Sowing & Growing Italian Ryegrass
Italian Ryegrass (Lolium multiflorum) is a short term species. It has a shorter persistence than perennial ryegrass, generally only lasting up to 2 years.
Italian ryegrass has been the subject of plant breeding for many years, which means there are a wide range of varieties available commercially.
When to sow: Ideal times are late March to September when there is adequate moisture for establishment. Sowing in the autumn will provide a full crop the following spring. Spring sowings can produce a lower yielding leafier crop, especially difficult for hay making.
Sowing Rates: 3.5 g/m2 - 14kg per acre - 35kg per ha.
Preparation: A non-selective herbicide should be used before seedbed preparation to create a stale seedbed and control as many weeds as possible. Good preparation of the seedbed before sowing is vital to achieve a fine tilth.
A cloddy (or lumpy) seedbed will hamper germination, so it is best to harrow or disc the soil to break it up. Once this has been done, it is important to roll the seedbed before sowing any seed. Rolling will consolidate the soil and make the seed bed firmer.
Sowing: Drill the seed at a depth of 10 - 20mm. Rolling with either a cambridge or flat roller before and after sowing is recommended. Broadcast seed should be harrowed lightly after sowing and before rolling.
Management: Cutting for silage will depend on the heading date of the plant as each ryegrass species is different in terms of its maturity. Generally, Italian ryegrass will head around the 3rd week of May. As the plant starts to mature and develop a seed head, the quality of the forage ( D-value) will decline. A D-value between 67-70 will provide good quality forage, which equates approximately to 25-50% ear emergence. When the plant is cut will depend on the type of stock the forage is to be fed to. Italian ryegrass normally provides 3 cuts on good ground and aftermath grazing. Grazing the sward in mid to late autumn is important because it stops the crop going into the colder winter temperatures in an upright leafy state, where it can be affected by hard frosts. Grazing also allows the base of the sward to be cleaned out by the livestock and fresh growth encouraged early next spring. Italian ryegrass is susceptible to a number of pests and diseases, including mildew and ryegrass mosaic virus. Modern varieties have a good disease resistance score, which can be found on the recommended list.
Italian ryegrass is very high yielding and reliably provides up to 18t DM per hectare on soils that suit it. (All ryegrasses yield less on light soils, especially in low rainfall areas.) It has a very open growth habit with fewer tillers than other grasses. It is therefore better suited to cutting than grazing.
Date Posted: 14th February 2023
