Is the application of lignocellulosic material an effective carbon storage improvement technique to peatlands?

Peatlands form due to the slow rate of organic matter decomposition  characteristic of waterlogged and anaerobic conditions. The resulting organic matter accumulation acts as a long-term store of organic carbon. However, historical use of peatlands, such as peat extraction and drainage, has been detrimental to the carbon storing capabilities of these environments. With the UK’s set aims to achieve a net zero greenhouse gas emissions by 2050 there is an increased interest in the restoration and management of peatlands to help achieve these goals. Biochar has previously been applied to the surface of a peatland, encapsulating carbon for long periods of time due to its refractory nature. This method proved an effective carbon store whilst having no recorded significant or detrimental impact on the peatland itself. However, biochar production is expensive, and therefore, there is a desire to find a cheaper alternative.

This study has assessed the application of lignocellulosic material, specifically Calluna Vulgaris (heather) brash, to a peatland as an alternative to biochar addition. This study was performed on Hatfield Moors in South Yorkshire, UK. Employing a triplicate random block design with doses of 1 cm and 2 cm depth heather brash application alongside controls with no heather brash application. The plots were visited on a monthly basis for two years and monitored for:

• Peatland surface water quality monitoring – water table height, pH, ionic conductivity, UV absorbance at 400 nm, and organic carbon concentration;
• Peatland surface water nutrient concentration (nitrate and phosphate concentration);
• Peatland surface water terminal electron acceptor concentration (iron and sulphate concentration);
• Gas exchange of peatland (net ecosystem respiration, gross primary productivity, net ecosystem exchange) ; and
• Degradation of Calluna Vulgaris over the course of the study.

The study shows that heather brash could be a viable alternative to biochar as a means of augmenting carbon storage within peatlands.