Concern at falling soil ph levels
In recent years the number of soil samples received by the advisory services for ph and nutrient testing has slumped to under half the level of 25 years ago, official figures have revealed.
The finding, included in a revised technical note on liming materials and recommendations published recently by the Farm Advisory Service (FAS), has been backed up by the results of a study into current use which have shown that ph levels were declining on grassland farms across the country.
“Maintaining optimum acidity status is required to achieve maximum yields,” said the report’s author, Dr Samantha Dolan. She said that the optimum soil ph range to aim for was 6.0 to 6.2 on mineral soils – and having a ph in this range would improve nutrient availability and crop yield.
However nearly half of the soil samples collected from the Farm Advisory Service Soil and Nutrient Network farms were found to be suffering from low ph levels.
The study carried out by SAC consulting, which looked at 273 soil samples from around the country, showed that almost half of the soil samples were below ph 5.8, one third were between 5.8 and 6.2 and 18 per cent were above ph 6.2.
Chris Mcdonald, who runs the crops and soils theme of FAS, said that analysis had also found large variations in the nutrient contents of organic manures and slurries used on these farms:
“This report demonstrates how important it is to test soil and organic manures for nutrient content and by using the FAS fertiliser technical notes, farmers can do accurate nutrient management which will make a big difference to the profitability of the business,” said Mcdonald.