Teagasc researcher Gary Lanigan has described how many Irish tillage farms may already be carbon neutral and described ways in which farms that are not carbon neutral can become so.

Lanigan was speaking at the last of Teagasc’s Tillage Thursday series, where the focus was on malting barley.

He displayed a potential carbon footprint for a 100ha farm growing malting barley, winter wheat and spring beans and described how nitrous oxide was the main greenhouse gas emitted from tillage farms, while fuel for field operations and grain drying also emitted carbon dioxide.

Lanigan also listed the manufacture of fertiliser and pesticides as some of the contributors to carbon emissions.

Cover crops and straw incorporation were detailed as ways to increase carbon sequestration. Lanigan noted that 10-20% of the carbon in straw which is incorporated remains in the soil.

Accounting for forestry on the farm, as well as improved hedgerow management, he estimated that the 100ha farm’s emissions were actually carbon positive at -3.4tCO2e.

Lanigan added that research is underway on the impact of direct drilling on soil carbon storage. Soil carbon was found to increase in the top soil with minimum tillage, but significant gains were not seen further down the soil profile.

The Teagasc researcher outlined the carbon footprint of a tillage farm as 3,500/kg CO2 per grain produced.