Can we do without them?
Posted on June 13th, 2024

By Gunnar Rundgren, Courtesy  


June 13, 2024

Organic farm in Brazil

In this last in my series of nitrogen articles, I turn to the question if we can do without synthetic nitrogen fertilizers.

The Sri Lanka case – not an organic case

You have probably heard the story about how Sri Lanka turned organic” and that it ended in a disaster (if not, you can read here or here). This is taken as a proof of that organic farming, or any other farming system that rejects the use of chemical fertilizers is bound to fail. Still, you can’t draw any such conclusion from the failure of a ban on imported fertilizers in Sri Lanka. The rationale for the ban was mainly to save money as the country was in a desperate financial crisis. Since 1962, successive governments provided fertilizer subsidies in various forms. In 2019, the rate of fertilizer subsidy provided to paddy farmers was approximately 86% and it ranged between 48% – 88% for other crops. In 2020, fertilizer subsidy was provided for all crops at a subsidized rate. From mid – 2020, for the first time in history, fertilizer was provided free of charge for paddy up to a cultivation extent of 5 acres. This led to that more than half of the agriculture budget was spent on fertilizer subsidies (Weerahewa et al 2021). International fertilizer prices also started to climb rapidly towards the end of 2020. In 2021, the country found itself in a financial crisis and needed to cut spending drastically and among other measure, president Gotabaya Rajapaksa announced a ban on the import of agrochemicals. Almost overnight, farmers who were used to get fertilizers virtually for free could no longer use any. Clearly, not even an organic agriculture fanatic would recommend such a strategy for converting a whole country into organic.

Sri Lanka is rather a showcase for how not to convert or transition (the term more often used in North America) to organic. It is also an example for how many statements about the implication of a conversion to organic agriculture are produced. You take an existing farming system and quit the use of synthetic fertilizers and pesticides – the yield will drop dramatically depending on the baseline, the crop and many other factors. In the worst cases (in some pest stricken horticulture crops grown in huge monocultures) yields will go to zero, in some cases there will be hardly any effect (low intensity polycultures). But you can’t change one thing in an ecological system. The whole system will have to change if you exclude chemical fertilizers.

Organic, regenerative, agroecology, permaculture…

In this article, I will use organic” as shorthand for an agriculture system that works with natural processes without the use of agro-chemicals. There are competing” concepts such as regenerative agriculture, permaculture, agroecology. Many proponents of any of these claim that their concept is superior to the others. I will not go into any detailed argument about the strengths and the weaknesses of the concepts (I will quite soon write an article about it). I have used regenerative” as more or less synonymous to organic” for more than a decade already, and on my own farm I apply permaculture principles to a rather large extent. The social/political component of agroecology is good and largely missing in the other concepts. Having said that, organic is the only concept that consistently rejects the use of chemical fertilizers.* So the question boils down to if organic agriculture can feed the world”, even though I resent the question because it implies that who gets to eat is about production, which it is not.

Luis and Maria Vieria practice organic, regenerative, agroecological permaculture in Mato Grosso, Brazil, photo: Gunnar Rundgren 2011.

Researchers say no…

Pietro Barbieri and colleagues concludes, in an article in Nature food 2021, that in a fully organic world food production would go down with 36 % of dietary energy needs with nitrogen shortage the key determining factor. Protein would not be a problem though.


Turning to the paper Agroecological measures and circular economy strategies to ensure sufficient nitrogen for sustainable farming by T.G. Morais and colleagues in Global Environment Change (2021), the picture changes. They conclude that with sufficient mitigating measures 100 % organic is still a feasible option on a global scale.


A third paper on the possibility to reshaping the European agro-food system published in One Earth (2021) by a team headed by Gilles Billen claims that Europe can be self-sufficient in a fully organic diet, with a huge reduction in the consumption of animal products.

All three papers are, quite naturally, based on modelling and the results are basically determined by the input data as well as the assumptions made and constraints imposed.** Knowing these assumptions and constraints it becomes considerably easier to understand the difference in results and conclusion. The main difference between Barbieri et al (Global organic impossible) on the one hand and Morais et al (Global organic possible) and Billen et al (Europe organic possible) on the other is that Barbieri et al assume fewer and less effective mitigating measures. Billen et al assume substantial recycling of waste from food system and a tripling of biological nitrogen fixation. Morais et al count on a rather radical improvement in nitrogen use efficiency, covering around half of the anticipated nitrogen shortfall and improved/increased biological nitrogen fixation for most of the rest.

In my view, all three papers have some weaknesses (it would be strange if they hadn’t). Barbieri et al apply a far too static perspective on the response of farmers and society. This is unrealistic and undermines their main conclusion – that organic can’t feed the world. It is quite obvious that large-scale recycling of waste from the food system, including human excrements, would be a necessity in a 100 % organic scenario. Also, their projected increase in biological nitrogen fixation is just 4%, why so little is not explained.

In the paper of Billen et al, I am a surprised that they don’t include the opportunity to expand grassland areas or intensify grassland use. In many parts of Europe huge tracts of grasslands have been abandoned the last century and in many parts grazing is underutilized because it is cheaper to buy feed than to use grazing and to breed monogastric animals instead of ruminants. They assume, instead, a 46% decrease in the production from grasslands.  That may be a realistic assumption for grasslands which today are fertilized with synthetic N with no other changes in management. But in many European countries just a small fraction of the permanent grasslands receives any fertilizers (in Sweden it is even prohibited to spread fertilizers on permanent grasslands).

All three papers also discuss diets, which is quite natural as diet is just the other side of production. Obviously, diets will change with a production system without N-fertilizers, in the same way (but in an opposite direction) as diets have changed dramatically with N-fertilizers. See more below.

My reading of the three articles demonstrate quite well that models of this kind shouldn’t be referred to as evidence of that one or the other opinion is correct. Food and agriculture systems are far too complex to allow for such conclusion. One change, such as the elimination of synthetic nitrogen triggers a cascade of changes, which in turn cause new changes. Emergent properties, such as soil fertility, are not easily captured in models.

I say yes

Having farmed organically for more than forty years, I can agree with the basic tenet of all three articles; that N-supply is a major challenge for organic. Of course, if you grow vegetables, fruits and berries, pests can be a bigger challenge some years for some crops. Under some circumstances phosphorus or potassium supply can also be a problem. With bad management, also weeds can cause severe crop losses.

Don’t we need more animals if there were no N-fertilizers?

There is a common misunderstanding that without chemical fertilizers we would need more animals to get sufficient manure. But there would actually be fewer animals in an agriculture system without chemical fertilizers. If you go back and check the graph in the first N-article I think you will understand why, there will simply be less feed produced. We could do with more grazing ruminants in a scenario without chemical fertilizers, but we could certainly not feed the same number of chicken and pigs that are fed today, or feeding ruminants on grain. The reason for this is that the current number of chicken and pigs as well as cattle in feedlots are dependent on feed crops grown with N-fertilizers.

Without N-fertilizers we would not be able to feed the same number of animals. But ruminants can graze on land that is not fertilized and they can be integrated in the production system in a way that makes them net contributors of food and nutrients to the whole system.  Pigs, and to a more limited extent chicken, can also play a beneficial part of the food system if they are eating leftovers and by-products or feed themselves in niches on or off the farm. But their numbers will certainly be fewer than today. Even if there would be fewer animals as a global average, in many places there will be more animals as animals need to be integrated in all local agro-ecosystems.

The availability of an almost unlimited supply of nitrogen has clearly steered the food system in a certain direction that goes all the way from how we (don’t) handle human waste to an enormous increase of the consumption of chicken. Clearly it is totally impossible to take this system and just exclude nitrogen fertilizers. But farmers and societies will adapt and adjust to new conditions. The changes needed include, but are not limited to:

  • Recycling of organic waste from all parts of the food system, including human excrements.
  • Reducing food waste.
  • Integration of livestock and crop production.
  • Increased focus on a living soil/soil health.
  • Considerable use of permanent, non-fertilized grasslands. This doesn’t necessarily mean expansion of grasslands, but rather better use.
  • Expanded use of biological nitrogen fixation through, among others, the cultivation of leguminous plants. This is not limited to peas and beans for direct human consumption but also clover and alfafa for forage, the growing of leguminous plants as cover crops or living mulches and leguminous trees in forest gardens, permaculture, silvopastoral or agroforesty systems.
  • Adaptation of diets to what works well in an organic production system and to higher prices of food.

Many of the measures needed have been common practices for centuries. A circular food economy is nothing new but rather standard practice for centuries, now discarded by the capitalist market-economy. Global flows of nutrients are largely incompatible with the closing of the nutrient cycles. That doesn’t only apply to trade in feed for animals but equally for food to people. These changes will, in turn, trigger new changes.  This points to a relocalization of the food system. In the end, in the same way as the current food system is both a driver and a result of a capitalist industrial civilization, another food system points toward another society. More expensive food also points towards increasing self-provisioning of food. Some measures will happen as a result of changes in costs.

As food will be more expensive, food waste will be lower, something that has been apparent during the last years’ food inflation in Europe. Similarly, as feed crops will increase considerably in price and nitrogen become more valuable livestock production will shift back to land-based integrated systems. On a practical level, the recycling of human waste is the most challenging as it is linked to basic infrastructure that is very slowly changed and where the investments need to be made by other (estate owners and local governments) than those benefitting (the farmers). As you can see from the graph in the second N-article human waste and food waste together emit nitrogen corresponding to almost one third of the current supply of N-fertilizers. Eliminating losses and recycling the rest (without contaminating it) is crucial.

What shall we eat?

By and large, many food systems research papers and reports have their focus on consumption and prescribe certain diets as being sustainable or in some other way preferable. In my view that is putting the wagon before the horse. The food system is not consumer driven, but producer driven. All through history, people have eaten what could be produced. Which is the obvious reason for why diets have differed enormously over the planet. Therefore the right question is not what we shall eat but rather what we can eat.

The notion that there is one good global diet with largely the same composition is socially, culturally and ecologically inappropriate. On the contrary, the diet should be adapted to what can readily be produced locally – I talk about a landscape diet”. In the case of temperate Europe, I envision a diet with a big role for ruminant meat and milk, potatoes and grain with a lower consumption of pork, chicken, vegetable oil***, exotic fruits and delicate vegetables (tomatoes, lettuce etc.) and a higher consumption of pulses, coarse vegetables (onions, cabbages and root crops) compared with today.

Enough for 10 billion?

Well, I don’t know. There are limits for any system. There are also limits for how many people that can be fed by conventional agriculture and for how long. The discussion is in any case far too simplistic with a growing population being seen as taken for granted, despite the fact that under most of humanity’s history populations have been stable or fluctuating rather than constantly growing. It is quite obvious that there are a number of socio-economic factors regulating the size of population and that the exponential growth of population is just a part of the same system of growth in the economy, with capitalism as the main driver. Population growth has also slowed down rapidly lately, even if the inertia in the system (those giving birth today were born 20-40 years ago) makes it less apparent. My guess is that the population will start to decline within a couple of decades, for a number of reasons linked to the limits to growth as well as cultural factors linked to modernity.

Will it be good for the environment?

Yes, without doubt it will reduce all the many negative impacts associated with N-fertilizers. Among the three research articles discussed above, Barbieri et al project a 77% reduction of N losses to the ecosystems while the main focus of Billen et al is to reduce N losses to the biosphere and their results show a reduction to the half of current emissions. According to Morais et al, N losses can be reduced with 70% and greenhouse gas emissions can be halved in a fully organic scenario.****

The only potentially negative environmental impact would be an increased land-use. Having said that, there is no automatic chain linking lower yields to higher land use. Regionally, e.g. in Brazil, we can see agriculture expansion being linked to increasing yields. The main factor regulating land-use is which use is profitable, possible and legal. In general, the land-sparing argument for intensification is flawed.

Will the poor starve?

The linkages between agriculture production, agriculture prices, food prices and the access to food for poor people are many and complex. One can certainly not suggest that an increased production and low prices are good for the poor. If so, there would be no hungry people on the planet. I did write an article on the subject not long ago, so instead of repetition, here is the link.

The great transition

The discussion about nitrogen in the food system is quite similar to the discussion about fossil fuels in the human civilization, and they are closely related as N-fertilizers are made with fossil fuels. I see both fossil fuels and N-fertilizers as essential components of the Great acceleration. Both are also closely linked to population growth and capitalism. All of that will change.

* I am aware of that there are many organic farms which are not ideal and that are based on massive inflow of manure from conventional farming systems. After all I was a founder of the Swedish organic certification program, KRAV, and also the president of IFOAM for five years.

** In this article I go into detail about the three articles.

*** It will be hard to produce rape seed (canola), sunflower and soybean oil in the quantities needed in Europe and olive oil has too narrow climate demands to expand considerably from the 2% share of global vegetable oil production it has now. Less fat and more animal fat in the diet is the most likely solution in Europe – which was the situation just 50 years ago in any case, when butter, tallow and lard where the main fat sources.

**** All three papers use IPCC standard emission factors which actually are misleading when it comes to N2O emissions. Nyameasen et al (2021) concludes that the IPCC default emission factors overestimate N2O-N emissions from organically managed pastures in temperate climates. Rafique et al (2011) establish that N2O emissions on grazed pastures in Ireland increase exponentially with N-input so that an unfertilized grassland emit around 1.5 kg N2O per hectare, when fertilized with 100 kg N the emissions are 2.2 kg per hectare while a rate of 300 N gives 6 kg of emissions and 400 kg N leads to emissions above 9 kg per N2O per hectare. The emissions from unfertilized grasslands are basically background emissions that should not be counted as emissions at all as all natural ecosystem also emit similar quantities of N2O. A meta-analysis of 422 studies of nitrous oxide emissions from land fertilized by animal manure or chemical fertilizer revealed that emissions are considerably lower than the IPCC standard emission factors for manure and considerably higher for chemical fertilizer (Anaïs et al 2017). Under low availability of inorganic N, soils can even under certain conditions act as a N2O sink (Chapuis-Lardy et al 2007).

Previous N-articles:

How nitrogen fertilizers changed the food system. Part 1. Nitrogen fertilizers is disrupting natural process on par with fossil fuels

N-fertilizers have changed how we farm, what we farm and what we eat. How nitrogen fertilizers changed the food system. Part 2.

From the law of the minimum to soil health. How nitrogen fertilizers changed the food system. Part 3.

You are what you eat, How nitrogen fertilizers changed the food system. Part 4.

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