Leaving Certificate Agricultural Science

1. Leaving Certificate Agricultural Science Grassland – Part 2- SPECIES

2. Learning Outcomes • Grass species • Merits of Grass

3. Important Grassland Species • Between 200 and 300 species of grass exist in Ireland but only a small number are of any real importance to the farmer. • Some of the common species found in the different types of grassland are shown below: Hill and Mountain Grazing: • Heathers • Purple Moor grass • Bent Grasses* • Sheep’s Fescue* • Creeping Red Fescue* • Meadow Grasses*

4. Important Grassland Species - 2 Permanent Grassland: • Bent Grasses* • Fescues* • Meadow Grasses* • Cocksfoot* • Meadow Fescue* • Timothy* • Perennial Ryegrass*** • White Clover**

5. Important Grassland Species - 3 Leys: • Cocksfoot* • Timothy* • Perennial Ryegrass*** • Short Duration Ryegrasses*** • White Clover** • Red Clover** • The asterisks determine the palatability and productivity of the species.

6. Grass Rating • Grassland in Ireland is used solely for feeding livestock. • Therefore the agricultural importance of any grassland is measured in three ways: Productivity, Palatability and Digestibility. • Productivityrefers to the ability of a grass to produce large amount of herbage. • It also refers to the ability to respond to a fertiliser. • Perennial ryegrass has the highest productivity while mat grasses have low productivity. • Palatability refers to taste etc, in other words how appealing the grass is! • Sheep and cattle are selective eaters and will only eat the most palatable grass.

7. Grass Rating - 2 • Therefore the sward should be made up of appealing varieties. • PRG and IRG are the most palatable grasses followed by cocksfoot. • Digestibility is a rating of the ability of an animal to digest a certain feed. • It is measured in terms of DMD (Dry Matter Digestibility) – how much of the dry matter the animal can digest. • Digestibility of grass varies throughout the grass’s year also. • Before flowering the DMD may be 80 – 90%, and after flowering as little as 50%.

9. Perennial Ryegrass • Perennial Ryegrass is a persistent, aggressive, dominant grass. • It will take over a sward if: • Fertility Levels are high • Grazing is extensive • It is the most palatable, most digestible and most productive of the grass varieties. • It is ideal for grazing and for silage. • Makes up to 85% of the total grass seed sold each year to Irish Farmers. • It has a shiny dark green colour, which gives the sward a glistening sheen.

11. Italian Ryegrass • Similar in appearance to perennial ryegrass but has awned seeds • A more erect growth habit and less aggressive growth pattern. • It is however the highest producing grass, nearly 20% more than perennial in the first year. • In subsequent years it begins to die back. • It is a biennial. • It is ideal for early grazing or 3-4 cuts of silage.

13. Clover • Clovers are legumes which mean that they can fix Nitrogen. • This generally means that they can change atmospheric Nitrogen into forms that the soils can absorb and use. • Very high in protein. • Therefore they are of huge importance to the farmer and they improve the quality of the sward and soil. • However they can have a negative reaction to artificial fertilisers that contain Nitrogen. • They also have deep roots and spread throughout the soil by stolons, which then inhibit weed growth.

15. Other Important Grass Species • While Perennial ryegrass, Italian ryegrass and clovers supersede all other grass species in seed sales each year, there are other important species. • These include: Timothy, Cocksfoot, Meadow Fescue and Meadow Grasses. • These were traditionally used many years ago but are still very important in permanent grasslands. • Farmers should be able to recognise them and encourage their growth. • Use your book for more detail on these varieties. • Below are the inflorescence of a) Timothy, b) Meadow Fescue, c) Cocksfoot and d) Meadow Grass

20. Seed Mixtures • Seed mixtures are very different for grassland as opposed to silage. • In previous years it was usual practice to sow a number of different varieties as to have a uniform grass growth throughout the year. • This has changed over the last number of years, towards mainly ryegrasses and clovers. • This is mainly due to the emergence of new strains of perennial ryegrass, which have different peak growth times. • Now seed mixtures for grazing have different strains of PRG, which have a range of heading dates.

21. Seed Mixtures - 2 • This gives the following advantages: • Encourages uniform growth patterns • Ensures there is always young, leafy digestible grass available as feed. • Makes grazing management easier – all the grass can’t go “stemmy” at the same time. • For silage or hay, seed mixtures contain either strains with the same heading dates or seeds from the same strain only. • This is to ensure that the entire sward comes to a head at the same time. • This gives a sward that is all at the height of its digestibility when cut.