What is Tillage?
Tillage is the preparation of land for growing crops. In 2017, there were 7,387 tillage farms in Ireland (Teagasc). Over 300,000 hectares of the best land in Ireland is engaged in tillage farming, or the annual production of crops for harvest. Cereal crops are the main output, led by barley, then wheat and then oats.
Between 2000 and 2010, Ireland recorded the highest average wheat and second highest average barley yields in the world, according to John Spink, Head of Crops Science with Teagasc.
There are cereals grown in every county in Ireland, although the area in 2010 ranged from just 29 hectares in Sligo to 41,569 hectares in Wexford. This is mainly explained by differences in the suitability of the land and, to a lesser extent, more hours of sunshine in the south east.
Apart from the cereal crops, Irish farmers grow maize, beans, oilseed rape, carrots, beet and potatoes. Potato growing in particular has become very intensive.
The crop requires exceptionally good land and is now confined to parts of Meath, Louth, Dublin, Wexford, Donegal and Cork. Donegal has a noted tradition of growing potatoes for the seed trade, while Dublin and Meath growers supply the table market in Dublin, as well as the crisp making requirements of the Largo Foods plant at Ashbourne, Co. Meath.
Maize in Ireland is mainly grown as a forage crop that is harvested and ensiled for winter feeding to livestock. It requires warm south facing fields and tends to be grown more in the South. It is also popular in Meath, driven by the high prevalence of intensive dairy and beef herds.
Growth Stages of Barley
After germination the first leaf emerges soon after the crop initially emerges. The crop continues to produce leaves at a continuous thermal rate. This thermal rate is a set number of degree days between the emergence of successive leaves.
Spring sown barley produces fewer leaves than autumn sown barley as the crop has less time to grow. On average the plant will produce eight leaves.
The production of tillers is key in the production of grain and ultimately grain yield. Tillers emerge after the third leaf has emerged on the barley plant. Shoots are produced from the tillers, so therefore the more tillers that are produced the more shoots are produced.
The growth of the canopy is slow initially as leaves emerge on the barley plants. As leaves emerge the rate of photosynthesis increases as the plant can absorb more sunlight and the crop canopy expands rapidly.
Until the stem begins to grow, all crop growth is at ground level. Once the stem starts to grow the crop is more susceptible to frost damage at the growth point. Four of the leaves on the barley plant will grow at ground level and four will be on the stem. The crop will be at its maximum height after the ear emerges and biomass accumulation begins in the grains. At harvest the ear bends over and lies parallel to the stem.
As the crop develops more leaves and has a bigger canopy, it increases the amount of sunlight it absorbs. In turn, the biomass it produces accumulates at a greater rate. The production of biomass goes through several different stages of production. Initially biomass production centres on leaf emergence, followed by stem and ear production. Once the stem has reached its maximum height, biomass production is focused on grain production, as starch accumulates in the developing grains.
The greater the number of shoots produced, the greater the number of ears formed on the barley plant. Grain yield is determined by the number of ears per metre squared. The crop ceases vegetative growth when ears start developing. It takes approximately 35 days for an ear to fully form on the barley plant.
Grains begin to fill once the ear has emerged. It takes approximately 40 days for the completion of grain filling in the barley ear. The products of photosynthesis, which were stored in the stem, are now transferred to the grains. Crop production can be maximised through adequate fertiliser application to ensure the maximum number of tillers on each plant which in turn maximises ear production and grain filling.
Harvesting and Processing
Barley, wheat and oats are harvested with a combine harvester. When barley is ripe, the ear bends over and lies parallel to the stem. The grains are hard and dry and the golden colour of the crop fades. It is important for the grain to have low moisture levels otherwise it will have to be dried out. Farmers are also paid based on the moisture content of the grain.
Winter barley is harvested in July and Spring barley is harvested in August.
Grain is stored in large ventilated sheds. Grain that is kept in storage is treated with propionic acid which prevents the grain being attacked by pests, fungi and bacteria. Low temperatures and low moisture content are important for grain storage to prevent germination and spoilage.
Barley straw can be used for animal feed and bedding or ploughed into the soil for winter crops. Straw can be made into round or square bales and used on the farm or sold. Barley straw can also be burned in a biomass boiler to provide energy.
The combine harvester combines three separate functions, first reaping which is cutting the stalks of grain, threshing which is loosening the grain seeds from the straw and the chaff, the inedible husks or seed casings on cereal grains. Finally winnowing which is separating the seeds from the straw and the chaff. These three processes are carried out by the combine harvester in one continuous operation.
Potatoes have been in Ireland since around the 1600’s. They are classified into three main categories, first earlies, second earlies and the maincrop.
First and second earlies are planted as early as February/March. However, potatoes are not frost-resistant and for this reason they are grown in coastal areas of counties Cork and Wexford. The soils in these regions are sandy soils and warm up early in spring. Earlies are harvested immaturely from late May onwards. As a result, there is a lower yield but they obtain a higher price. Home Guard and British Queen are the most popular early varieties grown in Ireland.
Maincrop potatoes are harvested fully mature in September and October and give higher yields than early varieties. Rooster, Kerr’s Pink, Record and Golden Wonder are the most popular maincrop varieties in Ireland. Over half of the land planted with potatoes in Ireland is planted with Roosters.
The haulms are first killed off using a contact herbicide. The potatoes are left in the ground for up to 3 weeks to allow the skins of the tubers to harden, this prevents them from being bruised when harvesting. The potato crop is then harvested with a potato harvester, usually an elevator digger. The machine separates the potatoes from the soil and either leaves the potatoes on the top of the soil to be gathered by hand or carries them to a storage bin. Potatoes must be stored in purpose built buildings that are well ventilated, leak-proof, insulated and frost-proof. They must allow access to a tractor and trailer as well as being stored in stacks.