SoNaRR 2025: Soil

Natural Resources Wales

This webpage is part of the State of Natural Resources Report 2025

Formed by the weathering of rocks and minerals and the accumulation of organic materials, which often takes hundreds to thousands of years. Soil formation is a continuous process although rates of loss can be much greater than formation and therefore should be treated as a non-renewable resource. Soils are the foundation of land, ecosystems and habitats.

Key messages

  • Healthy soils are key to supporting our terrestrial ecosystems and providing a diverse range of ecosystem services that benefit our communities.
  • The state of soils across Wales are generally stable, with some initial indications of topsoil carbon loss in arable soils, and high phosphorus levels and localised compaction in improved soils.
  • Climate change and unsuitable management practices are the key concerns for future trends of soils. Soils in a degraded state are less resilient to climate change.
  • We must use and manage soils in ways that maintain and enhance soil organic matter; protect soil from erosion; maintain and improve soil structure; protect and foster soil biodiversity; and balance soil nutrient cycles. 
  • Timely, accessible, and meaningful data sharing is essential for sustainable soil management. Collecting detailed, long-term data on Welsh soils is crucial for tracking trends, targeting interventions, and assessing policy effectiveness.

Assessment of SMNR

This soils assessment is one of three natural resource and eight ecosystem assessments that inform the overall SoNaRR2025 report. It builds on the findings of SoNaRR2020, drawing together updated evidence from subject experts, national datasets, and collaborative projects such as the National peatland action programme. This assessment is closely linked to all ecosystem and resource assessments.

The assessment is structured around four interlinked aims that guide Wales’ progress toward the sustainable management of natural resources (SMNR), helping to communicate the relationship between the environment, well-being, and the economy.

Aim 1: Stocks of natural resources are safeguarded and enhanced

Soils in Wales face multiple pressures that threaten their long-term health and productivity. Climate change is a major driver, with wetter winters, warmer summers, and more frequent storms increasing erosion and compaction risks. These changes are geographically variable but affect soil workability periods throughout the year, reducing resilience and impacting agriculture, forestry, and ecosystem services. Pollution also poses some challenges. While nitrogen and sulphur deposition have declined, nutrient enrichment and other pollution remain a concern, affecting soil quality, and contributing to ecological harm.

Efforts to enhance soil resources include monitoring erosion and compaction, which are localised in improved grasslands. Topsoil carbon levels are stable overall, but losses are evident in arable and horticultural areas. Excess phosphorus is increasing, with more sites exceeding leaching thresholds, posing risks to water quality. Policy responses include the Agricultural Soil Policy Statement (2025) and the upcoming Sustainable Farming Scheme (2026), which aim to improve soil health through more sustainable land management and reduced pesticide use. These initiatives support integrated strategies to protect and enhance soil as a finite natural resource.

Aim 2: Ecosystems are Resilient to Expected and Unforeseen Change

Soils underpin ecosystem resilience by supporting biodiversity through the provision of ecosystem services such as regulating carbon, nutrient, and water cycles. Healthy soils reduce downstream impacts on freshwater and marine ecosystems by limiting sedimentation and nutrient runoff. However, degradation through erosion, compaction, and nutrient imbalance threatens ecosystem stability. Contaminated land also disrupts ecosystem functions, with pollutants migrating into water systems and affecting coastal and freshwater habitats.

Progress includes the Sustainable Farming Scheme (2026), which promotes soil health and habitat connectivity, and the Agricultural Soil Policy Statement (2025), which prioritises soil function and data sharing. The National Peatland Action Programme has restored over 3,600 hectares; addressing hydrology and erosion issues, and completed restoration actions over a further 8,000ha to improve habitat and protect the peat resource. Actions to maintain soil structure, adopt holistic land management, and sustainable farming practices are key to enhancing resilience. These efforts aim to mitigate climate-driven pressures and support long-term ecosystem health across Wales.

Aim 3: Healthy Places for people, protected from environmental risk

Soils contribute to healthy environments by storing carbon, filtering water, and supporting food production. Welsh soils hold an estimated 410 million tonnes of carbon, but poor management can lead to emissions, particularly from degraded peatlands. Contaminated land poses direct risks to human health through exposure to toxic substances. Over 9,000 sites in Wales require inspection, with at least 414 considered high priority. Remediation is costly and often reliant on redevelopment through planning systems.

Peatlands in good condition help store carbon, regulate flood risks by reducing rapid flushes of water, and have a reduced fire risk ensuring resilience for the provision of clean drinking water. Restoration efforts under the National Peatland Action Programme have improved hydrology and reduced fire and flood risks. Regulatory measures such as the Water Resources (Control of Agricultural Pollution) (Wales) Regulations 2021 and the updated UK Forestry Standard (2024) aim to reduce nutrient pollution and protect soil downstream. Continued collaboration, improved data on contamination, and integrated planning are essential to safeguard public health and environmental quality.

Aim 4: Contributing to a Regenerative Economy, Achieving Sustainable Levels of Production and Consumption

Soils are central to Wales’ economy, supporting agriculture, forestry, and water supply. In 2024, agriculture employed 12,200 people and contributed £1.1 billion to the economy. However, soil degradation from compaction, erosion, and nutrient imbalance reduces productivity and resilience. Arable land, though limited in extent, faces particular risks from crops like maize and oilseed rape, which are more likely to degrade soil structure. Built development and infrastructure also threaten soils through sealing, loss of high-grade land, and loss of peat, contributing to loss of valuable soil resource.

Restoration of peatlands and improved planning guidance offer opportunities to protect soil resources. The Agricultural Soil Policy Statement (2025) and Sustainable Farming Scheme (2026) promote sustainable practices and environmental benefits. While past schemes like Glastir had few positive outcomes for soils, new approaches aim to better integrate soil health into economic planning. Protecting soils from development, adapting to climate pressures, and restoring degraded areas are vital for a regenerative economy that balances production with long-term sustainability.

Key changes since SoNaRR2020

Welsh soils remain broadly stable across measures and ecosystems, but show some initial indication of topsoil carbon decline for arable land and broadleaf woodland, and an increase in arable soil bulk density. Soil acidity shows trends of reversing previous recovery, with pH declining in semi-natural habitats and bogs. Phosphorus enrichment has worsened on improved land. Soil biodiversity remains poorly understood; no new national data exists, though mesofauna decline has been linked to intensive land use, chemicals, and extreme weather. Pressures have intensified: climate change is driving heavier rainfall and droughts, increasing erosion and compaction risks, and sea-level rise could remove up to 3% of Best and Most Versatile land by 2100. Crops with a higher risk for soil erosion have expanded in area, and pollution concerns remain including microplastics and PFAS alongside legacy nutrients.

Read the full Soil assessment in our State of Natural Resources Report 2025.

Read this assessment



Underlying evidence

In writing our assessments and to better identify opportunities for action we have gathered evidence that helps us understand these key aspects:

  • the drivers of change and pressures on soil in Wales.
  • the state and trends of state of soil in Wales.
  • the benefits and dis-benefits provided by soil in Wales, depending on its state, and the impacts these can have on human well-being and ecosystems.

Access the detailed evidence through our SoNaRR 2025 Evidence portal.

View full screen version.

Evidence needs

Evidence gaps remain in understanding Welsh soils at local, regional and national scales. Comprehensive baseline data across land uses and soil types is required. Particularly emphasis on stability, erosion, compaction rates, carbon stocks and sequestration potential and their variability under extreme weather. Soil biodiversity is poorly understood, with limited national data and uncertainty around the impacts of pesticides and veterinary medicines. Evidence on the extent of soil loss through sealing and land take from development, and the interaction of climate change and land use, as well as long-term effects of forestry and afforestation on organo-mineral soils and greenhouse gas balances are insufficient. These gaps limit our ability inform resilient land management.

Further evidence is also needed to improved understanding of nutrient dynamics, especially phosphorus and micronutrients in a Welsh context. Research is required on existing and emerging threats to soil. These threats include the fate, transport and ecological risks of pollutants, as well as contaminated floodwaters and pathways. Predictive modelling of soil responses to combined pressures like drought and flooding, and socio-economic links between soil condition, productivity, and water quality, are also required.

Read SoNaRR 2025 Evidence needs.

Key evidence sources

Explore some of the evidence we have used to inform our assessment:

Case studies

The National Peatland Action Programme

The National Peatland Action Programme is a 5-year plan of peatland restoration in Wales, 2020 – 2025. Restoration action on over 1650 hectares in the first two years means the programme surpassed its initial restoration targets of 600-800 hectares of public and private land every year.

Natural Resources Wales / The National Peatland Action Programme

 

Sustainable Farming Scheme

Welsh Government’s Sustainable Farming Scheme (SFS), which starts in 2026, aims to support farmers in the sustainable production of food whilst addressing both the climate and nature emergencies. It addresses the Sustainable Land Management objective in the Agriculture (Wales) Act 2023 to maintain and enhance ecosystem resilience. The scheme will support climate resilience and should support Nature Based Solutions.

Introduction to the Sustainable Farming Scheme | GOV.WALES

 

Agricultural Soil Policy Statement

The Agricultural Soil Policy Statement (published April 2025) raises awareness of soils in the policy landscape and sets out the vision for the sustainable use and management of agricultural soils for future generations.

Agricultural Soil Policy Statement | GOV.WALES

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