Early indicators to monitor changes in soil health: evidence to update guidance for UK farmers (research call)

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

Contract Reference: Early indicators to monitor changes in soil health

Contract period: October 2025 – March 2026

Publication date: 5 August 2025

1. Introduction

The Agriculture and Horticulture Development Board (AHDB) is a non-departmental Government body, funded by levy income from farmers, growers and others in the supply chain, and managed as an independent organisation (independent of both commercial industry and of Government). The role of the AHDB is to help improve the efficiency and competitiveness of various agriculture sectors within the UK. Our purpose is to help our farmers, growers and industry to succeed in a rapidly changing world.

As AHDB is funded in this manner, value for money is paramount, and we welcome suppliers who can offer innovative and cost-efficient solutions to meet our needs, whilst also offering superlative service that will enable us to create a world-class food and farming industry. Solutions should look to help us not only reduce costs but increase business flexibility, lift productivity, bring people together to collaborate, innovate and drive change throughout. Further information about AHDB can be found here: https://ahdb.org.uk/

This document is an invitation to tender for a project to collate and evaluate UK-relevant data to provide evidence for cost-effective soil health indicators that can detect change when used on a frequent (e.g. annual or seasonal) basis to track soil health improvements.  The aim is to provide information to support levy-payers in measuring and monitoring soil health on their own farms, based on an improved understanding of which metrics i) are most practicably suited as sensitive yet robust early indicators of change, backed by validated data, and ii) can be further integrated as an interim measure into a longer-term on-farm soil monitoring regime.

Submissions should be based on the information contained within this document and in the format outlined in section 8.  Deadlines and submission instructions are contained in section 10.

2. Background

Good soil health is pivotal for UK agriculture, to maintain sustainable productive systems and deliver a range of environmental functions such as carbon cycling and storage, nutrient cycling, water regulation, and habitat for soil biodiversity. Simple yet robust indicators to measure and monitor soil health, along with an associated interpretation framework, are key to making informed decisions about soil management approaches, and to track and demonstrate improvements using site-specific data. Correlating improvements in soil health with desired outcomes such as improved productivity, economic gains, or delivery of environmental benefits also remains vital to inform decision making on-farm.

On a national scale, there has been substantial work undertaken on soil monitoring, with various initiatives underway (see Approaches to Soil Monitoring across the Four Nations - LUNZ Hub). Examples include the Soil Nutrient Health Scheme in Northern Ireland, the England Ecosystem Survey (as part of the Natural Capital and Ecosystem Assessment Programme), and the UKCEH Countryside Survey, the latter two covering a broad range of habitats. Soil health indicators have recently been extensively reviewed to inform the development of an indicator for soil health in England (25 year Environment Plan Outcome Indicator E7). 

At farm-level, and with a focus on sustainable productivity, the soil health scorecard was developed through the AHDB-BBRO Soil Biology and Soil Health Partnership (2017-2022). The scorecard brings together core physical, chemical, and biological indicators of soil health, and provides farmers and agronomists with a benchmarked traffic-light system to help inform where management interventions might be required to improve soil structure, pH and nutrient balance, soil organic matter, or biological activity. The scorecard was developed to assess soil health on a rotational basis (every 4-5 years), returning to the same geo-located spot in the field to track changes routinely over time. It is integrated into a range of resources available via the AHDB GREATsoils webpage to support soil management decisions. The soil health scorecard has also been referenced as a tool to help support suppliers in meeting sustainability goals, and was highlighted as a source of guidance for the Sustainable Farming Incentive action CSAM1.

As it does for governments, supply chains, and wider industry, the topic of soil health remains a priority for levy-payers. A key question being asked is how quickly improvements will be seen in soils following a change in management. This is an important consideration for practical decision-making, and to maintain a positive trajectory in sustainable soil management.

The core indicators selected for inclusion in the soil health scorecard were shortlisted from a longer list of potential metrics and measures. In-field assessments (e.g. visual evaluation of soil structure or earthworm counts) can be carried out as frequently as required, to track progress in between the full suite of soil health indicators being tested routinely once every 4-5 years.  

Other soil health indicators that are not included on the scorecard have potential to be used on a more regular (e.g. annual) basis to indicate that progress is being made towards improved soil health and delivery of environmental functions. However, quantifiable evidence from a range of soil types and farming systems may be lacking to provide a robust dataset and interpretation framework relevant for UK agriculture, to improve guidance at farm-level.

3. Related information

Some examples of recent AHDB soil health projects include:

A review of soil health indicators has recently been published by JNCC: Review and evaluation of existing soil health indicators being used in the UK and internationally. JNCC Report 737: Annex 1

4. Purpose of the tender

The intention of the current AHDB research call is not to develop novel metrics and indicators of soil health. Applicants should consider the large body of work that has already been done on assessing soil health indicators. 

This call is for a short-term project to collate and review evidence specifically for existing soil health indicators that are most informative for use as an interim measure of soil health, which can be used to track progress in soil health improvements on a short-term (e.g. annual or seasonal) basis. The focus is on UK-relevant data. Outputs will be used to update AHDB guidance for farmers on practical soil health assessments and are expected to complement the AHDB soil health scorecard.

Findings from this project will also inform future research on measuring and monitoring agricultural soil health and environmental functioning. Relevant indicators (and interpretation framework) may be tested at scale in future years to obtain further data and support knowledge exchange.

The focus of the current project is to examine the existing evidence base for relevant soil health indicators (as described), with reference to UK agro-climatic conditions and soil types. Applicants are expected to specify which indicator(s) their proposal will cover, with justification for inclusion. The option is available to include soil sampling and analysis within the project to add new data for different soil types or systems, where gaps have already been identified, although this is not an essential requirement. Note that the project timeframe does not allow for yield or harvest data to be collected within the duration of this project.

5. Tender Objectives

Proposals should build on existing research (funded by AHDB and others) to deliver the objectives outlined below. The output should aim to improve levy-payer confidence in measuring and monitoring soil health, based on an improved understanding of which metrics i) are most suited as early indicators of change, backed by validated data, and ii) can be further integrated as measures of interim progress into a longer-term on-farm soil monitoring regime, in a cost-effective way.

1. Identify indicators that are most useful and practicable on-farm as early indicators of change for the following outcomes:
   1. Agricultural productivity (e.g. yield, cost of production)
   2. Environmental function (e.g. carbon storage, water regulation, nutrient cycling)
2. Critically evaluate the evidence for the chosen indicators, considering the following (non-exhaustive list):
   1. Availability and robustness of independent data, relevant to UK agriculture
   2. How clearly the indicator can be linked to an outcome
   3. How responsive or sensitive the indicator is, to be able to track progress in improving soil health on a short-term basis (e.g. annually or seasonally)
   4. Sampling strategies required - including temporal and spatial replication, location, frequency and correlation with other environmental factors - to account for high levels of soil variability (i.e. ease of sampling and/or assessment)
   5. How cost-effective the measure is
   6. Ease of interpretation of results to provide actionable insights
3. Identify any related evidence to show links between the soil health indicators and quantification of economic value (e.g. increased yield, reduced inputs)
4. Produce an interpretation framework for farmers based on robust and repeatable data, and consider how this can be integrated into the soil health scorecard, highlighting where further development may be required
5. Produce a final report
6. Optional: Soil sampling - with adequate replication - and analyses to add to the evidence base and to inform the development and/or validation of the chosen indicator(s).

A final project report will be required along with participation in our annual project monitoring exercise. Further information and example templates for these reports can be found at AHDB Cereals & Oilseeds research report templates.

6. Scope and Approach

The scope covers UK farmland soils (all soil types and systems, for arable and grazed land). Indicators under consideration should be relevant to both agricultural productivity and environmental functions (e.g. carbon cycling and storage, water regulation or nutrient cycling), and evidence and data should be relevant to UK agro-climatic regions.

The project should consider indicators beyond those included as core metrics on the AHDB soil health scorecard. Inclusion of biological indicators would be welcomed, including direct measures and/or proxy measures of soil biological functioning, linking presence or activity of soil biology to outcomes (productivity or environmental function). In-field assessments should be accessible to farmers or have the potential to be developed for wider uptake in the near future.

7. Project Duration, Budget, and Collaboration

AHDB has set aside a maximum total budget of £34,000 inclusive of VAT, over 5 months.

Joint proposals from two or more contractors are acceptable and encouraged where there is added value. AHDB may, if it is deemed desirable, request applicants to form a consortium to work together. There should be one organisation designated as the lead organisation for the Research Partnership which is responsible for project management and delivery. The group size should be manageable. Prospective partnerships can comprise both research institutes and industrial partners, be multi-disciplinary, and draw on a range of research experience for a number of crops. Therefore, the group does not necessarily need to have a history of working together previously. Further, priority will be given to the applicants with in-kind and or cash funding from the industry.

8.Structure/format of submission

Applicants should complete AHDB Research and KE Application Form - Full Proposal Small, referring to the guidance notes to aid completion. Applicants should also refer to Section 9 below for criteria used in evaluation of proposals, noting that this replaces the “Full project proposal assessment form” on page 12 of the full proposal document.

Completed application forms should be submitted to research@ahdb.org.uk no later than 12:00 noon on 15 September.

The earliest date of commencement for work funded as a result of this call will be 13 October 2025.

On submitting a proposal, please ensure you have read and accepted our terms and conditions, these are available on our website here under the “Standard contracts” heading. Any organisation receiving funding from AHDB shall comply with the terms and conditions specified in the Research Funding Agreement. AHDB will not be held responsible for any expenses or losses incurred by applicants in the preparation of an application(s).

AHDB reserves the right to not proceed with any application or, if appropriate, to request applicants to form a consortium to work together to deliver a programme of activities.

An evaluation panel will assess submissions in line with the scoring criteria and weightings in Section 9 to decide the best outcome for this research project. The selection will be an open and fair competition according to AHDB’s procurement policy, which complies with the UK’s international subsidy control commitments.

9. Evaluation and award of contract

All submitted proposals will be reviewed by cross-sector research representatives within AHDB, and members of the Research and Knowledge Exchange Committee. If required, external peer reviewers may be sought. The selection will be an open and fair competition according to AHDB’s procurement policy, which complies with the UK’s international subsidy control commitments.

Evaluation of proposals will be on the following basis:

10. Proposal submissions

Quotes must be received by 12:00 noon on 15 September 2025. Submissions to be made electronically to research@ahdb.org.uk with the subject line 'Early indicators to monitor soil health - PROPOSAL'. Submissions will remain unopened until after the closing date and time has passed.

11. Timetable

Please note these timescales are approximate and may change.

A project initiation meeting will be held between the successful bidder and the project funders at the commencement of the contract.  Additional meetings will be held as required for progress updates.

12. Terms/conditions of participation

Research and KE funding | AHDB terms and conditions shall apply to any contract awarded as a result of this request for quote.

If you have specific questions relating to this call, please email research@ahdb.org.uk. All Questions & Answers will be published.

As part of the open tender process, AHDB cannot discuss specific programme details prior to proposal submission.

If you have any questions relating to this tender please contact research@ahdb.org.uk with the reference 'Early indicators to monitor soil health - QUESTION'

Download this invitation to tender as a PDF here

13. Questions and Answers

Q1: Is attention to be directed towards on-farm indicators performed by farmers (such as aggregate stability/VESS/worms) or to support supply chain credentials (e.g. claims about regenerative practices, supporting evidence for biodiversity credits etc). 

 A1: The aim is to support farmers in monitoring their soil health. 

Q2: As there is an interest in using technology for soil health by farmers (e.g. Barclays agri-tech report) but neither the scorecard nor JNCC report include these developments e.g. Chirrp or farmland bird count - bird monitoring as a proxy of soil health, ecoacoustics - recording soil sonoscopes (spatio-temporal complexity of ecological processes)  etc. would 'soil' sampling comparing these approaches, if appropriate, to the scorecard. 

A2: We are open to any suggestions on how the soil health could be monitored, However, it would not be appropriate for levy money to be used to undertake testing that a commercial organisation should do themselves to test the accuracy of their products 

Q3:  The call text states that: “Applicants are expected to specify which indicator(s) their proposal will cover, with justification for inclusion.” Please can you clarify whether shortlisting and screening of indicators is expected to have taken place at the proposal development stage, or whether shortlisting and screening of indicators is expected as part of Objective 1 (“Identify indicators that are most useful and practicable on-farm as early indicators of change…”). 

A3: The call is not intended to be prescriptive in the approach taken.  However, as noted in the call text, applicants should consider the large body of work that has already been done on assessing soil health indicators. 

Where suitable candidates for early indicators of change have already been identified through previous research (either the applicant’s own research or more broadly), applicants could build on this work in the current call, to extend the evidence base for one or more specific metrics.  In which case, applicants should justify why the chosen indicator(s) are the focus of the bid. 

Equally, where applicants intend to evaluate a broader range of early indicators to monitor change in soil health (which may have been shortlisted at the proposal stage), the call includes the scope to evaluate the evidence base for these using the applicant’s preferred/chosen approach.  

Q4: Is farmer/industry consultation expected within this project, and if so, what format should that take? 

A4: Although not an essential requirement, input from stakeholders (including farmers) would be welcomed at any stage of the project where this would add value.  Where any form of industry/farmer consultation is included in the proposal, applicants should provide details and justification of the approach taken (examples of activities include workshops, surveys/questionnaires, focus groups etc).  

Q5: The ITT notes sampling is optional. Would AHDB consider a small, highly targeted sampling effort (e.g. on 3–4 contrasting sites) a valuable addition, or should the emphasis be solely on desk-based evidence collation? 

A5: AHDB is open to a range of approaches to deliver the project objectives. Targeted soil sampling and analysis could be a valuable addition to the project where evidence gaps are already known to exist, and where resultant data would increase the robustness of the UK evidence base for specific indicator(s).  Inclusion of soil sampling and analysis is optional to allow flexibility in the approach taken to deliver the project objectives; proposals will be evaluated on their merit according to the criteria outlined in the ITT. 

Q6: Is formal economic modelling required to demonstrate a link between soil health indicators and economic value (e.g. yield, reduced inputs), or is it sufficient to collate and summarise existing evidence? 

A6: Existing evidence should be identified, collated and summarised to demonstrate any links between soil health indicators and economic value.  Formal economic modelling is not required for this call, although applicants are welcome to include this as part of their proposal, providing details and justification of the approach taken. 

Q7: How long is the interpretation framework expected to be (e.g. concise decision-support summary vs. detailed technical guidance)? Similarly, what length/level of detail is anticipated for the final project report? 

A7: There is no set length for the interpretation framework, although it is expected to be understood and used by farmers/land managers, aligned with the AHDB soil health scorecard approach. A more concise interpretation framework should be backed by robust evidence detailed in the final report.  

There is no set length for the final report. However, it should provide sufficient detail to fully describe the project activities/methods, as well as including full results, interpretation and discussion.  Examples of previous research reports can be found online here: Soil Biology and Soil Health Partnership | AHDB 

A report template will be provided, and the AHDB project manager will provide feedback on early drafts before the report is finalised for publication. 

Q8: Should the critical evaluation be based only on publicly available resources (published papers, reports, datasets), or can it also include private data and qualitative experience contributed by consortium members (e.g. farm trials, adviser records), provided methods are transparent? 

A8: All data sources can be considered, provided methods are transparent.  The availability and robustness of independent data should be critically evaluated as part of the project.  

Q9: Is the AHDB interested in looking at soil health in cereal and oilseed rape only or would you be interested in grazing stock fields as part of this bid? 

A9: The scope for this call covers UK farmland soils - all soil types and systems, for arable and grazed land.  

Q10: Would the AHDB look for a differentiation in early soil indicators between wheat and oilseed rape cropping systems? 

A10: Indicators should be applicable to all UK agricultural systems and not be specific to one cropping system.    

Qs Contract queries: 

i. Please can you confirm if you will consider any amendments to the proposed contract template if our submission is successful, or if it is fully non-negotiable? 

Although we can consider minor amendments on a case-by-case basis we always prefer to use our standard terms where possible. 

 ii. Clause 4.1 of the agreement is not clear and has two options (either Annex 2 applies or Annex 3 applies in regard to intellectual property). Please can you clarify which annex is applicable to the agreement? 

 This will be agreed with the successful applicant at the time of contract award; however, it is not the intention for AHDB to take ownership of pre-existing IP at the time of contract award. 

 iii. Clause 4.5.1 notes that AHDB’s Terms and Conditions for the Purchase of Goods and Services shall apply in addition to the RFA Terms to the provision of such goods and services. Please can you provide us a copy so that we can have sight of these? The agreement notes that these T&Cs prevail over the RFA T&Cs 

These are available on AHDB’s website here: https://ahdb.org.uk/research-and-knowledge-exchange-funding-applications 

 iv. Clause 6.3 – it is not clear whether this clause should read as “amended and agreed in writing by both parties”. Please can you clarify 

 Yes, liability changes do need to be agreed by both Parties in writing. 

 v. The contract price is inclusive of VAT, can we have confirmation as to who will be responsible for paying VAT? 

If your organisation is registered for VAT then you should be invoicing with VAT. We are not in a position to offer VAT advice 

 vi. Can clause 6.2(b) be amended as follows: (b) the maximum aggregate liability of the Researcher shall be the greater of £100,000 or 125% of the cumulative total of the payments identified in Schedule B. 

 Changes to the liability clause, if any, will be agreed with the successful applicant at the time of contract award.