Category: Insights

Sustainable crop rotations

Looking back at 2023, it can safely be defined as a challenging year with the wettest autumn / winter we have seen for decades. Farmers have not only faced the challenge of maximising yields and optimising soil health, but also battling against the elements to drill crops into the ground. Hoping for a kinder 2024, this blog explores options to build resilience into crop rotations aiming to cultivate a balance between high yields and optimum soil health.

Minimising cultivation

First things first, this blog is not telling you to get rid of the plough. All machinery serves a purpose, it is just about knowing when to intervene. Within systems that have reduced their cultivations or those that have been adopting conservation ploughing (i.e. ploughing one year in three or more), soils tend to be more resilient through improved soil structure. Good soil structure has a matrix of small, medium, and large pore spaces able to retain and drain water as well as provide pockets of air for respiration and gaseous exchange and water for nutrient exchange. When we till the soil, especially when ground conditions are sub-optimum, we run the risk of squashing the pores and causing compaction and soil degradation, reducing water infiltration, increasing anaerobism (lack of oxygen) and building up toxic gases, all contributing to poor soil health and disappointing crop yields.

Carry out a VESS: Visual Evaluation of Soil Structure

It is important to get out there and dig holes; get to know your soil and how it behaves under certain environmental conditions. When you assess the soil structure, look for compaction and note its depth. Can this be remedied by deeper rooting species, or does it require mechanical intervention? Always keep the depth in mind as it’s no good going in too deep or too shallow.

Diversity

Sustainable rotations begin with diversity. A multipronged approach combining arable crops, legumes and cover crops takes full advantage of all the tools we have in the box as arable farmers. Diversity in species above ground matches diversity in species below ground: helping to break pest and disease cycles and improve soil health through provision of various rooting architecture, root exudates and crop residues. The soil is alive and many of the nutrients available to crops and plants come from the activity of soil-dwelling organisms that are busy stabilising, consuming and releasing nutrients for the benefit of the crop. Diversity in crops and roots therefore contribute a rich source of food for soil fauna to feast on, enhancing soil fertility and subsequent crop health and crop yield. 

Where pests and disease more commonly thrive is within monocultures e.g. continuous cereals. We are seeing an increasing reliance on chemicals to control and abate problems within these systems, depleting our soils of beneficials in the process. Similarly, a lack of diversity in roots are only supporting a limited community of microorganisms. This is not sustainable; therefore, we must explore how we can incorporate more species within the rotation. OSR is one of many good examples. It has deep roots and is easily diversified with companions e.g. vetch / buckwheat / berseem clover. Maximising the number of crop species in a rotation will optimise the diversity of organisms below ground.

On farm, an easy way to measure how biologically active our soils are is by monitoring earthworm numbers. Earthworms are at the top of the soil food web and will travel to and reside where there is lots of food; they are also brilliant at breaking down residues and redistributing nutrients throughout the soil profile. How many worms do you count in a spade full of soil? Where are you finding the most? And can those numbers be replicated elsewhere on farm?

Legumes

The blog wouldn’t be complete without talking about legumes. Approximately 78% of the air is nitrogen. If we can harness the power of leguminous plants to fix some of that nitrogen, we can cut costs by reducing the amount of artificial fertiliser whilst also minimising our environmental impact. Consider incorporating peas or beans into the rotation as stand-alone crops, clover as a companion crop or include legumes as part of a cover crop mix. Farmers are often able to reduce the amount of bagged fertiliser used after legumes.

Legumes to build fertility: field beans in an arable rotation

If possible, trial a small reduction across a proportion of the field first and see how your yields fare – you might be pleasantly surprised.

Cover Crops

Utilising cover crops between winter and spring cropping is an excellent approach to building soil health in between cash crops: stabilising soil structure by maintaining living roots in the soil throughout the year, feeding the soil biology and acting as a buffer protecting the soil from adverse weather conditions. 

On top of this, one of the biggest advantages of cover crops is that they are great at scavenging and holding onto residual nutrients left over from the previous crop, reducing losses from leaching. Once destroyed, the nutrients will be released back into the soil, improving nutrient use efficiency, and potentially enabling a reduction in artificial inputs required by the next crop. 

Cover crop mixes should be tailored to your needs and soil type. It’s better to choose species type based on what you are trying to achieve: building fertility, keeping the ground covered, and/or alleviating compaction. 

If possible, conduct trials and aim to include 3 or more species in the mix to capitalise on diversity in both the above-ground biomass for optimised photosynthetic potential (think assortment of leaf shapes to increase surface area from which to harness the sun’s energy), and below-ground biomass through varied rooting structures, depths, shapes and sizes (pumping sugars and carbon into the soil, building soil organic matter and feeding the soil biology).

Livestock Integration

Integrating grazing livestock into your rotation offers an alternative technique to destroying cover crops whilst also adding valuable organic matter to the soil in the form of manure. Including grass and clover leys also gives the ground a break, allowing time for recovery and offers another income stream from grazing or silage / hay making. The benefits of perennial roots in the ground over an extended period, especially if a mix of roots at different depths, will help to improve soil structure and build fertility for future crops.

Grazing livestock returning soil organic matter and building soil health.

Explore the Sustainable Farming Incentive options to see if herbal leys or a 2-year legume fallow could be economically viable.

Monitoring and Adapting

It is important to remember that there is no one-size-fits-all approach; be adaptive and tailor options to local environment and conditions. Trial different methods and see which suits your system best.

Regularly monitoring soil health, accounting for all nutrient sources, and keeping an eye on pest and disease prevalence alongside crop performance and weather is crucial to make informed adjustments to rotations as needed.

In summary, farmers are in a unique position in that yes, we produce emissions in the process of producing nutritious food however, we can also build soil health and boost biodiversity simultaneously contributing to offsetting our own emissions and future proofing our farms and landscapes. Implementing a sustainable crop rotation in the UK is not just about growing crops; it’s about promoting a future where productivity and soil health co-exist. By diversifying crops, integrating legumes, embracing cover crops, minimising tillage, incorporating livestock, and tailoring practices to local conditions, it is possible to achieve a resilient and sustainable agricultural landscape supporting local and wider communities for years to come.

Building trust in Carbon Calculators in Agriculture

Farm carbon calculator logo

By Liz Bowles, Farm Carbon Toolkit Chief Executive

In a recent blog post, we explored all the factors that influence the accuracy of carbon footprint, from the data the user inputs, through to the processes that ensure the Farm Carbon Calculator’s calculations and emissions factors are correct, and the ongoing testing carried out. Here we would like to tell you about how we are involved with activity to support Calculator harmonisation to increase levels of trust in all UK Farm Carbon Calculators.

Defra is very keen to support the agricultural sector in embracing greenhouse gas accounting. To this end in 2023, they commissioned ADAS to look at a number of leading UK Carbon Calculators to improve our understanding of the differences between them and to support methodology harmonisation going forward. Not surprisingly the differences between the Calculators investigated arise from three main areas – scoping, factors and standards.

Scoping describes what is measured, and some calculators include things that others don’t. At the Farm Carbon Calculator, for instance, we measure as much as possible of a farm business.

There are some standard and some non-standard emissions factors used. For instance, the UK Government produces a comprehensive list of emissions (UK GHG Inventory Conversion Factors) from fuels & energy, livestock and crops that all calculators will use. But some of the other factors come from a range of other scientific papers and there may be some variability in which ones are used by different calculators. 

There are a number of standards that describe what and how to measure carbon footprints. Whilst there are a number of standards that relate to food and farming, there is a lack of consensus over which standard is ‘the one’ to adhere to.

Guidance for all carbon calculators

A series of recommendations for all Carbon Calculators, Industry and UK governments were made by ADAS as a result of this work – ADAS report . Here we list those recommendations and how we are implementing them.

SectorWhat is the ask?What is FCC doing?
Industry and GovernmentClearly define the scope required for farm level carbon assessments and how they will be usedWe are actively working with industry bodies to harmonise the way emissions data is collected and calculations are made
CalculatorsAlign with the requirements of the latest standards and guidance – currently GHG Protocol standardsFollowing our Carbon Trust Review we are implementing our agreed action plan to ensure full alignment with the GHG Protocol
CalculatorsRegularly review and update Calculators to account for changes in scientific knowledge, carbon accounting methodologies and new emission factorsWe update the Calculator in spring and autumn each year, covering all three areas outlined in the recommendation
CalculatorsComply with the latest IPCC guidanceWe already adhere to IPCC guidance
CalculatorsTo use emission factors from agreed sources for the embedded emissions in fertilisers, feed and fuelsWe base emissions factors on the GFLI database, which is considered the most robust source of this data. However, we would welcome a more UK-centric database which is required to be used by all Calculators. Agricultural carbon tools have been struggling with the challenge of embedded emissions in purchased livestock for years
IndustrySupport the development of appropriate emissions factors for the embedded emissions in purchased livestock
CalculatorsPresent outputs in compliance with the latest standardThrough our adoption of the Carbon Trust Recommendations our outputs will align with the latest standards
Government and industryDefine consistent disaggregated output categories for use by all calculators.(not applicable)
Calculator providersBuild user confidence through transparency of approach and third-party verification of the alignment of calculators to minimum standardsOur methodology is freely available on our website and we annually carry out an independent review of the Farm Carbon Calculator

Alongside the work of ADAS, FCT is working with other UK Calculators as well as industry bodies such as Dairy UK to support more rapid harmonisation to reduce report results variation for farmers. Watch this space!

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

How to get an accurate farm carbon footprint report

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

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 Financial Reward of Reducing Carbon

By Robert Purdew, Farm Carbon and Soils Advisor

There is a growing concern about carbon “tunnel vision” in agriculture, where the sole focus is on reducing emissions without considering the bigger picture. Reducing emissions is crucial, yet it’s important to acknowledge that it is only one piece of the puzzle and focusing solely on carbon can neglect factors such as soil health, water quality, biodiversity and other issues such as pollution. There is also often concern from farmers about how the pressures to achieve net zero targets can impact profitability, especially when incentives to be net zero are limited or non-existent, and investments in the infrastructure and technology required to transition to low-carbon farming are high.

But this doesn’t have to be the case. We can use an understanding of a farm’s emissions to make informed decisions to change management practices that can lead directly to both reduced emissions and increased profitability, and we can point to an increased number of farmers who are doing just this.

Mike and Sam Roberts farm 435 acres at Blable Farm, of which a large proportion is down to herbal leys. After Sam returned to the farm in 2018 a decision was made to review the whole operation and, in conjunction with James Daniel of Precision Grazing, the decision was made to reduce the herd slightly from 180 to 150 cows, implement rotational grazing on diverse leys and to focus on reducing inputs and improving soil health.

Cattle out wintering at Blable Farm

The effects were immediate and obvious. Soil health has seen a rapid improvement with better structure, increased earthworm numbers and soil organic matter is on the rise. The grazing period has been increased from 6 to 12 months and the farm hasn’t bought fertiliser since 2021, with none being used last year. Importantly, animal performance has increased in line with improved soil health and while cow numbers were reduced initially Mike and Sam are looking at increasing numbers again. All of this has seen a significant saving on input costs which has been re-invested into the business, including a full soil audit to better understand how soil health is improving. In line with reduced costs on-farm emissions have been reduced significantly with Mike confident the farm can reach net zero within 5 years, a commitment made as part of being a demo farm for the Farm Net Zero project.

Another example of a farmer using an understanding of their carbon footprint to drive down costs and improve profitability is Tom Burge of Oaremead Farm. Tom farms 760 acres of grassland on Exmoor and runs both a suckler herd and commercial sheep flock. In 2017 Tom began shifting to a more regenerative farming system which predominantly focussed on an improvement in grazing management, once again aided by James Daniel from Precision Grazing.

A person standing in a grassy field with cows

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Over 5 years, Tom has completely cut out the use of artificial fertiliser and reduced his feed use by over 70%. This has been made possible by an increase in dry matter grown of 0.9 tDM/ha, through improved grazing management, and has reduced input costs by 50%, with a similar reduction in emissions from inputs, as shown in the chart below. Crucially the farm is now profitable before taking into account income from subsidies and environmental schemes. In the next 5 years, Tom plans to completely cut out bought-in feed and to have halved fuel use and, like Mike and Sam, be well on the road to net zero while remaining highly productive and profitable.

Oaremead Farm emissions from inputs

These are just two of an increasing number of examples that we are coming across as we work with more and more farmers who are using their carbon emissions as just one metric to help improve their farm businesses. And far from impacting just a farm’s emissions and bottom line, the management changes that are being implemented are having beneficial impacts on those ecosystem services mentioned previously, soil health, biodiversity, water quality and reduced pollution. Proof if ever it was needed of the potential for long-term sustainability within our farming systems.

Five farms in Cornwall on a journey towards Net Zero

We’re excited to share a series of five new videos that showcase some of the farms in Cornwall that are part of the Farm Net Zero project.

Each video shares a different farm’s journey as it works to improve the environment, produce nutritious food, while also responding to climate risks, such as flooding. There is a specific focus in these videos on how the farms are engaging within their local communities, to help tackle these issues. The Farm Net Zero project includes practical advice for farmers on how to reduce greenhouse gas emissions, showcases innovation, provides robust science through soil testing and carbon footprinting, and inspires other farmers to tell their stories to consumers on the steps that they are taking to address climate change and protect soil health.

The full-length video below includes all of the following five stories. If you prefer to view each story separately, please simply click on each of the links here:

The complexities of calculating livestock emissions

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.

The importance of managing manure on-farm 

Written by Becky Willson, Business Development & Technical Director.

Manure is a fantastic on-farm resource. This is because it can deliver a source of nutrients that can be used to grow crops, as well as enhancing soil biological activity, feeding the soil microbes and helping provide a steady supply of organic matter. This can ensure that soils are in the best condition structurally, chemically and biologically. Manure is one of the most important resources that is produced on-farm, and should be valued rather than seen as a waste product. 

A key way to be able to reduce reliance on fertilisers is to develop efficient and effective strategies for managing nutrients and manures on-farm. 

Nutrient management planning

Managing nutrients in a systematic way through planning is a vital aspect of sustainable farming. It is a ‘win-win’ practice which generates advantages across economic and environmental parameters, and allows for the creation of a sustainable agricultural system which is resilient to climatic and economic change. 

Nutrient management planning facilitates optimal use of nutrients from all available sources. Matching inputs of nutrients (from fertilisers and organic manures) to the demand from the crop will allow for an optimal yield, minimise the use of nutrients (which saves costs) and minimises the risk of losses to the environment from nutrients.  

Slurries and solid manures are valuable fertilisers but may also be potential sources of pollution. Within increasing economic and environmental pressures on farm businesses, it makes sense to exploit the fertiliser value of manures while taking action to prevent pollution. 

Most farm assurance schemes require a manure management plan to be completed as part of the certification process. However even without the compulsion of a scheme, having a plan which marks out any environmental features, watercourses, sloping fields which may cause run off and any areas will be a useful resource to consult before applying manures.  

The need for effective manure management

The most effective way of dealing with livestock manures is to apply them at appropriate rates to agricultural land for the benefits of soil and crops. Getting manure management right allows for sustainable use of resources which provides economic savings and reduces the amount of artificial fertiliser that is required. Manures, when stored and applied correctly have fantastic benefits in building resilience within your farming system, cutting costs and lowering your carbon footprint, however if they are applied in too high a quantity or at the wrong time of year then they are an environmental risk. So it is the job of farmers to maximise the benefits that can arise and minimise the risks.

Nutrient management planning to mitigate greenhouse gas emissions

Nitrogen emissions to the air from farms include greenhouse gases, the most potent of which is nitrous oxide. Nitrous oxide is one of the biggest contributions that agriculture makes to climate change. Soil nitrous oxide emissions originate from three sources, soil microorganism activity (55%), organic manure applications (18%) and Nitrogen fertiliser applications, (27%). As such, careful management that maximises the efficiency of any fertiliser applied, takes account soil and climate conditions, and uses the nutrients within manures for crop growth will help to reduce the amount of nitrous oxide lost. 

Nutrient and manure management planning will also help reduce ammonia emissions. While ammonia isn’t a greenhouse gas, it negatively impacts air quality and human health. The amount of ammonia which is lost depends on a variety of factors including manure type, the method and timing of applications, soil pH, the weather conditions at spreading, the soil moisture content and how the manure is stored. As such there are a variety of mitigation options available that are made easy by planning how manure is managed to reduce these risks. 

Soil Testing

Although not always considered as linked to nutrient management planning, monitoring and controlling the pH of soils on-farm is the first step toward good nutrient management. If soil pH is not correct then any nutrients that are applied through fertiliser or manure applications will not be available to the crop and may be lost from the soil incurring costs, reduced yields and pollution issues. 

Effective use of manures – Storage

Having sufficient slurry or manure storage means that effective nutrient management planning is much easier. With sufficient storage capacity, slurries and manures can be applied at the optimal time for plant growth and crop uptake, as well as being applied when the soil and field conditions are right and damage (including compaction and run off) is minimised.  However for some farmers who don’t have enough storage, slurry has to be spread in less than ideal conditions, when there is little crop growth and nutrient uptake. It is in these situations where environmental losses can be the highest. 

Thankfully there are ways that storage can be optimised. This can include minimising the amount of rainfall that is able to enter the store. Rainfall can dilute the nutrient content of the slurry but also costs more in manure application – more water is held within the slurry leading to a higher volume to be spread. Mending guttering, diverting clean water away from stores and covering yards to minimise the amount of water that is entering the store are all low cost ways to help maintain the nutritional value of the manure and also reduce costs. Covering stores is also an option and there are various cover options that are available depending on the store type and design. Floating covers will also reduce the amount of ammonia which is released into the atmosphere which has air quality benefits. 

With solid manure it is important to consider the siting of field heaps and managing the heap to ensure that Nitrate leaching is minimised. Composting of FYM will provide a more stable and uniform material which will have benefits for soil biology, but will not provide such a high readily available Nitrogen source as fresh manure. 

Effective use of manures – Application 

Ensuring that manures are applied at the right rate and the right time is the most important step to reducing environmental risk and improving economic performance of the farm.  The method of application can affect the amount of nitrogen that is available to the crop. Although the total nitrogen content within the manure cannot be altered by the method of application, the proportion of the nitrogen that is available to the growing crops is improved by using low trajectory machinery.

Spreader technology has developed over recent years so that now there are numerous options available for spreading slurry (where losses are potentially higher). Broadcast spreaders will waste nutrients, but this can be minimised by using injection or band spreaders which put the slurry directly on the soil surface or into a narrow slot. For solid manures, the evenness of spreading is far improved by using a rear discharge spreader. If manure or slurry is to be incorporated, ensuring that it is done quickly after application and not just left on the surface where the nutrients may well be lost is important.

Optimising the use of manures and slurries on-farm will provide benefits through improving profitability, resilience and soil health. For more information on manures and nutrient management planning please visit the FCT toolkit pages to access a range of resources.  

Soil Farmer of the Year 2023 – Farm Walk with Bronagh O’Kane

Written by Emma Adams on behalf of The Farm Carbon Toolkit

In a first for the Soil Farmer of the Year competition, in October 2023 our series of farm walks took place in Northern Ireland. A group of farmers, academics and industry professionals met at Drumard Farm, just outside Cookstown in County Tyrone, to hear from Bronagh O’Kane on how she is transforming her farming business with resilient soil at its heart.

Bronagh introducing the farm to the group

Having come back to the farm in 2020, Bronagh began a journey to transform the soil. Historically the farm supported continental cattle breeds with a high reliance on imported feed, Bronagh has transitioned this system to more traditional breeds managed on herbal leys and ever-increasing diversity grasslands. Utilising a rotational paddock system she has extended the grazing period so that cattle can be out by 4 weeks and soils are more resilient to the extremes of dry and wet weather. Bronagh has started producing vermicast and composting to improve soil biology; focusing on natural inputs and a softer approach with foliar fertilisers where needed to manage historically compact and imbalanced soils. The walk will provide the opportunity to discuss and demonstrate the practices undertaken at the farm and the ongoing challenges and successes that Bronagh sees in her system.

The beginning of the farm walk

At Drumard Farm, Bronagh was told she had poor soils and no doubt they are a challenge, with testing suggesting an average of 45% silt and 45% clay they are tight and sticky, with little aggregation or infiltration. As such, understanding what was needed for the soil to function better was a priority for Bronagh, with a great deal of research it was understood that the high magnesium, bacterially dominant soils were being held back by a mineral imbalance, compaction from big tractors and heavy cows. 

Inspecting the soil condition following the autumn rain

Changing the livestock system at the farm has been central to Bronagh’s evolving management. The cattle business has been streamlined, and as such the previous finishing and store systems have been stopped instead to focus on a suckler system with pedigree Charollais sheep. The sheep are high value stock, as Bronagh suggests there isn’t the acreage for a larger flock, instead, she buys in September before selling the ewes with lambs at foot in the spring and runs the rest of the flock throughout the year. This system works well as there is the housing space available over winter and also the sheep provide a good opportunity to clean up the last of the grass when it is too wet for the cattle to graze. Previously the farm also had Charolais cattle, but these have been restocked, reducing numbers from around 80 to 50 on a sucker system focussing on more native breeds such as Speckle Park, Shorthorn and Hereford crosses with an Angus Bull. Even with these changes, Bronagh found that those animals with a Limousin cross within the breeding still comparatively lost condition on the new system which is thought to be from underlying epigenetic traits. This has led Bronagh to source more local Shorthorn heifers which are better adapted to a grass-based system. 

Bronagh utilises plant diversity as an indicator of the status of the soil. The species that may dominate in a field or area can suggest what the underlying composition may be – chickweed for excess nitrogen, low calcium or high potassium or creeping buttercup thrives where there has been poaching, bare soil and a low pH. Like many farms, docks have historically been widespread at the farm, often indicating compaction and an anaerobic soil environment. Bronagh’s approach to dock management is to change what has historically not been working – sprays and topping – and instead let them grow and allow the dock beetle to get to work combined with a cut for silage around June. This understanding of what the plants are indicating has led Bronagh to stop spraying and minimising fertiliser use to zero, instead focusing on balancing the soil and improving the health of the biome. She explains:

“Biodiversity, long rest periods and grazing management can change soils – you’re not stuck with what you have”

Grassland management is central to how the business is now run. Bronagh has diversified existing grasslands into multi-species swards despite the testing conditions and low pH of the farm. On the walk, the group visited a newly established herbal ley that had been planted in a field that was pH 5.8.  

The newly established multi-species herbal ley

The 15-way mix contained species such as sainfoin, plantain and chicory and Bronagh has subsequently experimented with both cutting and grazing, which has led to discussions with contractors on cutting heights, timings and more to best maintain the sward. For Bronagh, managing these lays to allow the full diversity is important, with the understorey plants encouraged through the aforementioned considerations in combination with the paddock grazing system. Bronagh has experimented with the paddock grazing timings and methods, including grazing the cows on knee-high swards which resulted in moving them faster but increasing the size of the paddock as the cows were found to be trampling rather than eating following heavy rain. Bronagh suggests:

The definition of overgrazing is letting them get that second bite – it is so important for my fragile, shallow roots to rest”

In addition to the home farm, Bronagh also has a 30ac National Trust tenancy on a zero-input system supporting both a rotational grazing and cutting platform. For Bronagh, having the right livestock that will thrive on a grass based system is key to success. As such, she puts the heifers on the poorest fields to determine which animals will be kept as some breeding is adapted better to the system than others. 

The walk also incorporated learning more about how Bronagh is using vermicast to provide nutrition and balance to her soils. Vermicast, or worm castings is made by using worms to compost organic amendments such as farmyard manure, food waste, wood chip etc to create a soil conditioning fertiliser.

Worm farm whereby organic materials are broken
down to create the vermicast

On the farm, vermicast is used to provide nutrients, stabilise pH and also as a coating on any new seed that is established. Bronagh applies her vermicast through a sprayer after making a ‘compost tea’. The vermicast is added to a porous ‘tea bag’ within an IBC filled with water which is then agitated and aerated using a bubbler to extract the nutrients and beneficial organisms which vermicast contains, the resulting liquid is then applied to land to stimulate soil biology and provide nutrients. Bronagh is aiming for a 1:1 ratio of fungi to bacteria which the vermicast and good soil management will help promote.

Bronagh explains the process of using vermicast
to make a compost tea

Regularly conducting Brix testing has allowed Bronagh to understand how to best apply the vermicast and the benefit it is having to her land, with fields which have had no fertiliser, slurry or inputs other than vermicast scoring 12, with Bronagh suggesting that every 1% increase in a Brix result can give a 0.5-0.75kg improvement in liveweight gain in the cattle. Any amendments which Bronagh applied to the land are designed with this goal in mind, alongside the cost and feasibility within her system. An example of this is that she has been experimenting with using egg shells to help aid the calcium balance and flocculate the soil; this can be spread with a conventional fertiliser spreader rather than other products which can have additional costs due to the price of both material and the contractor required to apply the product. 

Since 2015, the Soil Farmer of the Year Competition has helped to find, promote and champion UK farmers who are passionate about safeguarding their soils and building resilient businesses. As part of the competition, the top three farmers host farm walks that bring farmers together to share good practice and innovations that improve soil health. The 2024 round of the competition opens on 5th of December 2023, which is World Soils Day – if you are interested in finding out more, entering the competition or nominating someone who you think is deserving of this award further details can be found on the Farm Carbon Toolkit website or https://farmcarbontoolkit.org.uk/soil-farmer-of-the-year/ 

Lessons Learnt at Erth Barton

Wednesday 18th October 2023

Tim Williams has now completed three years of a contract farming agreement with Antony Estates, working to convert Erth Barton into a regenerative farming system, rebuilding soil fertility. This event was a chance to hear about some of the successes and challenges encountered during the transition. This event was made possible with thanks to the National Lottery Community Fund who fund the Farm Net Zero project.

Tim took on the 300-acre (121 hectare) farm in two halves, arriving with very little kit and limited funds for inputs. This has meant he has built a simple, zero-input system focusing on restoring and feeding the soil microbiology in order to provide fertility.

A very diverse cover crop/herbal ley was drilled to increase rooting depth and diversity and then grazed with beef cattle (averaging 0.8 Livestock Units per hectare) with the aim to eat a third, trample a third and leave a third. Tim has learnt that it is best to focus on managing grass to build up a reserve rather than eating into it. Frequent moves leave grass to regrow, meaning there is always grass ahead of the livestock throughout the rotation.

Another method Tim has trialled to improve soil microbiology has been applications of compost created using a system called “complete microbial composting” developed by the Land Gardeners. This involves mixing brown (cattle dung, soil, straw) and green (fresh cut plants) material from around the farm in long windrows and turning. Three methods of application were trialled – direct spreading, compost tea brewing and “biopriming” (mixing compost with the seed prior to drilling). Tim felt that the biopriming technique has the potential to be the most successful. However, soil microbial testing conducted by the University of Exeter showed no difference so far between areas with and without compost application.

Tim has also experimented with pasture cropping alongside WildFarmed, this involved using a Moore Unidrill to direct drill a heritage wheat blend into a hard-grazed herbal ley. The aim was for the existing ley to provide ground cover and nitrogen-fixation. Tim described the first attempt at pasture cropping as a “disaster”, with chicory swamping the wheat and making harvest impossible. A second attempt meant tweaking the herbal ley mix to make it less competitive, grazing tight, sub-soiling and spring tine harrowing for seed/soil contact and then direct drilling. This appeared to have good establishment up until May, at which point Tim noticed that about two-thirds of the crop was Westerwolds grass. Again, harvest was abandoned and the field grazed instead to utilise the crop and keep organic matter in the field. In future, Tim plans on removing grass from the mix and replacing with a species that has more winter-kill such as sunflowers/millet/sorghum.

As Tim’s time at Erth Barton draws to a close, we would like to thank him for his work on Farm Net Zero and wish him all the best for his future endeavours.

Key takeaways:

  • Bringing pasture and livestock back onto the farm has helped to improve soil quality.
  • Fertility extraction should be balanced with fertility building. This can be done as part of a rotation.
  • Even when experiments do not go the way we first thought, we can still learn valuable lessons from them.