Digestate Spreading: Equipment, Best Practice and Application Methods

Digestate spreading is an essential final stage of many anaerobic digestion (AD) operations. Choosing the right equipment, calibrating it correctly and applying digestate at an appropriate time can improve nutrient recovery, reduce fertiliser costs and limit ammonia emissions, soil compaction and water pollution.

However, digestate is not simply livestock slurry under another name. Its dry matter content, fibre characteristics, readily available nitrogen and contamination risks can vary considerably according to feedstock, digestion conditions and separation equipment.

This technical guide explains digestate spreading equipment, application methods, machinery selection, calibration and best practice, with particular reference to England’s regulatory requirements as they stand in October 2026.

It also preserves three historical digestate spreading equipment case studies from the original article published in October 2018.

Key Takeaways: Digestate Spreading Best Practice

• Analyse digestate before spreading: Determine dry matter, total nitrogen, ammonium nitrogen, phosphorus, potassium and other relevant characteristics.
• Select equipment for the material: Liquid digestate generally suits low-emission band spreading or injection equipment; fibrous digestate requires suitable solid-manure spreading machinery.
• Prefer low-emission application: Trailing hose, trailing shoe and shallow injection systems can reduce ammonia losses compared with splash-plate broadcasting, subject to operating conditions.
• Calibrate spreading equipment: Accurate flow measurement, forward speed, working width and distribution uniformity are essential.
• Protect soil structure: Consider axle loads, tyre pressures, soil moisture, compaction risk and field access.
• Follow a nutrient management plan: Application rates should reflect soil and crop requirements rather than simply the quantity of digestate available.
• Check current rules: England’s Farming Rules for Water, applicable NVZ requirements and digestate waste-status conditions must all be considered.

What Is Digestate Spreading?

Digestate spreading is the controlled application of anaerobic digestion residue to agricultural land or other land where its use is appropriate and legally permitted.

Digestate is the material remaining after microorganisms have converted part of the biodegradable organic matter in a digester into biogas.

It typically contains water, residual organic matter, mineral solids and nutrients including nitrogen, phosphorus and potassium.

Digestate can be used as a fertiliser or soil amendment where its quality, nutrient content and legal status allow. However, its agricultural suitability cannot be assumed merely because it has undergone anaerobic digestion.

For a fuller explanation of digestate composition and agricultural nutrient value, read our related guide: Digestate Fertilizer: What It Is and How to Use It in Agriculture.

This article concentrates on the machinery and engineering involved in spreading the material accurately and responsibly.

The Three Main Digestate Fractions and Their Spreading Requirements

The physical characteristics of digestate are particularly important when selecting pumps, pipelines, tankers, applicators and spreading machinery.

1. Whole Digestate

Whole digestate is the material discharged from the digester before mechanical separation into liquid and solid fractions.

It is generally pumpable, although its dry matter content and rheological properties vary considerably.

Digestate produced from cattle slurry may behave differently from that produced from food waste or fibrous agricultural feedstocks.

Whole digestate may be suitable for tankers or umbilical spreading systems, provided the pumps and applicators can handle its solids, fibres and viscosity.

If at this point you need refresher on the basics of digestate, here is the YouTube video we made a good few years ago, on the subject:

2. Liquid Digestate or Separated Liquor

Liquid digestate is commonly produced by mechanically separating whole digestate using equipment such as a screw press or centrifuge.

Depending on the separation process, it may contain substantially less suspended material than the original whole digestate.

Liquid digestate is often well suited to:

• Trailing hose and dribble-bar spreading equipment.
• Trailing shoe applicators.
• Suitable shallow injection systems.
• Umbilical pumping and distribution arrangements.
• Tankers equipped with accurate flow and application controls.

Nevertheless, separated liquor can still contain fine suspended solids, grit or residual fibres capable of blocking distribution systems. Filtration or maceration requirements should be established before selecting equipment.

3. Separated Digestate Fibre

The solid fraction normally contains a higher proportion of fibres, residual organic matter and solids.

It may be sufficiently stackable to be handled and spread using appropriate manure spreaders, depending on its dry matter content and consistency.

Suitable systems include rear-discharge or side-discharge solid-manure spreaders, sometimes equipped with beaters or spreading discs.

Conventional liquid-digestate applicators are not suitable for spreading stackable fibre.

Separated fibre should be assessed for nutrient content, stability, contamination and storage requirements. It must not be assumed that separation has removed contaminants or rendered the material safe for unrestricted agricultural use.

Digestate Spreading Equipment: Main Types Compared

Selection of a digestate spreader should consider the material to be handled, required application rate, field conditions, transport distance, pumping requirements and the environmental performance of the application method.

1. Splash-Plate and Broadcast Spreading Systems

Traditional splash-plate systems project liquid slurry or digestate into the air and distribute it across the ground surface.

They are mechanically straightforward and may have relatively low capital costs, but their open distribution method creates substantial contact between liquid digestate and the atmosphere.

This increases the potential for ammonia volatilisation, particularly in warm, windy or dry conditions.

Some digestates contain high concentrations of ammonium nitrogen. Consequently, ammonia losses during surface broadcasting can reduce their fertiliser value considerably.

Where low-emission application equipment is available and suitable, it is generally preferable to conventional splash-plate spreading.

Practical assessment: The low purchase cost of a splash-plate applicator should be weighed against potentially greater ammonia losses, odour and reduced nutrient recovery.

2. Trailing Hose and Dribble-Bar Applicators

A trailing hose system distributes liquid digestate through multiple flexible hoses mounted on a spreading boom.

The material is deposited in bands close to the ground rather than being projected into the air.

This generally reduces the exposed surface area and airborne dispersion compared with splash-plate spreading.

Key advantages include:

• Reduced ammonia emissions under suitable conditions.
• Potentially improved fertiliser nitrogen recovery.
• Less aerosol production and drift.
• Suitability for both tanker-mounted and umbilical systems.
• Relatively straightforward integration with wide spreading booms.

However, trailing hoses can leave digestate on grass leaves or crop surfaces. This may reduce some of the potential ammonia-saving benefits and affect subsequent grazing or forage harvesting arrangements.

Distribution uniformity depends on correct flow division, hose condition, material characteristics and applicator maintenance.

3. Trailing Shoe Digestate Spreaders

A trailing shoe applicator uses shaped outlets that run close to the ground, often parting grass or vegetation to deposit digestate towards the soil surface.

This can reduce contact between digestate and the crop canopy compared with ordinary trailing hose equipment.

Trailing shoe systems are particularly relevant to grassland, where accurate low-level placement can improve nutrient use and help reduce crop contamination.

Advantages include:

• Application near the soil surface.
• Reduced vegetation contamination under suitable conditions.
• Potentially lower ammonia losses than broadcast spreading.
• Useful application on established grassland.

Disadvantages include increased equipment cost, additional mechanical complexity and the need to ensure the shoes maintain suitable contact with uneven ground.

Selection should also consider the material’s fibre content and risk of blockage.

4. Shallow Injection Systems

Shallow injection systems place liquid digestate beneath or within the upper soil layer using discs, tines or other injection equipment.

Because less digestate is exposed directly to the air, properly operated injection systems can provide substantial reductions in ammonia emissions.

Some systems create narrow slots, while others disturb the soil more extensively.

Injection may be attractive where maximising ammonium nitrogen retention is a priority.

However, its suitability depends on soil condition, crop type, root damage risk, stones, slope and field access.

Potential disadvantages include:

• Greater draught requirements and fuel consumption.
• Increased machinery weight or power demand.
• Potential soil disturbance and compaction.
• Risk of crop or root damage.
• Unsuitability for some stony, shallow or very wet soils.
• Higher machinery purchase and maintenance costs.

Injection equipment should not be selected solely on the basis of potential ammonia reduction. Soil damage and field suitability must also be considered.

5. Umbilical Digestate Spreading Systems

Umbilical spreading systems pump digestate from a storage tank, lagoon or temporary receiving facility through a long hose to a tractor-mounted applicator.

The tractor carries the applicator and manages the flexible supply hose rather than transporting a full tanker load across the field.

This arrangement can reduce the weight imposed on the soil by the spreading tractor.

It can be particularly useful for large volumes of pumpable digestate and fields accessible from a fixed or temporary pumping station.

Typical system components include:

• Feed storage or intermediate reception tank.
• Pumping equipment.
• Appropriate maceration or screening equipment.
• Main supply pipeline or lay-flat hose.
• Flow measurement and pressure monitoring.
• Field applicator with trailing hoses, shoes or suitable injection equipment.
• Hose-handling and retrieval equipment.

Umbilical systems require careful hydraulic design. Excessive friction loss, unsuitable pump selection, fibres, grit and long hose lengths can cause poor performance or blockages.

Hose routing also introduces risks at gateways, public rights of way, roads, ditches and field boundaries.

Operators should have arrangements for preventing and responding to hose failures and digestate spills.

6. Tanker-Based Digestate Spreading

Digestate tankers transport the liquid directly to the field applicator.

They may be mounted, trailed or integrated into specialist self-propelled machines.

Advantages include operational independence from long supply hoses and flexibility when working across multiple separated fields.

Disadvantages may include substantial field traffic, high axle loads, greater compaction risk and increased time spent travelling between storage facilities and fields.

Large tankers may be unsuitable for fields with limited load-bearing capacity, narrow gateways or difficult access.

Where digestate must be transported substantial distances, a combination of road tankers, temporary reception storage and an umbilical applicator may provide a more effective arrangement.

7. Solid Digestate Fibre Spreaders

Separated digestate fibre normally requires solid-manure spreading equipment rather than liquid-handling systems.

The most appropriate spreader depends on:

• Moisture and dry matter content.
• Stackability and bulk density.
• Presence of long fibres or cohesive lumps.
• Required spreading width.
• Target mass application rate.
• Ability to achieve a uniform transverse distribution.

Solid spreaders should be calibrated by measuring actual material output and checking the distribution pattern across the effective working width.

Spreader performance with ordinary farmyard manure should not be assumed to represent performance with separated digestate fibre.

Digestate Spreading Equipment Comparison Table

The table is a qualitative engineering comparison. Actual environmental performance depends on material characteristics, machine configuration, operating conditions and application timing.

How to Choose the Right Digestate Spreading Equipment

Before purchasing or hiring machinery, the operator should establish a design brief based on the expected annual digestate quantity and the fields receiving it.

Digestate Composition and Pumpability

Confirm the dry matter range, suspended solids characteristics, fibre content, grit, viscosity and any known contamination problems.

Consider the possibility that feedstock changes will alter these characteristics during the year.

Where necessary, carry out pumping trials using representative digestate rather than relying exclusively on data obtained from water testing.

Annual and Seasonal Spreading Volumes

The machinery must have sufficient operational capacity to complete applications during suitable weather, soil and crop conditions.

Calculate the annual digestate volume and the realistic number of available spreading days.

Allowance should be made for maintenance, transport, rainfall interruptions, seasonal cropping and any statutory closed periods.

Transport and Field Access

The distance between digestate storage and receiving fields can have a major influence on equipment selection.

Tankers may be suitable for dispersed holdings, whereas an umbilical system may offer logistical advantages for large quantities spread over connected field blocks.

The assessment should consider public roads, crossing points, gradient, soil bearing capacity and access restrictions.

Application Accuracy and Nutrient Recovery

A suitable machine should apply digestate consistently at the intended rate and working width.

It should also minimise avoidable ammonia losses and prevent significant runoff or soil damage.

Accurate spreading is particularly important where nutrient application rates are constrained by crop requirements or environmental rules.

Digestate Spreader Calibration: A Practical Engineering Guide

Incorrect calibration can lead to under-application, over-application, uneven crop growth, wasted nutrients and pollution.

Calibration should therefore form part of the equipment commissioning process and be repeated when material characteristics or operating arrangements change.

Step 1: Determine the Required Application Rate

Start with the nutrient management plan, recent digestate analysis and soil and crop requirements.

The intended nutrient contribution should then be converted into a target digestate application volume or mass per hectare.

Do not assume that a previously used spreading rate remains appropriate after changing feedstocks, separation equipment or digestate storage arrangements.

Step 2: Check the Flow Meter and Delivery System

Verify that the flow measurement equipment is suitable for digestate and is maintained and checked in accordance with its manufacturer’s instructions.

Confirm that the displayed flow corresponds reasonably with measured volume delivered over a known interval.

Where no reliable meter is fitted, a controlled volume or mass discharge test may be necessary.

Step 3: Calculate Forward Speed and Working Width

For liquid digestate, application rate can be estimated using:

Application rate (m³/ha) = 600 × flow rate (m³/min) ÷ [forward speed (km/h) × effective working width (m)]

For example, consider:

• Measured flow: 2.0 m³/minute.
• Forward speed: 6 km/hour.
• Effective spreading width: 12 metres.

The resulting application rate is:

600 × 2.0 ÷ (6 × 12) = 16.7 m³/ha.

This is an illustrative calculation, not a recommended nutrient application rate.

Actual rates must be checked against the nutrient content of the digestate, crop needs, legal restrictions and site-specific environmental risks.

Step 4: Check Distribution Uniformity

Correct total flow does not guarantee that digestate is being distributed evenly across the applicator width.

Check individual outlets for blockage, uneven discharge, damaged hoses and incorrect distributor settings.

Where practical, carry out an outlet discharge or distribution test using representative material.

Step 5: Record and Verify Performance

Useful records include:

• Date and field identification.
• Area treated.
• Digestate source and analysis reference.
• Target and measured application rates.
• Total volume or mass delivered.
• Machine calibration and operator details.
• Relevant weather and ground conditions.
• Any incidents, adjustments or equipment faults.

These records can support both operational performance reviews and regulatory compliance.

Soil Compaction, Field Traffic and Spreading Efficiency

Digestate spreading machinery can damage soil structure if heavy equipment operates when the ground is insufficiently strong to support it.

Compaction may reduce drainage, restrict root growth, increase surface runoff and reduce crop performance.

Equipment selection should therefore consider:

• Machine and tanker mass when fully loaded.
• Individual axle loads.
• Tyre dimensions and operating pressures.
• Wheel traffic patterns.
• Soil moisture and bearing capacity.
• Field gradient and access arrangements.
• Opportunities to minimise unnecessary passes.

Umbilical systems can reduce the need to move heavy liquid loads across fields, but the spreading tractor, hose equipment and any support vehicles can still cause damage under unsuitable conditions.

Similarly, low-ground-pressure tyres can reduce some surface pressures without eliminating the effects of heavy axle loads at depth.

The most effective soil-protection measure is often to postpone spreading when conditions are unsuitable.

Ammonia, Odour and Pollution Prevention

Digestate spreading must be managed to reduce nutrient losses and other environmental impacts.

Minimising Ammonia Emissions

Liquid digestate may contain a substantial proportion of nitrogen in ammonium form, which is susceptible to ammonia volatilisation when exposed at the soil surface.

Important mitigation measures include:

• Using suitable low-emission spreading techniques.
• Minimising the time digestate remains exposed before incorporation, where incorporation is appropriate.
• Avoiding unnecessary application during conditions likely to increase ammonia losses.
• Ensuring application rates do not exceed crop requirements.
• Maintaining gas and liquid-tight storage arrangements where required or appropriate.

Low-emission equipment can improve nitrogen retention, but the effect varies with digestate composition, crop cover, soil conditions and weather.

Preventing Runoff and Water Pollution

Operators should identify watercourses, drains, springs, wells, boreholes, steep slopes and vulnerable soil areas before spreading.

Particular attention is required where land drains provide rapid pathways from fields to receiving waters.

Spreading must be postponed where soil or weather conditions would create a significant pollution risk.

Managing Odour and Neighbour Impacts

Digested material may have a lower odour potential than untreated manure in some circumstances, but it is not necessarily odour-free.

Odour risk depends on the feedstock, stability of the material, storage conditions, spreading technique and local weather.

Practical precautions include selecting appropriate spreading times, maintaining equipment and avoiding unnecessary surface exposure of the material.

Digestate Spreading Rules in England: 2026 Compliance Guide

Important: The following is a summary of requirements applicable in England as at October 2026. It is not a substitute for checking the relevant legislation, environmental permit, nutrient management plan and site-specific restrictions.

1. England’s Anaerobic Digestate Resource Framework

On 20 October 2025, the Environment Agency published the Anaerobic Digestate Resource Framework, replacing the former Quality Protocol arrangements for qualifying digestate produced from source-segregated biodegradable waste.

The framework describes the conditions under which qualifying digestate can cease to be waste.

These include requirements relating to permitted feedstock types, process controls, quality assurance and compliance with the applicable PAS 110 specification.

Producing PAS 110-compliant digestate alone should not be assumed to establish end-of-waste status in every case. The relevant framework conditions and evidence requirements must also be satisfied.

Where digestate remains waste, appropriate waste-management authorisations and controls apply to its storage, transport and spreading.

The waste status of digestate should be determined before land application. Material derived from agricultural feedstocks should not automatically be assumed to fall under precisely the same waste-control arrangements as food-waste-derived digestate.

Official reference: Environment Agency – Anaerobic Digestate Resource Framework.

2. Farming Rules for Water

England’s Farming Rules for Water apply to the use of organic manures, including digestate, on agricultural land.

They require land managers to plan applications to meet soil and crop nutrient requirements, taking into account the risks of pollution.

Under the published guidance, organic manure must not be applied:

• To waterlogged, flooded or snow-covered soil.
• Where soil has been frozen for more than 12 hours during the preceding 24 hours.
• Within 50 metres of a spring, well or borehole.
• Within 10 metres of inland freshwaters or coastal waters, subject to specified exceptions.
• Where site conditions would create a significant pollution risk.

For the relevant precision spreading methods, including trailing hose or shoe band spreaders, dribble bars and shallow injectors operating no deeper than 10 centimetres, the published guidance allows application no closer than 6 metres from inland freshwaters or coastal waters, subject to the other applicable rules.

These distances are not a general permission to spread wherever the minimum distance is achieved. Greater setbacks may be needed because of field conditions or additional regulatory obligations.

The guidance also identifies correctly calibrated, leak-free equipment and prompt incorporation where appropriate as reasonable pollution-prevention measures.

Official reference: Defra and Environment Agency – How to Comply with the Farming Rules for Water, updated 4 February 2026.

3. Nitrate Vulnerable Zone Requirements

Additional controls apply where agricultural land lies within a Nitrate Vulnerable Zone (NVZ).

These include requirements relating to nitrogen applications, record keeping and restrictions on the timing and quantity of certain organic manures.

Liquid anaerobic digestate is generally treated as an organic manure with high readily available nitrogen for the purposes of the relevant NVZ guidance.

The applicable closed periods vary according to soil type and whether the land is grassland or tillage.

For high readily available nitrogen organic manures, the published England guidance specifies the following principal closed periods:

These dates are a summary of the principal restrictions, not a complete statement of NVZ rules. Further restrictions, exceptions and limits can apply before and after the closed periods.

Operators should verify NVZ status and all relevant requirements before arranging spreading.

Official references: Using Nitrogen Fertilisers in Nitrate Vulnerable Zones and Nitrate Vulnerable Zones.

4. Waste Digestate and Landspreading Permits

Where digestate remains legally classified as waste, its application to land may require an appropriate environmental permit or a valid exemption, depending on the waste type, proposed activity and relevant conditions.

It is incorrect to assume that all agricultural digestate can automatically be spread under a simple exemption or that PAS 110 certification always removes waste-management controls.

Where a landspreading permit is required, the activity must comply with its conditions, including any requirements for deployment, benefit assessment, storage, environmental protection and record keeping.

Official reference: Environment Agency – Landspreading: How to Comply with Your Environmental Permit.

5. Regulations Outside England

Regulatory requirements differ in Scotland, Wales, Northern Ireland and other countries.

Operators outside England must check the requirements of their own environmental regulator, including digestate waste status, agricultural nutrient controls, spreading restrictions and any applicable water-protection measures.

Equipment-selection principles such as low-emission spreading, calibration, soil protection and nutrient recovery remain widely relevant, but the English legal distances and NVZ dates quoted above should not be treated as universally applicable.

Historical Digestate Spreading Equipment Case Studies

The following three examples are retained from the original version of this article, published in October 2018.

They illustrate practical digestate handling and spreading arrangements in use at that time. Equipment specifications, operating practices, company services and regulatory arrangements may have changed since these examples were originally reported.

Case Study 1: J.M. Stratton & Co. – Umbilical Digestate Spreading

The original case study described a large-scale agricultural AD operation producing approximately 75,000 tonnes of digestate annually.

Digestate was reported to be applied to arable land and dairy grassland, with nutrient analysis used to inform application requirements.

The reported spreading arrangement included a tractor-mounted Vogelsang applicator with a nominal 27-metre working width and an umbilical pumping system operating over distances of up to approximately 3,000 metres.

A hose-management arrangement described as a cow-horn system was used to assist field operations.

The example demonstrates how strategically located digestate storage facilities and long-distance pumping can support application across large agricultural areas.

Engineering lesson: Umbilical distribution can avoid repeated tanker movements through fields, but the pumping system, hose hydraulics, solids management and field access must all be correctly designed.

Historical source: J.M. Stratton & Co.. The figures above are retained from the 2018 account and have not been independently verified as current operating specifications.

Case Study 2: RC Baker Ltd – Claas Xerion Digestate Tanker Spreading

The original article described contractor-operated digestate spreading on wheat stubble ahead of oilseed rape establishment.

Equipment was reported to include a Claas Xerion 3800 Saddle Trac and a Claas Xerion 3800 Trac VC working with tanker-based digestate application systems.

The original account mentioned a 24-metre boom configured to match field tramlines, with other possible working widths, and a separate trailing shoe arrangement.

This example illustrates the versatility of specialist high-capacity machines for handling and applying digestate across large arable areas.

Engineering lesson: High-capacity tanker spreading can provide operational flexibility, but machine weight, field traffic, compaction, distribution uniformity and transport logistics must be evaluated alongside spreading output.

Historical source: Original contractor video reference, RC Baker Ltd. Equipment descriptions are preserved from the 2018 article and are not presented as current fleet specifications.

Case Study 3: Digestate Solutions – GPS-Controlled Umbilical Spreading

The original article described a system in which digestate or liquid sludge was delivered by road tanker to a temporary headland receiving tank.

From there, material was pumped through an umbilical system for application using equipment with GPS-assisted field operation.

This arrangement combined road transport with reduced field tanker traffic.

The use of GPS-supported guidance and spreading controls can assist accurate application and reduce unnecessary overlaps, particularly on irregularly shaped fields.

Engineering lesson: Combining road tanker delivery, intermediate storage, appropriate pumping and GPS-assisted application can be advantageous where fields are too distant for direct pumping from the main digestate store.

Historical source: Digestate Solutions, as identified in the original 2018 article. Current equipment and service availability have not been independently verified.

Digestate Storage and Spreading Logistics

Storage capacity is closely linked to the success of digestate spreading operations.

An AD plant may produce digestate throughout the year, while suitable land application opportunities are restricted by cropping, ground conditions, weather and legal requirements.

Storage should therefore be designed to accommodate the periods when spreading cannot safely or lawfully take place.

Important considerations include:

• Expected annual and seasonal digestate production.
• Separation into liquid and solid fractions.
• Applicable NVZ restrictions.
• Realistic agricultural application windows.
• Extreme weather allowances.
• Additional storage needed for interruptions or machinery failures.
• Environmental permit and waste-status requirements.
• Potential methane and ammonia emissions during storage.

Digestate storage must also be designed to prevent leakage, overtopping, uncontrolled discharge and other pollution risks.

Separation may reduce the quantity of fibrous solids entering liquid storage, but it does not eliminate the need for appropriate agitation, settlement control or residual biogas management.

Where digestate remains biologically active, residual methane generation should be assessed. Gas-tight storage or suitable gas recovery arrangements may be necessary to control emissions.

Hiring a Digestate Spreading Contractor: What to Ask

Where the digestate volume or land area does not justify purchasing dedicated spreading machinery, specialist contractor services may be economically attractive.

Before appointing a contractor, ask the following questions:

1. What type and consistency of digestate can your equipment handle?
2. Do you offer trailing hose, trailing shoe or shallow injection systems?
3. Can you use an umbilical system, tanker arrangement or both?
4. What are the maximum practical pumping distances and working widths?
5. How is the application rate measured and verified?
6. Is flow proportional to forward speed, and is GPS or section control available?
7. How do you manage hose blockages, pipeline bursts and spill response?
8. How do you reduce soil compaction and excessive field traffic?
9. What records are supplied after each application?
10. What insurance, operator competence and relevant environmental procedures are in place?

Request clear quotations explaining mobilisation, transport, pumping, field application, labour, downtime and any additional charges.

A nominal charge per cubic metre may not represent the lowest total project cost if a system causes excessive delays, poor application accuracy or additional soil damage.

Frequently Asked Questions About Digestate Spreading

What is the best equipment for spreading liquid digestate?

Trailing hose, trailing shoe and suitable shallow injection equipment are commonly used where low-emission application is required. The best choice depends on digestate consistency, crop, soil conditions, field layout and available machinery.

Is a trailing shoe better than a trailing hose?

A trailing shoe can offer improved placement of liquid digestate beneath or between vegetation, particularly on grassland. However, the most suitable system depends on crop and soil conditions, digestate properties, machine costs and operational requirements.

Can digestate be spread with a conventional slurry tanker?

Yes, provided the tanker, pump, distributor and applicator are suitable for the material and can meet the required environmental and application standards. High solids, long fibres and grit may cause problems with some equipment.

Can solid digestate fibre be spread with a liquid applicator?

Stackable separated digestate fibre normally requires suitable solid-manure spreading machinery. Whether a material is pumpable or stackable depends on its actual physical characteristics, not simply whether it is called digestate.

How do you calculate digestate spreading rates?

Calculate the required amount from recent digestate analysis and the nutrient management plan. Then calibrate the spreading equipment using measured flow or mass output, effective working width and forward speed. Verify actual application and distribution uniformity in the field.

What is an umbilical digestate spreading system?

It is a system that pumps liquid digestate from a storage or reception facility through a supply hose to a field applicator. It can reduce the need for loaded tanker traffic across agricultural land.

Can digestate be spread in winter?

Not automatically. Winter application may be restricted by NVZ closed periods and is prohibited under certain frozen, snow-covered, flooded or waterlogged soil conditions. Other pollution risks must also be considered. Operators must check the rules applicable to the receiving land and material.

Does spreading digestate cause ammonia emissions?

Yes. Digestate containing ammonium nitrogen can release ammonia during storage and application. Suitable low-emission spreading, appropriate application timing and prompt incorporation where appropriate can reduce losses.

Does digestate always meet PAS 110?

No. Digestate quality varies. PAS 110 compliance requires applicable process and product-quality controls. In England, a waste-derived digestate must also satisfy the relevant conditions of the Anaerobic Digestate Resource Framework to qualify for the end-of-waste arrangements described by that framework.

Do digestate spreading contractors need specialist equipment?

Contractors should use equipment suitable for the digestate and conditions, with effective flow control, accurate distribution and appropriate environmental protection arrangements. Pumping capacity, safety procedures, spill response and machine calibration are important selection criteria.

Conclusion: Selecting Digestate Spreading Equipment for Reliable Results

Effective digestate spreading requires the integration of agricultural nutrient management with sound mechanical and hydraulic engineering.

There is no single machine suitable for every digestate type or farm.

Trailing hose and trailing shoe systems can provide effective low-level application for many liquid digestates. Shallow injection can provide additional ammonia-control benefits where suitable. Umbilical systems may reduce field tanker traffic, while tanker-based systems can provide greater flexibility across dispersed fields.

Separated fibre requires different handling and spreading equipment, and every system must be appropriately calibrated.

For operators, the most important requirement is to match the equipment to the digestate, soil, crop, field layout and environmental obligations, rather than selecting spreading machinery solely on nominal capacity or purchase price.

Done correctly, digestate spreading can make a significant contribution to nutrient recycling and the efficient operation of anaerobic digestion plants.

Further Reading

• Digestate Fertilizer: What It Is and How to Use It in Agriculture – nutrient composition and agricultural benefits.
• Biofertiliser Resource List – definitions and regulatory information.
• What Is Digestate? – introduction to digestate production and uses.
• Self-Propelled Slurry Spreader Hire and Application Services UK – specialist contractor equipment.

Technical and Regulatory References

1. Environment Agency: Anaerobic Digestate Resource Framework (20 October 2025).
2. Defra and Environment Agency: Farming Rules for Water (updated 4 February 2026).
3. Using Nitrogen Fertilisers in Nitrate Vulnerable Zones.
4. Nitrate Vulnerable Zones: Designations and Guidance.
5. Environment Agency: Landspreading – How to Comply with Your Permit.
6. AHDB: Nutrient Management Guide (RB209).

Originally published 7 October 2018. Substantially revised October 2026 to update the equipment guidance, regulatory framework, spreading methods and operational recommendations. Historical equipment case studies have been retained and identified accordingly.

By Steve Last, MICE, MCIWM, CEnv – IPPTS Associates. Chartered Civil and Environmental Engineer, Chartered Waste Manager and Chartered Environmentalist, with more than 30 years of environmental engineering experience.