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Leaving Certificate Agricultural Science

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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 ... – PowerPoint PPT presentation

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Title: 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
  • Sheeps 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.
  • 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.

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
    grasss year also.
  • Before flowering the DMD may be 80 90, and
    after flowering as little as 50.

8
Type Productivity Palatability Digestibility Persistence
PRG ??? ??? ??? Very
IRG ???? ??? ??? Bienniel
Timothy ?? ??? ?? Poor
Cocksfoot ?? ?? ?? Good
Meadow Fescue ? ??? ? Poor
Meadow Grass ? ? ? Poor
Meadow Foxtail ? ? ? Poor
Bent ? ? ?? Poor
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.

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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.

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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.

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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

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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
    cant 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.
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