It is well documented that there is a major shortfall in the volume of lime being applied on an annual basis. Current application rates are less than half of the annual application rate of 1.7m tonnes applied in the 70s and 80s. This is despite lime having the ability to greatly enhance the biology of soil and generate a return in investment of 7:1.

To put this in terms of output, increasing soil pH to the optimum level can underpin an increase in grass growth rate of 1t to 1.5t DM/ha.

This increased soil biological activity will also significantly improve drainage

Soil pH or lime status is a hugely important factor in optimising the productivity of permanent plants such as grassland swards. Maintaining mineral soils at the optimum pH of 6.3 or greater will enhance nutrient availability, improve the physical structure of the soil and also promote increased soil micro-organism activity with earthworms benefitting most. This increased soil biological activity will also significantly improve drainage.

Application rates

Lime is removed from the soil through the production of milk, beef or lamb and in conserved forages and tillage crops.

It is also depleted somewhat by the application of nitrogen fertilisers while a big drain on soil lime reserves in Ireland is through rainfall and leaching from the soil. The exact lime requirement of soils can be easily identified through soil analysis. This approach is also recommended to avoid the risk of over liming in areas which have a natural lime content or in areas with a high soil molybdenum content which can lead to health issues in animals.

Lime is removed from the soil through the production of milk, beef or lamb and in conserved forages and tillage crops.

The general recommendation is to apply 2t to 2.5t ground limestone per acre and to top-up or repeat the application three years later (ground limestone is available over three years).

Granulated lime products offer convenience where small volumes are being applied or small areas are concerned but must be applied on an annual basis.

A useful lime programme is to view the liming of lands as an essential practice and on the same footing as applying fertiliser.

Targeting 20% of lands on an annual basis will spread the cost while ensuring soil pH levels are maintained at the desired level.