Carbon levels in agricultural soils can be accurately measured and used as the basis for payments to farmers, a committee of MPs has been told.

“There are challenges. It is not going to happen quickly. Changes in carbon stocks occur over five, 10 or 20 years,” said Professor Pippa Chapman from the University of Leeds.

“It is long-term, and you need to think about the permanency of that carbon. There is the potential to release carbon back into the atmosphere,” she added.

Speaking in Westminster on Tuesday, Chapman raised concerns about existing schemes where farmers capture carbon from the atmosphere and sell credits to other businesses who then use these credits to reduce their own greenhouse gas emissions on paper.

“Currently these carbon markets are unregulated and so farmers have a lack of confidence in them. They are unsure whether to engage with private finance. I think there is an urgent need to regulate carbon markets,” she said.

Chapman told MPs that tests for calculating soil carbon levels are “expensive and time consuming” although she pointed to the Soil Nutrient Health Scheme (SNHS) in NI where all farms here are getting offered free soil tests over a four-year period.

“They are currently doing a baseline for the soil nutrient and carbon status of all farms,” she explained.

The SNHS was also praised during the meeting by Richard Bramley from the National Farmers’ Union, who suggested that a similar initiative should be rolled out in England.

“In NI, soil testing is a government service. That is something that would be a really good step. From that, you would gather a lot of data, although you need to be very careful about how it is used,” he said.

“The data belongs to the farmer but it can be aggregated to create pictures of a baseline and then incrementally over time you can start to see how that alters,” the Yorkshire arable farmer said.