The Bayer Carbon Programme

Agriculture is one of the many activities that can help reduce greenhouse gas (GHG) from the atmosphere. World soils are the second largest carbon sink, second only to oceans. Strong scientific evidence shows that on-farm technology coupled with the widespread adoption of regenerative and climate-smart agriculture practices – such as no-till, cover crop and nutrient and manure management – can reduce GHGs emissions through avoidance and sequestration.

Climate change and food security are major concerns in today’s world. Our EU Carbon Programme works to support the decarbonization of the food-value chain by focusing on three areas. We bring key stakeholders together to find the best climate solutions that work for our farmers, consumers and our planet.

Our monitoring, reporting and verification tool (MRV tool) will be a unique part of the carbon project. The tool will allow stakeholders across the agri-food value chain, such us input suppliers or retailers, to value their carbon assets, rewarding those who implement carbon smart practices and those who enable carbon markets to become a reality.

“The carbon project has helped concentrate my mind and learn more about how we use fertiliser. The results from 2021–22 showed that reducing the carbon footprint and producing the highest yield don’t always go together.”

“That was the biggest surprise, the higher nitrogen treatment had 1.5 tonnes/ha higher yield but a much greater carbon footprint per tonne of crop. I expected the carbon footprint per ha to be higher but not per tonne, I thought the yield would dilute the effect.”

The compared a lower rate of 160kg/ha which yielded 11.6t/ha at 1.63% grain nitrogen to a higher rate of 220kg/ha with 13.1t/ha yield at 1.94% grain nitrogen. The carbon footprint of the lower rate was 91kg CO₂/t, the higher rate was 112 CO₂/t.

“The protein content of the wheat was much better at the high rate, but I grow feed wheat, so it doesn’t matter in the same way as milling. I think the main message is that we need to learn how to improve yield without just adding more nitrogen if we are going to cut the carbon footprint and be profitable.”

A second trial looked at the benefit of applying molasses; the treatment with molasses yielded 0.3t/ha better than without, both received the same 190kg/ha rate of nitrogen

“Molasses provides sugar to the crop and soil microorganisms which is food for the plant and appears to improve nitrogen use efficiency. We use it on the majority of the farm already but wanted to learn more about it.”

This season, trials are continuing to look at improving nitrogen use efficiency. Three treatments will compare the farm standard (190kg/ha) to 150kg/ha and 150kg/ha + 20L of Nutrino Pro which contains 4.6kg N/ha but as a foliar product is claimed to be equivalent to 40kg of soil applied Nitrogen.

In another part of the farm, tests have been done on catch crops and cover crops to measure the amount of nitrogen it fixed in the soil. “The overwintered cover crop was grazed off in early February. Tests done in November showed it captured 4–18kg/ha, the catch crop did 0–16kg/ha. The catch crop was broadcast so establishment was inconsistent whereas the cover was drilled.”

“Soil nitrogen supply is a black box because it’s so variable across a field because of soil type, drainage and so on. It’s not possible to measure it in high resolution so I prefer to use a nitrogen sensor to measure what the crop needs and apply variable rate nitrogen. We have done it for fifteen years; it doesn’t save money but puts fertiliser in right place and increases yield.”

As he has shifted to low disturbance establishment, Mr Williamson has adopted other tools to measure what is happening on farm. “The data through FieldView gives you an idea of where to look in the field, shows how things change over time. Digital tools are non-destructive, but it has to be ground-truthed. Soil organic matter and soil organic carbon are both things we’ve started looking at more as we can see the physical appearance of the soil is improving.

Farming in south Shropshire, Andrew Williamson is keen to learn as much as possible about the fast developing area of carbon.

“Reducing carbon emission is something we are already working towards, and I think it is important that we demonstrate the positive impact of farming.

We have adopted a predominantly direct drilling system driven by economics and the practicalities of farming. Soil health is a big part of this and will obviously help with respect to carbon and greenhouse gas emissions. Overall, I am always looking for ways to improve the profitability and resilience of the business.

There are still lots of unknowns with regards to carbon. We are still quite a long way off being able to confidently measure and then hopefully sell carbon while still producing a profitable crop. But we have made some of important steps already.

Reducing cultivation helps because exposed soil loses carbon. We have also changed rotation to introduce cover and catch crops so that there is something growing for more of the year to capture CO₂. I would think there is a big opportunity to use fertilisers more efficiently too. Typically, only 60% of the nitrogen applied is used by the crop.

In the project we are looking at two fields, one field has been direct drilled for several years while, the other has had a lot of cultivation in recent years. I think it takes much more than three years to make a difference with regards carbon, so picking fields at different stages in the transition to direct drilling gives us more information.

Both fields are currently in winter wheat. In one field, this was established after a catch crop that followed oilseed rape. Unfortunately, a slight delay at harvest meant that the catch crop was drilled in the second week of August, not in July where you will get more benefit. Establishing cover and catch crops after harvest is always a difficulty but if you can get good cover, it’s worthwhile.

Overall, I think the first we need to do is to quantify the gains, once we have done that, we can start to monetise it. I imagine, it will be some kind of ‘insetting scheme’ where other parts of the grain supply chain like millers or bakers, buy carbon credits to improve the sustainability of their operations.

Participation in the Bayer Carbon Programme is one of several steps farmer Harry Heath has taken to improve the environmental footprint of the family farm near Newport Shropshire. Farming 200ha of owned land and several hundred under contract farming agreements, Mr Heath is looking at sustainability across the farm which produces arable crops, cold pressed oils and pigs.

“The biggest change over the last year is pigs. We have gone from rearing indoors to a new venture with outdoor extensive pigs in collaboration with a London-based chef. It’s early days, but I am pleased with progress so far.”

Mr Heath has also started pressing rapeseed and sunflower seed with the seed cake going into the pigs feed ration. “With the pigs we are looking to home source all the protein and grain. We have started growing peas which are important for feed and in the rotation. Crop nutrition goes back into the pigs so want to get things right. “

Mr Heath points out that much like fertiliser in arable farming, using soymeal in feed greatly increases the carbon footprint hence the move to home grown feeds. He expects that the carbon footprint of foodstuffs will become more important in the years ahead. In addition, the farm is currently assessing its agroecological status including birds, insects and water quality.

In 2022 as part of the Bayer Programme, the farm tested a programme with foliar N (70, 70, Nufol) versus lower input (70, 70) and higher input conventional programmes (70, 70, 40). All three treatments yielded the same, probably due to the dry spring (map) capping the possible yield of all crops.

“The increase in fertiliser prices has made many farmers look more carefully at their rates and how they could cut down. We have been quietly trimming rates for years, with yield maps and set tramlines it’s possible to do your own trials on farm and get useful results.”

“Replacing the final fertiliser split with a foliar spray seemed like a logical step to improve efficiency. You need the correct conditions for soil applied fertiliser but foliar goes straight onto the leaf.”

Carbon footprint analysis from last year’s trial shows the potential benefit of using foliar rather than bagged nitrogen.

Carbon footprint in 2022 trial

Mr Heath uses sap analysis during the season to monitor crop health and potential deficiencies. He thinks this is useful for identifying other factors that limit nitrogen use efficiency rather than adjustments to nitrogen rates.

This season the farm standard is three 50kg splits followed by 10kg as foliar urea. In the Bayer carbon trial, the splits are 40, 50, 50 (PLEASE CONFIRM ED), followed by two 10 kg foliar applications.

“We are trying to look at how much soil applied nitrogen we can replace with foliar urea. In the trial we are doing two foliar applications 2-3 weeks apart which place 30kg N each. We will compare this to the farm standard,” says agronomist Ed Brown of Hutchinsons. “I think we should be able use the two foliar treatments instead of 60kg bagged Nitrogen without any effect on yield. I look at this mainly from a cost-saving and plant health angle, but the smaller carbon footprint is another plus.”

“The sap analysis tells us whether any micronutrients need to be added to the mix to maximise nitrogen usage. When using foliar urea, applying a carbon source at the same time also improves uptake.”

There are four other farms in the UK Carbon Programme, each farm is trialling foliar nitrogen at the final split to reduce carbon footprint and maintain yield. In the first year of the project several trials found that that even when high N rates improved yields, carbon footprint per tonne was higher; the increased yield couldn’t dilute the effects of more fertiliser.

Farms in the project are using different tools to fine tune applications including N testers to adjust rates in season based on crop condition and N sensors for variable rate to even up inconsistencies across the field.  

Farm Manager Harry Heath is responsible for 200 hectares of owned land plus more under contract farming agreements. Taking part in the carbon project is one of several steps the farm is taking to improve its environmental footprint.

“Several years ago, we recognised that the soil health indicators were in decline such as low worm counts. We were cultivating too deep and had soil issues such as slumping which required further cultivation.

When we moved from conventional cultivation to direct drilling, we saw our establishment fuel use drop from 35–40 litre per hectare to 7–8 l/ha. This has helped immensely because it has reduced costs allowing us to maintain margin even when yields have been low. In the early part of the transition to regenerative agriculture, it is common to see a yield drop while you wait for the soil to start cycling nutrients properly.

From an industry perspective, fuel is a relatively minor consideration for greenhouse gas emissions. Carbon sequestration and fertiliser use are more important. Learning more about the soil is really important so we can unlock the nutrients in the soil and reduce fertiliser input. I have read about people reducing nitrogen input to 90kg/ha, at the moment we use about double that. Choosing the right fertilisers is also important, for example, MAP and DAP can both be harmful to soil health.

In the first year of the project, we are going to be measuring the baseline of soil health. We are already doing many of the regenerative practices such as cover crops and direct drilling, but there is lots more to learn particularly about fertiliser application.

It will be good to put a number on carbon sequestration and greenhouse gas emissions so we can see the changes have made a difference. If you claim you are doing wonderful things for carbon sinking you need to prove it, especially if it is part of a carbon credit or other payment scheme.

The bigger picture is that we are all going to have to learn to farm without a subsidy. Any future payment will most probably involve working harder for public funds by delivering public goods such as carbon sequestration.

John Barrett, Director at Sentry which is a farming and rural advisory business who manage over 20,000 hectares across the country.

“There are different aspects to sustainability such as financial, environmental and rotation. The farm has to turn a profit first and foremost so it can provide the other aspects of sustainability.”

“Improving soil has been the starting point, twenty years ago Sentry began using more manures and organic materials on the soil. Organic matter content has risen, and soils are more resilient. For example, March saw up to 200% higher than average rainfall in many parts of the South and April to June 2022 saw  up to 95% less rain than  average. But the more resilient the soil the better it will cope with these extremes.

“In general, we see that crops are not as stressed and yields are more consistent, in addition healthy crops tend to be less vulnerable to pests, weeds and diseases. All of which helps improve environmental and financial sustainability.”

Where appropriate, Sentry managed farms have also reduced tillage which also contributes to soil health. Although, rotations with roots and farms without self-structuring soils can’t do this to the same extent. Each farm needs to be assessed and farmed according to it’s own soils.

According to Mr Barrett, cover crops are particularly important for retaining nutrients in the soil and preventing losses into water. Reducing nutrient levels in water is growing in importance and he expects many farmers will have more involvement with water companies in the future. It can be frightening to see financially what is actually leached out of our soils.

Sentry has carried out Cool Farm Tool benchmarking audits across all their farms as well as carbon audits, funded through the Food and Farm Resilience Fund, carried out by our own in-house consultancy business.

“The upshot of it, is that fertiliser is the main contributor to our carbon footprint, so our focus has been on optimising fertilisers - it is the ‘low hanging fruit’. Improving organic matter is part of this as it tends to increase nitrogen availability in the soil and help nitrogen use efficiency.”

“We use N testers to sample the crop and apply nitrogen accordingly. Last year, on a 110ha block of wheat in South Norfolk we manged to get 96% nitrogen use efficiency whereas, the benchmark used in carbon calculators is 60%. We are still learning but I know we can, and have to, get consistently better efficiency than 60%.”

The wheat yielded 10.23 tonnes from 165kg Nitrogen, the crop was destined for feed, however Mr Barrett admits that milling wheat is more challenging because of the protein specification but there are ways to do it without busting the carbon budget.

“There are quite a lot of tools available that added together will make the difference. We use an N tester, but perhaps an N sensor on the spreader could optimise rates a little more or we can use satellite imagery.”

Mr Barrett points out that setup and maintenance help to prevent overlaps and inconsistent spread. It will be hard to see with the naked eye but added together it means nitrogen application is not being optimised. We can’t afford financially or environmentally to have  wastage.

“Timing is also important; the crop needs to be actively growing without heavy rainfall forecast that will potentially leach the nitrogen away. These are all fairly basic things, but you have to get them right if you want to optimise nitrogen usage.”

This season, like other farmers participating in Bayer’s carbon project, Sentry will look at the value of foliar N to replace the final 40kg split. As nitrogen prices have now dropped, the economic argument for foliar applications is not as strong but it can make a lot of difference to the carbon footprint of the crop.

Mr Barrett views carbon benchmarking as a way to future proof the business. Although carbon payments are relatively small at the moment, he expects demand for carbon will increase as all types of companies, as well as our own, will need to demonstrate how they mitigate carbon emissions. Likewise, schemes such as SFI are part of a bigger picture where farmers are paid for a range of services and products not just producing food.

This approach extends to rotation planning where he tries to avoid rigid thinking: “I’ve never been one for fixed rotations, you need flexibility to react to the market or weather conditions. Wheat is generally profitable and lower risk than some crops but there has to be diversity for a bunch of reasons – pests, diseases, black-grass, ryegrass etc. – so every crop, every season has to be judged on its merits. For example, one year we grew a lot of spring oats as the price was £240/t when beet was only £19/t, this has now flipped with beet up at £40/t improving the opportunity to turn a sensible profit.

In 2022, Mentmore Park Farms, tested the use of urease inhibitors to improve uptake of liquid UAN as part of the Bayer Carbon Programme. Alex Morris is part of the team at Mentmore which manages 1000ha of owned land and over 2000ha in contract farming agreements.

Much of the farm sits on heavy clay, disc cultivators and deeper tines are used rotationally to solve compaction problems. The farm has investigated no-till and low disturbance systems, but they have not worked well with the predominant soil type.

The trials compared three alternative nitrogen programmes to the farm standard of 160kg ammonium nitrate followed by 80kg liquid urea.

There were no statistically significant yield differences between the treatments but the Liqui-Safe appears to have improved nitrogen uptake. The treatment with 60kg UAN + Liqui-Safe reduced the carbon footprint by 4% and increased margin by £33/ha. The highest nitrogen rate had 13% higher C footprint compared to the other treatments.

“We have been interested in using Liqui-Safe as a way to improve use uptake of liquid urea, and the trial results last season were encouraging.”

From the results, it seems that 2022 was a year where rates could be cut slightly below the farm standard, but Mr Morris is aware that this is not always the case.

“Everything varies a lot year-on-year and there are lots of things we have to estimate for example soil nitrogen supply and crop potential. It’s not possible to make an exact plan in February, you have to be prepared to adapt it in season depending on conditions.”

The farm already does this to some extent with milling wheat, the decision to push for the milling premium is made in June based on price and crop condition. Crops destined for milling receive foliar nitrogen to get them to the milling specification. The farm is also intending to purchase a nitrogen sensor to test crops during the season to help improve decision making.

“If you have a droughty spring, that can cap potential so you can probably reduce rates, but if the potential is there, it makes sense to apply more nitrogen and go for yield. We need to understand how to accurately predict when you will get a response from applying more and when you can cut rates.”

“At the moment, I think many farmers apply a higher rate and get a benefit say three out of five years. But we want to work out the two years when it isn’t worth it because of the cost and environmental benefits.”

Farms Manager Simon Beddows is keen to learn more about carbon but knows that growing food profitably will always be his number one priority. Based near Reading, Coppid Farmer Enterprises grows a range of crops across several soil types.

 “We have to be open-minded about how we develop as a business. We want to diversify but continue to focus on our core activity of producing food. This project is a good opportunity to look at carbon with the support of large company.

As a business, we have started to consider our carbon footprint and have made steps forward as a by-product of other things we have changed. We were cultivating deeper and deeper which required larger tractors. About four years ago, we got off this treadmill and lost 275hp from the tractor fleet and aimed to cultivate as little as possible and direct drill. This reduced the diesel bill considerably which also cuts CO₂ emissions.

We have also been working on improving how we use fertilisers through variable rate application. It’s definitely a step forward but I think there are more gains to be made with fertiliser to improve the use efficiency. I think there is a knowledge gap here that needs to be filled with public and private research. If you look at farming, methane from livestock and fertiliser use across all types of agriculture are the big greenhouse gas emitters.

There is also an opportunity for the supply chain to help out. We grow milling wheat, and it takes a lot of nitrogen to hit the protein specification, but after a certain point, the extra nitrogen doesn’t seem to greatly improve overall yield. If there was a sliding scale for protein in milling wheat it would be a lot easier to optimise fertiliser use.

Soil carbon is the big unknown for me that I am hoping the project can shed some light on. I understand how carbon is locked in soil, how cover crops or manure can increase soil carbon and how carbon is released following cultivation. What I don’t understand is how you can get a ‘carbon credit’ unless carbon is locked away long-term for 20-30 years. But it is difficult to plan that far ahead, especially now with so many changes and unknowns in agriculture and the wider economy.

Some companies seem to suggest they nearly have a system to measure and trade carbon. But this makes me sceptical, I think there is a lot to learn before we can do anything on a commercial basis. That’s why I like Bayer’s wait and see approach, it’s more realistic. At the moment, there is no universally accepted way for arable farming to contribute to the reduction of greenhouse gas emissions.

We have committed one 20ha field to the project. It is on a lower yielding soil type, without maize and farmyard manure in the rotation. This is to make it easier to measure and create a baseline for soil carbon.

I am also part of the YEN Carbon Project where I have committed two other 20ha blocks. One is also on the lower yielding soil type but with farmyard manure and the other is on our high yielding land. Across the three blocks there should be some interesting comparisons.

Fundamentally, YEN tries to reduce the carbon footprint per tonne by achieving the highest possible yield to dilute the impact of any inputs. In the Bayer Initiative, I think it is more about reducing the carbon footprint in a way that allows you to sell a credit.

In the ‘Bayer’ field, we currently have a winter cover crop ahead of spring barley. We have been looking at cover crops for a several years but still haven’t properly adapted them to our system. Generally, deeper rooting crops like phacelia and oil radish seem to be the most beneficial.