Irish soils have a natural requirement for lime to control soil acidity, due to our high levels of rainfall. Lime will neutralise this acidity and restore a more favourable soil pH for crop growth, nutrient release and soil quality.
Over 1 million tonnes of ground limestone were spread on Irish farms in 2018, an increase of almost 40% on 2017 levels. While weather conditions played a part in this increase, it is clear, that Irish farmers are utilising the benefits of lime to unlock soil fertility on their farms. It is likely that lime usage on Irish farms will continue to increase following the Government’s acceptance of the recent recommendations by the Nitrates Expert Group following its review of the Nitrates Derogation. The recommendations included a compulsory farm-scale liming programme on derogation farms and on farms with a stocking rate above 170kg Nitrogen (N)/ha.
- Timing – lime can be applied at any time of the year, including after grazing or after silage harvest.
- Nitrogen / Slurry – to avoid N loss through volatilization, apply urea / slurry first followed by the application of lime 7 to 10 days later.
- Farmyard Manure – lime can be applied 7 to 10 days after applying farmyard manure (FYM).
- Results – lime will begin working once it has been applied and washed into the soil. The finer fractions of the lime will adjust soil pH immediately, while larger components will continue to work over the following 2 years.
- Damage – on soils which poach more easily after liming, applying a reduced rate of lime on a more regular basis will avoid damage to soils.
- Safety – once lime is washed into the soil it poses no risk to cows but slight tainting to grass leaves during dry conditions after application may cause slight scouring.
- Nitrogen and Phosphorous (P) – maintaining correct soil pH will result in the release of both N and P from soil reserves.
While lime usage on Irish farms is increasing, it remains substantially below the levels recorded over 20 years ago. The following is some practical advice which might help answer some questions farmers may have. Where required, further advice should be sought from Teagasc or from independent agricultural consultants.
Grolime is the certified trademark under which companies who meet necessary criteria are authorised to promote and sell their ground limestone. All Grolime certified companies are licenced by the Department of Agriculture, Food and the Marine (DAFM) to manufacture and sell ground limestone for use as a soil conditioner in Ireland. In addition, all Grolime companies undergo independent testing bi-annually for compliance with the national specification for ground limestone. Therefore, it is essential to ensure you source your lime through one of the Grolime suppliers. To view the full list of Grolime approved companies, click here.