Leaving Certificate Agricultural Science Grassland Part 1

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.

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.

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.

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.

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.

Grassland Distribution - 2 Category of Grassland Area (Ha, millions) % of Agricultural Land Mountain / Hill Grazing 1.04 18.2 Permanent Grassland 2.93 51.3 Leys 1.24 21.7

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.

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.