Bulk density is a soil property commonly measured when soil testing, particularly in relation to measuring soil carbon. An important component of measuring soil health, it can provide farmers and growers guidance on what to focus on following testing.
What is Bulk Density?
Bulk density measures the mass of a known volume of soil, including the pore space – i.e. how tightly or loosely it is packed together – which has a huge impact on important soil processes. For example, if a soil is unusually tight it can affect porosity, which in turn affects water infiltration and soil aeration. Consequently, when these processes are inhibited it can negatively impact soil and plant health, reducing farm productivity. This is why compaction issues are a key focus of soil health discussions.
Soil Texture and Bulk Density
In order to understand what the bulk densities of our soils should look like, we also need to understand how soil texture plays an important role in determining the natural range of bulk densities.
Peat generally has a very low bulk density (as low as 0.2 g/cm3) due to its high organic matter content, allowing for a high amount of porosity. Cultivated fine textured soils, such as clays and silt loams, often have bulk densities in the middle of the range (between 0.9g/cm3–1.5g/cm3), whilst cultivated sandy soils tend to have higher bulk densities (1.25g/cm3–1.75g/cm3). To give you an idea of what an extremely high bulk density looks and feels like, concrete has a value of 2.5g/cm3.
The key part to remember is that each soil type has an inherent bulk density range, and while occupying a lower or middle part of the range is generally desirable, this is heavily context dependent.
Bulk Density and Management
Although bulk density is determined by soil texture, how soil is managed will also contribute to the final figure. Heavy equipment, cultivation or grazing in unsuitable conditions and unsuitable nutrient management can all drive up bulk densities into ranges that will cause problems later on. Avoiding these practices – whilst increasing soil organic matter (SOM) and optimising soil health – will help to keep bulk densities in a range suitable for optimal productivity. If in doubt about what your range should be on farm, finding and examining the soil in undisturbed areas that share the same soil texture as your main cropping or grassland areas (such as in hedge bottoms) can help to give a baseline.
Bulk density and carbon
Although bulk density can reveal insights into soil structure and health, it is most commonly measured in order to quantify carbon stocks. When carbon samples are taken and analysed they are expressed as a carbon concentration (C%) of the soil sample, but in order to quantify the amount of carbon in the specific field we must know the mass of soil within a given volume. If soil carbon is being measured at different depths, then a measurement of bulk density must also be taken at those depths.
How do we take it?
There are different approaches to taking bulk densities. The most common method used is the intact core approach, which is what we use at FCT. For each depth being sampled, we use a core of a known volume, insert it into the soil at the depth and then carefully remove it to be sent away for lab analysis. When we receive the data back we can then use a simple formula to calculate the carbon stock.
SOC stock (tC/ha) = Bulk Density g/cm³ x Depth (cm) x OC(%) x 10
Conclusion: Key points about bulk density
On farm sampling is a balance between scientific rigour, cost and practicality. In order to help farmers with this, we offer the following guidance on bulk density sampling:
Measuring Carbon Stocks – When sampling for carbon, bulk density should also be taken to enable carbon stocks to be quantified
Accounting For Depth – Bulk density will change at different depths, so taking at least a sample per depth per field is necessary in combination with the sampling for carbon at different depths
Choosing Location – The location for a bulk density sample should be representative of the primary field conditions. As with sampling for other soil properties, atypical areas such as gateways and headlands should be avoided
Stony Soils – If you have stony soils, you may be required to take multiple bulk density measurement as stones can introduce variability that requires more data to overcome
If you’ve read this article and still feel overwhelmed by the information about soil sampling, please feel free to contact us with your questions. As the science evolves and new technologies develop, more user friendly and practical approaches are emerging for farmers and growers to use.
By Becky Willson, Business Development & Technical Director
Attend any soil-related farm event, and you will be recommended to go home and take samples for analysis to give you a baseline. When I am giving talks myself, I have a slide that says – the best time to start testing soil organic matter (or carbon) was 20 years ago; the second best time is now – so data and baselining is really important. With the rise of regenerative agriculture and the focus on agriculture’s ability to provide climate solutions, having data and evidence to quantify the impact of activities is crucial.
However, within agriculture anything to do with delivering climate solutions is not linear and predictable; we are dealing with complex biological systems inherently dependent on the weather and huge variability in soil type, farming systems and management. This is where sampling can provide insights – sampling (as long as it is representative and taken following best practice) over time can provide insights into the impact of practices on individual farms and give confidence that things are moving in the right direction. But this takes time, and can prove challenging when results from the lab don’t show what we would like.
There can be many reasons why samples show a reduction in organic matter (or carbon) when results are received. This can seem disheartening and lead to a lack of confidence in practices or management change. Through extensive resampling we have done as part of various projects; we have seen a real mix of fields that have increased, dropped and maintained carbon, which can often beg the question – what is happening?
Consistency matters
If you are re-sampling fields that have been previously sampled, then the golden rule is consistency. It’s imperative that samples are taken at the same time of year, sent for analysis to the same lab, and using the same analytical technique. This is because in order to have confidence that the change in organic carbon is down to management, all other variables need to be controlled for.
One of the key challenges that often occurs is that historically, any samples may well have been analysed for organic matter (using Loss on Ignition analysis) and now recommendations (and requirements for carbon markets) are to analyse organic carbon content (using DUMAS analysis).
The conundrum is therefore: do you maintain consistency and use LOI to be able to show progress over time, or start using DUMAS analysis and thus negate your ability to compare to previous samples? For new fields that haven’t been sampled before – and for accuracy and to give yourself the best chance of accessing funding in the future – analyse for carbon using DUMAS. However, for fields that have been previously analysed using LOI, then consistency is required. Because loss on ignition analysis is more variable it is even more important to ensure that sampling locations, seasonality and the lab are consistent, otherwise results that you get back may not be truly reflective of what’s actually happening in the field.
For best practice in sampling for carbon, why not read our guidance document.
Sample location in the field should also be marked to allow for resampling to be taken in the same locations. Fields that are in perennial cropping or are managed using a direct drill or min till system will tend to be more variable than fields which are cultivated regularly, and so sample location is even more important in these fields.
Depth of sampling
Sample depth is very important when sampling for carbon. Ultimately the agronomic benefits of increasing soil organic carbon lie in improving soil function, nutrient cycling, water infiltration and resilience. If we are able to manage fields in a way which allows for deeper rooting, limited disturbance and diverse rotations, carbon is more likely to be sequestered in the lower soil horizons. The highest concentration of carbon is in the top soil, however this carbon is the most likely to be released due to biological activity; as you go deeper into the soil, there is a lower concentration of organic carbon, but it is more stable.
Ensuring that you are sampling to a consistent depth is important, for example – if you have sampled in year 1 to a depth of 10cm, and then you sample a bit deeper when you resample, it may well be that the carbon percentage declines; not because you have lost carbon, but because the sample is from lower in the soil profile. The FAO recommendation for carbon sampling is to sample to 30cm, and sampling for carbon markets often takes several samples from the same pit down to 1m to be able to quantify the total carbon stock and concentration at different depths.
There are also some thoughts that, as soils are managed in a way that builds carbon, the total volume of soil increases; thus you may be sampling to the same depth but the horizons have moved, and previously you were sampling top soil and now you are sampling sub soil. More research into being able to take account of total soil volume and identifying horizons will allow for a deeper understanding of key practices that are building soil.
Weather and sampling frequency
Weather plays a major role in shaping soil carbon levels, influencing both how much carbon is stored in the soil and how quickly it is lost. Warm temperatures tend to accelerate microbial activity, which can increase the breakdown of organic matter and release carbon dioxide back into the atmosphere. In contrast, cooler conditions slow this process, helping soils retain carbon for longer periods. Rainfall is equally important: adequate moisture supports plant growth and the return of crop residues to the soil, boosting carbon inputs, while excessive rainfall can lead to waterlogging and carbon loss through runoff or erosion. Drought conditions reduce plant productivity and limit organic matter inputs, gradually depleting soil carbon stocks.
As such, understanding these weather-driven patterns is key to managing practices – such as cover cropping, reduced tillage, and residue management – that help protect and build soil carbon despite changing climate conditions. This is why sampling frequency is important; don’t sample too often as results may well be showing fluctuations in microbial activity rather than stable carbon. Recommendations are to sample no more frequently than every 5 years (ideally every 10 years), but this is often difficult to balance alongside the need to have data to ‘prove’ the impact of farming systems.
Anecdotally, we are seeing some farms – especially during extended hot periods like last summer – managing to maintain performance (either forage quantity or crop growth), despite a loss of soil carbon. This may well be that these farms are utilising the carbon within the soils to drive production (almost like withdrawing funds from your bank account), as part of the carbon cycle in the extractive phase, which will then be rebuilt over time. As we are seeing more and more extreme weather, the link between soil carbon and resilience is crucial for maintaining in-field performance.
Is it all just about carbon?
One of the challenges that we have, especially with the development of the carbon marketplaces, is that soil metrics become solely about carbon. Carbon is one metric and one option for soil analysis but it isn’t the only metric. Something that has been incredibly valuable for us while completing numerous soil samples across projects is completing soil health observations to be able to complement the lab analysis. When we therefore get a result that doesn’t go the way that we want from a soil carbon perspective, we then have other data to correlate it with; as such, can we see that the field is compacted, or that the biological activity is lower than we would like.
Conversely, it can also be really encouraging for farmers who are changing their practices to see that while carbon levels may be not increasing at as fast a rate as they would like; other measures of soil health and performance are, which gives confidence that it is the right thing to do.
We should not only be focusing on increasing soil carbon but increased soil health and functionality, which allows us to be more resilient and profitable.
We have too often in the past seen the impact of only focussing on one metric, especially on a metric which is still very early in development. If you can go and dig a hole at the same time as taking your samples for lab analysis and note down how the soil is structured, what the plant roots are doing and the number of worms you find, it will allow for much more detailed understanding of management and engage you so much more in your soil than merely receiving a report back from the lab.
Carbon is important, yes, but in isolation can lead to mistrust and confusion. So as we move into the spring, let’s go and assess our most cherished resource on the farm and ensure that it is functioning well across all parameters which provides a solid foundation for a resilient business.
The core mission of a farm carbon calculator is to provide a comprehensive view of the emissions and sequestration your farm is responsible for, both directly and indirectly. As footprinting standards evolve, our ability to calculate this complexity is becoming more complete, but we are not perfect, and there is a gap in embedded emissions that the current standards and guidance overlook.
Footprinting recap: what are Embedded Emissions?
Indirect emissions (often called embedded emissions) are those generated by the goods or services your farm purchases. This includes the emissions from manufacturing the fertilisers being spread or the emissions from the mill rolling barley and trucking it from a merchant to your gate.
Accounting for these embedded emissions is no longer optional; it is critical for supply chain reporting and meeting rigorous standards like the Product Environmental Footprint Category Rules (PEFCR) for dairy or the World Resources Institute (WRI) Corporate Value Chain Standard, so it is essential that we capture the embedded emissions in ALL farm purchases.
The “Gap” in Farm Footprinting
While calculators have long tracked emissions for fuels, feed and fertiliser, one area has historically been overlooked: the embedded emissions in purchased livestock.
Whether you are buying replacement dairy heifers, or store calves or point-of-lay hens, those animals arrive on your farm with a “carbon debt” from their previous life stages. Excluding this data leads to:
Underestimated footprints for finishing farms or flying herds.
Inconsistent comparisons between farms that breed replacements versus those that buy them.
Missed opportunities for supply chain mitigation.
A Harmonised Approach
Rather than waiting for international bodies to catch up, we have collaborated with Agrecalc, Cool Farm Platform, and Eggbase to create a standardised, globally applicable methodology for embedded livestock emissions. As key players in the UK farm carbon footprinting field, it is important that we not only hold each other to a high standard, but we make sure that all tools are improved and present farmer data in the fairest and most consistent manner possible.
As a collective, we have created a three-tiered approach to accounting for embedded livestock emissions using publicly available data from the Food and Agriculture Organization (FAO). We are leading the charge on implementing these methods, and in our April 2026 update, we are introducing our baseline approach for accounting for livestock embedded emissions in the calculator.
The embedded emissions update
From April 1st, you will see a new option in the Farm Carbon Calculator’s livestock section, where you can add embedded emissions from livestock based on the number of purchased animals and their average liveweight at the time of purchase. Then using the FAO’s Global Livestock Environmental Assessment Model (GLEAM) data set we attribute emissions intensity values based on the average energy required and emissions produced to rear the livestock to the point of sale. This is a highly reliable and repeatable starting point for all users, and is the base implementation we would expect from all carbon calculators. Two higher tiers of implementation are outlined in the upcoming whitepaper, and we will be aiming to add these to the Farm Carbon Calculator in due course.
How Will This Change Your Footprint?
If you operate a closed flock or herd and do not purchase livestock, your footprint will not change.
However, if you purchase animals for fattening, finishing, or as replacements, you will see an increase in your total emissions to reflect the carbon cost of rearing those animals before they reach your farm, below are some examples of the footprint changes:
Enterprise Overview
Purchased animals
Farm emissions without embedded emissions (current)
Farm emissions with embedded emissions (proposed)
Finishing farm, purchasing low weight beef youngstock for fattening, and ewe lambs for expanding breeding flock.
Soil is the most important resource that we have on the farm – and as those soils start to warm up and the grass starts to grow in the Spring, it’s a really good time to start thinking about soil analysis.
With volatile fertiliser prices and an increasingly extreme weather system, sampling can put you on the front foot. By providing us with insights into how our soils are performing, understanding the nutrient content of what you’ve got in the field is a great business benefit – allowing you to adjust your inputs accordingly.
Where do you need to start?
If you’re going to spend the money sending samples off for analysis, it’s really important to take a good sample. So, make sure that you are taking a representative sample of your field by:
Walking the field in a W.
Avoiding tram lines and gateways, to really make sure that the sample is a representative of that field – and so you can have confidence when making management decisions.
Making sure that when you send samples off you understanding the test that you’re doing:
Are you just looking at pH and those macronutrients?;
Do you also want to think about organic matter?;
Is carbon an aspect you may want to consider?
And while you’re out, it’s a really good opportunity for you to use your spade to really start to look at the impact of the winter on your soil health. Because if you can get that soil working well, not only are you going to have a resilient farm, but you’re really going to set yourself up to have a really good season moving forward.
Image credit: Version 1 – GHG protocol LSRS, World Resources Institute
The Greenhouse Gas (GHG) protocol provides standards and guidance for how carbon footprints should be constructed and calculated, to ensure that the results are comparable between businesses or projects. After many years of draft versions and public consultations, the GHG protocol has released a finalised ‘Land Sector and Removals Standard’ (LSRS).
This standard outlines how emissions from agricultural holdings should be reported and provides a framework for reporting carbon removals. It forms one of the many reporting standards that farm businesses are required to report to – Scope 2 standard, Scope 3 standard, relevant specific product footprint standards – and this may affect how carbon calculators (such as the Farm Carbon Calculator), will display your results on your reports. The LSRS aims to improve carbon footprint data transparency in supply chains, which is why there is a heavy focus on Scope 3.
The Farm Carbon Calculator has been working towards aligning with the draft versions of the LSRS (previously the LSRG) for the past few years – meaning we are in a great position to align with the new standard without significant change, should you need to produce LSRS-compliant reports. Below, we briefly discuss the key takeaways and explain how this may affect reporting.
Reporting emissions and removals separately is the new normal
Change: While your carbon ‘balance’ (the sum of emissions and removals) is important for understanding your farm’s impact, it is now mandatory to also present the data separately as total GHG emissions and total carbon removals from the atmosphere.
Solution: The calculator already does this! Your reports already show these separate values so no change is needed there! The advantage of separating emissions from removals is the ability to more closely examine the emissions reduction or mitigation possibilities, as well as maximising carbon removals from the atmosphere.
Including carbon removals from the atmosphere has been formalised
Change: This is the first reporting framework that includes removals accounting. Accounting for removals has been done in the past, but the GHG protocol is seen as the gold standard, and we now have guidance from the top down on how the brilliant sequestration work of farmers can be included in reports.
Solution: The removals that can be included in an LSRS-compliant report will need to be from ‘empirical data’ from lands within the farm’s boundary, so this includes direct soil samples – but don’t worry, this is easy to identify in the sequestration tab, where eligible options are labelled with ‘Direct Measurement’.
You will need to think about the history of your land
Change: It is now mandatory to include any land use change (LUC) that has occurred over the last 20 years on farm.
Solution: There is an area to log this on the calculator, but to be able to see the LUC calculator tab you need to answer ‘Yes’ to the question ‘Has there been any major change in land use on the farm in the past 20 years?’. Read more about the LUC tab here.
This is referred to as direct or major LUC and is focused on significant changes in land types (i.e., woodlands into arable cropping, or grasslands into built environments) and not looking at the management changes (i.e., going from full to no tillage cropping, or from pastoral grazing to silvopastoral grazing). Sowing a rotational grassland in an arable rotation, does not count as major land use change.
LUC emissions will be allocated based on when they occurred – so if it was 19 years ago you will only see a small section of emissions in your report, and this will be presented separately from your annual GHG emissions total and carbon removals total, in line with the new disaggregated reporting guidance.
An additional metric to report – land tracking
Change: A key part of the guidance is the need to better track land areas and how they are used – this is primarily because supply chains often lack traceability to individual farms. It is now mandatory to report a land tracking metric, meaning a product can be assessed on its land use efficiency and not just emissions. This also means that where supply chains reduce food production in one area, they must account for the ‘emissions leakage’ onto other lands (likely on different farms, causing LUC). Sometimes this effect is called accounting for “ghost acres”.
Solution: The calculator already asks you for land area at the farm and crop scale, with yield KPIs that have the land area included. Your land occupation for a given product is presented in the ‘Yield table’ on the results page, which shows the areas needed for the production of that crop or livestock product. The calculator currently prevents you from overrepresenting sequestration (i.e. on a land area bigger than your farm area), so there are no changes required here.
Image: Yield and Land Occupation table on the Farm Carbon Calculator.
Changes to emissions accounting categories
The LSRS has defined certain categories in which emissions and removals need to be reported in. This becomes increasingly important moving up the supply chain. For example, it notes that ‘fossil fuel and industrial emissions’ should be reported separately from land emissions (in a similar way to SBTi FLAG). For farmers, your business’ fuel use would be reported under this category rather than land-based emissions.
However, further up the supply chain, the standard recognises that the category ‘land emissions’ may include fossil fuel burning – for example, if it’s already allocated in a product footprint. Therefore, for companies further down the supply chain, all emissions from farms can be accounted for in the land emissions category. The LSRS, like SBTi, notes that you just need to make sure not to double-count fossil fuel emissions across these categories. At this point in time, the FCC calculator categories can be mapped to the new LSRS categories, but future updates may include report summary changes. If you need a detailed breakdown of what emissions align to the LSRS categories, get in touch at calculator@farmcarbontoolkit.org.uk.
Image credit: Alex Bebbington, Land at Trewen, Launceston. Farm Net Zero (2023)
It’s not perfect and we will continue to lobby for farmers
As with any new standard there are teething issues, and we have questions and grey areas that we would still like clarity on. For example, the team behind the LSRS and the independent standards body were unable to confirm how forestry and adjacent non-productive lands can be included in a farm footprint, and in the current guidance, including woodlands, forestry and hedgerows in LSRS-compliant reports is not possible. The LSRS team has put together a consultation, and aims to have forestry-specific guidance available in the near future – however, no timelines have been given. For now, we would recommend that fully LSRS-compliant reports should only include sampled soils data to evidence sequestration, however further clarity is needed from the standard. We are investigating this on your behalf to ensure your woodlands, hedgerows, and other sequestration are reflected in the future.
As a community interest company focused on supporting farmers, we’ll keep speaking up in the world of carbon accounting to make sure all the amazing work farmers do – especially around carbon sequestration and storage on your land – gets recognised.
If you have any specific questions or requirements, please reach out to us for help.
Email us at calculator@farmcarbontoolkit.org.uk or use our Contact Form here
Replacing half the soya bean meal in livestock feed with homegrown pulses has the potential to reduce agricultural emissions by 3.4m tonnes of CO2e p/a – a result of reduced deforestation and land use change, lower synthetic fertiliser use, and fuel savings. This is equivalent to more than 7% of agriculture’s total emissions in 2022.
We have long known the benefits of beans and pulses in supporting improved soil health within arable rotations, as well as their potential to replace soya bean meal and increase forage protein levels within livestock diets. Indeed, as many as 30 years ago, UK research money was being applied to the potential for UK lupin production as a feed for ruminants.
Since the mid-1970s, UK imports of soya bean meal have risen significantly – from 600,000 tonnes per year in 1979, to a peak of 2.3 million tonnes in 2020. Prior to this, imports sat fairly consistently at around 300,000 tonnes per year:
During much of this period, the increasing reliance on soya bean meal imports for UK livestock was met with scant concern – despite the environmental impact caused by the deforestation required to grow the crop, and the damage to the fragile soils across the areas where this crop increasingly has been grown (commonly South America). Now, it is a very different story, with many UK retail supply chains requiring their suppliers to feed alternative proteins to minimise reliance on soya bean meal from deforestation sources.
Started in 2023, the Nitrogen Climate Smart project (NCS) aims to support a transition toward increasing the UK’s pulse and legume cropping in arable rotations to 20% (it is currently at 5%). In turn, the farmer-led research project is looking to work toward replacing 50% of imported soya meal used in livestock feed rations with home-grown legumes.
Benefits of growing pulses in the UK
As these plants fix nitrogen into the soil, growing pulses like peas and beans reduces the reliance on synthetic nitrogen fertilisers – both during the pulses’ cropping year and for subsequent crops.
In 2023 the UK applied an average of 125kg of artificial nitrogen per ha, totalling 546,266 tonnes of N across the UK and emitting 3.6Mt CO2e. By expanding pulse cultivation the UK could save 74,867 tonnes of nitrogen fertiliser annually, directly avoiding 494,925t CO2e emissions. Moreover, pulse residues can enhance nitrogen availability for subsequent crops, with the potential of up to 35–70kg N/ha depending on soil conditions. This could save an additional 20,963–41,926 tonnes of nitrogen annually across the UK, equating to the avoidance of a further 138,580-277,160t CO2e emissions.
Expanding the pulse cropping area will result in GHG emissions reductions in the following areas:
Reduced fuel usage
Direct fertiliser avoidance
Indirect fertiliser avoidance as a result of leguminous residues
Providing a low emission feed alternative to imported soya
In 2023, the UK imported 2.37 million tonnes of soya feed – 74% from South America – resulting in 7.3Mt CO2e emissions. UK grown beans could replace some of this soya, substantially reducing the footprint of animal feed. If all UK-grown beans within the scenario proposed by NCS were used within compound feeds and straights, they could replace 96% of soya imports, avoiding 5.3Mt CO2e. However, a more realistic scenario is replacing 50% of imported soya with 1.95 million tonnes of UK beans, requiring 454,468 hectares (52% of beans/peas cropping area) – this would cut feed emissions to 4.5Mt CO2e, saving 2.8Mt CO2e compared to current levels of soya imports.
Challenges to overcome
Before UK-grown proteins are the norm within UK livestock diets, there are challenges to come for both arable farmers and livestock producers. In turn, substituting faba beans for soya bean meal brings challenges for animal feed manufacturers – such as the need for more ingredient bins and accessing a sufficient scale of beans of similar quality and consistency. A secondary challenge for feed manufacturers is the higher inclusion rate required for faba beans compared to soya bean meal, as they are lower in protein.
Faba – image courtesy of Encyclopædia Britannica
For livestock producers the key challenge is around the performance of UK grown pulses compared to soya bean meal. To help provide confidence to producers, the NCS project is engaged in feeding trials with cattle and broilers to understand the impact – with the results being published in a series of case studies which will be available on the project website.
One feeding trial investigated the impact on broiler performance of partial soya bean meal replacement with faba beans. Prior to the trial, broiler feed accounted for close to 51% of total greenhouse gas emissions for the enterprise, with soya being the key driver.
The trial confirmed that raw faba beans can be incorporated into broiler diets without compromising bird health and welfare. However, higher inclusion levels resulted in wetter litter (requiring increased management attention); higher FCR; and increased cost of production. These findings point towards some form of processing (such as extrusion) as a likely route to unlocking greater nutritional value, through reducing the antinutritional factors and improving protein digestibility. However, the trial did result in an overall reduction of 12% of the emissions associated with broiler feed.
A second trial with beef cattle investigated the impact of roasting faba beans in comparison to feeding them raw. The results show that roasting the beans doubles rumen degradable protein, while protein digestibility in the small intestine increased by 4%. Roasting also increased bypass starch by up to 47% with no impact on digestibility. With the cattle on the trial diets for 126 days, the group fed on raw beans achieved an average daily liveweight gain of 1.44kg/day (corrected for one animal which had to be withdrawn from the trial due to illness) across this period, while the group fed on roasted beans achieved growth rates of 1.54kg/day. Although unit feed costs were higher for the roasted beans due to the cost of roasting, the feed cost and the emissions per kg liveweight produced were reduced by 5% and 7.5% respectively.
Full details of all the feeding trials can be found on the NCS website.
For arable farmers, the challenge has been producing consistently good crops of faba beans alongside achieving a market price that makes them an attractive crop to grow within the rotation. The farmers of NCS’ “Pulse Pioneers” aim to improve the quality and consistency of faba bean crops through a range of on-farm trials. Unsurprisingly, pod development and pod fill are key to pulse yield – and as always, attention to detail through the crop life generally leads to better outcomes. However, there is a need for the whole chain to incentivise arable farmers through recognising the overall lower level of GHG emissions offered by UK grown pulses compared to imported soya bean meal, to make up for generally lower rotation level margins when beans make up 20% of the rotation area. This should result in an“emissions reduction premium” underpinning the market price, commanded by its nutrient content and value within least cost ration formulations. To make this a reality supply chain intervention is vital, both to make this a requirement and support the additional costs in exchange for being able to report lowered chain emissions.
Livestock feed manufacturers are already responding to the requirements of some supply chains in requiring alternative feed to be included within livestock rations. An increased scale of production will be critical to improve these manufacturers’ ability to consistently include beans within livestock diet formulation, and to improve the consistency of quality.
FCT is one of the partners within the NCS project. To find out more about the project findings, you can visit the NCS website or contact FCT through info@farmcarbontoolkit.org.uk to find out how we can help your business on its journey towards more climate and nature-positive farming systems.
by Rob Purdew, Senior Farm Carbon and Soil Advisor
Two recent Innovative Farmers Field Labs trials have taken an in-depth look into different aspects of grazing within dairy systems – providing valuable insights on the relationship between herbal leys and milk yield, quality and composition, and the effect of extended pasture resting after grazing on soil health and microbiology.
A discussion of the results, recorded at a recent webinar and featuring FCT Farm Advisor Hannah Jones, is available to watch back above.
Do herbal leys affect milk yield and quality?
The first trial, run by dairy farmer Andrew Brewer as part of the Farm Net Zero project in Cornwall, monitored differences in milk yield and composition between cows grazing a conventional ryegrass sward and those grazing a herbal ley.
Drawing a comparison between cows grazed on perennial rye grass/white clover leys or multi-species swards, the trial found that there was no significant difference in milk yield and composition between the two swards – despite a difference in the nutritional analysis.
The results showed that:
Multi-species swards had lower dry matter, water-soluble carbohydrates and neutral detergent fibre.
Higher crude protein and ash was found in multi-species sward yields (largely reflecting the greater diversity of legumes and herbs in the mix).
On average, multi-species swards produced 40% more forage than the rye grass sward, and both pre and post grass sward heights were greater.
While the different leys produced similar milk yields, a significant positive from the study is that it demonstrates the ability to deliver the wide range of benefits of multi-species sward without having to compromise on yield – a commonly held belief. You can read and download the final report here.
Alongside their relationship to herbal leys, there are numerous additional benefits to growing herbal leys, as they:
Improve soil structure and health
Provide resilience in dry periods
Extend the grazing season
Benefit carbon sequestration
Nitrogen fixation from legume species – so requires little fertiliser
Improve livestock growth rates when rotationally grazed
Improve biodiversity of bird and insect species
Some species have anthelmintic properties – so less need for wormers
Andrew Brewer’s Ennis Barton farm
Does extended pasture resting after grazing improve soil microbiology and soil health?
A second field lab study has been investigating the impact of longer rest periods and resulting taller swards on soil health.
Tall grass grazing (often referred to as mob, holistic or adaptive multi-paddock grazing) has seen good uptake from beef and sheep farmers but less so in dairy systems, where concerns of a drop in forage quality has limited its use. Encouragingly, the trial was shown to have a good impact on soil health – with a much higher fungi-bacteria ratio in the trial plots after 3 years, and a higher-retained moisture content – something that was very important in a year of severe drought. Further observations from the study included:
Improved soil structure at depth was observed as roots reached deeper into the soil profile.
Forage quality remained largely consistent with the trial plots, having slightly higher sugars and dry matter and the controls higher ME, D value and crude protein.
Interestingly the tall grass plots had higher levels of beneficial macro and micro nutrients, and lower levels of antagonistic minerals – and cows were observed to be more settled and fuller.
Milk yield was not affected by the taller sward heights but there were mixed results in terms of total forage grown.
Half the farms grew more forage in total than compared to the control plots; but half also saw diminished total forage.
All the farmers have an appetite to continue the trial and see if the results are consistent over a longer time period.
—
Farm Net Zero is a major project from the farming community in Cornwall to show the contribution that agriculture can make to achieving Net Zero.
Manure is one of the most valuable resources produced on-farm. When managed well, it boosts soil health, cuts fertiliser bills, strengthens resilience and reduces environmental impact. The key is maximising the benefits while minimising the risks.
Treat manure as a valuable resource
Manure doesn’t just supply nutrients – it feeds soil biology, builds organic matter and improves soil structure, chemistry and resilience. Shift the mindset: manure is an asset, not a waste product.
Develop a nutrient management plan
Nutrient planning is a win-win for profitability and the environment. A good plan will:
Match nutrient inputs (fertiliser + manure) to crop demand
Identify high-risk areas (watercourses, slopes, compacted soils)
Reduce nutrient losses
Improve efficiency and lower costs
Most farm assurance schemes require a manure management plan — but even without certification, having one is invaluable.
Match nutrients to crop demand
Applying the right rate at the right time is the single most important factor in manure management. Correct timing:
Maximises nutrient uptake
Reduces losses to water and air
Improves yield potential
Lowers fertiliser requirement
Avoid spreading when soils are waterlogged, frozen, or when heavy rainfall is forecast.
Know the nutrient content of manures and slurries
To ensure that you can make the most of the nutrients within your manures and slurries, it’s important to know what is in them. You can use published values found in guidance such as RB209 to minimise the risk of over application, or you can send samples off to the lab to get a more precise understanding on what is in your manure and slurry.
Samples can be taken from the field at spreading by collecting material in containers and then sending them to the lab. Ensure that if you are going to the trouble of taking samples, that you integrate the results into your nutrient management plan.
Test and manage soil pH
Correct soil pH is the foundation of good nutrient management. If pH is suboptimal:
Nutrient losses increase
Nutrients become unavailable
Yields suffer
Monitoring and correcting soil pH ensures applied nutrients are actually used by the crop.
Improve storage to improve timing
Adequate slurry and manure storage gives flexibility to apply nutrients when:
Crops are actively growing
Soil conditions are suitable
Environmental risk is low
Insufficient storage often forces spreading in poor conditions — when losses are highest.
Simple storage improvements include:
Repairing gutters
Diverting clean water away from stores
Covering yards
Installing floating or fixed covers
Reducing rainfall entry maintains nutrient value and lowers spreading costs. Covers also reduce ammonia emissions, improving air quality.
Manage soil manures carefully
For farmyard manure (FYM):
Site field heaps carefully to reduce nitrate leaching
Consider composting to create a more stable material
Composted manure benefits soil biology but releases nitrogen more slowly than fresh manure.
Use low-emission spreading techniques
Application method affects how much nitrogen is retained for crop growth. To improve nutrient efficiency:
Use trailing shoe, band spreaders or injection systems
Avoid high-trajectory splash plates where possible
Incorporate manures quickly if cultivation is planned
Use rear discharge spreaders for more even solid manure application
Better technology = better nitrogen retention and lower ammonia losses.
Reduce greenhouse gas and ammonia emissions
Agriculture contributes to climate change through nitrous oxide emissions, which arise from:
Soil microbial activity
Organic manure applications
Nitrogen fertiliser use
Careful nutrient management reduces these losses.
Planning also reduces ammonia emissions — improving air quality and protecting human health. Emissions are influenced by:
Manure type
Application timing
Soil pH
Soil moisture
Weather conditions
Storage method
Managing these factors makes a real difference.
Maximise benefits, minimise risk
When stored and applied correctly, manures:
Improve profitability
Build soil resilience
Cut artificial fertiliser use
Lower carbon footprint
But applied at the wrong time or in excessive quantities, they become an environmental liability.
The goal is simple: Maximise nutrient value. Minimise losses. Plan ahead.
Optimising manure management strengthens both farm performance and environmental stewardship — delivering economic savings today while building resilience for tomorrow.
From June 2024 to August 2025, Farm Carbon Toolkit worked with the Suffolk Wildlife Trust on the ambitious and very exciting Connecting Constable and Gainsborough Country Landscape Recovery (CCGCLR) Project. The project is one of the largest of its kind in England, working with two farm clusters – the Wool Town Farms Cluster and the Stour Valley Farmer Cluster – and covering 18,500 hectares, starting from just below Bury St Edmunds at the top of the landscape recovery area, to just west of Manningtree in North Essex at the bottom. With its productive soils and closeness to continental Europe, this ecologically rich landscape has drawn human settlement for thousands of years, resulting in a wealth of historical and cultural associations that continue to make it such an attractive place to live and work.
The conundrum of balancing sound ecological management and sound socio-economic management is at the heart of CCGCLR project, and is reflected in the goals of the project:
Supporting sustainable, productive farming – nature friendly practices, taking action for soil health, working towards Net Zero
Restoring Habitats – enhanced woodlands, grasslands and floodplains, collaborative solutions to deer management, long term nature based solutions to climate change
Connectivity – improving connectivity across the area through joined up habitat corridors
These goals highlight the fact that long term productivity and sustainability go hand on hand in a resilient landscape under threat.
Farm Carbon Toolkit’s work on the project has been in two stages. The first has been the carbon baselining of project farms, where we meet with the farmers, collect the relevant information for the footprint and discuss how a subsequent report should be tailored to support the goals of the farmer. From an early stage it became clear what a wide range of farms were on the project – each of them wanting to do the right thing for their local landscape, but within the confines of conflicting economic and practical pressures.
After the collected data was entered into our Farm Carbon Calculator, we used the output to produce baseline reports for each farm showing where the areas of emissions and sequestration were, and suggested actions for how to get closer to Net Zero – or in the case of farms that were already there, how to further solidify this position.
One of the benefits of a carbon footprint is that it can often highlight areas which are both costly and high in emissions. When such patterns reveal themselves it often causes the farmer to evaluate whether the current way of doing things is actually benefitting the farm or whether there might be a better way to utilise resources.
In the second stage of our work on the project, each farm completing a footprint was offered an extra day of time and a set of options for things such as calculator training for future use, and advice on implementing sustainable farm strategies etc. There was a wide range of sessions that took place as a result, including the following:
Modelling future farm changes (such as bringing on livestock) to see the impact on the carbon footprint
Advisory sessions based on foliar feeding, grazing management, crop nutrition, soil health and other sustainable farming strategies
Creating follow-up footprints reports and then comparing the changes between the baseline and the new report
Calculator tutorials for farmers and land agents, showing in-depth use of our calculator, using modelling, scenario planning and report comparison to gain further insights
The discussions in the footprint report handbacks and the follow-up sessions revealed a large appetite for positive action and learning. One of the results of this was the organisation of our BASIS certificate in Greenhouse Gases, Carbon and Climate Change mitigation in November and December 2025 for the first time in the East of England. Supported by a grant from the Dedham Vale National Landscape team, this was held at the wonderful Tudor barn at The Hall, Milden, and drew a diverse group of participants from the project area including farmers, land agents and farm advisors. Our own Becky Wilson and Hannah Jones were the course tutors and the sessions were rich in discussion and sharing ideas.
Lastly, all the data from our work has been amalgamated into a landscape report which highlights emissions, sequestration and areas of opportunity and will be included in the submission to DEFRA. This also enables the project team to forecast the carbon impacts of proposed habitats for phase two and compile monitoring and evaluation frameworks alongside providing the value to the individual farmers. There are further exciting developments to follow, so please watch this space.
Farm Carbon Toolkit is proud to have worked on the Connecting Constable and Gainsborough Landscape Recovery Project and work with a fantastic group of farmers. We hope for a positive outcome when the project plan is submitted to DEFRA in early 2026.
The Science Based Targets Initiative (SBTi) is a framework that offers a standardised way for companies to reduce their greenhouse gas (GHG) emissions and reach net zero by 2050 at the latest. The Forest, Land and Agriculture Guidance (FLAG) is specifically for land-intensive sectors like agriculture which guides us to reduce emissions, aligning with the 2015 Paris Agreement’s 1.5℃ global warming target. Participating in the SBTi is currently a voluntary process, but many larger corporations have committed to making these reductions to participate in climate action.
As a farmer, you might have heard of SBTi FLAG targets through your biggest customers (e.g. supermarket buyers and food processors) and it’s likely this isn’t just another piece of corporate paperwork — it is now driving the demands of your supply chain. The world is now getting on board with this initiative, with ¼ of global revenue covered by a target and ~11,000 companies committed to setting them. You likely aren’t setting an SBTi target yourself, particularly if you are a small enterprise, but your operations are a vital part of your supply chains’ Scope 3 emissions. Here is how and why this framework may influence the way you operate.
How it Affects You: The Practical Shifts
The FLAG guidance requires food companies to account for land-based emissions and land-based carbon removals – if sufficient data is available. This may mean a more detailed request for information about your farm and how you operate:
Granular Data Requests: Your buyers may now be asking for more than just “average” carbon footprint data. They may ask for specific figures on your nitrogen fertiliser use, livestock practices including manure management or feed regimes as they are required to prove they are meeting their own 5- to 10-year reduction targets. You will already have a lot of the necessary data to hand. It’s just a case of keeping good records and collating the data where you can. Producing your farm’s carbon footprint is a good place to start!
The Rise of Carbon Sequestration: SBTi FLAG and the updated GHG protocol Land Sectors Removals Guidance (which it is heavily based on) is the first global standard that allows companies to count soil carbon sequestration and hedgerow/woodland growth toward their targets if the supply chains have direct traceability to your farm. This means your buyers will be increasingly interested in farms operating with practices that can maintain or build soil carbon (min-till, cover cropping, leaving stubble in the field, etc) and they’ll want robust evidence for it, such assoil test results. Getting your soils tested over time could unlock potential new customers for your business.
Land Use Change Accounting: Under FLAG, companies must commit to zero-deforestation and no land conversion by no later than 2025. In 2026, this means you must be able to prove that no high-nature-value land (like ancient woodland or permanent peatland) has been converted to arable use on your holding. It also requires you to know and log any previous changes in land use over the past 20 years as part of footprinting your farm. Our guide on land use change may help.
SBTi FLAG v1.1, Dec 2023
Why it Affects You: The Commercial Reality
The “why” is simple: the UK’s major retailers (Tesco, Waitrose, Sainsbury’s, etc.) and global processors (Nestlé, Arla) have signed up for these targets to keep investors and consumers happy. People want to know the products they’re buying are not harming the planet.
Market Access: In 2026, having a carbon audit for your farm is becoming a condition of trade. If you can’t provide the data or demonstrate progress, you may find yourself moved to the “high risk” list for certain premium contracts.
Supply Chain Incentives: Some processors are now offering sustainability premiums—small top-ups on the milk or grain price for farmers who can prove they are employing regenerative practices or using low-carbon fertilisers or maintaining high soil organic matter.
Value of Natural Capital: Because the FLAG guidance validates carbon removals on farms, your land’s ability to store carbon has a tangible financial value to your supply chain. This is shifting their perception of a farm from “food production” to a “climate solution.”
Joining the dots with other schemes
It is important to see the SBTi FLAG framework not in isolation, but alongside other public and private schemes in the UK, for example the Sustainable Farming Incentive in England (SFI; see the Table below), Whole Farm Plan in Scotland, Sustainable Farming Scheme (SFS) in Wales and how they can compliment each other. Additionally, it’s important to be aware of the competing interests on your land and the restrictions on reporting with other opportunities from the Voluntary Carbon Market. The SBTi guidance has rules regarding the use of offsets in inventory accounting. To avoid carbon double-counting you need to make sure that the ownership of the carbon is clear, particularly when reporting for multiple different schemes. For example, if you sell the carbon credits from your woodland to a bank, your milk buyer (the supermarket) cannot count those same removals toward their Scope 3 FLAG target. You have to decide which “market” offers you the best long-term value.
Example Feature
How FLAG and SFI Work Together
Soil Health
SFI pays you to test soil; SBTi FLAG gives that data a “home” in the supply chain to prove carbon storage.
Nutrient Management
SFI pays for precision grazing/fertiliser plans; FLAG uses the resulting lower N2O emissions to hit supermarket emissions reductions targets.
Hedges & Trees
SFI pays for the planting; SBTi FLAG reporting framework allows the sequestered carbon to be counted in the “FLAG inventory” of your buyer.
What’s next?
Start collecting and organising your farm data:
Many farm management softwares will hold a lot of your data already, getting all of this into one place by doing a carbon footprint can help with the process
When you get requests for data, don’t be afraid to ask your buyers questions as well:
Do they have incentive schemes that you can join?
What are the soil sampling requirements, e.g. 30 or 50cm depth? Multi-year data?
Recent Comments