Leaving Certificate Agricultural Science

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Leaving Certificate Agricultural Science
Grassland Part 2- SPECIES
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Learning Outcomes

• Grass species
• Merits of Grass

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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

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Important Grassland Species - 2

• Permanent Grassland
• Bent Grasses
• Fescues
• Meadow Grasses
• Cocksfoot
• Meadow Fescue
• Timothy
• Perennial Ryegrass
• White Clover

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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.

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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.

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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.

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

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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.