The importance of soil carbon monitoring

New schemes are emerging for soil carbon management, whether through supply chain incentives or carbon offset markets, so ensuring land managers have the correct information to use potential income is increasingly important.

“The first course of action is to have a baseline. This will provide you with an understanding of where you are in terms of soil carbon,” explains Becky.

When considering where to take soil samples, Becky advises selecting a range of fields that best represent the farm and its soils, accounting for soil texture, cropping, land use and management. “The more soil samples you take, the better the information you will have to identify land requiring carbon investment and prioritise where carbon inputs should go to maximise sequestration and farm efficiency.

“I strongly advise taking samples in the spring or autumn and not just after cultivation, especially ploughing. Ideally, leave at least three months and avoid sampling just after spreading manure or slurry as this can also skew results. It’s good practice to record the timing of the sampling and the conditons, as this may influence soil health results.

“Depth is important,” she stresses. “It’s good, if you can, to sample to 30cm and also split out 0-10cm and 10-30cm as the levels will be different. This helps establish where it might be possible to build carbon, especially in grassland systems where carbon levels at 0-10cm may already be high.”

Once you have the baseline, you can then review your land management and consider ways to improve your overall carbon status.

“To improve grassland, ensure there are periods of rest within the rotation. This allows the grass roots to fully recover and elongate, which builds rooting mass, accesses nutrients and improves resilience.”

Tracking farm carbon is key to becoming carbon neutral

Becky also suggests you could look to improve diversity within the grassland. “This helps produce a variety of rooting depths which can improve biological activity and as such, resilience and nutrient availability. Also, by incorporating legumes you can reduce fertiliser applications and save money.

“Generally speaking, the less disturbance a field has, the more organic carbon there is. Therefore, grasslands typically have more carbon than arable fields. With this in mind, arable farmers should review tillage management. Reducing the amount of cultivations has a positive impact on soil carbon as well as saving fuel and labour. Adding high carbon cover crop mixtures to your rotation is also beneficial.

“For all systems, manures and slurries are a great source of organic matter to feed into the soil. Using an even coverage across the farm makes the most of this fantastic resource.”

Efforts to improve and track carbon levels have many practical benefits for both crop and livestock farmers, as well as possibly becoming a necessity and income stream for all future farming systems. “It potentially lowers your carbon footprint, so tracking carbon will inform you of your progress in creating and maintaining an efficient and ‘carbon neutral’ farming system,” she concludes.

For more information, visit https://farmcarbontoolkit.org.uk