Teagasc baffled by ongoing decline in lime application

Only one-fifth of farms using the ‘forgotten fertiliser’

GRANT aid may need to be introduced to reverse the shortfall in lime application on Irish soils, Teagasc has warned.

A joint Teagasc study on fertiliser usage on Irish farms from 2005-15 found that the gap between recommended rates of lime application and those actually applied had widened in the 11 years of the study period.

Only 20pc of farms used lime year on year in the period 200515, and 45pc of drystock farmers never limed at all. For dairy farmers, the figure was 21pc.

Teagasc researcher Cathal Buckley said he was baffled by the falling usage of what he described as, “the forgotten fertiliser”.

“In terms of improving fertility, lime is the first place to start and the benefit is a multiple of the cost,” he told last week’s Teagasc Soil Fertility conference in Kilkenny.

Lime is usually around €30 per tonne compared to average fertiliser prices of €250-400 per tonne.

Mr Buckley said that adequate liming is essential to achieve optimum soil pH which, in turn, is necessary to maximise the effectiveness of fertilisers.

Higher rates of liming were associated with dairy farms but also those with wide land use potential and those with higher stocking rates.

In terms of mineral fertilisers, the study found that application rates on grassland were 11-16pc lower at the end of study period compared to the start, which is remarkable as requirement across the period would have increased.

“Demand has gone up as soil fertility has gone down,” said Mr Buckley.

The study found a similar pattern in both the dairy and livestock sectors, and the gap between recommended levels and actual usage has widened over time. Also, the gap was wider in the livestock sector than in the dairying.

Similar shortfalls were recorded for P and K in the dairy and livestock sectors.

However, there were some variations in the patterns of artificial fertiliser use. A dramatic drop in usage in 200809 coincided with a period of higher fertiliser prices, while higher rates in 2013-14 were associated with the aftermath of a national fodder shortage.

The study focused on agronomic factors and did not examine the reasons for the decline in fertiliser usage.

However, the researchers do point out that on farms participating in an agri-environmental scheme, application rates were 34-38pc lower than recommended in the case of grassland farms and 3-15pc in cereal production.