Early indicators to monitor changes in soil health: evidence to update guidance for UK farmers

The challenge

Soils are the foundation of agriculture and provide a range of ecosystem goods and services, helping to regulate the climate and water, sequester carbon and cycle nutrients. Understanding and improving soil health is part of the UK Government's 25-year plan to improve the environment.

Many recent research projects have contributed to the definition of soil health, including its component parts and their measurement. Further to improving knowledge, this research has also revealed the complex nature of soil health, which encompasses a wide range of physical, chemical, and biological properties.

Additionally, there are many UK soil types in a wide range of environments (e.g. climate/weather and agricultural systems). As a result, each field has its own unique soil fingerprint. The AHDB soil health scorecard was developed to help farmers manage this complexity, as part of the AHDB/BBRO Soil Biology and Soil Health Partnership (which concluded in 2022).

The scorecard provides a consistent way to track changes to soil health on a rotational basis (every 4 to 5 years). It uses practical indicators of the physical, chemical, and biological condition of soil and benchmark values to highlight potential issues (using a traffic-light system) and ways to address them. It has been cited as a tool that can help meet sustainability goals and a source of guidance for Sustainable Farming Incentive (SFI) actions that cover soil management planning.

The project

This desk study will explore whether it is possible to use additional field assessment methods to monitor soil health changes more regularly (e.g. on an annual or seasonal basis).

The work will use the expertise of a multidisciplinary team to propose candidate early indicators of soil health (EISH) that are sensitive to recent changes in soil management and linked to an improvement in the delivery of ecosystem goods and services in the long term (including those linked to agricultural productivity).

The researchers will use a ‘logical sieve’ framework to provide an objective and quantitative means to rank the candidate indicators. The framework simply scores each of the indictors against defined criteria. In this project, the criteria are:

• Data robustness
• Links to ecosystem services
• Sensitivity to agricultural management
• Ease of sampling
• Cost-effectiveness
• Interpretability

The scoring process will be informed by a review of knowledge from a variety of sources, including the literature and open-data repositories, as well as consultation with experts, commercial laboratories, agronomists, farm advisors and other industry stakeholders.

The work will also develop detailed guidance (an interpretation framework) for the top three ranked indicators, based on rates of change and thresholds, which can account for key variables, such as soil texture, climate and cropping system.

The intention is to develop guidance that is complementary to the traffic-light approach in the soil health scorecard.

Finally, the research will provide a comprehensive summary of the state of evidence for all indicators considered in the project, as well as highlight knowledge gaps.

The core project objectives are as follows:

1. To produce a ranked list of EISH based on a critical evaluation of the strength of evidence, linked to the delivery of key ecosystem services from soils and agricultural production, sensitivity to management change, cost effectiveness, and optimal sampling approach.
2. To refine the ranked list of EISH through engagement with industry to identify robust and reliable EISH that will be most practical and economical to implement, acceptable to the farming community, while producing results that are easy to interpret and actionable.
3. To produce an interpretation framework for the EISH and promote its use as a complement to the existing soil health scorecard approach.

The partners

The project is led by Organic Research Centre (RSK ADAS Ltd). SRUC is a collaborating organisation that will specifically examine the potential to integrate EISH into the current soil health scorecard.

*Non-AHDB funds

The project has secured £9,750 (in-kind funds) from collaborating companies providing expertise and perspectives on soil health analysis:

• Vedant Carbon: £3,750
• Hill Court Farm Research: £3,000
• Frontier Agriculture: £1,500
• Eurofins: £1,500

Providing answers to your questions

This research project was funded via a levy-payer-led commissioning process.

View the original research call for this work