Official Statistics

Agri-climate report 2021

Published 28 October 2021

Applies to England

Key messages

  • When compared to 1990 all agricultural greenhouse gas emissions (GHG) saw a decrease up to 2019.
  • Since 1990 emissions intensity from Beef, Dairy, Pigs and Sheep has either decreased or stayed at the same level in 2019.
  • The 2021 Farm Practices Survey (FPS) indicated that 67% of farmers thought it important to consider GHGs when making farm business decisions, whilst 27% considered it not important.

Section 1. UK agriculture estimated greenhouse gas emissions

Figure 1.1 UK estimated greenhouse gas emissions for agriculture, 1990 and 2019

Year Carbon dioxide emissions Nitrous oxide emissions Methane emissions UK Agriculture: total GHG emissions
2019 6.0 15.0 25.2 46.3
1990 6.5 17.6 29.0 53.1

Source: Department for Business, Energy & Industrial Strategy

The entire time series is revised each year to take account of methodological improvements in the UK emissions inventory.

1.1 Drivers of emissions

Drivers of recorded sector emissions: The methodology used to report agricultural emissions has been predominantly based on the number of livestock animals and the amount of nitrogen-based fertiliser applied to land. A variety of important factors influence emissions which are not captured by this methodology (see “Other drivers of emissions” below for details); research has been undertaken to better reflect the position. The results of this research have been incorporated into an upgraded greenhouse gas (GHG) inventory for agriculture, implemented since 2017.

Other drivers of emissions: There are other factors which are not captured in estimated emissions, but which are likely to affect the true level of emissions. For example, some areas of farming practice will have an impact, e.g. timing of fertiliser application, efficiency of fertiliser use, feed conversion ratios, genetic improvements. Some of these relate to efficiency: there have been productivity gains in the sector, through more efficient use of inputs over the last twenty years and some of these gains will have had a positive impact, though some may have had a negative impact on emissions. Soil moisture and pH are also highly important to soil emissions. On a national basis these drivers are expected to have a subtle, but significant impact, rather than a dramatic impact on the true level of emissions over the period. On a regional basis, the drivers of soil emissions are likely to have a more dramatic impact for some land use types.

1.2 Total emissions

The chart below provides an overall picture of the level of estimated greenhouse gas (GHG) emissions from agriculture. In 2019, when compared to total emissions from all sectors, agriculture was the source of:

  • 10% of total GHG emissions in the UK
  • 68% of total nitrous oxide emissions
  • 47% of total methane emissions
  • 1.7% of total carbon dioxide emissions

Figure 1.2 Greenhouse gas emissions from UK agriculture

Greenhouse gas emissions from UK agriculture

Source: Department for Business, Energy & Industrial Strategy

1.3 Nitrous oxide emissions

Direct emissions of nitrous oxide (N2O) from agricultural soils are estimated for the following: use of inorganic fertiliser, biological fixation of nitrogen by crops, ploughing in crop residues, cultivation of histosols (organic soils), spreading animal manures on land and manures dropped by animals grazing in the field. In addition to these, the following indirect emission sources are estimated: emission of nitrous oxide from atmospheric deposition of agricultural nitric oxide (NOx) and ammonia (NH3) and the emission of nitrous oxide from leaching of agricultural nitrate and runoff. Also, nitrous oxide emissions from manures during storage are calculated for a number of animal waste management systems.

Figure 1.3 Emissions of nitrous oxide from UK agriculture by source

Emissions of nitrous oxide from UK agriculture by source

(a) Direct soil emissions consists of leaching/ runoff, synthetic fertiliser, manure as an organic fertiliser, atmospheric deposition, improved grassland soils, crop residues, cultivation of organic soils, N-fix crops, deposited manure on pasture (unmanaged).

(b) Other includes: stationary and mobile combustion, wastes and field burning of agricultural wastes.

Source: Department for Business, Energy & Industrial Strategy

The fall in estimated nitrous oxide emissions over the last twenty years has been driven by substantial reductions in the overall application rate for nitrogen fertilisers, particularly to grassland; whilst arable application rates have remained relatively stable, grassland application rates have reduced. Over this period, wheat yields have increased, suggesting that the UK is producing more wheat for the same amount of nitrogen.

1.4 Methane emissions

Agriculture is estimated to have been the source of 47% of the UK’s methane (CH4) emissions in 2019. Methane is produced as a by-product of enteric fermentation and from the decomposition of manure under anaerobic conditions. Enteric fermentation is a digestive process whereby feed constituents are broken down by micro-organisms into simple molecules. Both ruminant animals (e.g. cattle and sheep), and non-ruminant animals (e.g. pigs and horses) produce methane, although ruminants are the largest source per unit of feed intake. When manure is stored or treated as a liquid in a lagoon, pond or tank it tends to decompose anaerobically and produce a significant quantity of methane. When manure is handled as a solid or when it is deposited on pastures, it tends to decompose aerobically and little or no methane is produced. Hence the system of manure management used affects emission rates.

Figure 1.4 Emissions of methane from UK agriculture by source

Emissions of methane from UK agriculture by source

Source: Department for Business, Energy & Industrial Strategy

The majority of the fall in estimated methane emissions since 1990 is due to reductions in the numbers of cattle and sheep in the UK. Measures relating to the greenhouse gas (GHG) emissions intensity of agriculture are explored in Section 2.

1.5 Carbon dioxide emissions

1.7% of carbon dioxide (CO2) emissions in the UK are attributed to agriculture, these relate mainly to fuel use. Since 1990 there has been an overall decline in estimated carbon dioxide emissions from agriculture.

Figure 1.5 Emissions of carbon dioxide from UK agriculture by source

Emissions of carbon dioxide from UK agriculture by source

Source: Department for Business, Energy & Industrial Strategy

1.6 Uncertainty in emissions

There are relatively large uncertainties in estimating agricultural emissions as they are generated by heterogeneous natural systems for which we do not have precise measures. Uncertainties around N2O emissions are particularly large; they incorporate spatial and temporal variation in emissions factors (e.g. soil texture variations etc), and more structural uncertainties relating to the way the farming industry and biological processes are represented in the current model. Some of these uncertainties are already understood to some extent, whilst others have undergone further research as part of the recent inventory improvement programme.

The table below shows typical uncertainties (for 2019 estimates) in the current methodology and reflects recent improvements in the analysis[footnote 1] although, it will not be possible to remove all uncertainty.

Table 1. Emissions uncertainty

IPCC Category Gas 2019 emissions (Gg CO2e) Combined activity and emission factor uncertainty (%)
3A Enteric fermentation Methane 21,213.52 13.7%
3B Manure management Methane 3,994.92 8.4%
3B Manure management Nitrous oxide 2,727.68 9.5%
3D Agricultural soils Nitrous oxide 12,250.42 11.2%

Source: UK National Inventory Report Annex 2

Section 2. Emission intensity and background

2.1 Why Agriculture produces GHGs

Greenhouse gas emissions in agriculture are dominated by non CO2 emissions that occur from three main sources:

  • Emissions of methane from ruminant livestock burps: Ruminant livestock produce methane during their digestive processes. Micro-organisms in the rumen degrade carbon from feeds in the absence of oxygen, producing methane gas. This gas is subsequently emitted to air by eructation (burps). Emissions are affected by diet, health and livestock management. In addition it may be possible use treatments that regulate or destroy methane producing micro-organisms in the rumen.

  • Further information on Defra Livestock numbers webpage

  • Emissions of nitrous oxide from fertilisers applied to land: Nitrogen in fertilisers and manures is transformed to nitrous oxide during the biological processes of nitrification and denitrification. These processes are driven by soil bacteria and are mediated by soil type, soil management and weather. Emissions can be controlled to some extent by nutrient planning, fertiliser application methods and management of soil condition. In addition Urea based fertilisers produce carbon dioxide when applied to soils during the process of hydrolysis. Liming of soils results in emissions of carbon dioxide from the breakdown of lime but can enhance carbon sequestration on acidic grasslands.

    All nitrogen containing fertiliser media applied to soils can release ammonia gas (an important air pollutant) when applied to soils in a process called volatilisation. This is particularly true of anaerobic digestates, slurries and urea based fertilisers. Although not a GHG in itself, deposition of ammonia to land results in indirect emissions of nitrous oxide.

  • Emissions of methane and nitrous oxide from livestock manures during storage and application to land: Livestock excreta contain carbon and nitrogen that is subject to chemical transformation via biological processes. Depending on how excreta is managed and applied to land varying amounts of methane and nitrous oxide are produced.

  • Further information on the Soil Nutrient Balances, Fertiliser Usage and Farm Practices Survey webpages

In addition there are two CO2 based sources of emissions from agriculture:

  • Emissions of carbon dioxide from machinery use, heating etc: these only account for 9% of agricultural emissions. The 2016 inventory estimate (which covers the period 1990 to 2014) of 4.7 million metric tonnes of carbon dioxide equivalent (Mt CO2e). These emissions can be controlled by low energy technologies, changes in management practice (e.g. minimum tillage) and implementation of renewable energy generation

  • Emissions of carbon dioxide from land use change and land management: Soils store carbon at equilibrium concentrations that reflect the balance of organic material inputs versus biological turnover of carbon (bugs eat organic materials and respire CO2). Croplands have lower soil carbon content than grasslands due to lower organic inputs and greater disturbance from ploughing etc. Lands converted to cropland produced about 12 Mt CO2e in 2014. About 10% of the cropland emissions result from historic drainage of lowland peat for agriculture. This is offset to some extent by land converted to pasture, which sequestered about 9 Mt CO2e in 2014. Agriculture was therefore a net source of land use emissions (3 Mt CO2e) in 2014. Overall the LULUCF sector was a net sink 9 Mt CO2e in 2014 due to the large forest sink.

Agriculture has a complex set of biological processes that control emissions of three major GHGs via a diverse range of pathways. In addition soils and biomass possess the ability to absorb (sequester) carbon to some extent. As such agricultural emissions can be difficult to model and monitor. However, the range of gasses and emissions pathways also means that there is a diverse set of entry points for mitigation of emissions from the sector.

It is always important to ensure mitigation of GHGs does not result in detrimental impacts to other environmental outcomes (for example air and water quality) and this is particularly true in agriculture, where there are real risks of unintended consequences if mitigation is not planned carefully. Fortunately, many agricultural mitigation options (in particular those that reduce the losses of nitrogen to the environment) provide co-benefits for air and water quality as well as reducing soil acidification and protecting biodiversity. Since nitrogen in fertiliser and feed is procured at a cost to the farmer, such options are often economically beneficial as well.

Enquires about Section 2.1 to farmingscience@defra.gov.uk

2.2 Emission intensity, UK

This section includes graphs detailing the greenhouse gas emissions intensity in four agricultural industries, these are beef, dairy, sheep and pigs. The emissions intensity is calculated using animal emissions data from the United Nations Climate Change National Inventory Submissions, meat production data from Defra slaughter statistics and milk data from Defra milk statistics. All of this data is presented below and is indexed to 1990 to show trends from that reference year.

Figure 2.1 Beef Emission Intensity

Beef Emission Intensity

Source: Defra

In 1995 there was a significant increase in the emission intensity from beef which corresponds with the introduction of the over thirty months rule introduced in 1996 after the spread of BSE (Bovine Spongiform Encephalopathy) in the 1990’s. Since then, the emission intensity has shown a gradual decrease up to 2019. This was driven by both an overall decline in emissions and an overall increase in meat production.

Figure 2.2 Dairy Emission Intensity

Dairy Emission Intensity

Source: Defra

The emissions intensity for dairy has seen a steady decrease since 1990, this is driven by both an overall increase in milk volume and fall in emissions.

Figure 2.3 Pig Emission Intensity

Pig Emission Intensity

Source: Defra

For pigs, the emissions intensity has seen a steady decrease from 1990 to 2019. This was driven by an overall reduction in emissions and an overall increase in production. This was the biggest decline in emission intensity for that timeframe when compared to Dairy, Beef and Sheep.

Figure 2.4 Sheep Emission Intensity

Sheep Emission Intensity

Source: Defra

The emission intensity for sheep has fluctuated throughout the timeline above remaining at nearly the same level in 2019 as that of 1990. This reflects similar trends for both production and emissions which have fluctuated over this period and shown an overall decline of similar magnitude.

Section 3. Farmer attitudes and uptake of on-farm mitigation measures, England

3.1 Background information

The following section provides key summary statistics on farmer attitudes and views - what farmers think about greenhouse gases (GHGs) and their uptake of a range of mitigation measures.

The farming industry, in England and the UK is comprised of a large number of relatively small businesses. The characteristics of the many businesses and individual farmers are critical to the uptake of climate change mitigation measures where there is a need for farmers to understand the issues and be willing and able to implement measures. Understanding what practices are adopted, and why, can help highlight the barriers and motivations to action on GHGs.

Many farmers recognise the significance of GHG emissions but some remain unconvinced about the business benefits of reducing emissions. Greater understanding of GHG emissions is likely to encourage adoption of practices to reduce emissions, although this is not guaranteed. A greater understanding may also lead to the adoption of more measures and cost-effective solutions for reducing agricultural GHGs that fit with the farm business.

While research suggests that most practices to reduce GHG emissions could save farmers money (and many farmers are likely to be influenced to change their practices because it makes good business sense) there are several key barriers to uptake which are non-financial, or not directly financial. These include a lack of willingness to undertake (e.g. limited trust in what is being asked and the outcomes that will result) and a lack of ability to undertake (e.g. a lack of understanding, skills, time or capital). Whilst most farm businesses should be able to implement key actions, not all measures are suitable for all farm businesses.

The industry-led Greenhouse Gas Action Plan (now linked with Tried & Tested within the Campaign for the Farmed Environment) is intended to convey coherent messages covering good farming practices which include resource use efficiency and nutrient management as well as farmland biodiversity and resource protection.

This Section links to data on farmer understanding and awareness of actions towards reducing GHG emissions. This includes actions undertaken to reduce emissions and motivations and barriers to action.

3.2 Awareness of greenhouse gas emissions

Measuring awareness of the importance of GHGs for the farm business and sources of emissions can provide an indication of the ease with which mitigation measures will be adopted and help to highlight motivations and barriers. However, whilst important, improving understanding and attitudes towards GHGs are not a guarantee of the adoption of mitigation practices; business sustainability and financial implications are important drivers for change.

Attitudes to, and knowledge of GHGs is one of the GHG indicators and covers all farming sectors.

Figure 3.1 How important is it to consider GHGs when taking decisions about crops, land and livestock?

How important is it to consider GHGs when taking decisions about crops, land and livestock?

Source: Farm Practices Survey 2021

The 2021 Farm Practices Survey (FPS) indicated that 67% of farmers thought it important to consider GHGs when making farm business decisions, whilst 27% considered it not important. There were a relatively small number that still consider that their farm did not produce GHGs (6%). Dairy farms placed the greatest importance on GHGs followed by cereal and other crop farms.

Proportion of farmers taking action to greenhouse gas emissions by views on link to profitability

Source: Farm Practices Survey 2021

47% of farmers thought that reducing emissions would improve farm profitability, a decrease from 55% in 2020. Dairy and cereal were the most likely to recognise the link to profitability while farmers who grazed animals on less favoured areas were least convinced.

Of those strongly agreeing that reducing GHGs increases profitability 19% were still not taking any actions (compared to 11% in 2020) while 32% of those strongly disagreeing that reducing GHGs would increase profitability nevertheless took action (compared to 46% in 2020).

3.3 What farmers say they do to reduce greenhouse gas emissions

The 2021 FPS results indicated that 56% of farmers were taking actions to reduce emissions. Larger farms were more likely to be taking action than smaller farms. Less favoured area (LFA) and lowland grazing livestock farms were less likely to be taking action (42% and 44% respectively) than other farm types. The results are similar to 2020 where LFA and lowland grazing livestock farms were also least likely to take up action. Unsurprisingly, those who think that reducing emissions is important are more likely to undertake an action to reduce, for example 74% of those who thought it was very important, took action.

The most common actions to reduce GHG emissions were recycling waste materials, improving nitrogen fertiliser application and improving energy efficiency. These are actions that are relevant to most farm enterprises. Those actions more suited to livestock enterprises had a lower level of uptake.

Figure 3.3 Actions being taken by farmers to reduce greenhouse gas emissions

Actions being taken by farmers to reduce greenhouse gas emissions

Source: Farm Practices Survey 2021

In general, larger farms were more likely to take action, but there were some key differences between enterprises which reflected the nature of the business. Grazing livestock, dairy and mixed farm types had the highest uptake of clover in grassland (as fits the nature of management). However, grazing livestock and mixed enterprises were less likely to take action in relation to manure / slurry management and feed efficiency when compared to dairy farms. This suggests that there are still opportunities for improved practice. In another example, 90% of cereals and 80% of other cropping farm types are taking actions to improve nitrogen fertiliser application compared to 72% of dairy farms. Figures for grazing livestock farms are lower at 39% of lowland farms and 30% of LFA farms taking action. It is also recognised that not all enterprises apply nitrogen fertiliser e.g. organic farms and some grazing livestock farms. In 2021, 50% of LFA and 49% of lowland grazing livestock farms were improving slurry / manure management compared to 88% of dairy enterprises. Less than a third of grazing livestock farms were improving nitrogen feed efficiency compared to 67% for dairy enterprises, similar levels to those seen over the last 3 years.

3.4 What are the main motivations for undertaking the actions to reduce greenhouse gas emissions?

Figure 3.4 Main motivations for taking action to reduce greenhouse gas emissions

Main motivations for taking action to reduce greenhouse gas emissions

Source: Farm Practice Survey 2021

3.5 What farmers say are the barriers to reducing emissions

For those farmers not undertaking any actions to reduce GHG emissions, informational barriers are important i.e. the lack of information (33%) and lack of clarity on what to do (41%) were key reasons for not taking action. This could be described as ‘personal capacity for action’. However, there is also a wider issue around understanding or willingness to take action with 35% not believing any action is necessary,14% believing there is not much they can do and 7% believing they have done enough. These findings show little variation from those in the FPS surveys of 2013 to 2021.

Actual financial barriers are smaller in comparison, with 28% saying not enough incentive and 18% too expensive. Some smaller farms considered that they did not produce enough emissions (43% thought action was not necessary for this reason compared to 18% of larger farms). The recognition that action was necessary also varied by farm type with only 12% of dairy farms thinking they did not need to take action compared to a higher percentage of grazing livestock farms (58% LFA and 41% lowland grazing livestock farms) and 33% of Pigs and poultry farms.

For those already taking actions, financial barriers are stronger (26% saying too expensive). Information barriers are still important i.e. the lack of information (30%) and lack of clarity on what to do (31%). However, the need to take action was reflected in only 15% believing that action is not necessary and just 4% believing that there is not much they can do. Nearly a third (30%) of those taking action believe that they have already done enough. The recognition of the need for action again varied by farm type with only 6% of dairy farms thinking they did not need to take action compared to 29% of lowland grazing farms.

Figure 3.5 Factors preventing action to reduce greenhouse gas emissions

Factors preventing action to reduce greenhouse gas emissions

(a) Not necessary as don’t think my farm produces many emissions.

(b) Unsure what to do due to too many conflicting views.

Source: Farm Practice Survey 2021

3.6 Uptake of on-farm mitigation measures

Details of uptake rates for a wide range of on-farm mitigation measures can be found in the results of the February 2021 Farm Practices Survey.

The survey focused on practices relating to greenhouse gas mitigation with topics including nutrient and manure management, manure and slurry storage, farm health plans, cattle and sheep breeding and feeding regimes and anaerobic digestion.

Section 4. Greenhouse Gas reduction indicators, England

See Indicator methodology for background information on Section 4

4.1 Uptake of mitigation measures

Rationale: monitoring the uptake of a wide range of farm practices that can reduce greenhouse gas (GHG) emissions from agriculture.

Indicator: overall progress is measured by the reductions delivered through the uptake of a range of mitigation methods.

Desired outcome: increased uptake of these mitigation methods will be reflected by reduction in estimated GHG emissions.

Figure 4.1 GHG reduction on uptake of key on-farm mitigation measures

Year MT CO2e
GHG reduction potential 2.8
GHG reduction achieved by Feb 2021 0.9

By February 2021, approximately 0.9 Mt CO2 equivalent reduction in GHG emissions had been achieved from the uptake of the key mitigation methods. In terms of moving to the desired outcome this compares to an estimated maximum technical potential[footnote 2] reduction of 2.8 Mt CO2e were all of these methods to be fully implemented on relevant farms.

The headline indicator has been sub-divided into five activity groups each containing related, relevant mitigation methods. Progress for each of these groups is shown in the chart below

Figure 4.2 GHG reduction based on the uptake of key on-farm mitigation methods by activity grouping

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Nutrient management 957 353
Plants with improved nitrogen use efficiency 702 91
Land and soil management 592 259
Livestock breeding 294 102
Livestock nutrition 229 97

Nutrient management

Good nutrient management can bring a number of important benefits: minimising GHG emissions, reducing the incidence of diffuse water pollution, and helping farmers save money through optimising productivity. This group of six mitigation methods collectively provides the greatest potential reduction in emissions (957 kilotons of carbon dioxide equivalent (Kt CO2e)) on relevant farm types. By 2021, uptake of nutrient management mitigation methods has been assessed to have delivered an estimated GHG reduction of 353 Kt CO2e, 37% of the maximum technical potential reduction.

Figure 4.3 Potential and achieved GHG emission reduction: nutrient management mitigation method

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Use a fertiliser recommendation system 563 187
Integrate fertiliser and manure nutrient supply 334 152
Do not apply manufactured fertiliser to high-risk areas 27 0
Fertiliser spreader calibration 12 9
Use manufactured fertiliser placement technologies 15 4
Avoid spreading manufactured fertiliser to fields at high-risk times 7 1

The uptake of each mitigation method has been assessed using relevant survey data. In some cases where relevant data are not available (i.e. Do not apply manufactured fertiliser to high-risk areas), the default Farmscoper uptake has been assumed, based on an assessment of uptake by ADAS. This default implementation rate is a pre-determined level of adoption set within the model[footnote 3]. For some of the mitigation methods data are currently available to make the short term assessment only; as data continues to be collected it will be possible to assess longer term trends.

Plants with improved nitrogen use efficiency

This group of mitigation methods also offers a significant GHG emission reduction potential (702 Kt CO2e). Plants with improved nitrogen use efficiency (i.e. able to remove more mineral nitrogen from the soil) offer the greatest abatement potential within this group. Improving the nitrogen use efficiency of plants potentially offers reduced nitrogen fertiliser applications and improved nutritional characteristics of fodder.

Using clover within a grass sward reduces the need for manufactured nitrogen use and potentially reduces costs. It can be applied to most grassland systems but may entail a reduction in stocking rates where high rates of manufactured nitrogen fertiliser have previously been used.

Figure 4.4 Potential and achieved GHG emission reduction: plants with improved nitrogen use efficiency

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Use plants with improved nitrogen use efficiency 563 35
Use clover in place of fertiliser nitrogen 139 56

The 2021 assessment of emission reductions suggests that 91 Kt CO2e has been achieved,13% of the maximum technical potential reduction (702 Kt CO2e).

Land and soil management

Land and soil management mitigation methods can help to preserve good soil structure preventing erosion and compaction, both of which can lead to GHG emissions. The mitigation methods in this activity group include using low ground-pressure tyre set-ups to reduce soil compaction, loosening compacted soil in grassland fields, adopting reduced cultivation systems and keeping livestock away from water courses. Together these have been estimated to have achieved GHG emission reductions of 259 Kt CO2e by 2021, 44% of the maximum technical potential reduction (592 Kt CO2e).

Figure 4.5 Potential and achieved GHG emission reduction: land and soil management mitigation methods

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Adopt reduced cultivation systems 236 120
Loosen compacted soil layers in grassland fields 203 27
Locate out-wintered stock away from watercourses 99 69
Reduce field stocking rates when soils are wet 44 37
Use correctly-inflated low ground pressure tyres on machinery 7 3
Construct bridges for livestock crossing rivers/streams 3 2

Livestock Breeding

Breeding practices can play an important role in herd and flock productivity and efficiency, factors which can in turn influence GHG emissions. The mitigation method within this group relates to the use of improved genetic resources. Uptake has been assessed by the use of bulls and rams with a high Estimated Breeding Value (EBV) when breeding beef cattle and lambs and the use of bulls with a high Profitable Lifetime Index (PLI) when breeding dairy cows. By 2020, uptake of these mitigation methods has been assessed to have achieved an abatement of 102 Kt CO2e, 35% of maximum technical potential reduction of 294 Kt CO2e.

Figure 4.6 Potential and achieved GHG emission reduction: livestock breeding measures

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Make use of improved genetic resources in livestock 294 102

Livestock nutrition

Livestock feeding regimes also play an important role in productivity and efficiency, factors which can impact on GHG emissions. Mitigation methods relating to livestock nutrition have been assessed to have a maximum technical potential GHG reduction of 229 Kt CO2e.

There is currently little data available to assess these methods. However, using the default ADAS estimates of uptake (see Indicator Methodology for more details) it is estimated that a 97 Kt CO2e reduction had been achieved by 2021.

The livestock productivity indicators also provide a high level insight into improvements in productivity across the livestock sectors.

Figure 4.7 Potential and achieved GHG emission reduction: livestock nutrition mitigation methods

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Reduce dietary N and P intakes: Dairy 122 11
Reduce dietary N and P intakes: Poultry 42 34
Adopt phase feeding of livestock 41 32
Reduce dietary N and P intakes: Pigs 25 20

4.2 Slurry and manure

Rationale: systems for the management of manure and slurry are relevant to the control of environmental risks to air and water including greenhouse gases (GHGs).

Indicator: overall progress is measured by the GHG reductions delivered through the uptake of a range of mitigation methods relating to slurry and manure storage and handling.

Desired outcome: slurry and manure increasingly handled and stored in ways that can help minimise GHG emissions. This will be reflected by a reduction in estimated GHG emissions.

Figure 4.8 GHG reduction based on uptake of slurry and manure methods

Year MT CO2e
GHG reduction potential 1.5
GHG reduction achieved by Feb 2021 0.1

Estimates indicate that the maximum technical potential[footnote 2] GHG reduction from uptake of mitigation methods relating to slurry and manure is around 1.5 MT CO2e [footnote 4]. Uptake of these mitigation methods by February 2021 suggests that the GHG reduction achieved has been around 0.10 MT CO2e.

The headline indicator includes five mitigation methods relating to slurry and manure handling and storage. Progress for each of these is shown in the charts below.

Figure 4.9 Potential and achieved GHG emission reduction: slurry and manure mitigation methods

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Increase the capacity of farm slurry stores to improve timing of slurry applications 5 1.7
Store solid manure heaps on an impermeable base and collect effluent 4 0.4
Use liquid/solid manure separation techniques 1 0.09
Cover solid manure stores with sheeting 1 0.07

Figure 4.10 GHG reduction based on uptake of anaerobic digestion of livestock manures and slurries

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Anaerobic digestion of livestock manures 1478 97

The uptake of each mitigation method has been assessed using relevant survey data. In some cases where relevant data are not available (i.e. increase the capacity of farm slurry stores to improve timing of slurry applications) the default Farmscoper uptake rate has been assumed, based on an assessment of uptake by ADAS.

This default value is a pre-determined level of adoption set within the model[footnote 3]. For some of the mitigation methods data are currently available to make the short term assessment only; as data continues to be collected it will be possible to assess longer term trends.

Store solid manure heaps on an impermeable base and collect effluent

Storing solid manure heaps on an impermeable base prevents seepage of nutrients which may then be lost to groundwater through leaching or runoff. In 2021, uptake of this method has been assessed to have achieved a reduction in GHG emissions of 0.4 KT CO2e, approximately 10% of the maximum technical potential reduction.

Increase the capacity of farm slurry stores to improve timing of slurry applications

On farms with limited storage capacity, expanding facilities can provide greater scope for the timing of application allowing spreading at lower risk times and when the crop can make best use of the nutrients. The Farmscoper tool suggests that increasing storage capacity for slurry on these farms could provide a maximum potential reduction in GHG emissions of 5 KT CO2e. Using Farmscoper default uptake levels (see previous page and Indicator Methodology for more details) the estimated uptake of this practice achieved a reduction in GHGs of 1.7 KT CO2e.

Cover solid manure stores with sheeting

Covering solid manure heaps primarily prevents the loss of ammonia to the air. Although nitrous oxide emissions are likely to increase during storage, indirect emissions are likely to reduce through lower leachate losses. Increased uptake could lead to improved nitrogen use efficiency and a reduction in manufactured nitrogen fertiliser inputs. The Farmscoper tool indicates that covering solid manure stores can provide a maximum potential reduction in GHG emissions of 1 KT CO2e while current uptake of these practices is achieving a reduction of around 0.1 KT CO2e.

Use liquid/solid manure separation techniques

Separating the suspended solids from slurry allows the two manure streams to be handled separately. The solid fraction can be stored on a concrete pad or in a field heap, while the liquid fraction can be stored and transported/pumped to fields for land application. Such separation can reduce storage space and improve the efficiency with which nitrogen is applied to land and this has the potential to reduce emissions. Use of a slurry separator is estimated to have achieved a GHG reduction of 0.1 KT CO2e compared to a maximum potential reduction of 1 KT CO2e.

Install covers to slurry stores

Covering slurry stores primarily helps to reduce ammonia emissions. Increased uptake of this method could lead to improved nitrogen use efficiency and a reduction in manufactured nitrogen fertiliser inputs. Although this method does not have an associated GHG reduction potential, uptake has been included here as a contextual indicator due to the associated positive impacts from reduced ammonia emissions.

Slurries used in anaerobic digestion

Estimates from the Farmscoper tool suggest that the use of slurries for anaerobic digestion (AD) has a GHG reduction potential outweighing that from improved storage of slurries and manures. Methane emissions from the storage of slurries and manures are reduced and the methane generated from livestock manures during AD can be used to produce heat and power to replace fossil fuel use. In addition, there is the potential to increase nitrogen use efficiency and reduce the required quantity of manufactured fertiliser if the digestate is subsequently spread to the land. However, significant start-up and running costs are barriers to uptake.

4.3 Organic fertiliser application

Rationale: the form, method and timing of application for organic fertilisers can influence associated greenhouse gas (GHG) emissions.

Indicator: progress is measured by the reduction in GHG emissions delivered through the uptake of a range of organic fertiliser application methods.

Desired outcome: increased uptake of these mitigation methods will be reflected by an improvement in the estimated GHG emission reductions.

Figure 4.11 GHG reduction based on uptake of organic application methods

Year MT CO2e
GHG reduction potential 0.45
GHG reduction achieved by Feb 2021 0.34

By February 2021, approximately 0.34 MT CO2 equivalent (e) reduction in GHG emissions had been achieved from the uptake of the mitigation methods within this indicator. This compares to an estimated maximum technical potential[footnote 2] reduction of 0.45 MT CO2e if all of these methods to be fully implemented on relevant farms.

The headline indicator is made up of five mitigation methods[footnote 5] relating to organic fertiliser application practices. Progress for each of these is shown in the chart below.

Figure 4.12 Potential and achieved GHG emission reduction: organic fertiliser application methods

Year GHG reduction potential (Kt CO2e) GHG reduction achieved by Feb 2021 (Kt CO2e)
Do not spread slurry or poultry manure at high-risk times 262 210
Do not spread FYM to fields at high-risk times 157 126
Use slurry injection application techniques 21 2
Manure Spreader Calibration 12 5
Do not apply manure to high-risk areas 0.3 0.2

Note: Use of band spreading application techniques (not shown) is included in the indicator but as a qualitative assessment only.

The uptake of each mitigation method has been assessed, wherever possible, using relevant survey data. In some cases where precise data are not available (i.e. Do not apply manure to high-risk areas), the default Farmscoper uptake rate has been assumed, based on an assessment of uptake by ADAS. This default value is a pre-determined level of adoption set within the model[footnote 3]. For some of the mitigation methods data are currently available to make the short term assessment only; as data continues to be collected it will be possible to assess longer term trends.

Do not apply manure to high-risk areas

Applying manures close to water courses creates a high risk of the rapid spread of pollutants, which can in turn lead to GHG emissions. Avoiding spreading manure to high risk areas can provide an estimated maximum technical potential reduction in GHG emissions of 0.29 Kt CO2e. There is currently no suitable survey data to assess uptake of this mitigation method. However, using the Farmscoper default uptake levels (see above table and Indicator Methodology) it is estimated that a reduction in GHGs of 0.20 Kt CO2e has been achieved by 2021.

Manure spreader calibration

Manure spreader calibration can ensure evenness of application helping to minimise risks such as leaching and run off. Efficient use of manure can also, in some cases, lead to a reduction in the need for manufactured nitrogen fertiliser. The Farm Practices Survey asked questions about manure spreader calibration for the first time in 2013. Until more data are collected on this the Farmscoper default uptake levels have been used (see table above and Indicator Methodology). The estimated uptake of this practice has achieved a reduction in GHGs of 4.9 Kt CO2e which is 40% of the estimated maximum technical potential (12.1 Kt CO2e).

Use of slurry injection application techniques

Methods of slurry application can have a bearing on GHG emissions; slurries have a high nitrogen content in available forms, leading to high levels of both direct emissions and indirect emissions from ammonia losses.

Certain methods of application, such as injection, can help mitigate these losses. Estimates of uptake suggest that using slurry injection techniques could give a maximum technical potential GHG reduction of 20.7 Kt CO2e. Current uptake of this practice is estimated to have achieved a reduction of 2.1 Kt CO2e.

Avoiding the spreading of slurry, poultry manure or farm yard manure at high risk times[footnote 5]

Of the mitigation methods considered within this indicator, those focused on avoiding spreading farm yard manure (FYM), slurries or poultry manure at high risk times have been assessed as offering the greatest potential reductions in GHG emissions. Slurries and manures can produce emissions at application (as well as during storage) and if they are applied to the land in the autumn and winter months there is also a risk of surface run off and leaching, which can lead to indirect emissions. Autumn and winter can also be a time when applications are less effective as there is little or no crop uptake. Current uptake suggests that not spreading FYM, poultry manure or slurries at these high risk times delivered a total estimated GHG reduction of 209.6 Kt CO2e which is around 80% of the reduction potential (262.0 Kt CO2e).

Section 5. What you need to know about this release

This section ensures any important information is clearly explained so users do not misunderstand the data.

5.1 Contact details

Responsible statistician: James Maguire

Email address: agri.environmentstatistics@defra.gov.uk

Enquiries: 020 802 65783

Media enquiries: 0345 051 8486

Department for Environment, Food and Rural Affairs
2 Marsham Street
Westminster
London
SW1P 4JA

5.2 National and Official Statistics

Publications with National Statistics status meet the highest standards of trustworthiness, quality and public value, and it is our responsibility to maintain compliance with these standards. These estimates have been designated as Official Statistics.

For general enquiries about National and Official Statistics, contact the National Statistics Public Enquiry Service:

Tel: 0845 601 3034

Email: info@statistics.gov.uk

5.3 Future publications

The next publication is due in Autumn 2022

  1. The 95% confidence interval given in the “Analysis of uncertainties in the estimates of nitrous oxide and methane emissions in the UK’s greenhouse gas inventory for agriculture” for the estimate of total N2O emissions from soils in 2010 is (−56%, +143%). This reduced uncertainty reflects improved analysis and is substantially different to that given by Brown et al. (2012). Their confidence interval, based on expert opinion, was (−93%, +253%). However (−56%, +143%) is still much larger than that derived by Monni et al. (2007) who quote a 95% confidence interval of (−52%, +70%). Their analysis was based on more conservative estimates for the uncertainty in emissions factors (from IPCC 1997) whereas the 95% confidence interval of (−56%, +143%) was derived using more recent IPCC guidelines (Eggleston et al., 2006). 

  2. Maximum technical potential is the amount that could be saved if all mitigation potential was enacted regardless of cost assuming no prior implementation of measures.  2 3

  3. The default implementation rates are based largely on survey data, in particular Defra Farm Practices Survey, with a focus on data between 2006 and 2012. A simple scoring system was used to estimate the range of uptake; this reflects the uncertainty in mapping farm practice survey questions to specific mitigation methods.  2 3

  4. This assumes no prior implementation of methods. 

  5. Assessment of the practices “Do not spread FYM to fields at high risk times” and “Do not spread slurry or poultry manure at high risk times” has been revised in 2017. Data for 2015 and 2016 shown in the chart on page 1 have been updated to reflect the change.  2