Reducing Nitrogen Emissions
Nitrogen fertiliser is a key nutrient that drives agricultural production. Some of this nitrogen is lost to the environment as a direct greenhouse gas nitrous oxide (N2O) or indirect source of N2O from nitrate (NO3) leaching and ammonia (NH3) volatilisation. N2O is a powerful GHG with a global warming potential 265 times greater than carbon dioxide (CO2) and has a lifespan of 100 years. In Ireland in 2022 N2O accounts for 5 MTCO2e or 22.3% of agricultural GHG emissions (EPA, 2024).
This research priority focuses on mitigation measures to reduce absolute emissions and the refinement of emission factors to reduce uncertainty and for inclusion in the national inventory.
Priorities
- Establish low nitrogen farming systems and refine emissions factors for N2O on a range of sward types and evaluate their efficacy to reduce chemical N use.
- Investigate the interaction between soil nutrient status (i.e. soil index) and soil pH on N2O emissions and N use efficiency
- Refine nitrous oxide and ammonia emissions factors from fertilisers
- Evaluation of the impact of lower crude protein diets in bovine and pig production systems on N use efficiency and N2O emissions
- Quantification of the genetic variability in N use efficiency in grazing livestock and its impact on N2O emissions
- Development of precision N application and grazing management strategies to increase N use efficiency and reduce N2O emissions
- Refinement of N2O emission factors for a range of excreta across a range of soil types and land-use/management practices
- Refinement of NH3 and CH4 emission factors for a range housing, manure storage and mitigation options to reduce emissions
- Improve activity collection data relating to N fertiliser use, excretion, manure storage, land-spreading.
- Develop a Tier 3 model for quantification of N2O emissions and nitrate leaching across a range of soil types, land-uses and management practices
Immediate actions
- Greater use of red and white clover in grazing systems
- Improved soil fertility/health
- Reduce crude protein in both bovine and pig diets
- Develop precision grazing technologies and fertiliser technologies
The Nitrogen Soil GHG Test Platform provides researchers and industry with a high resolution, automated infrastructure to examine the efficacy and derive emission factors of a range of novel fertiliser, bioactives, bio-stimulants, manure and digestate additives.
Current Research Projects
Current Climate Centre research projects focusing on Reducing Nitrogen Emissions
The National Fertiliser Database and Nitrates Action Programme changes
On this episode of the Signpost Webinar Series, which took place on Friday, 20 January 2023, Mark Gibson, Head of Teagasc Outreach & Innovation Department was joined by Dr. Finbarr O’ Regan & Ted Massey, Department of Agriculture, Food & the Marine (DAFM) Inspectors to discuss the National Fertiliser Database, the banding of dairy cows and recent changes under the Nitrates Action Programme. A questions and answers session took place at the end of the webinar which was facilitated by Pat Murphy, Head of Environment Knowledge Transfer, Teagasc.
Clover
How Does It Work?
Clover fixes nitrogen from the atmosphere. Nitrogen fixation is the name of this process whereby white clover can fix N from the atmosphere and make it available for plant growth, thereby reducing the requirement for chemical Nitrogen.
Benefits of white clover
The benefits of white clover tend to occur from May onwards as sward white clover content increases. The main benefits of white clover inclusion in grass swards are:
- Increased herbage quality compared to grass-only swards in the summer months.
- Increased dry matter (DM) intake in summer and autumn.
- Higher milk production and live weight gain.
- Nitrogen fixation – white clover fixes nitrogen (N) from the atmosphere making it available for plant growth.
Cover Crops
Cover crops are species or mixtures of species grown over the autumn-winter period between two cash crops mainly for the purpose of generating some benefits for the cropping system rather that as cash crops themselves. Benefits of cover crops can include reduced nutrient loss, improvement of soil organic matter or carbon levels, reduced soil erosion, improved soil structural characteristics, improved biodiversity, reductions in pests and diseases of the following crops, increased nutrient supply to the following crop and yield benefits in the following cash crop.
Paper: Cover Crops on Irish Tillage Farms (PDF)
Dr Richie Hackett presenting on Cover Crops at the Signpost General Assembly in November 2024.