Lime applications is essential to boosting returns on fertilisers
Published 08/07/2015 | 02:30
The use of lime has halved since the 1980s, despite the fact that 88pc of soils are at sub-optimum fertility.
"We used about 1.5 million tonnes annually in the 1970s and 1980s, but this has dropped to about 750,000t in the last decade," claimed grazing expert, Michael O'Donovan.
"Farmers basically gave up liming when quotas came in, but the fact is that every acre of grassland should be getting an average of 1t of lime annually," said the Teagasc specialist.
There is approximately five million acres of grassland on Irish farms.
Yet, 35,000 soil samples analysed by Teagasc over recent years show that only one in ten are at the target levels of pH, phosphorus (P) and potassium (K).
"We're losing the benefits of fertiliser and perennial ryegrasses if we don't get our pHs right. These are the invisible costs that we can't easily see on farm.
"But getting your pH right is the equivalent of an additional 60-80 units of nitrogen.
"The cost is small in comparison to other soil fertility measures at around €8/ha, compared to closer to €40/ha for P. Lime will actually increase the return from your P by 2.5 times," said Dr O'Donovan.