Teagasc has claimed that soil fertility is showing “some improvement” after years of stagnation, according to its 2018 annual review of soils samples.
The latest review tracks soil fertility between 2007 and 2018, and indicates an improvement in soil pH in recent years, and also shows that the decline in phosphorous (P) and potassium (K) levels appears to have halted.
Teagasc highlights that, across all farm enterprises, there has been an increase in the amount of soil within the optimum range for grassland mineral soils, i.e., a pH of 6.3 or higher.
Mark Plunkett, soil and plant nutrition specialist at Teagasc, said: “Improvements in soil pH levels are a reflection of the targeted advisory programmes promoting application of ground limestone.
“Average national lime use over the last five years has increased by 211,000t/year from the previous five years, and currently stands at approximately one million tonnes,” added Plunkett.
Teagasc says that it has been working with industry partners to promote increased lime usage over the last number of years.
According to Dr. David Wall, soil fertility researcher at Teagasc Johnstown Castle, levels of potassium in particular are showing positive trends, with a 10% increase in soils with optimum levels.
“This is a positive result as it indicates a halt to the steady decline in soil K, especially over the last five years, some of which may have been as a result of increased grass utilisation and the removal of high-quality baled silage from paddocks being routinely grazed”, said Dr. Wall.
Summarising the findings, Pat Murphy, head of environment knowledge transfer at Teagasc, said: “These positive trends in national soil fertility represent a foundation to build on, as soil fertility is a cornerstone of our grass-based animal production systems, and critical for enhancing crop yields and quality of stock.”