessary to keep ahead of the growth. Successive plantings, strip grazing, or mechanical harvesting may be required to avoid oversupplies of overly mature forage. Strip grazing is the best approach to pasture management, as it reduces trampling losses.
Plant sorghum-sudan grasses during the last part of May or early June at 14-20 kg/ha. Use the lower rate when seeding in 18 cm or 36 cm drill rows. The higher rate is for broadcast plantings. Fertility requirements are similar to corn.
Forage brassicas can provide good pastures from September to December. Forage rape, kale and stubble turnips are the 3 brassicas most commonly used for pasture. They produce up to 12 t/ha of high quality dry matter for fall grazing. Forage rape and kale are preferred by cattle and sheep.
Seed the brassicas in well-drained fields with a pH of at least 6 and adequate fertility. Crops planted on poorly drained soils do not do well and grazing losses are high. All 3 species are small-seeded and produce maximum yields when precision drilled into rows no more than 1.5 cm. deep. However, good stands can be established by broadcast seeding.
Plant all 3 brassicas in summer. They germinate and then not grow very much during hot dry weather. Once day and night temperatures cool, and more rain falls, they grow quickly. Seeding dates are important for all 3 of these brassicas as delays past the recommended dates causes large declines in yields.
Strip graze brassicas to avoid excessive wastage. Brassicas have a high moisture content, 85%-89%. To ensure enough fibre in their diet, either feed your animals hay or give them access to permanent grass/legume pastures.
If not well managed, all of the brassicas can cause animal health problems. Refer to Chapter 7, Animal Health Disorders.
Kale, also called marrow stem kale, has a short (75 cm- 1.5 m) upright growth habit with highly digestible leaves and stems. It is frost-hardy and will continue to provide fresh forage after snowfall. Its crude protein level (on a dry matter basis) ranges from 19% in September to 15% in late fall.
Seed kale in early June. Kale grows slowly after seeding so good weed control is essential during the early growing season. The best yields are obtained when kale is drilled in rows 15-70 cm wide at a rate of 2-4 kg/ha. Do not plant kale seed deeper than 1.5 cm deep. Kale can be broadcast seeded at an increased seeding rate of 6 kg/ha. It requires approximately 80-120 kg of nitrogen/ha and grows well if manure is used.
Two main types of forage rape are used for pasture. The broadleaf or giant types are leafy and upright growing and are best pastured by cattle or sheep. Dwarf types are shorter and branching, and may be used for fattening lambs. Do not confuse forage rape with oilseed rape or canola.
Seed rape in early July for grazing from September to November. For maximum yields, drill rape in 50-70 cm rows at 2 kg/ha. Rape can be broadcast seeded at 6 kg/ha but yield will be lower. Rape requires 80-100 kg nitrogen/ha.
Rape poisoning can occur if stunted, low growing, purple coloured plants are pastured.
These crops occur more frequently in wet years, on poorly drained land and when inadequate fertilizer is used. Early frost may aggravate this condition on wet, poorly drained fields.
Cattle can bloat on rape.
When cattle are grazing rape, always have dry feed present to prevent cattle from eating large quantities of rape at any one time. Make sure cattle are full before putting them out to graze rape the first time.
Forage turnips, also called stubble turnips, fall turnips, white turnips, or Dutch turnips, produce a thick mass of bushy tops and large white roots. The animals will first graze the tops off the turnips and then graze the area a second time, feeding on the roots. The roots are high enough out of the ground that animals find them easy to get a hold of. Strip grazing is recommended to make best use of this crop. Plant turnips the same way as rape and fertilize with 100 kg nitrogen/ha. Despite the fact that animals can use both roots and tops, turnips are still lower yielding than rape or kale crops.
... on forages and pastures, visit Forages
and Pastures (OMAFRA)
For more information:
Toll Free: 1-877-424-1300