Written Evidence submitted by Professor John Quinton (SH0014)

1         How can the Government measure progress towards its goal of making all soils sustainably managed by 2030? What are the challenges in gathering data to measure soil health and how can these barriers be overcome?

1.1          Recognise that soil is essentially a non-renewable resource (Soil formation rates in the UK are between 0.026 to 0.096 mm yr1 [1]), but a critical national infrastructure which we rely on for food, clean water, flood prevention, biodiversity and carbon storage.

1.2          Understanding soil change requires a combination of monitoring and modelling. Monitoring to understand the current state of our soils, how they have changed and to provide data for modelling. Modelling is needed to understand the future trajectories of soil change.

1.3          Currently there is no active soil monitoring scheme in England. Previous schemes include the National Soil Inventory carried out by the Soil Survey and Land Research Centre at a 5 x 5 km resolution across England and Wales in 1980 (6,127 points) and partially resurveyed in 1995 (about 1/3 of points). There is also the soil component of Countryside Survey carried out by CEH, last conducted in England in 2007 with 591 sample squares across England, Scotland and Wales. 

1.4          National scale soil modelling, such as that on soil carbon change[2], offers the potential to forecast soil health change in response to management changes under schemes, such as ELMS, but is hampered by poor availability of basic soil information.

1.5          Basic soil information for England and Wales collected between 1939 and 1985, covers approximately 25% of the country’s soils. These c25% are surveyed at scales better than 1:50,000. National coverage is available only at 1:250,000 scale and behind a paywall.

1.6          1:250,000 mapping is not suitable for local decision making i.e. where to site a housing development.

1.7          The non-availability of open high resolution soils information is stifling innovation in the agri-environmental sector.

1.8          Cost remains a barrier to collecting soils information. Advances in digital soil mapping, soil sensing, remote sensing and proximal soil sensing offer opportunities to streamline data collection and reduce cost. However, they will not completely remove the necessity for field-based data collection.

1.9          Additionally rapid throughput soil analysis offers the potential to streamline and reduce the cost of soil analytical procedures. Approaches such as near infrared spectroscopy have been used successfully in other countries.

1.10      There is potential for citizen scientist to be used to collect soil samples and make some basic field observations leading to some cost reductions.

2         Do current regulations ensure that all landowners/land managers maintain and/or improve soil health? If not, how should they be improved?

2.1          Current regulations have had little impact. Soils are poorly represented in legislation and are the poor relation of air and water. There is no mention of soil in the 2021 Environment Act. There is provision in the Agriculture act (2019) for protecting or improving the quality of soil. I am unaware of any statutory protection for soils.

2.2          The soil action plan for England is eagerly awaited, but there is concern that it will not offer legal protection for our most vulnerable soils.

2.3          There is little protection for soils on constructions sites. 28 million tonnes of soil material from construction is dumped in Landfill each year. More than is estimated to be lost from Agricultural land via soil erosion.

3         Will the standards under Environmental Land Management schemes (ELMs) have sufficient ambition and flexibility to restore soils across different types of agricultural land? What are the threats and opportunities for soil health as ELMs are introduced?

3.1          The entry level ELMS scheme with its emphasis of promoting year-long soil cover is welcomed[3]. However, this is a first step and while having the potential to control erosion and enhance soil organic matter it fails to address other aspects of soil health.

3.2          Soil disturbance via tillage, particularly on steep slopes, is a major threat to soils.  Our recently published work in Nature Food[4], demonstrates that significant amounts of soil are moved downslope by tillage and that this increases the impacts of droughts on crop production. By reducing soil depth tillage is also likely to have a significant negative impact on soil fertility and soil health.

3.3          Ploughing grasslands to reseed releases significant amounts of carbon and has a negative impact on soil biota.

3.4          Incentivising zero or minimal cultivations would protect UK soils on slopes for future generations.

4         What changes do we need to see in the wider food and agriculture sector to encourage better soil management and how can the Government support this transition?

4.1          Promote the principles of conservation agriculture: cover the soil, minimise soil disturbance, promote plant diversity.

4.2          Revise and republish the code of good agricultural practice for soil (current version is 2009).

4.3          Legislate to prevent unsustainable practises e.g. maize potatoes and other row crops growing on steeper slopes.

4.4          Promote research and innovation in the livestock sector to provide evidence of best practices that protect soils.

4.5          Translate advances made in the arable sector to soil management in grasslands e.g. controlled traffic to minimise compaction and precision farming approaches.

5          What does the UK Government need to do to tackle other stressors on soil health such as soil contamination?

5.1          Perhaps the single biggest stress is the removal, storage and compaction of soils associated with the construction industry. Significant amounts of soil are sent to landfill each year. The government’s own figures suggest 28 million tonnes. This is far in excess of that which is estimated to be lost via soil erosion.

5.2          Soil carbon losses associated with soil loss from construction sites may be significant. Assuming soils contain 5% carbon and 28MT of soil removed gives 1.4 million tonnes of soil carbon sent to landfill. To put in context UK CO2 emissions from agriculture are estimated at 5.5 million tonnes[5] CO2 of which 1.5 MT is carbon: Almost the same value. The fate of soil carbon which is landfilled is unknown.

5.3          It is recommended that eight principles to reduce the loss of soil from construction sites outlined in Building on Soil Sustainability: principles for soils in planning and construction[6] are adopted.  They are: plan, design and construct for soil functions; engage local communities and stakeholders on soil issues; reuse or share soil; maximise permeability; minimise compaction; stockpile correctly; minimise erosion; and learn through training.

[1] Evans DL, Quinton JN, Tye AM, Rodés Á, Davies JAC, Mudd SM, Quine TA. 2019. Arable soil formation and erosion: a hillslope-based cosmogenic nuclide study in the United Kingdom. SOIL 5: 253-263. DOI: 10.5194/soil-5-253-2019

[2] Janes-Bassett, V, Bassett, R, Rowe, E, Tipping, E, Yumashev, D & Davies, J 2021, 'Changes in carbon storage since the pre-industrial era: a national scale analysis', Anthropocene, vol. 34, 100289. https://doi.org/10.1016/j.ancene.2021.100289

[3] https://theconversation.com/bare-winter-fields-to-disappear-as-part-of-new-plan-for-healthy-greener-countryside-173190

[4] Quinton, J.N., Öttl, L.K. & Fiener, P. Tillage exacerbates the vulnerability of cereal crops to drought. Nat Food 3, 472–479 (2022). https://doi.org/10.1038/s43016-022-00533-8

[5] Defra 2022.  Offical Statistics. Agri-climate report. Total CO2 equivalents 44.8 MT.

[6] R. O’Riodan, J. N. Quinton, J. Davies, P. Hatch, S. Dart, R. Richards, A. Birchall, et al. 2022. Building on Soil Sustainability: Principles for Soils in Planning and Construction. Lancaster: Lancaster University. Available from www.soiltaskforce.com