Revegetating a Challenging Railway Embankment

TerrAffix trial vegetated embankment

TerrAffix Soil Solutions was invited by Murphy Rail to trial our re-vegetation system on a rail embankment that was proving particularly challenging.

The site was a steep slope of thick, cold clay sub-soil and it was susceptible to heavy run-off over the winter. Previous attempts at establishing vegetation had failed as this sort of soil can be a difficult material for new plants.

Clay can shrink and expand in response to heat and water and it can go from being very wet and cold to very dry.

These changes can sometimes happen quite quickly, making it difficult for plants to cope.

TerrAffix trial in background

TerrAffix trial in background

To get plants to grow it is essential to provide the basis for life: moisture, sufficient organic matter to act as a soil-forming material, nutrients and a stable surface during germination.

Following the site survey we decided to use a two-stage revegetation system for the most effective results. We began with an application of TerrAffix-HydraSoil with a microbiological inoculant and a nutrient carrier. This mixture also helps to retain water within the developing root zone during the summer months.

We applied our own fully biodegradable tackifier formula which is composed of a mixture of natural, plant-based materials and sugars. No polyacrylamide was used, which is an everyday tackifier used in hydroseeding.

We then applied a coat of TerrAffix-HydraMulch with seed and natural plant nutrients. This application creates a stable surface on steep slopes, securing the seed in place through germination.

Vegetated soil on the railway embankment post treatment with TerrAffix-HydraSoil and TerrAffix-HydraMulch

Vegetated soil on the railway embankment post treatment with TerrAffix-HydraSoil and TerrAffix-HydraMulch

We selected seeds from a mixture of fast-establishing species to get some initial cover as well as some deep rooting species. Deep rooted plants tend to be more resilient to drought and act as natural near-surface ground anchors.

The application was made in November which happened to coincide with above-average rainfall. Nevertheless the vegetation established successfully and created a robust, resilient sward.

A key material we use is biochar which is produced at our centre. Biochar not only confers a considerable advantage to plant growth but also sequesters atmospheric carbon dioxide.

Our products come with a carbon lock guarantee which can be accounted for within any corporate social responsibility targets.