Written Evidence submitted by Professor Jim Harris, Cranfield University (SH0058)

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 how can these barriers be overcome?

Rolling out soil measurements to all land users, not just those opting in to the recently announced ELMS and associated schemes - measurement of Soil Organic Matter (SOM) and other parameters need to be carried out in a consistent and coherent way, would be a good start. 

Soil scientists have been recommending that SOM be measured routinely for at least a decade, if not two, and yet there has been little movement to apply it, until recently.  Confounding issues include how best to measure parameters, particularly SOM – the solution is to pick one and stick with it – we are looking for sign of change, not absolutely precise amounts.  We see the same issues arising in, for example, air monitoring with a desire to measure accurately to the nth degree, whereas in fact we mainly need to know if soil condition is getting better, worse or staying the same. Although it may take some time to detect the effects of changes in soil management, if we had started measuring SOM two decades ago we’d have 20 years data by now. Soil is our biggest terrestrial resource, but we don’t know by and large what state it is in, until it ends up in our surface waters, or is blown across the landscape.  Recent work to link soil condition to the delivery of Ecosystem Services is also a good step forward.

It is also worth noting that we should be considering good management practices wherever soil is being handled or affected, and for guidelines to be universally applicable, be this in agricultural production, the management of semi-natural areas, or civil engineering.  Although there is an understandable focus on soils in agricultural contexts, this is not the whole picture.

Remote sensing offers great opportunities to monitor our natural resources, including soil, and needs to be deployed consistently at a large scale, with any necessary ground truthing. Also emerging evidence of emergent properties, such as “critical slowing down”, may enable pinpointing areas at risk, offering opportunities to inspect and intervene to correct management practices.

Challenges - what is soil health? The use of the term “soil health” has brought significant problems, since its widespread adoption in the 1990s, not least because it led to calls from regulators for a single indicator of an extremely complex system – if not the most complex system on the planet.  We don’t measure human health with a single indicator, for example.  Essentially only organisms and systems can have “health”, and this can only be measured dynamically, and crucially by detection of emergent properties, such as resilient response to perturbation.  Point measurements of simple components can only take us so far, and this approach has led to significant understanding, but do not take us far enough – long term data gathering and dynamic measurement of diversity, complexity (including soil architecture) will be required to see at which scale emergent properties manifest. If you cannot detect them, then you are either looking at the wrong scale, the wrong property, or not looking at a system at all.  Focus on these system level characteristics will allow us to determine direction of travel from degradation to “health” in a comprehensive systems-based way. (see Harris JA, Evans DL & Mooney SJ, 2022, A new theory for soil health. European Journal of Soil Science, Article No. e1329. DOI: https://doi.org/10.1111/ejss.13292).  In the meanwhile, it is more logical to recognise that “soil health” is a useful metaphor, or shorthand for discourse, and soil condition is a better term for scientific understanding at this point – but don’t expect that a single number will summarise condition or effects of management.

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

Most obligations seem to revolve around reducing or eliminating offsite harm, rather than purely on-site consequences – and even then enforcement seems to be rather hit and miss.  Regulations may be in place, but that will not stop some instances of misbehaviour, and outright reckless treatment of soil. 

Crucially, routine, consistent and comprehensive measurement of soil condition should be seen as an “Passport” for access to ELMS/SFI and other schemes, as good soil condition is fundamental to the other components of sound land management, rather than an optional extra in a menu. What is more the SFI agreements are currently for 3 years only – it will probably be at least 5 years before significant change in soil condition is detectable.  Short term tenancies are a barrier to adoption also.

Support for land owners who are moving from conventional to conservation and regenerative practices would also lead to more take up, to compensate for losses during conversion before premiums on produce may be claimed.  Similarly “wilding” should be supported in some circumstances, beyond support for food production alone as a key crossover between food centric and wildlife/ecosystem recovery programmes.

3) Will the standards under Environmental Land Management schemes 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?

Unless this is rolled out to all farms (and for that matter anyone managing soils) we shall not be seeing the whole picture. Lack of measurement and monitoring leads to an inability to manage effectively, and there is no requirement to do this as a basic measurement.  This could lead to continued degradation of soils on a wide scale, with concomitant implications for air and water quality, food security and biodiversity loss. Soil condition measurement should be allied to routine measurement of surface water quality – essential if we are to improve land management generally and secure ambitions to reverse the loss of biodiversity, and restore ecosystems, whilst producing good quality food sustainably.

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?

Trusted intermediaries: Currently there is no “one stop shop” for farmers and landowners to get impartial advice consistently across all cognate areas for soil, farm/landholding and landscape scale management.  Making such advice available routinely from the public sector could give land managers confidence, and enable large scale alerting, research and action. This would allow the translation of research into easily digestible synopses linked to practical advice, as a result of a coherent response to issues arising in the land management sector.

Certification: It would be worth considering certification for anyone managing land on a large scale, and certainly for food production, especially if there are going to be soil operations – i.e. a permit to practice.  Management of all other large infrastructure requires such certification – why not soil? 

It will also be good to take a look at what agricultural colleges are offering as part of their core curriculum – is soil management and practices to move along the reduced intensity of input spectrum from intensive through conservation to agro-ecological approaches being offered as essential?

References

Harris JA, Evans DL & Mooney SJ (2022) A new theory for soil health. European Journal of Soil Science, Article No. e1329. DOI: https://doi.org/10.1111/ejss.13292

February 2023