Forty-four percent of soils sampled on farms in the Teagasc Signpost programme have a soil pH level of less than 6.2, meaning it is most likely not at the optimum level for the crop it is growing.

Soil pH on grassland soils should be at approximately 6.5, while levels differ for different tillage crops.

Some 2,993 soil samples were taken from 101 farms last autumn as part of the Signpost programme, according to Tom O’Dwyer, who detailed the results at the Signpost general assembly in Co Wexford on Monday 29 August.

Huge variation

There was huge variation between soil sample results, as the data was examined across sectors. For example, 79% of tillage soils had a pH greater than 6.2, but only 34% of the sheep farms sampled had a soil pH level above 6.2.

However, when soils were examined for optimum soil pH, phosphorus and potassium levels, there was very little difference.

Some 42% of dairy farms were at optimum levels, 43% of beef farms, 34% of sheep farms and 42% of tillage farms.

Soil carbon levels

Looking at soil organic carbon levels, 73% of tillage farms sampled had soil carbon levels of 2% to 4%, while 19% had levels of 0% to 2%, leaving 8% above 4%.

For comparison, none of the beef or dairy farms sampled had soil carbon levels below 2%. Seventy-five percent of dairy farms, 81% of beef farms and 85% of sheep farms had soil carbon levels above 4%.

This means there is plenty of room to improve soil carbon levels on tillage land, which is good for the soil and good for offsetting carbon emissions.