Agricultural Peat Soils
Discover the story of Ireland's agricultural peat soils and how FarmPEAT's project farmers manage them for nature.
This story map can be used as a resource for agricultural and environmental science students at the Leaving Certificate or Higher Education Level. You can find resources for younger age groups on the Irish Peatland Conservation Council website.
What are peat soils?
Peat soils contain partially decomposed organic matter formed under wet, anaerobic (i.e. little or no oxygen) conditions. Peatlands cover approximately 1.46 million ha or 21% of Ireland's land surface. Peatland habitats include fens, blanket bogs, and raised bogs. These form in different ways and have their unique characteristics.
Fens are groundwater-fed, alkaline, and nutrient-rich, while bogs are rainwater-fed, acidic, and nutrient-poor. Blanket bogs formed on poorly-drained soil in mountains with heavy rain. Raised bogs formed in lakes in the Midlands of Ireland.
Peatland habitats store carbon, control the flow of water through the landscape, and support unique plants and wildlife. View fun facts about bogland biodiversity here .
The most important plant on bogs is Sphagnum moss. It has no root system, so absorbs nutrients from the surrounding water. Due to its sponge-like hyaline cells, it stores up to 20 times its weight in water and builds the bog as it grows and dies off. When there's a low water table, the hyaline cells fill with air and become bleached. This reflects sunlight and prevents further water loss.
Timeline of Farm Drainage
The reduced management intensity and rewetting of agricultural peat soils is contrary to what the government of Ireland has asked farmers to do in previous years. For the past 60 years or so, Ireland has encouraged farmers to make their land more productive and has provided grants to drain ‘marginal’ wet ground, including peaty soils. Farm families still have memories of helping their grandparents and parents to drain the land and convert it to profitable, productive grazing ground, something they were, in most instances, extremely proud to achieve (FarmPEAT farmers, personal communication).
The Department of Agriculture now intends to ask these farmers to reverse this back-breaking work. It is not expected that farmers will readily take this up unless they believe there is sound science and government commitment behind them. The results-based approach is a way of incentivising a change in management practices on farms. Therefore, the FarmPEAT Project was set up to pilot a results-based scheme on agricultural peat soils in the Midlands.
The timeline below is derived from Tuohy et al. (2023) and outlines the recent story of farm drainage of peat soils in Ireland:
Solution: Raising Water Table
In FarmPEAT, rewetting means managing the water table and reducing artificial drainage, it does not necessarily mean flooding the land or restoring it to peatland vegetation.
Figure 1. Raising the water table to within 30cm of the surface reduces carbon emissions but allows farming to continue.
The water table is the boundary between the unsaturated soil and saturated soil. The higher the water table, the more saturated the soil is with water. When soil is saturated, the lack of oxygen slows the decomposition of organic matter and the release of carbon. Therefore, the height of the water table is the single most important factor determining the greenhouse gas emissions from peat soils.
The good news is that we can partially raise the water table without flooding the land on the surface, enabling farming to continue. Evans et al. (2021) found that every 10cm increase in the water table reduces emissions by 3 tCO2e/ha/year. In other words, every little helps! In FarmPEAT, we aim for the water table to be at least within 30cm of the bank level.
What are the factors affecting the success of raising the water table?
These factors were explained in Dr Florence Renou-Wilson's webinar with Birdwatch Ireland in 2023:
- How long has it been drained or how long has it been rewetted?
- What is the vegetation on top?
- What is the current and past land management?
- What is the nutrient status?
- What is the residual peat depth?
- What is under the peat?
- What is the climate/geography/topography?
- Do you want to do active rewetting – can you easily yourself manage how much water is moving into the field or not? Is it independent on you? Are you mostly dependent on surface water or is the hydrology mostly subsurface?
- How intensively are you managing the site? How many cows, sheep, grass are you taking out of your site? Are you planning on going the whole way towards paludiculture use?
How to Raise the Water Table
Scroll to see the before-and-after of a peat dam installed at a project farm in Co. Roscommon. The black L-shaped pipe is placed at a height agreed on together with the landowner. Water flows in one end and out the other, which controls the level of water in the drain.
Scroll to see the before-and-after of a plastic dam installed at a project farm near Clonboley Bog, Co. Roscommon. The central notch is cut at a level agreed on together with the landowner. It allows water to continue flowing once it reaches the desired level.
Paying for Results
We developed six scorecards with habitat-specific criteria divided into ecological integrity, hydrological integrity, and damaging activities. Categories are weighted according to their relative importance. A higher score, indicating better habitat quality for nature, produces a higher results-based payment for the farmer.
- Low Quality (Score 0-3) = €0-75/ha
- Moderate Quality (Score 4-6) = €150-250/ha
- High Quality (Score 7-10) = €300-450 /ha
We had a scorecard for peatland, wet grassland, dry grassland, woodland, field boundaries, and the Whole-Farm Assessment.
Higher Nature Quality = Higher Payment
This is multiplied by the whole-farm assessment captures the farm’s overall risks to water quality and greenhouse gas emissions. E.g. livestock accessing drains and watercourses. It affects the final score as a multiplier:
- Very Poor Score = Payment reduced by 40%
- Poor Score = Payment reduced by 20%
- Good Score = Maximum Results-Based Payment
- Excellent Score = Payment multiplied by 20%
How can farmers increase their score?
Supporting actions are voluntary measures designed to enhance the environmental quality of participating farms. These actions aim to improve habitat quality, reduce risks to water quality, and enhance the hydrological condition of peat soils.
FarmPEAT funds 25-100% of the supporting actions. For example, some farm access improvements (e.g. footbridges) are 25-50% funded, water protection measures (e.g. fencing) are 50% funded, invasive species control (e.g. Rhododendron clearance) is 75% funded, and peat restoration measures (e.g. dam installation) are 100% funded.
- An annual works plan is made collaboratively between the project team and the farmer. It proposes potential supporting actions including their location, scope, and estimated costs.
- The farmer, with support from the project team, pays for and completes the work.
- The farmer submits a payment claim, including a declaration of completion and supporting documents, e.g. receipts or photos.
- The project team verifies the actions are completed to the standard set out in the specifications, this may involve a site visit.
- The project team submit a claim to the Department and then reimburse the farmer.
These supporting actions payments are additional to the results-based payment. They can help the farmer to improve their habitat quality and reduce environmental risks, therefore increasing their results-based payment for future years.
