A newly-published study compiled from a Teagasc-led project looking at the relationship between rainfall and water levels on peat soils will be crucial to identifying sites on which to roll out water-table management measures.

The project took measurements at four fens and two raised bogs between September 2023 and last August to determine the relationship between rainfall, water table fluctuations and soil water storage capacity.

The measurements revealed that fen peat sites “were significantly more” deeply drained than raised bogs, despite both land types assessed having similar drainage systems in place.

They also showed that water levels in raised bogs were less reactive to rainfall, drought and artificial drainage, where the fen peat sites assessed had a larger reaction to rainfall and seasonal variability in water levels.

Teagasc has said these results reinforce previous findings which found that, although there are around 340,000ha of grassland on peat soils, there are just approximately 140,000ha that is effectively drained.

It also stated that actively managing the water table of peat soils will be an “important tool” in meeting the EU-wide target of net zero emissions by 2050, as when water levels drop on peat soils, emissions increase.

“Peat soils are being targeted for active water table management, but it is essential that we understand the initial water table behaviour at such sites so that their potential response to water table management can be predicted,” study author and Teagasc researcher Patrick Tuohy said.

Its lead author Hilary Pierce suggested that the water-level fluctuation measurement system used in the study can give insights to “whether a site has potential for rewetting and enables the targeting of specific types of carbon farming efforts to specific sites”.

Fluctuations on in the water table of fen peat sites will make future water table management in areas with these land types “more challenging”, Pierce commented.

The head of Teagasc’s climate centre Karl Richards said that the findings highlight the need peatland water management to be tailored on a site-specific basis.

“Such tailored approaches are essential for maximising carbon storage potential and supporting climate action across European grassland landscapes,” Richards added.