80% of farms in dire need of lime

TEAGASC in conjunction with Kerry Agribusiness have embarked on a lime promotional campaign this summer to rectify the seriously low pH on many grassland farms in the catchment.

Soil analysis results on dairy farms indicate that 80% of soil samples in Kerry and Co Clare have a pH less than 6.3 with over 60% of soil samples in Co. Limerick being sub- optimal.

Recent lime usage data from lime suppliers indicate that lime usage in Co Kerry has been stagnant at c 43,000 tonnes per annum since 2014.

This compares poorly with 2013 when 63,000 tonnes was applied in the county. It is necessary to get back to that level of lime usage again in 2017 in order to maximise the value we get from fertilisers and maintain or increase grass production.

The autumn is the most popular time for lime usage but with the risk of poor weather conditions at that time of the year the opportunity can often be lost.

Hence there is a need to focus on summer applications of lime in Kerry.

The high annual rainfall in the southwest is a predisposing factor causing lower soil pH.

The lime application required to maintain pH is estimated at two tonnes/acre every five years in high rainfall areas such as the south west. Where soil pH is less than 5.5 you will find greatly diminished biological activity in the soil.

This in turn causes a poor response to applied fertilisers and locks up applied phosphorus resulting in a significant loss in grass production especially in the key shoulder periods of spring and autumn. Recent analysis from the Heavy Soils Programme showed that grass growth increased by two tonnes dry matter per hectare when pH was increased from 5.5 to 6.3.

So what are the barriers to applying a simple, cheap product such as ground limestone on a regular basis? In a recent survey of the Killarney Young Farmers Dairy Discussion Group 42% indicated that weather opportunities were a barrier to applying required lime application, cash flow was cited by 30% and paddock availability by 28% of the group. Clearly lime needs to be planned as a key part of the annual fertiliser programme. Based on soil analysis the tonnes of lime required to be applied needs to be established and the fields requiring lime need to be clearly identified.

So what are the financial returns to lifting soil pH from 5.5 to 6.3?? Research shows that in the three years after lime application for every €100 spent on lime you get back a return of €300.Taking a longer term view, from year 1 to year 9 for every €100 you spend on lime you get €600 back. Not too many investments give that kind of return in any walk of life!