Written Evidence submitted by Philipson Estates (SH0050)



This submission is made by Respira International and the Blaston Estate who concluded a pioneering transaction in 2022 to pay for the sequestration of carbon in 230 ha of arable land in Leicestershire.


We hope that lessons learnt from this transaction can assist the scaling of soil carbon opportunities in relevant scenarios across the UK, while acknowledging the limitations of the approach.


1.There is no definition of  “sustainably managed” soil. We suggest that this should be defined as soil which is in the process of restoring soil organic matter ( SOM ) – or at the very least maintaining levels of SOM and not degrading it.


2.Key to achieving sustainability is the adoption of regenerative principles – no plough; min till; cover crops and companion crops.


3.If regenerative practices are adopted on heavy clay that has been intensively farmed in the past, the opportunity for recovery is significant. Using the independent firm Ecometric, and Loss on Ignition testing at NRM laboratories, we have measured increases of 9 tonnes CO2 per acre per annum.


4.A number of challenges exist on measurement.


a) cost, partly driven by capacity issues at laboratories. The Sustainable Farming Incentive  ( SFI ) offering Pds 40 / ha goes some way to helping, but doesn’t cover the full cost of physical soil sampling.


b) accuracy, which can be overcome by adopting rigorous testing methodologies ie up to 50 core samples per ha mixed; and one blended sample sent to the lab – thereby avoiding the random readings from individual spots in the field. There also needs to be consistency in laboratory testing ( eg LOI or Dumas ) and measurements of bulk density.


c) lack of standardization. At present, there is no agreed approach on depth of sample – should it be 30cm; 60 cm or deeper ? nor on frequency of sampling. As most microbial activity occurs in the top 30cm of the soil, and that is the source of most emissions of CO2 if ploughing occurs, we suggest that measurement should be adopted at 30 cm as standard, with farming practices committing to no disturbance below 10 cm.


d) issues also arise on “permanence” – the length of time a landowner commits to non-reversal of farming practices. The longer the permanence period, the more valuable the credits should be – but farmers will be reluctant to enter into very long, possibly inter-generational, commitments.


e) there is also the question whether farms should only be able to sell credits net of all farm emissions, or be able to segregate eg the arable portion of a holding and monetise sequestration on that portion alone.


5.Restoration of soils across different types of agricultural land


Carbon markets can only reward “additionality” ie the increase in levels of C as measured from one year to the next. There is no mechanism to reward “maintenance” of existing stocks which are likely to be high on permanent pasture and organic land.


There are practical difficulties in engaging with smaller holdings when every transaction is bespoke. And NB clay soils have greater potential to sequester C than other classifications.




In order to promote sustainably managed soils, decisions need to be made on the extent to which it is practical to obtain funding from carbon markets to effect change. The lack of standardization; the fragmentation of ownership; the multiplicity of soil types and the challenges of measurement lead one to conclude that carbon markets may have a role on clay based arable holdings of 1,000 acres plus……but the concept will be challenging to apply to grassland; to existing soils that are sustainably managed; and to smaller holdings.


To trade with confidence, at price levels that would be attractive to farmers, carbon markets require quality credits generated on a measured, not modelled, basis.


The alternative is to design a Government funded scheme in which payments are based on modelling assumptions that reflect the adoption of regenerative farming practices; supported by baseline measurements and 5 yearly updates to ensure accountability and value for money.


February 2023