Grassland – Part 2- SPECIES

 Grass species  Merits of Grass

 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*

Permanent Grassland:  Bent Grasses*  Fescues*  Meadow Grasses*  Cocksfoot*  Meadow Fescue*  Timothy*  Perennial Ryegrass***  White Clover**

Leys:  Cocksfoot*  Timothy*  Perennial Ryegrass***  Short Duration Ryegrasses***  White Clover**  Red Clover**  The asterisks determine the palatability and productivity of the species.

 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.  Productivity refers 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.

 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%.

TypeProductivityPalatabilityDigestibilityPersistence PRGVery IRGBienniel TimothyPoor CocksfootGood Meadow Fescue Poor Meadow Grass  Meadow Foxtail  Bent

 Perennial Ryegrass is a persistent, aggressive, dominant grass.  It will take over a sward if: 1.Fertility Levels are high 2.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.

 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.

 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.

 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

 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.

 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.