Perennial ryegrass is the most widely used forage grass in the world. It is adapted to the temperate areas of the world and recognized, except in the USA, as the premier forage for pasture, hay, and silage. Because of its high digestibility and acceptance by livestock, ryegrass is unequaled. It makes the most milk, meat, or digestible fiber.
Why isn’t perennial ryegrass more popular in the USA? There are many reasons, and ignorance is certainly one of them. There are also many areas in the USA that are cursed with very cold, open winters like eastern Montana, North Dakota and Northern Wisconsin and Minnesota, or the humid, hot summers of the South and the south part of the midwest where perennial ryegrass just won’t persist. Ryegrass requires moisture and high fertility. Generally it does well in temperate areas with good rainfall and in hot areas under irrigation with nights that cool off. Of all the perennial cool season grasses, ryegrass is the least winter hardy so survival can be risky in those areas with cold winters with no snow cover. We have learned a great deal about winter hardiness and some of the new Barenbrug varieties, especially Mara and Remington are proving to be much more winter hardy. These cold tolerant varieties are prime ingredients in Barenbrug’s popular species mixtures along with of winter hardy orchardgrass, tall fescue and meadow fescue. (Dairymaster, Beefmaster)
Perennial ryegrass does require management. It is not a lazy man’s grass. It is designed for production agriculture. To maximize, you have to stay on top of it. It grows very rapidly and the trick is to keep it vegetative, which means less than 10 inches in height for silage and hay and at 6 inches for grazing. At 10 inches it is 8 inches of leaf and 2 inches stem. Any taller just means longer stem, which is fibrous, waxy and hard to dry, and of little value. As a rule of thumb, start at 6 inches height when grazing, taking it down to a minimum of 3 inches residual. The old rule, “take half, leave half” applies as the grass needs a good residual so it can rapidly regrow back to the optimum nutritive value 6 inch height. For silage and hay, cut when the ryegrass is no taller than 1 foot.
Ryegrass is a vigorous starter, therefore very easy to plant. It seems to jump out of the ground, often germinating in 7 days, and ready to harvest eight weeks later. Ryegrass is extremely competitive and will make a place for itself. It takes just minimum tillage to establish. Also, it no-tills the best of all grasses. This feature allows easy introduction into other grasses. A good combination for hay and silage is a Barenbrug tall fescue base established first with perennial ryegrass introduced later using no-till. Use only low rates of ryegrass if ryegrass is seeded with other forage grasses due to the risk that it will out compete the other grasses. Five pounds along with 25-30 pounds of tall fescue is just right.
There are two genetic types of perennial ryegrass: diploids and tetraploids. Diploid is ryegrass as Mother Nature created it, whereas tetraploids are man made manipulations developed by the Dutch breeders. Each type has a specific purpose. Diploids are used mainly for permanent pastures. They tiller more, making very solid, durable, and long lasting pastures. They have higher dry matter content. The tetraploids were originally developed in Holland for use in short term pastures, called leys. These are often machine harvested for silage, green chop, or hay. Tetraploids have larger cells thus lower dry matter content making them lusher, somewhat sweeter, therefore a bit more palatable. On the negative side, tetraploids don’t tiller as well, so the stands are more open than a diploid pasture. This factor, along with their having a higher crown, makes them less hardy under a grazing regime. Machine traffic can also inflict damage that has led to the greater use of diploid-tetraploid blends in an attempt to toughen the stand. Also, tetraploids do require higher fertility and moisture than diploids making them more susceptible to stress if these components are deficient. They are generally shorter lived. This lack of persistence is changing as the new, genetically improved varieties developed by Barenbrug have been selected for persistence, making them very suitable for pasture. The variety Remington is an example. On dairies, with finicky and high producing milk cows, the use of diploid/tetraploid blends is proving to boost production.
Barenbrug’s perennial ryegrass offerings are classified as early, intermediate, or late maturity, and by pasture or hay type, and whether diploid or tetraploid. Maturity denotes when the grass achieves 50% heading in the spring. Generally,the early varieties are 50% mature about mid-May, the late varieties by late-June, and the intermediate types somewhere in the middle. Most New Zealand origin varieties are bred to be early maturing and winter active, as that country has short, mild winters like our coastal WA and OR. They want and need winter growth. European origin varieties cover the full maturity range, with the intermediate and late maturing the most popular. Farmers from northern, continental Europe prefer late varieties as they are the most fall dormant and winter hardy. The winters there come quickly, can be severe and are often followed by wet springs that do not allow early traffic on fields. This is similar to northern USA. Farmers in Ireland and Great Britain tend to use more intermediate varieties which mature earlier as they have milder winters and earlier springs, much like middle America.
Winter hardiness is linked to fall dormancy and the country of germplasm origin, but not maturity. The level of dormancy (think of dormancy as growth shutdown and going to sleep) is bred into the plant by breeders in the country of origin based on the degree of hardiness needed for survival. A winter hardy variety stops growing and goes sound asleep in the autumn earlier than less hardy varieties, but continues photosynthesis that builds sugars which act as antifreeze in the plant cells. They will not awaken and grow again until spring, with the early maturity varieties being the first ones to awaken and commence growth. The lesser the degree of fall dormancy the lesser the winter hardiness, but the greater the winter production. The New Zealand origin varieties are the most winter active, with some varieties never going dormant. If they do go dormant they easily awaken and grow during a winter warm spell. If a cold snap follows then these varieties can winter kill. At the opposite end, European origin varieties especially those based on germplasm from Romania, are bred to be sound asleep during the winter which keeps them protected. Of course, continual snow cover further protects and enhances survival. For these reasons our European bred perennial ryegrasses are surviving the cold winters of New York, Michigan, and other northern areas.
Steps can be taken to enhance winter survival of ryegrass in the colder regions. Most important is to remove stock and cease grazing in the late fall, giving the grass a chance to grow about 2” beyond its residual height of 3”, to about 5”, before real cold weather arrives. This does two things. First it replenishes the root system giving the plant the strength to survive and regrow in the spring. Second, the 5” height is ideal for capturing snow and providing perfect insulation for the plant. Additionally, late fall nitrogen should not be applied as the result of accelerating growth can make the plant very vulnerable to winter kill. Good soil drainage is also important for winter survival. Standing water will drown out ryegrass or weaken it, making it more susceptible to cold, freezing weather killing it.
This concept would be considered heresy a short time ago and probably will still be considered so by many dyed in the wool purists. We are now finding that combinations of different varieties of diploid perennial ryegrasses along with genetically modern tetraploids gives great strength to a pasture stand. Differences in maturity should be considered, pairing like maturities or pair early and intermediates or intermediates and lates in combination only. Using combinations increases the probability that one or more of the varieties will be growing at full strength at all times during the growing season. This combination of varieties appears to perform synergistically causing the sum of the whole to far exceed the combination of the individual parts. Of course some thought must be given to the ingredients, the main criteria being winter hardiness. Farmers in mild winter areas have the latitude to use the full range of New Zealand, British/Irish, and Holland origin grasses. Those in areas with cold winters should use the grasses bred in continental Europe. In recent years the benefit of combinations versus the traditional single variety planting has been evidenced. After three years as seen on one farm, the weakness of the single variety plantings had permitted the white clover to gain the upper hand. It encroached from the desired level of 25% to an undesirable level of over 50%, while the strength of the combined variety pastures held the clover at bay at the 25% level. Also, results from an on-farm grazing trial put the combinations way ahead in production. (Source: Edgar Smith, Beaver Meadows Farm, Comox, BC, Canada; a 300 cow grass based, grazing dairy.)
Since introduction, Barenbrug’s BG perennial ryegrass variety combinations (e.g.: BG-14, BG-23T, BG-34) all scientifically formulated have led to greater stand longevity and increased performance.
Suggested Barenbrug Perennial Ryegrass Varieties:
D= Diploid, T=Tetraploid
D= BAR 1M, Mara, Barsprinter, Barnhem
T= Bargala, Remington
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