Nitrogen Reduction, Recycling and Reuse (Environment and Climate Change Committee Report)

In England, the total cost of nitrogen dioxide to the NHS and social care is estimated to be £230 million by 2035. That is why our report calls for a national nitrogen strategy rooted in robust data and a clear-eyed assessment of trade-offs. We recommend a UK nitrogen balance sheet, providing for nitrogen what the carbon budget provides for greenhouse gases—a transparent, accountable framework to understand where nitrogen comes from, where it goes and what damage or benefit it brings along the way. Only with such a framework can policy be coherent rather than piecemeal. The Government’s response acknowledges the problem but shies away from that necessary step. Warm words on existing initiatives are not a substitute for a cross-government strategy with measurable objectives and timelines.

Agriculture sits at the heart of the nitrogen challenge. Farmers are essential partners in the solution but they cannot be expected to transform practices in the absence of clear standards, fair incentives and practical support. Our report identifies major shortcomings in nitrogen regulation and enforcement, defined by piecemeal rules—for example, overlapping regulations such as farming rules for water, nitrate-vulnerable zones and silage and slurry regulations.

This confusing picture is further undermined by poor enforcement by the Environment Agency, which inspects under 2% of England’s 105,000 farms yearly. For example, checks were carried out on 2,213 farms in 2020-21. Breaches were found in about 50%, but sanctions were issued in just 0.1% of cases. That is more carte blanche than enforcement, which is a shame because, as we heard, if properly enforced, the farming rules for water have the potential to be effective in improving water quality as well as air and soil quality.

A key recommendation in our report was simplification of the regulatory system and toughening of enforcement action. There are some low-hanging solutions, such as improving manure management, mandating low-emission slurry spreading and covers by 2027, and extending permitting to large cattle and dairy farms within two years. We saw examples of this on our visit to an experimental farm in the Netherlands.

Our report argues for aligning air quality, climate and agricultural policy so that measures reinforce, rather than undermine, one another. Moving nitrogen towards a circular economy—reduce, recycle, reuse—should be a unifying objective, but it is disappointing that the Government do not recognise that a circular economy approach to reducing nitrogen emissions is not deliverable without a national nitrogen strategy. I beg to move.

Some of these nitrogen-fixing organisms are free-living bacteria, whereas others typically live in a symbiotic relationship with certain plants within their roots; leguminous crops are examples of such plants. In their root modules, the bacteria convert free nitrogen into nitrates, which the host plant utilises for its development. In return, the bacteria receive a supply of carbohydrates for their sustenance. When plants die and decay, they release nitrogen compounds that are available for uptake by other plants and crops.

The rapid growth of the population of Britain in the 18th century raised the threat of famine and starvation. After years of stagnation in European agriculture, an agricultural revolution occurred that proceeded in step with the Industrial Revolution, and Britain led the way.

The principal innovation in farming methods concerned the adoption of new crops and a new system of crop rotation. In the Norfolk system, which in fact originated in Holland, a four-field rotation of crops was adopted, which involved the successive planting of wheat, turnips, barley and clover. The effect of the turnips and clover was to enhance the fixation of nitrogen, thereby stimulating the growth of the cereal crops. As the nitrogen supply was improved, other nutrients, particularly phosphorus and potassium, became limiting factors. The only available supply of phosphorus compounds would have been via calcium phosphate from bonemeal.

Additional fertilisation of the soil would have come from farmyard manure and from roughage and litter collected from forests and meadows. By the middle of the 19th century, much of the farmland was already in intensive use and further supplies of foodstuffs could be obtained only by increasing the addition of fertilisers that were exogenous to the farming system. The requirement for fertilisers was met from a variety of sources; these included Peruvian guano, which has its origin in the droppings of sea-birds, of which supplies were virtually exhausted by 1875. Another source of fertilisers was the Atacama Desert, which spans Chile, Bolivia and Peru. When the production of sodium nitrate began in 1804, the nitrates were leached out of the soil by hot water and then purified and dried. The supply reached its peak in maybe 1930. The coking process that is associated with steel-making, which was used to produce town gas for domestic heating and lighting, was a source of ammonium sulphate fertiliser.

Given the increasing demand for nitrates, in view of the rapid depletion of the sources of mineral nitrates, it was inevitable that, at the end of the 19th century, industrial chemists should turn their attention to the business of creating synthetic nitrates. Without some new source of nitrogen fertilisers, there would have been widespread famine within two or three decades. Some intensive research ensued.

The demand was met, eventually, by the Haber-Bosch process, which deploys high temperature and high pressure to synthesise ammonia by combining hydrogen and nitrogen. A successful implementation was achieved in 1908, which was in time to provide Germany with wartime explosives.

Nowadays, the process is the basis for the supply of ammonium nitrate and urea, which are the fertilisers that sustain the worldwide production of food. It has been suggested that, in the absence of these fertilisers, only half the world’s population could be fed and at a starvation level. The combination of nitrate fertilisers, mechanisation, irrigation and the development of high-yield cereals has been responsible, since the 1960s, for what has been described as a green revolution. It is notable that the production of nitrate fertilisers has increased ninefold since the 1960s.

The gains of this revolution are now being lost through farming practices that threaten the fertility of the soil. A significant cause of the declining fertility is the salination of soils that occurs in irrigated lands that are subject to high rates of water evaporation. The salts that are carried by the irrigating waters are liable to be deposited in the soil, to the detriment of the crops. There has also been a massive overuse of nitrate fertilisers that can scorch the seeds of the crops. The rotation of crops that would otherwise serve to restore nutrients to the soil has ceased and been replaced by cereal monocultures sustained by fertilisers and pesticides.

Recent studies show that yields of corn and rice grown on saline soil in the Indus Valley of Pakistan have declined on average by 32% and 48% respectively, compared with the yields of crops grown on non-saline soil. The overuse of nitrate fertilisers is also a feature of agriculture in temperate climates. The effects of the misuse of nitrogen fertilisers are clearly apparent in the United Kingdom. The loose spreading of the fertilisers makes them liable to be washed away. When they reach the rivers, they enrich the water with nutrients that cause excessive growth of algal blooms that block sunlight and deplete dissolved oxygen. This harms and destroys aquatic life.

The availability of chemical fertilisers has encouraged farmers to neglect systems of crop rotation that can be used to maintain the quality of the soils. Farmers neglect to sow cover crops that would restore the nutrients and prevent soil erosion. Ploughed fields are left bare while sterile soil awaits further applications of chemical fertilisers and pesticides. A report from 2019 by the Environment Agency found that, within 60 million hectares of crop-land in England and Wales, almost 40 million hectares of soil are at risk of compaction, over 20 million hectares of soil are at risk of erosion, and intensive agriculture has caused arable soils to lose about 40% to 60% of their organic carbon.

The report of the committee reveals that the UK is lagging behind other European countries in its effort to redress the problems arising out of the intensification of agriculture. A visit to the Netherlands revealed a stark contrast in the relative efficacy of its regulatory systems and those of the UK. The Dutch have made significant progress in limiting the overuse of nitrate fertilisers and in preventing them leaching into water- courses. The report testifies to a confusing mass of UK legislative measures that are overseen by agencies that fail adequately to enforce them.

This state of affairs must surprise anyone who is familiar with the strict controls of farming practices and farm produce that occurred throughout the years of the Second World War and for an equal period thereafter. The Ministry of Food, in conjunction with the Ministry of Agriculture and Fisheries, exercised considerable control over farm production and farming methods. Such control was gradually ceded in post-war years under Conservative Governments. The lack of effective regulation and guidance of agriculture in the UK has been an inevitable accompaniment of the decline of the Civil Service during the periods of Conservative Governments. One is reminded of the period from 2014 to 2016 when Liz Truss was Secretary of State at the Department for Environment, Food and Rural Affairs. During that time, she was an advocate of all manner of unreasoned acts of deregulation.

I believe that the problems besetting agriculture in the UK need to be addressed by a reconstituted department of agriculture that would be active in imposing regulations and offering firm guidance to farmers.

As our debate in Grand Committee unfolds, it will reveal that farming is one of the greatest culprits with regard to nitrogen pollution. Some £420 million of fertiliser is wasted annually, as our chair said, through inefficient farming practices. The inefficient and unsustainable use of artificial nitrogen, and indeed farmyard manure, leads to large reactive nitrogen losses to the atmosphere and to terrestrial and aquatic systems. Undoubtedly, excess nitrogen use has a deleterious effect on biodiversity. It is this point that the two scientist friends I mentioned at the beginning of my speech were making. The area of nitrogen-sensitive habitats in the UK with exceedance of nutrient nitrogen-critical loads was 57.6% in 2017 and is probably more now. That represents just over 42,000 square kilometres. The area of acid-sensitive habitats of soil and forest ecosystems in the UK that exceed acidity-critical loads was 38.8% or 27,250 square kilometres.

There is a way that farming can also be a provider of one of the solutions. I am afraid that organic farming, although it clearly could be a solution to nitrogen pollution if overwhelmingly adopted, would lead to mass starvation throughout the world. Currently, only 2% of land in the UK is farmed organically.

Although I say I am a farmer, my degree was in history of art. So while I understand my businesses, I do not necessarily comprehend the detail and spend a lot of time asking silly questions of my team—and they are often the best questions. In 2019 I set our farm management team a challenge to see whether they could farm without agricultural chemicals and artificial nitrogen by 2030. It was an 11-year target. There was a sharp intake of breath but they accepted the challenge. Two years later, the broad acres manager came to me to say that he had stopped using insecticides —indeed, we have barely used them since 2021 except on some seed dressings—but he also told me that if we were to stop using nitrogen, our yields would plummet.

To illustrate this, from time to time this team experiments with applying varying degrees of nitrogen to the same crop in the same field. We have had a number of groups from the World Wildlife Fund, Nestlé and Marks & Spencer visit our fields. Some individuals express a preference for organic farming. When we show them our cereal trial plots, that usually convinces them that organic farming is not going to feed the world. The crop with no nitrogen at all looks markedly sparse when compared with those with 60%, 80% or 100% of the recommended fertiliser application. Financially we would not survive—although, granted, we have not built up experience in organic farming.

The farm manager says that he is now using his grey matter much more as he figures out how to make regen farming work, learning from mistakes, having an independent agronomist who is not attached to an ag-chem firm—who of course may want to sell you a little more product—and, when he sees insects in a crop, not immediately reaching for the spray can. He recognises that predator insects such as ladybirds, lacewings, parasitic wasps and hoverflies that attack swarms of aphids do the work for free.

Similarly, our potato enterprise manager took my aspiration to heart and reduced the recommended nitrogen application by 10%. The crop still looked well, and the yield was as expected. He did the same thing the following year, with similar results. In the third year—this is important because it demonstrates how improved technology also plays a part—we bought new precision potato planters that place the nitrogen fertiliser next to the seed. This yielded a further saving of 22% in the amount of nitrogen applied. Over three years he had achieved a compound cost saving of 37%, which goes straight to the bottom line, with no discernible diminution of yield. Importantly for this debate, he had also achieved a saving for the environment, with reduced run-off of unused nitrogen into watercourses or the atmosphere.

I take issue with the noble Viscount saying that these innovations first came in the Netherlands. If I can be a little immodest, my four-greats grandfather, Coke of Norfolk, along with Turnip Townshend, were very much involved in the agricultural revolution in Britain. The agrarian revolution of course facilitated the Industrial Revolution, which also happened first in Britain. Although the Dutch are jolly good at what they do, I take issue with the noble Viscount; maybe I will raise it with him afterwards and we can discuss where the agricultural revolution started.

Anyway, many agricultural research institutes, such as the John Innes Centre in my part of the world, Rothamsted Research and indeed UEA, have departments monitoring these reductions in nitrogen use without a deleterious effect to crop yields. The Government need to help to promulgate these well-researched messages from such august institutions across to the farming industry. Many progressive farmers are already taking advantage of financial savings achieved by reduced inputs and are proud of their resultant improved environmental credentials. Farm shows such as Groundswell, a regenerative farming conference started by the Cherry family in Hertfordshire, are championing these rediscovered wisdoms and, encouragingly, grow in size each year at the expense of more conventional shows.

While there are undoubtedly rogue farmers who need enforcement action taken against them, the vast majority are hard-working, honest people, many of them, in current economic and legislative conditions, grinding out a living. In my experience in life it is the carrot, not the stick, that works more effectively in a democracy such as ours, so I ask the Minister to advocate that training be prioritised rather than enforcement.

We were told that farmers pay a price for their inefficient use of fertiliser. We have already heard some of the figures—Natural England estimated the cost as between £21 and £52 per hectare, totalling about £397 million per year for the agricultural sector, while the Sustainable Nitrogen Alliance, as we have heard from others, quoted a figure of £420 million of fertiliser wasted annually—but there are also much bigger costs to society and to the economy that are not paid for by farmers, the so-called externalities. As our chair mentioned, nitrogen pollution is damaging our ecosystems and the services they provide. According to the Joint Nature Conservation Committee, about 30% of the loss of biodiversity in the UK is attributable to nitrogen pollution, and 99.9% of sensitive habitats exceed the critical load for nitrogen deposition.

Secondly, nitrogen pollution is causing global warming, with all the costs and risks that result. Nitrous oxide is a potent greenhouse gas that is 270 times more powerful than carbon dioxide. As I have said, 69% of atmospheric nitrous oxide in this country comes from agriculture.

Thirdly, nitrogen pollution damages our health. Many of our city streets exceed WHO safety limits for fine particulate matter that arises in part from agricultural nitrogen pollution. When you step outside the Palace of Westminster and breathe in these fine particles, remember that it is estimated that between a third and a half of them result from ammonia pollution from agriculture; also remember that they will increase your chances of developing various forms of cardiovascular disease, respiratory disease, cancer and dementia.

All these impacts of nitrogen pollution impose costs on our economy. As a nation, we would be wealthier, as well as healthier, if we got a grip on the problem. Estimates of the total cost of nitrogen pollution from all sources vary widely, but the WWF quoted a central estimate of around £11 billion per year; agriculture contributes a significant fraction of this. To get a fix on what that looks like, I checked: it is about a sixth of our annual expenditure on secondary education in this country.

Having heard the evidence, I was puzzled. If farmers are generating unnecessary nitrogen pollution that is costly to themselves and even more costly to society in general, why do they carry on doing it? The puzzle is even greater when you learn, as we did, that applying less fertiliser appears not to reduce crop yields; this is described in box 1 of our report. Over the past 40 years, crop yields have tended to increase irrespective of the amount of fertiliser applied. Perhaps, as the noble Earl, Lord Leicester, said, many other factors—rainfall, temperature and so on—affect variation in crop yield. But when fertiliser application went down because of the price increase following Russia’s invasion of Ukraine, crop yields were apparently unaffected.

This suggests that factors other than fertiliser use are limiting productivity and, therefore, that farmers are applying too much fertiliser. Why would they do this? We were told by several witnesses that at least part of the problem may be that farmers do not have easy access to appropriate and trusted advice on nitrogen management. The Government agree with this conclusion that clearer advice for farmers is needed. In their reply to our report, they say:

“Defra are developing an online, free-to-use, nutrient management planning tool for Great Britain (NMPT-GB)”—

catchy title. They go on:

“NMPT-GB will be designed to help farmers and land managers in England, Wales, and Scotland to plan and manage nutrient use on their land”.

The tool, which was launched in a public beta version last month, sounds very good but, as far as I could ascertain, it does not contain any new information about fertiliser application. Instead, it uses the pre-existing Agriculture and Horticulture Development Board’s Nutrient Management Guide (RB209). This guide has been available since 2017, but I was not able to find out whether it has been successful in persuading farmers to reduce nitrogen pollution from fertiliser application. I therefore ask the Minister: has there been an assessment of the impact of the AHDB guide so far?

The guide does, however, provide clear advice on how much fertiliser to apply. This is set out on page 16 of the document in a section entitled “Principles of nutrient management and fertiliser use”. The guide states the following:

“The crop nitrogen requirement is the amount of nitrogen that should be applied to give the on-farm economic optimum yield”;

this is the point at which the marginal financial cost of adding more fertiliser would not pay for itself in the marginal financial returns of increased crop yield. In other words, the advice from the AHDB is to maximise net financial gain per hectare; of course, this ignores the other costs of producing the crops, such as machinery and labour. The detailed guidance also provides recommended inputs of nitrogen and other nutrients according to crop type, soil type and rainfall. So the information is out there; it is the just the case that, apparently, farmers either do not use it or do not know about it.

However—I return to the point made by the noble Earl, Lord Leicester—when we heard evidence from the fertiliser industry, it suggested an alternative metric: nitrogen use efficiency. This is the ratio of nitrogen input to nitrogen output. For me—this is the reason why I debated this measure with the committee—the problem with this measure is that it does not tell you about profitability per hectare, which is the thing in which I would have expected farmers to be interested and on which the AHDB guidance is based. Does the Minister agree with me that maximising net financial gain per hectare, as in the AHDB guidance, is a more appropriate guidance metric than maximising nitrogen use efficiency, as claimed by the fertiliser industry?

However, this is not the end of the story. As I have already mentioned, the societal cost of nitrogen pollution is borne not only by the farmer but by the rest of us. The “polluter pays” principle, which is one of the five environmental principles that Ministers should consider when making policy, suggests that these costs should be borne by those who produce the pollution. I therefore ask the Minister whether it would be appropriate to amend the guidance on fertiliser use in future to reflect not just the direct costs of the fertiliser to the farmer but the total cost to the country. Perhaps, if the costs of nitrogen pollution and fertiliser use reflected its true impact and cost to society, as well as the specific cost to farmers, we would see more judicious management of nitrogen and less damaging nitrogen pollution. I look forward to the Minister’s reply and to other contributions to this debate.