Co Cavan: Landscape dominated by drumlins and lakes

Co Cavan is located along one of the most extensive drumlin fields in the world, so it is no surprise that the landscape here is dominated by drumlins interspersed with lakes. Drumlins consist of a thick cover of boulder clay that got deposited as ice retreated at the end of an ice age, resulting in small hills.

The northwest of the county is mountainous and this area is home to blanket bog found over sandstone and shale bedrock. There are many notable features in this area, including the Marble Arch Caves that are recognised by UNESCO as being of exceptional geological heritage.

To the east of this, the majority of the landscape is dotted with drumlin topography. For the most part, the drumlin areas of Co Cavan are associated with wet soils. Surface-water gleys predominant in glacial drift composed of limestone and sedimentary stones are commonly found on the slopes.

The inter-drumlin areas tend to be found with basin peat. Further east, around Bailieborough, the landscape is less wet and is better described as well-drained shale hills with lowlands comprised of sedimentary glacial drift.

The soils found here include brown earths on bedrock generally found towards the top of the slopes, with surface-water gleys found further downslope on glacial drift. Luvisols (downward clay movement) can be found occasionally interspersed with the brown earths. Many rivers have their source in Co Cavan, including the Shannon, which is the longest river in Ireland. Surface-water gleys are the most commonly found soil type in Cavan. These soils occur due to a slowly permeable sub-surface layer that impedes the movement of water through the soil profile. The presence of a grey coloured clay horizon will indicate gleying. These soils are widespread in Cavan, especially between the higher mountainous areas in the northwest and the lower areas in the east and southeast. The majority of these are the Kilrush series, found in association 0700h led by subgroup 0700.

Slower permeability

The slower permeability of these soils, coupled with their higher clay content, means that these are ‘heavy’ soils from a farming perspective and have limited use range. Typically, grass production is the optimum agricultural use for these soils. For grazing, good management is essential to reduce the risk of poaching.

Stagnic brown earths are the second most prevalent soil types in the county, and are commonly found around Kilnaleck, Ballyjamesduff and Cootehill. Most of these are the Moord series (found in association 1130a led by subgroup 1130). These tend to have a fine loamy texture with sedimentary stones. They are generally found on upper slopes and are suitable for improved grasslands. The wetness and plastic consistency of the topsoil are likely to be the main limitations when working with these soils.