Category: Calculator

How to get an accurate farm carbon footprint report

Posted on February 26, 2024 by - Calculator

Process of doing your carbon footprint report

When calculating the carbon footprint of a farm business, users should expect a result that is accurate, insightful, representative and replicable. However, farmers and growers can sometimes be unsure what the results from different carbon calculators mean, and why they are different. In general, it is good practice to find a carbon calculator which works for you and stick with it. Many calculators provide their methodology which demonstrates transparency and is a feature which users should look for.  In this blog we walk you through the process, and what affects the reports produced.

Inputting data into Carbon Calculators

Before starting the process of collecting data from your farm business, scoping is an important first step in understanding what’s in and what’s out of the report. For instance, a farm might have different enterprises, such as arable farming, a farm shop and some business units. Reporting on those enterprises separately makes sense from the perspective of understanding the carbon footprint of farming operations. In many instances, it is important to understand who the report is being completed for. Completing a whole farm footprint ensures that no details are overlooked and enables users to estimate farm carbon removals as well as emissions. However, increasingly the customers of farmers and growers are keen to understand the emissions associated with the products they are buying.

It should be noted, however, that producing separate reports that focus on the product can lead to overlooking important parts of a farm as a system – those parts of the farm that keep the system working but don’t directly result in a product.

Time period for the report 

This is generally over a 12-month period and can coincide with business accounting or harvest year, whichever is most convenient. It is perfectly possible to carry out emissions reporting over shorter periods to coincide with, for example, batches of livestock production. If you take this approach, be sure not to leave gaps between your reporting.

Data collection is a key part of the process and is generally undertaken by the business owner/employee. Getting this right is critical, and the quality of the data going in directly affects the accuracy of the results that come out. Our advice is quite simple – collect as much data as possible that is relevant to your business over the period to be reported on. We have a data collection spreadsheet to help with this part of the process https://calculator.farmcarbontoolkit.org.uk/resources. 

When entering data into the Calculator, it is important to ensure that data is entered correctly and in full. Users need to ensure that they’ve inputted everything collected in the data collection process and that units, decimal points and other important information are filled in correctly. There is much potential for error here, which will have a significant impact on the results!

Once data is entered and results can be viewed, interpretation of the report is very important. Is the report looking at a whole farm or enterprise footprint? Are you looking at the emissions only or the carbon balance? Are results being shown per hectare, per tonne, or for the whole business? Being clear about what has been measured, and what is being reported is crucial – particularly if comparing between different businesses or within a sector. 

Getting our bit right

As a provider of a leading carbon calculator for farmers, growers and food businesses, at Farm Carbon Calculator we take a huge amount of care in ensuring that we are getting our numbers right. 

Alongside your farm data, all Calculators will have a series of formulae and emissions factors which are used to calculate the farm’s emissions. Emissions factors tell us how much greenhouse gas is released from a certain activity – for instance using a litre of diesel in a tractor. At FCT, we do this on thousands of items! We update all our emissions factors on an annual basis, and sometimes more frequently if new and credible research comes along. 

Once we’ve entered the new emissions factors, which have to be backed up by rigorous and credible peer-reviewed science, we then test the Calculator to ensure that everything is working properly. This process is rigorous and any anomalies are corrected before the update goes live. We publish our methodology and references on our resources page. The next update is due in April 2024.

This ongoing process ensures that we are on top of the science, up-to-date, and maintaining a tool that users can expect to get accurate and reliable results from, in order to make informed decisions for their business.

Alongside getting the factors and formulae correct, there is increasing guidance on what needs to be included within any agricultural greenhouse gas audit and how the calculations should be completed. Examples of such guidance come from the draft Land Sector Removals guidance from GHG protocol which sets standards for how GHG accounting should be carried out and the Forest, Land and Agriculture Science (FLAG guidance) from the Science-based Targets Initiative (SBTi). At FCT, our Calculator has been analysed against the requirements of FLAG and our Calculator has been found to be well aligned with its requirements.

As an organisation that exists to help farmers and growers measure, understand and reduce their carbon footprint,  we always operate in the best interests of our users which includes ensuring our Calculator is as accurate as possible at all times. We are independent, providing a free carbon calculator for farmers and growers, and have a process of continual improvement in place. As a regular user of our Calculator you can always compare current and past results using the most up-to-date Calculator, allowing you to track business progress to net Zero.

You can find all you need to know about the Farm Carbon Calculator here If you need more information please contact us at [email protected] or phone us on 07541 453413 

In the next blog we focus on how we get externally reviewed, and are engaged with industry and Government to improve accuracy and standards.

Your beef enterprise: how to accurately estimate emissions and sequestration

Posted on February 13, 2024 by - Calculator, Insights

To accurately estimate the emissions and sequestration from your beef enterprise, you will need to add data to the following sections of the Calculator:

  • When setting up the report, make sure you enter the area of grazing (grassland) as well as any non-agricultural land area and cultivated land (arable or horticultural)
  • Use the Livestock section and select beef cattle. Add as many entries as you need to cover your herd. For example, you may have two groups of steers with different liveweights or kept on the farm for different lengths of time. In which case, enter the steers from the first group with one liveweight and then the steers from the second group as a separate entry with their own liveweight. This will give you more accurate emissions from their enteric fermentation (gut methane).
  • To calculate the average head of livestock on the farm over a 12 month period, take the number in a particular livestock category per month (so you have 12 “snapshots”) add these together and then divide by 12. Our data collection sheet has a help sheet for this. For growing animals, you may want to use the same approach for calculating average liveweight (our defaults assume a midpoint liveweight through the year for growing cattle but growth rates won’t be linear so using the snapshot approach may be more accurate)
  • Livestock entries also capture the CO2 equivalent (CO2e) of the methane emissions from enteric fermentation and of the nitrous oxide (N2O) emissions from the animals’ manure over the course of the year. The Calculator asks you how this manure is managed as this has an impact on the N2O emissions
  • You have the option to input the average dry matter intake (DMI) per animal per day (kgDM/head/day). The DMI can be used to more accurately calculate the enteric emissions of the cattle, and if left blank, a simpler algorithm will be used that does not consider DMI
  • You will need to account for any supplemental feeding via the Livestock > Animal feeds option – this is for brought-in feeds that were produced off-farm
  • Account for all your fuel use, electricity use, consumables, inventory items and waste produced using the relevant sections (Fuels, Materials,  Inventory, Waste). However, if you also have a dairy herd or arable operation, you may prefer to create a separate report and use this as an Overheads report to apportion shared capital items and energy usage emissions between your enterprises. Watch our video to see how this works in practice.
  • We recommend getting your soil sampled and have a guide on how to do this effectively and affordably. By monitoring your soil organic matter or soil organic carbon over time you can begin to log sequestration rates in your grazed (or other) soils. Once you have two years’ worth of soil sample results, you can enter these in the Calculator under Sequestration > Soil Organic Matter (you will also need bulk density measurements and a record of the depth of the sample).
  • If you don’t have directly sampled soil data for all your soils, you can use our range of proxy values for different Countryside Stewardship and habitat classes to estimate how much carbon your soils may be sequestering year-on-year. You can also measure the length of any hedgerows and field margins (ungrazed) and enter these to estimate the carbon sequestered in them on a yearly basis.

The complexities of calculating livestock emissions

Posted on January 11, 2024 by - Calculator, Insights

What do we mean by livestock emissions?

Emissions from livestock cover two broad categories:

  • Enteric methane emissions (this is the methane produced by the animals digestion)
  • Greenhouse gas emissions from the manure and slurry produced by the animals.

When you enter a group of animals in the Farm Carbon Calculator e.g. 100 dairy cows, the Calculator will consider both enteric methane emissions and the nitrous oxide, ammonia and methane emissions associated with the manure or slurry those 100 dairy cows produce over the course of 1 year.

It is really important to enter the average number of animals in a category over the course of the year rather than the total number. For example, if you have 100 dairy calves on farm for only 6 months of the year, you should enter 50 dairy calves. Otherwise the Calculator will have to assume that all 100 calves are on farm for all 365 days of the year, which would overestimate the enteric methane production and the amount of manure produced.

Why do the emissions associated with livestock vary?

In the Farm Carbon Calculator, we ask users to tell us the number of livestock in a range of different livestock categories. The emissions produced by animals will vary based on:

  • Number of livestock (more animals means more emissions)
  • Liveweight of animals (larger animals tend to produce more manure)
  • Type of livestock (ruminants produce enteric methane, monogastrics don’t. Each type of animal has its own “rate of excretion” and different animals’ manures produce methane at different rates)
  • Pregnancy and lactation (pregnant or lactating cattle produce more enteric methane for their size)
  • Manure or slurry storage (rates of methane and nitrous oxide, emitted indirectly through leaching and ammonia volatilisation, vary depending on how the manure is stored and for how long)
  • Where manure/ slurry is spread (if manure is spread, the type of land it is spread on will affect the rate of indirect nitrous oxide emissions through leaching).

What about slurry covers, storage bags, slurry bugs etc… ?

We are actively working on incorporating a lot more options into the Farm Carbon Calculator to allow users to give more detail on their manure management practices. We plan to include options in 2024 for sending manure and slurry to anaerobic digestion, adding detail on slurry pit coverage, storage timing, and different application or incorporation methods for slurry (e.g. trailing shoe versus splash plate).

We are also researching the possibility of including slurry bugs (bacteria that inhibit greenhouse gas production from slurry stores) and chemical nitrous oxide inhibitors (that reduce the emission of greenhouse gases when the slurry is applied to the soil) as options so that users can show the benefits of these in reducing their slurry emissions. Similarly, we would like to be able to include methane inhibitors that can help to reduce enteric methane emissions for livestock.. To date though, the quality of independent scientific evidence for these management practices is very variable and different products show variable results depending on the farm environment, so it is harder for us to give robust estimates of the effect they will have on a farm’s emissions.

Carbon Trust Reviews FCT Calculator

Posted on January 4, 2024 by - Calculator, News

Our role in helping to decarbonise agriculture brings many challenges, not least making sure that our underlying data and methodology are the best they can be, aligning with the latest science. We’re always striving to improve this, which is why, every year, we conduct an independent review of our Calculator to ensure we’re giving the most robust agricultural carbon footprints possible.

This year, the review of our Calculator methodology was conducted by the Carbon Trust and we’re pleased to be able to share their findings and keep our users updated as we update the Calculator in response.

Summary of the Carbon Trust Calculator Review

In October 2023, The Carbon Trust conducted an independent review and gap analysis of the Farm Carbon Calculator against:

  • The GHG Protocol standard (GHG Protocol);
  • The WRI Land-Use Change and Removals Draft Guidance (WRI LSRG);
  • SBTi Forest Land and Agriculture Guidance (SBTi FLAG)

The following aspects of the Farm Carbon Calculator were covered by the review:

  • User interface
  • Quality Control procedures
  • Emissions factors
  • Calculation methodologies
  • Approach to land-use change

The review identified several strengths and areas for improvement to support the alignment of the tool with the above standards and guidance.

The Carbon Trust has received a detailed action plan of how FCT will enact these recommendations over the next 12 months (with the majority of improvements scheduled for release in April 2024). The Carbon Trust considers that the action plan addresses the points raised in the review. 

Scenario Planning In The Farm Carbon Calculator

Posted on January 4, 2024 by - Calculator, News

At Farm Carbon Toolkit, we know that planning for the future is vital to any business. That’s why we’ve been working hard to create a more formalised system of scenario planning in our Farm Carbon Calculator. And today we’re excited to unveil the new beta version of this functionality, which will give growers and those in the supply chain key insight into the management of their business.

While it was previously possible to scenario plan in the Calculator, we’ve built brand new functionality that makes the entire process clearer and simpler to steer you towards achievable actions.

Scenario Planning In The Calculator

When planning for the future, it helps to be able to visualise the changes you want to make. Scenario planning can help you to plot a roadmap for your business, and see the impact that operational changes could have on your carbon emissions.

Here is a rundown of all the new scenario planning functionality in the Calculator, and how you can use it for key insights into your business.

Report Types

In order to make scenario planning easier and clearer, there is now a ‘report type’ option in the Calculator – which will make it clear if the report you’re looking at is a standard report, a test, or a scenario plan. It also helps us filter out scenario plans from our benchmarking datasets.

Creating Scenarios

There is now a ‘Scenarios’ button on the report results screen, which will bring up several options when you click it (see the screenshot below). When you’ve finished a report, use the ‘Scenarios’ button to start building your plan for reducing your footprint or explore how you could improve the sequestration potential of your farm.

Presets

Firstly, you’ll be able to choose preset scenarios that let you see the effect of changing business parameters. The presets are:

  • Reducing red diesel usage by 10%
  • Switching to a 100% renewable energy tariff
  • Reducing fertiliser usage by 10%

Selecting any or all of these options, and then clicking ‘Create Scenario’, will create a scenario based on the criteria you’ve chosen. You can also leave the presets blank, and just click ‘Create Scenario’, in order to build your own customised scenario plan building on the data you entered in your original report.

N.B. In time, we intend to make more preset options available – but the scenarios above represent fairly typical changes that many growers look to make, and so offer a useful starting point.

Editing Your Scenario Plan

Once you have created a scenario, you’ll need to click ‘Edit farm details’ on the report page so that you can edit the date your scenario plan applies to.

Setting the date is important for our timeline and comparison views, which you can use when you’re ready to see the effect of your scenario planning.

If you’re building a scenario yourself, or want to change some details on a preset, then simply click ‘Edit data’ in the report results screen. Here you can make any changes you want in the same way as in a standard report.

Comparing And Visualising Scenarios

There are two ways to access a report comparison – the first is through the ‘Scenarios’ button in the report results page – from here, you have ‘Scenario comparisons’ and ‘Scenario timeline’ options. These buttons will take you to the relevant comparison type – more on that below – for any scenarios associated with the report you’re working on.

Alternatively, you can also access comparisons by clicking ‘Dashboard’ and then selecting the ‘Comparisons’ sidebar button. From here, you’ll need to select the reports you want to compare – note that linked reports and scenarios appear next to each other automatically. Finally, select either the ‘Timeline’ or ‘Compare’ option – we’ll dive into what each of these options mean next.

Comparison Types – ‘Timeline’ And ‘Compare’

Our Timeline and Compare views offer two different ways of visualising your data. In the simplest terms, ‘Compare’ shows you key metrics and KPIs in a tabular format, while ‘Timeline’ shows your progress over time and towards a net zero target date (2050 by default).

If you want a detailed, granular view of your business, emissions and sequestration, then it’s best to use the Compare view. If you are looking for an overview and direction of travel, you’ll probably prefer the Timeline view.

Click through the image gallery below to see some examples of the ‘Compare’ view data.

And below are some examples of what the ‘Timeline’ view will show you.

Future Development

We’re excited to see how scenario planning will help businesses to reduce emissions and achieve their targets. Looking forward, in 2024 we’ll continue developing the Calculator, and as always our focus will be on helping farmers and businesses both track and reduce their carbon footprint.

You can always get in touch with us to find out more or let us know what you need from the Farm Carbon Calculator [email protected].

Introducing New Benchmarking on the Calculator

Posted on October 31, 2023 by - Calculator, News

Benchmarking graph

In recent weeks we’ve been working hard to revamp the benchmarking functionality in the Calculator. Today, we’re pleased to unveil a new beta version available for all of our users. Featuring an interactive graph and all-new metrics, you can now gain even more insight into how your business is performing. 

The existing benchmarking function will remain in the Calculator for the time being, while we gather feedback on the new version. You can access the new benchmarking function from the ‘View results’ section of a report.

Chart showing user's total emissions per ha compared to farm carbon benchmarking data from Farm Carbon Toolkit

New Benchmarking Explained

Our new benchmarking feature allows you to see how you compare against data from our Farm Carbon Calculator users going back to 2020. Currently, you can dig into 5 key metrics on the benchmarking page – these are:

  • Total emissions per hectare (tCO2e/ha)
  • Total crop yield (tonnes/ha)
  • Total emissions per tonne crops (tCO2e/tonne)
  • Total emissions per tonne liveweight sold (tCO2e/tonne)
  • Total emissions per tonne FPCM (tCO2E/tonne)

Configuring Your Benchmarking Plot

Once you’ve chosen which KPI to look at from the drop-down menu, you can also choose a category to split the plot by. You can do this by farm type, farm size, region and reporting year. 

Chart showing distribution of total emissions per tonne of crops for farm carbon benchmarking data from Farm Carbon Toolkit, split by farm size

Filtering The Data

Lastly, you can also filter the category, if you want to include or exclude certain data. By default, all categories are included but you can choose which data to focus on via the check boxes.

For example, if you are a small dairy farm in the South West, you may wish to only check boxes for “Dairy”, “Small (<100ha)”, “South West” in order to compare with similar types of farm.

Tickbox options for splitting farm carbon benchmarking data in the new benchmarking feature

Interpreting Benchmarking Data

In order to make benchmarking data easier to interpret, we used what’s called a ‘log transformation’ to be able to fit the range of data we hold into a simple graph. It is not easy to read the absolute value for a farm from the axis but it gives you a picture of the spread of the data so that you can see how your farm compares to others.

When you have data in your report to be able to calculate one of the key metrics, you will see your report’s value on the chart as a blue dashed line.

Rule of thumb: if your blue dashed line is towards the left hand side of the peak on the chart, you are doing better than most, while if it is to the right hand side of the peak, you may be doing less well for that metric.

Chart showing user's total emissions per ha as lower than average
Chart showing user's total emissions per ha as higher than average

What’s Included In Your Benchmarking Data?

The data for the new benchmarking feature comes from our own user-generated reports. This data has been carefully managed so as to exclude – among other things – duplicate values, outliers and test scenarios.

For example, reports for farms that have an area greater than 50,000 hectares, but no emissions or sequestration value, will be excluded from the result set. We will also exclude report names with fewer than 3 characters, or those whose names obviously mark them out as test scenarios.

Once any exclusions have been made, we perform some (minimal) cleansing of the remaining data. We may, for example, infer a ‘region’ value from the farm’s postcode. Or infer a reporting year based on the submission date (where there’s no other information available). Finally, we perform the log transformation explained above, in order to display the information in the most user-friendly way.

While every effort is continually made to validate and verify the underlying data, it’s worth keeping in mind that it will never be completely flawless. Nevertheless, the data is very robust and can help aid in planning and decision-making for your business.

What’s Next?

Our carbon Calculator is regularly updated with new features, emissions factors and general improvements. We will continue this work into 2024, and are excited to see how these changes can enhance carbon reporting for farmers and businesses. We plan to update the farm carbon benchmarking data available annually.

Product footprinting for farms and supply chains event at Houghton Hall

Posted on October 5, 2023 by - Calculator, News

Lizzy Parker and Jonathan Smith (Farm Carbon Calculator) answer questions from growers, processors, estate managers and retailers on the new supply chain carbon footprinting tools available from the Farm Carbon Calculator, during a showcase at Houghton Hall, Norfolk
Lizzy Parker and Jonathan Smith (Farm Carbon Calculator) answer questions from growers, processors, estate managers and retailers on the new supply chain carbon footprinting tools available from the Farm Carbon Calculator, during a showcase at Houghton Hall, Norfolk

Press release: 29th September 2023

New tools to footprint farm products along supply chains

Growers, processors and retailers met at Houghton Hall in Norfolk on 8th September 2023 for a showcase of new tools for carbon footprinting of whole supply chains that ultimately allow retailers to track their detailed scope 3 emissions.

These new tools are the latest improvements to the Farm Carbon Calculator, one of the industry’s most popular carbon calculators, which enables farmers and growers to measure and understand the carbon footprint of their business.

Lizzy Parker, Carbon Calculator Manager said:

“We have developed software that, with very little change to the way farmers use the existing Calculator, permits users to produce a product footprint from their whole farm footprint and then pass that information through to their customers. Within the tool, and using the same methodologies, the customer (for example a processor like RB Organic) can aggregate those product footprints from all their growers and add on their own business’ emissions to produce their own product footprint, which can in turn be passed further along the chain.”

Jonathan Smith (Farm Carbon Calculator) discusses management practices that can reduce the carbon footprint of carrot production with RB Organic suppliers and growers on the RB Organic managed land, Houghton Estate, Norfolk.

In the race for farmers and growers to reach net zero carbon and beyond, the Farm Carbon Calculator is focussed on providing the best tools to enable them to measure and manage carbon in their businesses. Working with RB Organic, part of Burgess Farms and their organic carrot supply chain, has enabled the team at the Farm Carbon Calculator to develop the tools with the input of a range of growers, suppliers and logistics companies, as well as the retailer, so that the process works for everyone involved.

Melissa Goodman, Head of Group Compliance at Burgess Farms, said: 

“Identifying our Scope 3 emissions in our supply chain will help us advance on our net zero journey. Developing additional tools that can provide a greater insight into emissions will not only deliver substantial benefits to our business but for the environment too in tackling climate change”.

One key development to enable UK supply chain footprinting has been to research and build an International version of the existing Calculator that can feed into the same carbon reports. Most food products on UK supermarket shelves have dynamic supply chains that rely on imports for parts of the year. Agronomists in Italy, working with RB Organic’s Italian carrot growers, supported the appropriation of the Calculator so that the tool can now provide both language translation and regional data for Italy, crucial for the footprinting of this fresh produce supply chain. 

Chris Negus, General Farm Manager for RB Organic, leads a tour of the organic carrot production on land at the Houghton estate, Norfolk and describes how management practices feed into the company’s carbon footprint in the long term.

The tools are currently in beta testing with existing supply chain partners of the Farm Carbon Calculator and any organisation wishing to use them can contact the team at [email protected] for more information.

The development of these tools for the Farm Carbon Calculator and the footprinting of RB Organic’s carrot supply chain has received funding through the Innovation Connections programme, which is a Tesco WWF partnership initiative.

Paul Marsh, Climate Change Specialist at WWF, said:

“The clock is ticking when it comes to taking action to address the climate and nature crises. Driving down harmful greenhouse gas emissions from the agriculture and land use sector is vital if we are to avert climate catastrophe. We welcome efforts to improve the tools available to UK farmers to measure, monitor, and mitigate emissions over time, and enable the flow of carbon data across supply chains. This can play a key role in supporting the sector to drive down its climate impacts, as part of a shift towards a sustainable food system.”

ENDS

Notes for editors

  1. The Farm Carbon Calculator is owned and managed by Farm Carbon Toolkit, a Community Interest Company dedicated to helping farmers and growers understand and reduce their carbon emissions for the past 13 years.
  2. Farm Carbon Calculator can be found here https://calculator.farmcarbontoolkit.org.uk/
  3. Farm Carbon Toolkit has received funding through the Tesco WWF Partnership Innovation Connections Programme: https://www.tescoplc.com/tesco-and-wwf-announce-winners-of-innovation-accelerator-programme/ 
  4. For press enquiries related to the Farm Carbon Calculator please contact Lizzy Parker, Calculator Manager at [email protected] 

Using the calculator: focus on fertiliser use & efficiency

Posted on August 19, 2023 by - Calculator

This month we’re focusing on how we account for emissions from fertilisers in our Farm Carbon Calculator.

Inorganic fertilisers can be entered in the Calculator using the “Inputs” tab and selecting either a “specific” (branded) or “average” product. The branded products included on the Calculator are those for which the manufacturers have been able to provide us with a robust carbon footprint or where they have communicated the formulation and country of production for the fertiliser ingredients so that we can estimate the carbon footprint for users. 

The “average” options ask you to select the region of the world that the fertiliser was produced in, which you can see from the chart below has a big impact on the total carbon emissions associated with fertiliser use. European produced fertilisers tend to have lower embedded emissions because the factories producing them are fitted with emissions abatement systems.

The Calculator takes the quantity of fertiliser and uses emissions factors (from Brentrup et. al 2016) to work out the embedded carbon associated with that quantity of the fertiliser (i.e. the carbon emitted as a result of producing it) and then also estimates the CO2 equivalent of:

  • the nitrous oxide (N2O) emissions in the soil associated with applying that quantity of fertiliser
  • indirect ammonia (NH3) losses to the air due to volatilization
  • emissions associated with urea hydrolysis (only for fertilisers containing urea)

Even small reductions in fertiliser use can have a big effect on a farm’s overall carbon footprint. The following chart shows a comparison of the same farm with three different scenarios. They are for illustration only as the impact on yield of reducing or changing the fertiliser usage can vary hugely from farm to farm. The baseline in scenario 1 (black) uses 30t of EU AN fertiliser and 30t of Mole Valley powerblend 26-14-14 to produce 1000t wheat on 100ha, 350t OSR on 100ha and 350t field beans on 100ha. They also spread 100% of the manure and slurry from their 40 head of beef cattle on the arable land.

In scenario 2 (brown) the quantity of AN fertiliser has been reduced by half to 15t but all other N sources have been kept the same. This reduces the carbon balance by approximately 40t CO2e. For some farms this might have a large impact on yield while for others the impact may be minimal depending on the soil quality, crop/ variety being grown, timing of applications and which crops are prioritised in terms of N demand. 

Even if this reduction in AN use resulted in  a 20% reduction in wheat yield, the per tonne footprint of the crops remains the same between the baseline fertiliser use and scenario 2. It is also worth considering the financial saving of reducing AN fertiliser by 15t (at the time of writing this would be a saving of approximately £5160 at £344 per tonne). 

Assuming the reduced fertiliser application is on the highest value crop (wheat in this example), and taking the price of Yorkshire feed wheat (£315.5 per tonne) to estimate the financial hit of an extreme 20% reduction in wheat yield between scenario 1 and 2, this would equate to a cost of £63 100. In contrast, in scenario 3, we have shown the same inputs but with only a 2% yield reduction for wheat compared to the baseline, for which the yield penalty would equate to £6310, assuming the fertiliser saving can be made by reducing application on the less valuable crops/ pasture. At the current price, the saving on fertiliser does not outweigh the cost of the yield reduction but with both markets fluctuating so much, there will be times when it is advantageous.

In scenario 4, we’ve gone so far as to remove any AN fertiliser (though of course in this example farm there is still 30t Mole Valley 26-14-14 and the beef herds’ manure and slurry being applied). This reduces the total emissions of the farm by 79t CO2e. We have modelled a 40% reduction in wheat yield here which would obviously equate to a huge cost of £126 200 (using the same assumptions as above) if the wheat were being sold. However this yield reduction may still  be acceptable where the wheat is being fed to the beef herd and the farm exceeds it’s requirements. Alternatively, in this case, the farm might consider switching to a different rotation to be able to feed the cattle the required ration without the need for the high cost of AN fertiliser (scenario 4 represents a saving on fertiliser of £10 320 compared to the baseline scenario 1).

This is an example report, and of course, the real-world decisions on how to reduce fertiliser use are much more complex. AHDB have some research and guidance on what may or may not be feasible here and a tool for calculating fertiliser adjustments here. Alternatively you can get in contact with our team of advisors who have lots of experience weighing up the pros and cons of fertiliser reduction in each unique setting.

Getting in touch

If you have any questions/comments please email [email protected]

Find out more

You can find all our useful calculator resources here.

This blog was written by Lizzy Parker, our Calculator Manager.

Using the Calculator: focus on sheep

Posted on July 17, 2023 by - Calculator

This month we’re focusing on calculating emissions and sequestration from your sheep enterprise.

To accurately estimate the emissions and sequestration from your sheep enterprise, you will need to add data to the following sections of the Calculator:

  • When setting up the report, make sure you enter the area of grazing (grassland) as well as any non-agricultural land area and cultivated land (arable or horticultural)
  • Use the Livestock section and select sheep. Add as many entries as you need to cover your flock. So for example, you may have two breeds with different liveweights, in which case enter the ewes from the first breed with one liveweight and then the ewes from the second breed as a separate entry with their own liveweight. This will give you more accurate emissions from their enteric fermentation (gut methane).

  • To calculate the average head of livestock on farm over a 12 month period, take the number in a particular livestock category per month (so you have 12 “snapshots”) add these  together and then divide by 12. Our data collection sheet has a helpsheet for this. For lambs you may want to use the same approach for calculating average liveweight (our defaults assume a midpoint liveweight through the year for growing lambs but growth rates won’t be linear so using the snapshot approach may be more accurate).
  • “Livestock” entries capture the CO2 equivalent of the methane emissions from enteric fermentation and of the nitrous oxide (N2O) emissions from the animals’ manure over the course of the year. The Calculator asks you how this manure is managed as this has an impact on the N2O emissions.
  • You will need to account for any supplemental feeding via the Livestock > Animal feeds option – this is for brought-in feeds that were produced off-farm.
  • If you use any additional fertility sources, you will need to account for these where they have been brought-in. For manures, slurries, AD digestate, water treatment cake, lime or mineral fertilisers, use the Crops tab. For chemical fertilisers, use the Inputs tab.
  • Account for all your fuel use, electricity use, consumables, inventory items and waste produced using the relevant sections (Fuels, Materials,  Inventory, Waste).
  • We recommend getting your soil sampled and have a guide on how to do this effectively and affordably. By monitoring your soil organic matter or soil organic carbon over time you can begin to log sequestration rates in your grazed (or other) soils. Once you have two years’ worth of soil sample results, you can enter these in the Calculator under Sequestration > Soil Organic Matter (you will also need bulk density measurements and a record of the depth of the sample).
  • If you don’t have directly sampled soil data for all your soils, you can use our range of proxy values for different Countryside Stewardship and habitat classes to estimate how much carbon your soils may be sequestering year-on-year. You can also measure the length of any hedgerows and field margins (ungrazed) and enter these to estimate the carbon sequestered in them on a yearly basis.

Getting in touch

If you have any questions/comments please email [email protected]

Find out more

You can find all our useful calculator resources here.

This blog was written by Lizzy Parker, our Calculator Manager.

Farm Carbon Calculator update May 2023

Posted on May 22, 2023 by - Calculator

Farm Carbon Calculator logo

This month we have launched further improvements to our Farm Carbon Calculator that enables farmers and growers to measure and understand the carbon footprint of their business.

In this upgrade there are a large number of improvements to the data and calculations that underpin the tool. This means we are up-to-date with the latest science and correspondingly your carbon reports are more accurate. We constantly aim to be reflecting the most recent emissions factors. In this upgrade we have updated factors and calculations in:

  • Livestock (including new category descriptions)
  • Fuels
  • Distribution
  • Materials
  • Processing

In addition, we’ve re-ordered and updated the list of sprays, as well as a new sub-section for molluscicides. Some additional mineral amendments and specific fertilisers have been added too.

Animal feeds are a very important issue, and the impact of feeds on the footprint of livestock farms can be very significant. We’re constantly trying to improve the information available in this area and have expanded the number of items on offer. This is a continual topic of research for us.

There are some changes to how users select a report date, so that a start and end date is required (for the 12 months of the report). This is due to how our database works, which is a hidden but important area of the improvements we’ve made.

Renewable energy exports now don’t show up as a carbon offset, in line with scoping guidance provided by GHG Protocol, which is a globally recognised carbon standards organisation.

Details of all the changes can be found here, including a list of sources of our emissions factors.

Next stages

Months of research, development and testing by the Calculator team have led to this point. We are proud of what we’ve achieved, and see it as a vital improvement for users. But, more excitingly, the development continues as part of the two projects that are going to radically improve the user experience of the Calculator. This first stage of these feature upgrades will be launched in early September.

The Tesco-WWF funded work, in partnership with Produce World, focuses on improving the user experience, building infrastructure to allow carbon data to flow through the supply chain, with improved benchmarking and target setting for users, and an international version.

A parallel Innovate UK funded project, in partnership with Velcourt, CHAP and Agrimetrics, will strengthen many of the above developments, as well as enabling better data flow into and out of the Calculator. This stage of the feature upgrades will be completed at the end of December.

These are hugely exciting developments for the Farm Carbon Calculator, so expect to see much more activity from us in coming months and, importantly, a much improved tool for our users. Alongside our project partners, we are supporting the food and farming sector to cut carbon emissions and reach beyond net zero.

Resources

There are a range of resources for users of the Calculator on this page https://calculator.farmcarbontoolkit.org.uk/resources, including the popular Data Collection Spreadsheet which gives guidance on how to complete data collection and the process of completing the report.

There are also useful FAQs and a ‘how to’ video on the Calculator homepage. You can also login to access your reports here, or set up a new account if you’re new to the Calculator https://calculator.farmcarbontoolkit.org.uk/