Leaving Certificate Agricultural Science

1. Leaving Certificate Agricultural Science Grassland Part 1

2. Learning Outcomes • Categories of grassland found in Ireland. • Grass species found in these grasslands. • Grassland Ecology.

3. Introduction • Grassland occupies 70% of the world’s agricultural land, making it the world’s most important crop. • In Ireland, grass provides 70 – 80% of our cattle’s feed requirements and over 90% of our sheep’s. • Approximately 90% of the farmed land area in the country is devoted to grassland and is the primary resource for almost all of our agricultural output.

4. Categories of Grassland • There are three main categories of grassland. Rough Mountain and Hill Grazing: • More appropriately called grazing than grassland as most of the land is taken up with heather, gorse, bracken and scrub rather than grasses. • It is characterised by large range in composition, low stocking rates and low production. • The land is usually acidic or peaty and generally stony. • It can therefore be very difficult or impossible to cultivate.

6. Categories of Grassland - 2 Permanent Grassland • This is grassland that is never ploughed. • It is different from Hill Grazing because it is dominated by perennial grasses and scrub, and trees are rare. • It again displays a large range in botanical composition from highly productive grasses to clover to highly unproductive weeds. • Generally permanent grassland is more productive than mountain and hill grazing areas and is also more highly stocked.

8. Categories of Grassland Leys • These are short term areas of grassland, sown by the farmers which display the following characteristics: • Little variability in botanical composition • High stocking rates • High levels of production. • Leys are associated with good farm practices and high levels of management and are re-sown and re-seeded regularly.

10. Grassland Distribution • Grass dominates most of the land in nearly all the counties in Ireland. • In Munster, Ulster and Connacht it can be up to 90% of all agricultural land. • In the south – east it is only about 75%. Why? • The following table shows the relative amounts of grassland in Ireland.

11. Grassland Distribution - 2

12. Grassland Ecology • The natural vegetation in Ireland is deciduous forest. • This basically means that if all agricultural and industrial activity stopped, the land would eventually return to forest. • The stages of progression are as follows: • Bare Soil • Grasses • Shrubs (Bramble, hawthorn and Blackthorn) • Forest species like Oak, Ash, Birch and other trees which eliminate shrubs by their shading effect.

13. Grassland Ecology - 2 • Intensive grazing prevents this series of activities to take place. • This is because grass species can regenerate from points below the grazing level. • If grazing was reduced or stopped, shrubs would take over and then eventually trees. • This is important as the farmer must manage his / her grassland so as to ensure that unwanted shrubs don’t take over the area.