Tillage farmers have an important role to play in meeting Ireland’s carbon sequestration targets of around of 2.7m tonnes of CO2e by 2030.

Attendees at the Teagasc’s National Tillage conference in Kilkenny on Wednesday heard that Ireland’s agriculture sector contributes 32% of national greenhouse gas (GHG) emissions.

The sector has been given stringent targets to cut these emissions by 10% by 2030. However, an amount of these targets can be offset by delivering carbon sequestration.

Teagasc’s Dr Karl Richards explains that the majority of the land use sequestration targets are expected to come from forestry plantations (2.1m tonnes of CO2e).

Growing cover crops and straw incorporation is expected to deliver carbon sequestration quantities of 0.1m tonnes and 0.06m tonnes of CO2e

Pasture management will also play a role (0.26m tonnes of CO2e), as will management of water tables in high-organic soils (0.44m tonnes of CO2e).

However, growing cover crops and straw incorporation is expected to deliver carbon sequestration quantities of 0.1m tonnes and 0.06m tonnes of CO2e respectively.

While these numbers may appear low in comparison with other abatement measures, Richards explains that there is no silver bullet to agriculture's GHG problems and all sectors will have to contribute.

Building soil carbon

Richards explained that in order to build soil carbon, adding organic manures will be vital in achieving this. For example, applying farmyard manure at a rate of 25t/ha will add around 2.5t of carbon per ha.

Cattle and pig slurry have substantially less carbon sequestration values at 0.6t and 0.4t of carbon per ha.

Growing cover crops also increases soil organic carbon by around 10t to 15t of carbon per ha over 20 to 40 years.

Through incorporating straw at harvest, 20% straw carbon remains in soil. At a rate of 4t/ha, straw incorporation will increase soil carbon levels by 8% over 20 years.