How biosolids nourish crops and build healthy soil
Biosolids provide nutrients and organic matter that support crop production and soil condition.
When applied to agricultural land in accordance with regulation and the Biosolids Assurance Scheme (BAS), biosolids are used as part of a planned nutrient management approach alongside other organic materials and manufactured fertilisers.
Applying biosolids on farm
Biosolids are typically used as part of a wider approach to managing soil condition and nutrients on farm and are recycled to agricultural land to:
Contribute organic matter to support soil condition and long-term soil management
Provide nutrients such as nitrogen and phosphorus as part of a planned nutrient management approach
Work alongside manufactured fertilisers and other organic materials to support balanced nutrient use
Fit within crop rotations, where timings allow for planned applications
Suitability is assessed on a field-by-field basis. This ensures biosolids are recycled to land in a way that is appropriate for the specific soil, crop and local conditions. This approach supports the responsible use of biosolids within agricultural systems.
Biosolids in agriculture
Recycling biosolids to agricultural land is a long-established practice in England, Scotland and Wales.
- Each year, around 3.6 million tonnes of biosolids are recycled to agricultural land
- This is applied across approximately 150,000 hectares
- This represents a relatively small proportion of total agricultural land in Great Britain
What biosolids provide
Biosolids contain nutrients and organic matter that contribute to soil and crop management when applied in accordance with regulation and the Biosolids Assurance Scheme (BAS).
| Component | What it contributes on farm |
|---|---|
| Nitrogen (N) | Contributes to crop nutrient requirements |
| Phosphorus (P) | Supports nutrient supply where required |
| Other nutrients | Sulphur, potassium and magnesium |
| Organic matter | Contributes to soil structure and water retention |
Organic matter and soil condition
Maintaining soil organic matter is an important part of long-term soil management.
Biosolids provide organic matter that supports:
| Area | What this supports on farm |
|---|---|
| Soil structure | Soil workability and structure over time |
| Soil biology | Soil biological activity |
| Water retention | Moisture retention in some soil types |
| Nutrient cycling | Breakdown of organic material and nutrient release |
Working with your nutrient management plan
Biosolids are typically integrated into a wider nutrient management plan, based on:
- Soil analysis
- Crop requirements
- Existing nutrient inputs
This helps ensure nutrients are applied at appropriate rates and in line with regulatory controls.
How biosolids are applied
The use of biosolids on agricultural land is regulated and follows a structured process to ensure applications are appropriate for the field, crop and conditions.
This typically involves:
Soil sampling and field assessment
Checks on suitability and restrictions
Crop and rotation planning
Rates set in line with regulation and crop need
Application at appropriate timings
Use of suitable spreading methods
Nutrient inputs incorporated into farm records
Applications recorded
Regulation
Recycling biosolids to agricultural land is subject to environmental and agricultural regulation to reduce and prevent diffuse pollution from nutrients.
Biosolids may also be supplied under the Biosolids Assurance Scheme (BAS):
The BAS Standard sets requirements across treatment, storage, transport and recycling
Conformance with the Standard is independently verified through audit by a UKAS-accredited Certification Body
Certification applies to defined activities within the scope of the audit and is subject to ongoing oversight
Understanding biosolids in context
Biosolids are a treated material derived from sewage sludge, which arises as part of wastewater treatment.
Recycling to agricultural land in Great Britain:
Is a long-established practice
Operates within a defined regulatory framework
Aligns with the UK waste hierarchy, which prioritises recovery over disposal
When managed in accordance with regulation and defined standards, it contributes to returning nutrients and organic matter to the soil.