2. SOILS AND TOPOGRAPHY
Soils
Topography

3. CLIMATE AND AGRO-ECOLOGICAL ZONES
Climate

4. RUMINANT LIVESTOCK PRODUCTION SYSTEMS
Dairy cow production
Beef production
Sheep production
Organic production systems

5. THE PASTURE RESOURCE
Botanical composition
Productivity
Grazing management
Fertilizer use
Reseeding
Clover in pastures
Provision of winter feed

6. OPPORTUNITIES FOR IMPROVEMENT OF PASTURE RESOURCES

7. RESEARCH AND DEVELOPMENT ORGANIZATIONS AND PERSONNEL

8. REFERENCES

9. CONTACTS

1. INTRODUCTION
The Republic of Ireland, which occupies the southern part of the island of Ireland, is located to the west of Europe’s land mass, between 51.43 and 55.38 degrees north and 5.43 and 10.51 degrees west. It has a land area of 70 280 km²: approximately five sixths of the island of Ireland which is 84 412 km² (see Figure 1a). For administrative purposes, the Republic is divided into 26 counties (see Figure 1b).

Figure 1a: Map of Ireland Source: The World Factbook

The population in 2006 was 4 239 848 according to a census taken that year (CSO, 2007 Volume 1), while the World Factbook estimates the July 2008 population at 4 156 119 with a growth rate of 1.133%. After a long decline from a population of over 6 500 000 in 1841 to a nadir of 2 820 000 in the census of 1961 (initiated by the disastrous potato blight-induced famines of 1845-1847 followed by emigration due to poor economic circumstances), the population has been rising, particularly since the 1996 census. This rise has been due to strong economic growth, which has resulted in many emigrants returning to, and in more recent years, many immigrants, mainly from Eastern European countries of the EU.

Figure 1b: Political Map of Ireland [Click to view full map]

The percentage of the population living in rural areas was 39.3% in 2006 (CSO, 2007, Volume 1), but this varied from 24.8% in the east of the country (the province of Leinster which includes Dublin, the largest city and the capital of the country), to 74% in the three northern counties of Donegal, Cavan and Monaghan (the three counties of the province of Ulster which are in the Republic of Ireland). The percentage of the population in the south of the country (the province of Munster) living in rural areas was 48.2%, while it was 65.9% in the west of Ireland (the province of Connacht). A total of 1 187 000 people live in Dublin, and 41.8% of the total population resides in Dublin and the surrounding counties of Louth, Meath, Kildare and Wicklow.

Of the total labour force in 2006, 4.19% was engaged in farming, fisheries or forestry (CSO, 2007 Volume 8), with the vast majority of these in farming (3 293 people engaged in fisheries and forestry). The proportion of the total workforce involved in farming has been declining over a long period. In the 2002 census, the percentage involved in farming, fisheries and forestry was 5.35%. The drop in the percentage working in the sector between 2002 and 2006 is due to a decline in the total number of workers in the sector (from 96 279 to 88 414) and to a substantial increase in the total labour force (up by 17% in this period, due mainly to strong immigration). The agricultural labour force is older than the norm. Of the people involved in farming, fisheries and forestry in the 2006 census, 34.3% were aged 55 or over, compared to 12.5% in the full labour force. On the other hand, just 3.7% of the people working in farming, fisheries and forestry were aged between 20 and 24, where for the full labour force, the equivalent figure was 11.2%.

Land area, arable and pastoral areas. Agricultural land is approximately 61 percent of the total land mass of the Republic. This is predominantly in grassland with over 90 percent of the agricultural area consisting of pasture, grass silage or hay, and rough grazing (Table 1). Land used for grass silage or hay revert to grazed pasture after the crop is cut in mid-season, although on some silage ground, a second and even a third cut is taken (see section on Provision of Winter Feed). The arable area consists mainly of barley and wheat with smaller areas of oats, potatoes, beet (since 2005, sugar beet processing has ceased in Ireland) and other crops. Crop yields are generally high. For instance, average yield of winter wheat is up to 10 tonnes/ha (Table 2).

The ruminant sector. Dairy and beef cattle production dominates agriculture in Ireland. The cattle herd is approximately seven million (Table 3) and has remained fairly stable over the years. This can be partly attributed to the support mechanisms of the European Union (EU) - e.g. milk quota, suckler cow and steer/bull premia - which have capped milk production and encouraged the maintenance of the beef cow herd. The cattle herd is spread fairly evenly throughout the country. The sheep flock has declined substantially in recent years due to low profitability. It is concentrated in the west, north-west and south-east. In the non-ruminant sector, pig and poultry numbers have been relatively stable over the years. Numbers of horses, ponies, goats and deer are few.

The cattle herd is based on a breeding herd of just over two million cows, evenly divided between beef and dairy breeds (Table 4). Dairy cows are concentrated in the south of the country (south east and south west); sucklers are concentrated in the west and north west. Dairy cows are almost all Friesian or Holstein-Friesian (96% in 2006, DAFF, 2007). The breed of bull used on dairy cows is shown in Figure 2. About half are put in calf to a Friesian/Holstein bull to provide replacement dairy heifers; most of the rest are put in calf to a beef breed bull because these calves are more valuable for beef production. The beef cow herd has a greater variety of breeds, most of which are crossbred. Many of these crossbreds have some Friesian/Holstein genes, resulting from a beef breed bull mated to a dairy cow (e.g. Limousin x Friesian), or a beef breed bull mated to an F₁ crossbred (Limousin x (Limousin x Friesian)). They are usually classified by the breed representing the greatest percentage of their genes, and the main breeds of beef cows on this basis are shown in Figure 3. The breed of bull used on beef cows is shown in Figure 4.

Figure 2. Breed of sire of calves born to dairy cows in 2006 in the Republic of Ireland (Fr = Friesian, AA = Aberdeen Angus, HE = Hereford, LM = Limousin, BB = Belgium, Blue, CH = Charolais) Source DAFF, 2007

Figure 3. Breed composition of beef cows in Ireland in 2006 (LM = Limousin, CH = Charolais, SI = Simmental, HE = Hereford, AA = Aberdeen Angus, BB = Belgium Blue, SH = Shorthorn) Source: DAFF, 2007

Figure 4. Breed of sire of calves born to beef cows in 2006 in the Republic of Ireland (CH = Charolais, LM = Limousin, AA = Aberdeen Angus, SI = Simmental, HE = Hereford, BB = Belgium Blue) Source: DAFF, 2007

Ireland is the fifth largest sheep producer in the EU and is the largest net exporter. However, after rapid growth in breeding ewes from fewer than two million in 1980 to a peak of almost five million in 1992, there has been a steady decline and the breeding ewe flock stands at three million in 2007 (Figure 5). This decline has accelerated in recent years as EU payments were decoupled from production, and profitability declined. In 2006 there were 35 277 sheep flocks with an average flock size of 102.

Sheep production in Ireland can be classified into hill or lowland. The lowland sector accounts for 75% of the ewes and 85% of the output. Lowland sheep production is predominantly grass based, with most ewes lambing in the spring and most lambs sold for slaughter before the end of the grazing season. In most hill sheep systems, lambs are sold at weaning for finishing in the lowland sector. Often, ewe lambs from the hill sheep are used for breeding in the lowland sector.

All sheep are meat breeds, with none bred specifically for wool production; very few sheep are milked in Ireland. The main lowland breeds are Suffolk, Cheviot, Texel, Galway (native Irish breed) and the Belclare, an Irish breed developed by An Foras Taluntais, the State Agricultural Research Institute, now part of Teagasc (see section 8). The main hill breeds are the Blackface Mountain and the Cheviot.

Total production of milk, beef and sheepmeat in Ireland is shown in Figures 6 and 7. Production has been fairly constant in the recent past, due to EU milk quotas restricting production and EU supports for beef production which were based on a headage system until recently which effectively fixed the size of the beef cow herd. Approximately 90 percent of beef and dairy production is exported, while the percentage of sheepmeat which is exported has risen to 80 percent in recent years. Currently the main markets for beef are the United Kingdom and the rest of the EU. There are some live exports that take place: in 2006, 250 000 cattle were exported live (out of total disposals of approximately two million head). Approximately a quarter of these were young (less than 6 weeks old) calves from the dairy herd and a third were weanlings (typically 7 - 9 month old) from the beef cow herd. France is the main market for Irish lamb (taking 70 percent of exports) while dairy products (mainly butter, skim milk powder, and cheese) are exported worldwide.

Figure 5. Number of breeding ewes in Ireland Source: Central Statistics Office, www.cso.ie

Figure 6. Intake of milk by milk processors in Ireland Source: Central Statistics Office, www.cso.ie

Average farm size was 36 ha in 2002, with over 136 000 farms. Their distribution by farm size is shown in Figure 8. Most land in Ireland is owner occupied. However, 42% of farmers held off-farm jobs in 2006, with the highest percentages on cattle farms, and the lowest on dairy farms. The dairy industry has a mixture of farmer owned and controlled co-operatives and publicly quoted milk processors (with substantial farmer shareholdings). The meat processing sector is mainly controlled by a number of privately owned companies, with a significant number of small abattoirs which mainly supply the domestic market. Farm profitability is a big issue facing the sector, particularly the beef and sheep sectors. This is reducing the number of people who want to enter farming, and leading to the age profile described above.

Figure 7. Total slaughtering of beef and veal and sheepmeat in Ireland Source: Central Statistics Office, www.cso.ie

Figure 8. Number of farms in various size categories in 2002. Source: Central Statistics Office, www.cso.ie

Soils:
In Ireland, the principal soil forming factors are parent material, climate and the rate of decay of organic material. Most Irish soils originate from glacial drift, predominantly calcareous in nature. Histosols and Gleysols predominate in the north with Cambisols on lower ground and Luvisols in central parts. Podzols are extensive in the mountainous regions, particularly in the south. Blanket and Basin peat accumulation is very important throughout western southern Ireland. In contrast with the blanket histosols which developed in the west due to high rainfall or where the sub-soil is sufficiently impermeable to give a high water table, the raised histosols and fens developed in the midlands in lake basins and open bodies of water and were then elevated by the growth of sphagnum moss.

The soil classification system used in Ireland is a modification of the system established by the United States Department of Agriculture. An indication of the categories used in this system with particular reference to the mapping units used on the General Soil Map is given in Table 5. The main Irish soil groups are shown in Figure 9.

Podzols mainly found on high ground in the north-west, west and south-west and on the Wicklow Mountains in the east. They are generally poor soils with high lime and fertilizer requirements. They are usually formed in hill and mountain areas where mechanical means of reclamation and cultivation are not feasible so they are often devoted to forestry.

Leptic Podzols are predominantly found inland in the north, south and south-east of Ireland. They are somewhat similar to the podzols and have been formed under the influence of the podzolisation process. Because of their desirable physical characteristics, Brown Podzolics are often devoted extensively to cultivated cropping and pasture production. Their inherent low nutrient status is easily overcome by addition of lime and fertilizer.

Cambisols are found in the north-east, south-east and south. They are usually formed from a calcareous parent material, which counteracts the effects of leaching. The lighter textured cambisols are good all-purpose soils, while the heavier textured members are highly suited to pasture production, responding well to manurial and management practices.

Luvisols are very extensive and are found throughout the midlands. They are relatively mature, well-drained, mineral soils possessing a rather uniform profile, with little differentiation into horizons. Most luvisols occur on lime-deficient parent materials, and are, therefore, acid in nature. Luvisols in general, possess medium textures (sandy loam, loam, sandy clay loam) and this, together with their friability, desirable structure and drainage characteristics, accounts for the fact that they are amongst the most extensively cultivated soils. Although often of relatively low nutrient status, they respond well to manurial amendments.

Gleysols occur extensively throughout the country particularly in the north and south-west. They are soils in which the effects of drainage impedance dominate and which have developed under the influence of permanent or intermittent waterlogging. The impedance may be due to a high water-table, to a ‘perched’ water table caused by the impervious nature of the soil itself, or to seepage or runoff from slopes. Most gleysols have poor physical conditions which make them unsuitable for cultivation or for intensive grassland farming. Their productive capacity is also affected by restricted growth in spring and autumn.

Figure 9. Irish Soils Click to view full map

Topography:
Since topography governs the position of a soil on the landscape it is important in many respects, especially in its effect on water runoff and drainage. The amount of water that moves through a soil is less on steep than on gentle slopes and low-lying and flat areas generally receive more water. Soils of poor drainage, however, may be found on good slopes where the lower soil horizons or parent material are of poor permeability, leading to retardation of water movement.

Elevation, with its attendant climatic and vegetation changes, has a strong influence in conditioning the soil development pattern. Other features such as erosion and those related to aspect are also associated with topography. Apart from its influence in soil formation, topography can be an important deciding factor in the use of soils.

In Ireland there is a close relationship between lithology and relief. The Carboniferous limestone of the Midlands forms a gently undulating “Central Plain” which is almost always below the 120 metre contour. Pre-Carboniferous and Tertiary igneous rocks form a peripheral discontinuous upland rim.

Quartzite and the Old Red Sandstone, because of their hardness, contribute significantly to Ireland’s geomorphology. Quartzites are widely scattered amongst the ancient schists of Galway, Mayo and Donegal and in parts of Wicklow. Quartzite outcrops are not extensive, but they form some 12% of the peaks over 600 metres in height e.g. Mount Errigal, Croagh Patrick and the Great Sugar Loaf mountain.

Old Red sandstone supports the topography of hills and mountains mainly in the south. Although it underlies only 10% of Ireland’s surface, it forms almost 50% of the 190 peaks that rise above 600 metres.

Figure 10. Ireland – topography Source: Teagasc, Rural Economy Research Centre, Kinsealy

The granites in some places give rise to mountains and in others they underlie extensive lowlands. Granite forms the bold massif of the Mourne mountains, the Leinster mountain chain and the Derryveagh mountains of Donegal, but in Galway, it underlies the subdued topography of the Connemara lowland; see Figure 10.

3. CLIMATE AND AGRO-ECOLOGICAL ZONES

Climate:
The Atlantic Ocean has a significant effect on Ireland’s climate. Although the country is as far north as Labrador in Canada, it has a mild maritime climate throughout the year with mild, moist winters and cool cloudy summers. The prevailing winds are westerly to south-westerly and blowing off the Atlantic Ocean they bring large amounts of moisture. Average relative humidity is high. Annual average precipitation, which exceeds evapotranspiration by over 500 mm, is highest on the west coast and in inland areas of high relief.

Figure 11. Mean annual rainfall in Ireland [Click to view full map]

Temperature: Average temperatures range from 9.0 °C in the north-east to 10.5 °C in the south-west. The pattern of the isotherms reflects the ameliorating effect of the Gulf Stream so that it has a warming effect in winter and a cooling effect in summer. Winter temperatures are higher in Ireland than in most other parts of the world at the same latitude. Soil temperatures are favourable for grass growth for about 11 weeks longer per year in the coastal districts of the south and south-west compared to the midlands.

Rainfall: Rainfall is highest in the western hills where it can exceed 3 000 mm and lowest along the east coast where it is generally less than 1 000 mm (see Figure 11). The 1 000 mm isohyet divides the country fairly evenly into two; the western half varies widely from the extremes of 3 000 mm in the high ground to 1 200 mm in coastal regions. The eastern half is much drier with rainfall ranging from 800 mm in the east to 1 000 mm inland. This intensity and variability in rainfall has had a marked effect on soil development. Although the driest month is April and the wettest is December, rainfall is rather evenly distributed throughout the year, the driest month having more than 40 mm. The number of days on which rain falls is high, ranging from less than 200 in the south east to 270 in the west.

Sunshine: The frequency of cloud cover and rainfall limit the amount of sunshine received. The average duration of bright sunshine per day varies from more than 4 hours along the south and east coasts, to less than 3.5 hours in much of the north-west. May and June are the sunniest months.

Frost: Frost occurs on an average of less than 25 days per year in coastal districts of the west and on more than 50 days in the interior of the country.

4. RUMINANT LIVESTOCK PRODUCTION SYSTEMS

Dairy cow production
Irish dairy production systems are highly managed and pasture-based. Because it is pasture-based with a focus on maximizing the proportion of the diet that comes from grazed grass, average milk yields of 4 700 kg/cow are low by standards in intensive (i.e. high concentrate) systems. A predominantly British Friesian herd has been transformed over the last 20 years to a predominantly Holstein-Friesian herd. Dairy cows are concentrated in the south of the country, but dairy farming is carried out in all counties. Average herd sizes are small at about 50 cows. The main system of production is to calve cows in the spring, shortly before or around the time that grass growth commences. Practically all cows are housed for the winter (2 – 6 months duration depending on location) and fed grass silage only during the dry period. Early-calved cows are fed grass silage and 6 - 8 kg of concentrates after calving until they are turned out to grass (Plate 1). Later calving cows go to grass immediately after calving. Concentrate feeding continues for a few weeks after turnout, but subsequently cows are fed very small amounts of concentrates for the rest of the grazing season and on many farms concentrate feeding ceases completely and cows only graze grass. The main breeding season is May - June, and compact seasonal calving is important because the system is based on grazed grass. Yields are good at about 5 000 kg/cow per year considering the pasture-based system that applies. Milk composition is moderate with fat averaging 3.79% and protein 3.32% in 2007. Fertility is the main technical problem on farms with conception rates to first service dropping gradually over the years. This problem is particularly important in systems based on grazed grass where it is important that a 12 month calving interval is maintained. Hygiene standards are high, and farmers are penalised for milk with high levels of TBC (total bacterial count), SCC (somatic cell counts) or contamination (e.g. antibiotic residues). BSt or antibiotic diet additives are not permitted.

Plate 1: Dairy cows grazing pasture in spring [Click to view full picture]

Beef production
The Irish beef industry is also highly managed but relatively extensive. Calves come from two sources: (i) calves from the dairy herd and (ii) calves from specialised beef cows. Numbers from both sources are about the same. Dairy calves have Holstein-Friesian dams, and sires include Holstein-Friesian, Charolais, Limousin, Simmental, Angus, Hereford and Belgium Blue (Plate 2). Generally the calves (which are mostly born in the spring) are bucket-fed for two months, after which they are put out to pastures for their first grazing season, during which time they experience good growth rates (0.8 kg/d). They are housed for the winter, and usually fed at slightly above maintenance (to gain 0.5 kg/d) during this first winter on a diet of grass silage and small amounts (1 - 2 kg/d) of concentrates. They are turned out to pastures again in the spring for their second grazing season, with good growth rates being achieved again (1 kg/d). Their second winter is usually their final winter, and they are fed diets of grass silage and 3 - 6 kg of concentrates/day so as to achieve good weight gains (0.9 – 1.0 kg/d). Beef cows are of many breeds, but all tend to have some Friesian/Holstein genes (Plate 3). Sires are predominantly Charolais, Simmental, Limousin and Belgium Blue. Most beef cows calve in the spring like dairy cows and the rearing systems are the same with the exception of the initial period and these calves are suckled for about 7 months. Single suckling predominates and calf weight gains in this period are very good (1.1 – 1.2 kg/d). For both dairy and beef calves, the males are generally castrated, and bull beef production is a small part of the overall production system. Parasite (internal and external) control is routine. No hormonal or antibiotic growth promoters are permitted in the production systems. While the systems described above are typical, there are many variations, and production tends to be fragmented with cattle moving to different farms for different parts of the system. Herd sizes are small on average; the average beef cow herd has about 18 cows.

Plate 2: Crossbred beef cow and calf [Click to view full picture]

Plate 3: Pastoral grazing in Ireland by beef cattle [Click to view full picture]

Sheep production
The sheep industry is the smallest of the ruminant systems. Sheep production in Ireland is based on meat, with the farm gate value of wool barely covering the cost of shearing. Sheep production is again usually highly managed but extensive, being based on grazed pasture with some supplementary feeding in winter and around the time of lambing. Sheep production can be divided into lowland and upland (the smaller of the two) systems. In lowland systems, most sheep lamb in the spring, about March. Sometimes they are housed for lambing, and generally, they receive supplementary forage (grass silage or hay) and supplementary concentrates for a few weeks prior to lambing. After lambing, they go to pastures, and supplementary feeding is soon stopped. Lambs are generally weaned at about 12 weeks, and usually are sold for slaughter between 4 - 6 months at a weight of about 38 kg liveweight, although the last of the flock can be up to a year old when slaughtered. A variation of the system is early lambing in December - January where lambs are targeted for sale at Easter time, when lamb traditionally makes the highest prices for the year. This involves higher production costs as more supplementary concentrates are fed, and breeding is out of season, so hormonal stimulation techniques are used. Upland ewes lamb about a month later, as grass growth commences later in their grazing ground. They are usually brought down to lowland areas for lambing, and will usually get some supplementary feeding at this time. After lambing, they are returned to the uplands. Lamb growth rates tend to be lower, and lambs are typically smaller and older when slaughtered. There are many breeds of sheep used (Plate 4). In the lowlands, the Suffolk, Cheviot, Texel and Belclare (a local improved breed) predominate, while in the uplands, blackface mountain breeds predominate.

Plate 4: Crossbred sheep on pastures in spring [Click to view full picture]

Organic production systems
Pasture based organic production is a small component of production systems in Ireland. A census carried out in 2002 (DAFF, 2002) indicated that 30 000 ha (less than 1% of the agricultural area) was devoted to organic systems. Approximately 80% of this area had attained full organic status, while the remainder was in conversion to organic status. The census indicated that there were a total of 923 organic producers with 747 of these having full organic status. A total of 577 of the organic producers (i.e. 62.5%) had bovines, with the vast majority of these having beef cattle. There were over 6 000 beef cows on these farms in 2002, but in the same year, there were only 23 organic dairy producers with 649 cows between them. Two hundred and eighty six farmers had organic sheep, with over 21 000 ewes between them. Over 12 000 of these were lowland ewes, while almost 9 000 were mountain ewes. Lack of markets and lack of profitability were cited by producers in this census as key barriers to future expansion, but the growth of farmers’ markets directly selling produce to consumers which is often organic suggests that there has been some growth in the sector since 2002.

5. THE PASTURE RESOURCE

Area
As outlined in Table 1, over 90 percent of the agricultural area in Ireland consists of grazed or conserved (silage or hay) pastures. This amounts to almost 4 000 000 ha. The agricultural land is almost equally divided between good and difficult (or marginal) land types (Lee, 1985).

The main classes of land are

1. lowland mineral,
2. mountain and hill and
3. peat.

The proportion of land in these categories is shown in Table 6. Lowland mineral soils can be divided into dry and wet soils. Dry lowland soils comprise 2 800 000 ha and are mainly in the south, midlands and east. Wet lowland soils are further sub-divided into Category A (high water tables, seep or spring problems) and Category B (impermeable soils); these account for 13 and 12% of the land area, respectively. Category B soils are more restricted in the range of possible uses than Category A. Mountain and hill land corresponds to land above 150 m and there is an estimated 1 140 000 ha (16.7% of land area) in this category. Of this, approximately 400 000 ha are estimated to be improvable (Lee, 1985), meaning it has relatively easy slopes and dry soils. Some of this land has been drained. Peat soils are either Blanket peat (high level or low level) or Basin peat. These extend to 800 000 and 410 000 ha, respectively. Where drainage is possible, grassland production potential can be as high as mineral lowland soils.

Botanical composition
The botanical composition of Irish grasslands was described by O’Sullivan (1982) and O’Sullivan and Murphy (1982) and is summarized in this section.

High quality swards – Class: Molinio-Arrhenatheretea; association Lolio-Cynosuretum. This is the main association found on highly fertile soils, and O’Sullivan and Murphy (1982) reported that it extends to about one million hectares. It is mainly found in areas of the east, south and southeast (counties Cork, Waterford, Wexford, Wicklow, Meath and Kildare). It is generally dominated by Lolium perenne, Poa trivialis and Trifolium repens, and includes most of the leys or reseeded pastures found in Ireland.

Moderate quality swards - Class: Molinio-Arrhenatheretea; association Centaureo-Cynosuretum. This association is widespread throughout the country. The main grass/legume species are Lolium perenne, Trifolium repens, Holcus lanatus and Agrostis spp., and the main other species (often considered as weeds) include Hypochoeris radicata, Lotus corniculatus, Luzula campestris, Centaurea spp., Senecio spp. and Carex flacca. Three sub-associations of this class are recognized, (i) galietosum (Type A) which is mainly confined to shallow, well-drained limestone soils and includes species such as Primula veris, Galium verum and Trisetum flavescens, (ii) Typical sub-association (Type B) which is widespread in the better brained lowlands on deep, well-drained Brown Earths and Grey Brown Podzolics and (iii) juncetosum (Type C) which is common on drumlins in the north midlands, the Castlecomer plateau and some soils in the mid-west, and which is characterized by the presence of Juncus effusus, Juncus acutiflorus, Juncus articulatus, Juncus inflexus, Carex ovalis and Carex hirta. These latter swards are subject to poaching in wet conditions. Together, these three sub-associations make up approximately two thirds of the grasslands of Ireland.

Low quality swards – Order: Molinietalia Caeruleae. This order is 11% of the grassland area and is composed of poor quality wet pastures on soils of low natural fertility. The main species include Juncus acutiflorus, Juncus effusus, Juncus conglomeratus, Lythrum salicaria, Lychnis flos-cuculi, Angelica sylvestris, Filipendula ulmaria, Achillea ptarmica, Senico aquaticus, Myosotis laxa, and Lotus uliginosus.

Productivity
The climate of Ireland is well suited to pasture production, with adequate rainfall in most regions in most years, temperatures which are sufficient for grass growth for up to 10 months of the year in most favoured areas and sufficient radiation for substantial production of pasture (Table 7). Annual average rainfall in lowlands varies from about 750 mm in parts of the northeast and east to more than 1 200 mm in the west, northwest and southwest. Average annual temperatures vary about 9 °C in the northeast to over 10.5 °C in the extreme southwest. Pasture growth is considered to be continuous at temperatures over about 6 °C under Irish conditions.

Pasture growth curves measured at three sites are shown in Figure 12. The typical pattern is low or no growth (0 to 5 kg DM/ha per day) over the winter months, with significant growth commencing in February or March depending on location and accelerating rapidly up to peak growth rates of approximately 100 kg DM/ha per day in May. Growth then declines gradually over the summer and autumn, sometimes with a second peak in August, until it virtually ceases in November. Average annual production is about 14 - 15 tonnes DM/ha at these three sites. Brereton (1995) had previously modelled grass growth (Figure 13) and suggested that average DM production varied from 15 tonnes DM/ha in the southwest to 11 tonnes DM/ha in the northeast. The data for Moorepark are consistent with this, but the data from Grange and Ballyhaise (north midlands) indicate higher values in these regions than the model indicates.

Figure 12. Grass growth curves for 3 locations in Ireland (mean of 1982 to 2006 for Moorpark, 1998 to 2006 for Ballyhaise and 2001 to 2007 for Grange)

Figure 13. Model estimates of annual dry matter grass production (t/ha) in Ireland (Source Brereton 1995)

Figure 14. Model estimates of starting dates of the grazing season in Ireland (Source Brereton 1995)

Brereton (1995) provided estimates of the start of the grazing season which showed it to vary from 25 March in the southwest to 20 April in the northeast (Figure 14). This gives grazing seasons of 235 days in the southwest (mid March to early November) and 200 days (mid April to late October) in the northwest. However, grazing starts significantly earlier and/or finishes later on many farms than these dates, as farmers use grazing management techniques to provide pasture for at least some animals. For example, dairy cows are often given access to pasture from the onset of lactation. Thus a portion of the herd may be grazing pastures from late January in favourable growing regions in the south and southwest. Other examples are ewes or weanling cattle grazing for some or all of the winter.

Grazing management
Overall stocking rates in Ireland are quite low given the production potential of the pastures. Stocking rates are higher on dairy farms than on beef and sheep farms. Most of the livestock population is grazed in some kind of managed system. This varies from intensive management where a rotational grazing system and techniques such as pasture budgeting are used to simple systems based on set stocking. In almost all cases, the grazing takes place on fenced land, although there is some grazing of ‘commonage’, particularly on hill or mountain pastures. Rotational grazing systems are almost the norm on dairy farms. Generally, cows will be allocated fresh pasture after every second or third milking. The rest interval between grazing varies from 17 - 21 days in periods of rapid growth (May), 25 -30 days in autumn, with the longest grazing rotation taking place at the initial and final rotations (start and end of the grazing season). Nitrogen fertilizer is usually applied after most grazings. Research by Teagasc has led to very specific and detailed recommendations for grazing systems for livestock (e.g., O’Donovan, 2000). Farm cover (kg DM/ha) is a measurement of pasture supply on farms, which is often measured at a cutting height of 4 cm. Dairy farmers, for example, are recommended to have 550 kg DM/ha farm cover at the end of the grazing season in autumn, 750 kg DM/ha at turnout (when animals are first allowed to graze pastures) in spring, 800 kg DM/ha during the main grazing season, and to have a peak farm cover of 1 200 kg DM/ha in mid September to ensure pasture supply into the late autumn. A lot of research work has investigated the benefits of introducing pasture into the diet of the dairy cows in spring. Therefore the use of pasture feed budgeting based on field measurements is vital to achieve high proportions of pasture in the cow’s diet. The use of pasture budgeting (farm cover estimates, keeping a stable pasture supply, reacting earlier to pasture surpluses and deficits) has proved to be an important technology for grassland farmers to optimise their grassland resource. Teagasc now have a grassland package available to farmers, where they can be trained and up-skilled in this technology to improve their pasture management skills.

Most beef cattle and sheep graze on set stocking systems, where animals graze a particular area for several weeks (or even longer), before being changed to fresh pasture. Intensive beef farmers do practice rotational grazing and pasture budgeting, although cattle are not usually allocated fresh pasture as frequently as on dairy farms.

Fertilizer use
The amount of fertilizer used on Irish grassland was reported by Coulter et al. (2005) for the period 2001 – 2003. This was based on farm management data from approximately 1 200 farms from the Teagasc National Farm Survey (NFS). The farms which took part in the survey were randomly selected to represent the major farm systems and sizes using information from the CSO Census of Agriculture 2000. The total amount of N, P and K used for grazing was 104, 8 and 18 kg/ha, respectively, with higher than average amounts being used in the south and southeast of the country (Table 8). Dairy farms have the highest usage of fertilizer with cattle farms the lowest for both N and K, while sheep farms had the lowest P usage (Table 9).

There is a strong relationship between the amount of fertilizer used and the stocking rate for both dairy and beef cattle (Tables 10 and 11). For instance, as stocking rate on dairy farms increased from 1.2 - 1.5 LU/ha to a level of 2.6 - 2.9 LU/ha, the amount of N fertilizer used on grazing land increased from 100 to 258 kg/ha.

The amounts of N, P and K used for silage were 120, 13 and 41 kg/ha on average, with the highest amounts used in the south, southeast and mid-east (Table 12). Again, dairy farms used the highest amount of N per ha, with beef farms using the lowest (Table 13).

Reseeding 
Humphreys and Casey (2002) described reseeding practices in Ireland. The total amount of reseeding is low on an annual basis, with about 3 percent of the agricultural area (c. 140 000 ha) being reseeded each year. There is some grassland renovation (i.e., reseeding of permanent grassland) but approximately half of the annual reseeding is on mixed tillage-grassland farms, where cereal and root crops alternate with grassland in rotations. In this situation, the grassland is generally sown for at least four years. Grassland reseeding may be done by inversion tillage or shallow cultivation following the killing off of existing vegetation (with glyphosate for example). Typical seeding rates are 32 - 34 kg/ha. Such high rates are not necessary and Moloney (1962) and Keane (1980) demonstrated that seeding rates of 13.5 to 15 kg/ha would allow optimum establishment of swards. Farmers tend to use higher seeding rates to establish a productive sward as soon as possible, to minimise ingress of weeds and to avoid risk of failure due to sub-optimal seedbed conditions, excessive sowing depth, drought etc.

Perennial ryegrass (Lolium perenne) is the dominant grass used for reseeding of pastures, and makes up between 70 and 82% of total seed used for grassland reseeding in recent years (Table 14). The perennial ryegrass cultivars used are dominated by late and intermediate heading date (ear emergence) varieties: late heading varieties make up approximately 50 to 60% of the total, with intermediate heading varieties making up 15 to 30% of the total. There are very little early heading cultivars used. Diploid varieties outweigh tetraploids by about 2 to 1. Generally, up to 5% white clover (Trifolium repens) is included in most mixtures, but its subsequent contribution to these swards is usually limited, mainly because they are not managed specifically to favour white clover.

Teagasc (the Irish Agriculture and Food Development Authority) run an active forage grass and clover breeding programme in tandem with the Government Department of Agriculture, Fisheries and Food (DAFF) who run a cultivar evaluation programme resulting in an annual list of grass and white clover cultivars recommended for use in Ireland (e.g. DAFF, 2008). The goal of the Teagasc forage breeding programme is to increase the profitability and reduce the environmental cost of animal production from grassland. Breeding has focussed primarily on perennial ryegrass and white clover, the most important plant species in Irish grassland. Sixteen perennial ryegrass and eight white clover cultivars have been commercialised to date. Examples of successful cultivars include the perennial ryegrass cultivars Millennium, GreenGold, Shandon and Giant and, white clover cultivars Aran, Avoca, Chieftain and Tara. New cultivars bred by Teagasc and other organisations are evaluated by DAFF at five locations throughout Ireland. Recommendations on perennial ryegrass cultivars are based on annual yield, spring yield, autumn yield, ground cover and quality (dry matter digestibility and water-soluble carbohydrate) measures. Recommendations on white clover cultivars are based on the combined annual yield of white clover and perennial ryegrass and, the proportion of white clover in mixed grass-clover swards. Most grass and clover cultivars used for reseeding are on the DAFF Recommended List. For example 84% of perennial ryegrass and 81% of white clover sold in 2005/2006 were on the Recommended List.

Clover in pastures
While there is some interest in clover (see section on reseeding), there are very few pastures that derive significant N from it. This is mainly because pastures are not managed appropriately to promote the survival of clover (fertilization, herbicide use, grazing management etc.). This is surprising given the low stocking rates which suggest that most of the N requirement of grassland could be met from clover, especially on drystock farms. The low cost of fertilizer N relative to product prices (milk, beef etc.) and issues like persistence and variable production from year to year contributed to low popularity among farmers. However, the ratio of fertilizer N costs to product prices have changed substantially in recent years. There is evidence of increasing interest in clover swards due to the escalating cost of fertilizer N, restrictions on organic N on farms under the EU Nitrates Directive, payments for white clover under REPS-4 (Rural Environment Protection Scheme) and developments in low-cost oversowing methods to overcome problems of persistence and variable production (J. Humphreys, personal communication).

Provision of winter feed
The pasture growth curve (Figure 12) clearly demonstrates the need for provision of winter feed in Ireland. Provision of adequate quantity and quality of winter fodder was one of the main constraints to animal production up to the 70s. Grass silage is now by far the most dominant source of winter feeding (Plate 5) being made on 87% of all farms and 99% of dairy farms (data for 2001 from the National Farm Survey). It has replaced hay which up to the early nineteen-seventies was the most common method of grass preservation. The big advantages of silage over hay are increased independence of weather, and the ability to successfully ensile material cut at an earlier growth stage, with consequently highly feeding value and improved animal performance. The lower labour requirement of silage making compared with haymaking is also a factor.

Just over 1 000 000 ha are harvested for silage at least once during the year, with the total area of hay now a quarter of a million hectares (Table 1). Together with grass silage, approximately one third of grasslands are cut annually for winter fodder (Figure 15). Most of the silage area is cut once but multiple cuts are taken on some of it. The National Farm Survey provides data on areas of first, second and third cuts of grass silage. The total cumulative area harvested across all cuts is 1 300 000 ha. The average proportions of this total area harvested for first, second and subsequent cuts of silage are 78, 21 and 1% respectively. The high proportion of the total silage area harvested for first cut is a significant recent increase from the values recorded in 1996 (72%) and 1999 (71%). The most recent proportions vary among enterprises, with dairy farms placing the highest emphasis on taking a second cut (69:30:1) and sheep farms the least (92:8:0).

Figure 15. Area of grassland conserved for silage or hay Source: Central Statistics Office, www.cso.ie

Most grass silage is harvested by precision chop equipment (Table 15), giving short chop lengths (Plate 6). The main benefit of these machines is high work rate rather than any difference in animal performance compared to single or double chop silage, except with sheep that tend to perform better on short chop silage (Mayne and O’Kiely, 2005). There has also been a significant trend to use of specialized silage contractors using self propelled silage harvesters, rather than farmers using their own equipment. Wilting has the advantage of reducing effluent production and ensuring good preservation under favourable drying conditions (Mayne and O’Kiely, 2005). However, because of unpredictable weather and incompatibility with contract-cutting of silage, wilting is difficult and silage dry matter content tends to be low. Wilting for up to 24 hours is done when the opportunity arises using mower conditioners and, to a much lesser extent, tedding or mowers with spreading devices which spread the cut grass over 80 to 100% of the area cut, thus increasing exposure to the natural drying elements. The amount of silage produced in big bale systems (individually wrapped with plastic film) has increased in the last 20 years (Plate 7) and is now about one third of silage harvested (Table 15). The biggest issue with baled silage is the implications of an imperfect seal, and Forristal and O’Kiely (2005) cited reports that 87% of farmers had bales with some mould growth. Nevertheless the system is popular, and is increasingly used as an aid to intensive grazing management, whereby some paddocks in a rotational system are cut for silage when grass cover gets too tall to above average growth rates.

There are no reliable data on farm level yields of silage or hay, but data collected under research conditions show cumulative yields up to mid-August of 12.5 tonnes of DM/ha under a three-cut systems (P. O’Kiely, personal communication).

The quality of silage is very variable, being affected mainly by stage of growth at cutting and preservation quality. A recent survey of farm silages (McEniry et al., 2006) showed silages to be on average of moderate dry matter digestibility (644 to 677 g/kg), with good crude protein contents, and to be well preserved (Table 16).

One of the main issues with silage making is achieving a good fermentation and a well preserved silage. Much research has been carried out in Ireland and elsewhere to optimise silage making techniques so as to increase the reliability of achieving good preservation. Many additive types were used in Ireland in the past, ranging from acids (formic and sulphuric), formaldehyde, molasses, enzymes and inoculants (Lactobacillus). However, there has been a decline in additive use in the last 10 - 15 years and now only 11% of silage is treated with an additive. Inoculants are now the most popular additives, with some molasses but very little acid additives are used (P.O’Kiely, personal communication). Additives are hardly ever used with baled silage.

Some other arable crops are used for winter feeding (Plate 8). Maize silage is increasing in acreage as new varieties are produced that are better at DM production in cool climates, and technology such as planting under plastic allow higher yields of DM and more consistent yields and quality, thus mitigating the effect of variation in growing conditions. There is also some interest in forage brassicas and red clover.

Plate 5: Cattle eating silage indoors in winter [Click to view full picture]

Plate 6: Silage making with a self-propelled precision chop silage harvester [Click to view full picture]

Plate 7: Baled and wrapped silage stored in a field for winter feeding [Click to view full picture]

Plate 8: A mixed crop of swedes and kale being grazed in situ by sheep during the winter [Click to view full picture]

6. OPPORTUNITIES FOR IMPROVEMENT OF PASTURE RESOURCES

Despite most pastures in Ireland being relatively well managed, the main challenge for pasture based agriculture is to improve the utilization of pasture and increase the output of animal products from this resource. Stocking rates on Irish grassland are low considering the high growth potential. For example, the national stocking rate on dairy farms is 1.9 livestock units (LU)/ha (where an adult cow is 1 LU) but a high performance target is 2.5 LU/ha (Teagasc, 2008). Similarly, the average herbage utilization on dairy farms is calculated to be 6.4 tonnes DM/ha while the high performance target is 12.9 tonnes DM/ha (Teagasc, 2008). Considering all factors, milk output per ha could be increased from the current national average of 8 900 kg/ha to over 14 000 kg/ha without any increase in concentrate usage per ha (Teagasc, 2008). However, it is unrealistic to expect the entire industry to reach these high performance targets, and Teagasc (the national agricultural research, extension and education organization) has set a target for the dairy sector to achieve an average output level of 10 800 kg/ha by 2015 (Teagasc, 2008). It must be recognized that the existence of milk quotas in the EU since 1984 has restricted the growth potential of the dairy sector, but the plans to remove milk quotas from EU production in 2015 (and the easing of quotas in the intervening period) will most likely lead to an expansion of milk output and allow progress towards these higher outputs. In the beef and sheep sectors, there is at least as much potential to increase output per ha by improving technical performance. The higher stocking rates and consequent higher output is possible by increasing herbage yield through greater and/or more efficient use of nitrogen (either fertilizer, manure or fixed nitrogen) and by achieving better utilization of herbage in pastures. Extending the grazing season by better management and new varieties of grass with better winter growth characteristics is a major goal of research and production in Ireland.

The low rate of reseeding could be seen as a barrier to pasture improvement, but research has shown that well managed permanent pasture can give performance just as good as reseeded pasture. Weeds are not a major problem on most Irish pastures, but in some instances, better weed control would increase output.

Plate 9: Pasture infested with creeping thistle (Cirsium arvense) [Click to view full picture]

In general, the nutrient status of Irish soils is good, following 50 years of soil analysis and fertilization. There is an opportunity to improve the use and recycling of animal manures. In particular, the utilization of nitrogen in animal manures applied to pastures is poor, and this is an on-going research issue. Also, there is an opportunity to reduce fertilizer nitrogen usage on many farms with low to moderate stocking rates, and to replace this with clover-based swards. As outlined above, critical factors in regard to this are low cost methods of establishing and maintaining clover in pastures, and avoidance of bloat in animals grazing these pastures.

Increased world demand for food products over the next 20-40 years should see food production in Ireland increase, but profitability is a big constraint, and production could contract in some sectors. Other issues include greenhouse gas emissions and water quality. In 2006, agriculture contributed 28% of Ireland greenhouse gas emissions, with most of this from ruminant livestock. Pressure to reduce emissions will intensify in the sector, but it appears to be quite efficient by international standards in regards to the greenhouse gas emissions per unit of product. The EU Water Frameworks Directive could put pressure on farmers to reduce fertilizer usage.

7. RESEARCH AND DEVELOPMENT ORGANIZATIONS AND PERSONNEL

Teagasc, the Irish Agriculture and Food Development Authority, Head Office, Oak Park, Carlow. Director: Professor Gerry Boyle.

University College Dublin, School of Agriculture, Food Science and Veterinary Medicine (Head of School: Professor Shane Ward) and School of Biology and Environmental Science
(Head of School: Professor Tom Bolger), Belfield, Dublin 4.

Irish Grassland Association, Curraghclooney, Ballylooby, Cahir, Co. Tipperary.
President: William Kingston.

Department of Agriculture, Fisheries and Food, Agriculture House, Kildare Street, Dublin 1.
Secretary General: Mr. Tom Moran.

Irish Cattle Breeding Federation, Shinagh, Bandon, Co. Cork
Director: Dr. Brian Wickham.

Bord Bia – Irish Food Board, Clanwilliam Court, Lower Mount Street, Dublin 2.
Chief Executive: Aidan Cotter.

Met Eireann – Irish Meteorological Service, Glasnevin Hill, Dublin 9
Director: Declan Murphy.

8. REFERENCES

Brereton, A.J. (1995). Regional and year to year variation in production. In: Jeffrey, D.W., Jones, M.B. & J.H. McAdam (eds) 1995. Irish grasslands – their biology and management. Dublin Royal Irish Academy, 12-22.

Coulter, B.S., Murphy, W.E., Culleton, N., Quinlan, G. & Connolly, L. (2005). A survey of fertilizer use from 2001-2003 for grassland and arable crops. End of Project Report, Teagasc, Johnstown Castle, Wexford, Ireland. 84p.

CSO, 2007. Census 2006, Volume 1 (Population classified by area) and Volume 8 (Occupations). Central Statistics Office, Cork. Available for download at www.cso.ie.

DAFF (2002). Census of Irish Organic Production 2002. Department of Agriculture and Food, Dublin, Ireland.

DAFF (2007). Cattle Movement and Monitoring System (CMMS) Statistics Report 2006. Department of Agriculture and Food, Dublin, Ireland. 60p. Available for download at www.agriculture.gov.ie.

DAFF (2008). Grass and Clover Recommended List Varieties for Ireland 2008. Department of Agriculture, Fisheries and Food, Dublin. 21p.

Forristal, P.D. & O’Kiely, P. (2005). Update on technologies for producing and feeding silage. In: Park, R.S. & M.D. Stronge. (eds) Silage Production and Utilisation – Proceedings of the XIV International Silage Conference, a satellite workshop of the XXth International Grassland Congress. Wageningen Academic Publishers, 83-96.

Humphreys, J. & Casey, I.A. (2002). Grassland renovation in Ireland. In: Conijn, J.G., Velthof, G.L. & Taube, F. (Eds.): Grassland Resowing and Grass-Arable Rotations. Proceedings of European Grassland Federation International Workshop Agricultural and Environmental Issues, Wageningen (The Netherlands) 18 & 19 April 2002. Plant Research International, Wageningen 2002, Report 47, pages 79-91.

Keane, G.P. (1980). Effect of seeding rate on the production from new leys. Irish Journal of Agricultural Research, 19: 141-145.

Lee, J. (1985). Land Resources, Land Use Relationships in Ireland. Proceedings Grassland Production Seminar, 1-32. An Foras Taluntais, Dublin.

Mayne, C.S. & O’Kiely, P. (2005). An overview of silage production and utilization in Ireland. In: Park, R.S. & M.D. Stronge. (eds) Silage Production and Utilisation – Proceedings of the XIV International Silage Conference, a satellite workshop of the XXth International Grassland Congress. Wageningen Academic Publishers, 19-34.

McEniry, J., O’Kiely, P., Clipson, N.J.W., Forristal, P.D. & Doyle, E.M. (2006). The microbiological and chemical composition of baled and precision-chop silages on a sample of farms in County Meath. Irish Journal of Agricultural and Food Research 45: 73–83,

Moloney, D. (1962). Rate of seeding trial. Research Report, Soils. An Foras Taluntais, Dublin. Page 109.

O’Donovan, M. (2000). The relationship between the performance of dairy cows and grassland management on intensive dairy farms in Ireland. PhD thesis. National University of Ireland.

O’Sullivan, A.M. (1982). The lowland grasslands of Ireland in studies on Irish Vegetation pp 131-142. White, J. (ed). Royal Dublin Society.

O’Sullivan, A.M. & Murphy, W.E. (1982). Grass production from old permanent pasture. In Grassland production seminar pp 125-133. Johnstown Castle Research Centre, An Foras Taluntais, Dublin.

Teagasc (2008). Sectoral Road Map: Dairying. Teagasc, Carlow. Available for download at www.teagasc.ie.

9. CONTACTS

Author: Dr. Frank O’Mara, Teagasc Head Office, Oak Park, Carlow, Co. Carlow, Ireland.

The author acknowledges the invaluable assistance of Drs. Padraig O’Kiely, Brian Coulter, Michael O’Donovan, James Humphreys, Pat Conaghan, Alistair Black, Michael Drennan and Réamonn Feely.

[The final draft of the profile was prepared in the first half of 2008 and edited in June 2008 by J.M. Suttie and S.G. Reynolds]