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15 Cards in this Set
- Front
- Back
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Why are grasslands important?
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Primary agricultural crop in the UK
~70% of UK is agricultural land It is a principal source of feed for herbivores. Dairy cattle: 60 – 65 % Beef cattle: 80 – 85 % Sheep: 90 – 95 % Horses: 80 – 90 % |
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What are the 2 types of Grasslands?
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Natural Grasslands = rough/hill grazing
Cultivated Grasslands 1)Permanent (permanent pasture) 2)Rotational (grass ley) |
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Describe Natural Grasslands.
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Rough grazing:
Uncultivated/unimproved includes: Mountains, hills moors Largely grazed by sheep Used for maintenance diet only Plant species include: Low quality grasses, heather, rushes and mosses Affected by soil type, topography and climate Management=Grazing, Burning Can be improved by Drainage, Fertilising, Liming and Re-seeding Some permanent pasture = improved rough grazing |
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Describe Permanent Cultivated Grasslands.
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Permanent pasture:
Improved pasture > 5 years old Maintaining without re-seeding Most abundant grassland/crop in UK (> 32%) Forms backbone of livestock industry in UK Grass more palatable and ↑ nutritive value Used sheep, beef and dairy enterprises – and for grazing horses Herbage species - diverse: ryegrasses cocksfoot Fescues Timothy meadowgrass |
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Describe Rotational Cultivated Grasslands.
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Leys:
Rotational pastures Common in mixed farms Sown every few years, usually as part of arable crop rotation Used for grazing, conservation (usually silage) or both < 5 years old, very productive Grass palatable, ↑ nutritive value Herbage – few plant species: Mainly ryegrasses or Ryegrass and legume mixes |
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What are 2 types of legumes and what are some of their general characteristics?
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Clovers:
White or red species Higher protein than grasses Higher in many minerals than grasses Present in mixed swards with grasses, esp. ryegrasses Lucerne: Very important in Europe and worldwide Grazed or conserved (not grazed in UK) Higher protein than grasses Higher in many minerals than grasses Associated problems: Bloat Phytoestrogens (red clover & lucerne) Legumes fix N into the soil |
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What are the differing characteristics of herbage?
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Herbage species:
Similar yields, but differ in: Rate of establishment Seasonality of growth Drought tolerance Ease of management Persistence Palatability Nutritive value |
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General management of grasslands involve:
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Management involves:
Fertilising (N, P, K, slurry, fym) Mechanical treatment (harrowing, rolling, topping, re-seeding) Drainage (essential for sward productiviey) Grazing (continuous, rotational, mixed/alternate, integrated conservation &grazing, zero grazing, Conserving |
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Describe the various grazing stratagies.
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Continuous:
Uncontrolled grazing of pastures Variable or set stocking rate Often grazed for whole grazing season – or year round Rotational grazing: Areas sub-divided into series of paddocks/fields Grazed in sequence (often a 21 day rotation) Grazing followed by a period of rest e.g. 4 paddocks Each grazed for 1 week, with a 3 week rest period Variant: strip grazing – using electric fences Mixed or alternate: Commonly used – simple Mixing animal species Or alternating animal species Exploits different grazing behaviour of animals Cattle graze taller herbage Sheep prefer shorter herbage – graze closer to dung Dilutes parasite infestation Integrating conservation with grazing: Conservation rests field from livestock/exploits patterns of grass growth Grazed in sequence (often a 21 day rotation) Common in 1-2-3 (⅓:⅔ system) Aftermath grazing Zero grazing: Grass cut and fed to housed animals Very high capital costs |
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Factors affecting growth/productivity
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Environment:
Season: ↓ growth below 5 oC April to June Climate, topography, soil type Light, temperature, water ↑ productivity in warm, wet conditions Nutrient supply: Fertiliser N fixing plant species Soil pH Other factors: Grass species Sward damage |
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Factors affecting nutritive value
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Dependent on:
Stage of growth: Most important factor in nutritive value of grass Plant species Soil type Grass responds well to soil with ↑ fertility Soil type can limit plant growth and nutrient content Environmental conditions Temperature Light Rainfall |
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Factors affecting growth/productivity
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Season:
Early summer: ↑ grass growth Nutritive value: Not just production/growth Correct nutritive value Dairy = young, ↑ nutritive value Beef = more mature grass Sheep = short grass length Horses = lower nutritive value |
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When is grass growth typically most productive
in the UK? |
April - June
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What is the single most important factor that
Determines the nutritive value of grass? |
Stage of growth
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Why does nutritive value of grass ↓ with
growth? |
Contains more lignin
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