Conservation verge trials

Dorset has over 4970 miles of rural verges. It is one of the most undervalued habitats in the county yet requires a lot of resources to manage. We spend vast amounts each year cutting verges but reductions in our resources mean we need to question the way we do things and why.

This project aims to improve the biodiversity in our verges and reduce the need for seasonal cutting.

Our aim is to:

• reduce costs
• seek alternate sources of revenue
• seek innovative ways of managing verges whilst maintaining road safety and complying with our statutory functions 

About the trials

If we continue to maintain our verges the way we have in the past:

• costs will increase
• safety will reduce
• more cuts will be required

What the trials aim to achieve

The aim of these trials is to determine whether new ways of managing the verges will produce cost savings in the long term. We need evidence to show that different management techniques will work.

The trials will involve different methods of management with the overall aim to reduce the soil fertility within the verge itself. This reduction in fertility will have the benefit of reducing the growth in the grass sward. To achieve this we will:

• strip topsoil to expose low fertility subsoil or mineral rock
• harvest "mini bales" from the roadside verges where applicable
• monitor subsequent growth to determine success, future maintenance needs, biodiversity enhancement and public perception
• create wildflower rich verges

Outcomes

The exposed subsoil will have low fertility compared to the topsoil and therefore require little maintenance once initial weed growth is suppressed. Removing cuttings by baling or other methods rather than allowing them to rot will reduce fertility and cutting frequency. The verges where bare mineral rock is exposed may require no annual cutting for up to 10 years. Those verges which have been harvested may only need one cut and collect after a few years. Both types of trial area can develop into wildflower rich meadows which are attractive and help provide a valuable source of nectar for bees, butterflies and other pollinating insects.

Additional benefits

The trials tie in with current fertility reduction projects and the use of parasitic wildflowers such as Yellow Rattle which reduces grass growth. We have been using these plants on certain junctions where we have found that there has been a reduction in grass growth and enabled better visibility. The trials can help deliver significant biodiversity and landscape benefits particularly when carried out adjacent to existing wildlife sites. Any topsoil excavated can be used for woodland tree planting which can be managed as a future biomass crop. Where there are suitable verges that can produce bales, these can be sold as animal bedding to help recover costs.

Carbon reduction

An idea that we wish to develop is the installation of biomass generators in rural areas across the county. The amount of food waste that households throw away and the quantity of grass that can be collected from the verges may enable the production of electricity via these biomass generators. If there is merit in this idea, the potential could be that we turn a waste product into a valuable resource. Given the necessity to cut verges throughout the county, this idea could create a sustainable method of managing the verges for the future and have the added benefit of generating clean electricity helping to reduce carbon emissions.

Current areas

• Blandford
• Sandford
• Spetisbury
• St Leonards and St Ives
• Upton
• Verwood
• Wimborne

We plan to cut these areas twice a year and remove all the cut material. Cutting periods will be in June and late summer. By cutting the plants just as they come into flower, it will encourage them to flower again for a longer period over the summer months.