Can organic agriculture sustainably feed the world in 2050? A new study published in Nature Communications addressed the question. There is no clear-cut answer. Adrian Müller, senior researcher at the Research Institute of Organic Agriculture (FiBL), and his co-authors show that a 100% conversion to organic agriculture reduces nitrogen surplus and pesticide use but needs more land than conventional agriculture because it has lower yields. But when it is combined with other strategies — reductions of food wastage; of food-competing feed from arable land; and thus of production and consumption of animal products — it becomes better for other indicators such as greenhouse gas emissions while land use remains below their reference scenario. Having adequate nitrogen supply remains a challenge though.
There is an ongoing discussion on whether organic agriculture can feed the world or not but this is usually looked at with a focus on lower yields. We thought this was too restricted a view on the issue. Our key message is that to address sustainability in agriculture, we really have to look at the whole food system and not only food production alone. To solve this question, we need to reduce the size of the whole system, to produce less. We also have to reduce wastage because it directly enlarges the food system without adding to food security to a certain extent. It would mean drastic changes in consumption patterns. In our western and liberal societies, we do not have an intuition for our planet’s limits, nor can we tell people how much to eat or what to eat. I am therefore convinced that there needs to be a fundamental debate in our societies on what sufficiency means and what it means to live in a world where we have a global impact.
Paris Innovation Review — Why did you and your team decide to conduct this research?
Adrian Müller — We decided to conduct this research because there is an ongoing discussion on whether organic agriculture can feed the world or not. This is usually looked at with a focus on lower yields in organic agriculture. Some people argue that because of these lower yields, organic agriculture cannot play a role in sustainable food security. On the other hand, proponents of organic agriculture usually argue that these lower yields are not that dramatic and use some examples where they are actually not lower.
We thought this was a too restricted view on the whole problem. We wanted to assess and discuss the question in a food system context to really see what could be the contribution of production systems such as organic agriculture or concentrate feed-free livestock systems. This is why we build such a food system model, to have first-hand a systemic assessment of organic agriculture.
We were also interested in having a more detailed assessment of the nitrogen supply in organic agriculture, which is a big part of the yield discussion. The opponents of organic agriculture are really emphasizing that there is not enough nitrogen in the system with organic agriculture. On the contrary, those who support organic agriculture usually say that it is not a problem, arguing that it is possible to use off-season legume crops in order to have enough nitrogen. But they do not look at the water demand of those crops.
Is it the first time that a study has been done in such a comprehensive way on this topic?
For organic agriculture, yes. There are food system models that look at other production systems but usually they have a lower level of regional detail and also, regarding crops and livestock activities, and they do not capture organic agriculture.
Which methodology did you use?
It is a so-called mass-flow-model which traces all the biomass and nutrient flows through the whole system. It is important to note that it is an assessment of agronomic viability but that it is not addressing economic or behavioral aspects. For instance, it does not take into account economic restrictions and market effects relating changes in quantities to changes in prices. It only outlines options, trade-offs and synergies from a biophysical point of view.
Your hypotheses are quite conservative. Why?
We choose to be conservative on the yield gap between organic and conventional agriculture. We were actually criticized for not using a more favorable yield gap but we decided to use the most conservative one because it comes from the best available study on the subject. Therefore no one can claim that we are biased towards organic agriculture. We try to address all these questions in an unprejudiced way.
According to your results, what would be the positive and negative consequences of a 100% conversion to organic agriculture by itself?
Switching to 100% organic production would have positive effects on ecotoxicity and nitrogen surplus, which would lead to improvements in terms of biodiversity. But it would increase land use - between 16% (low yield gap) to 33% (high yield gap) - and therefore have a negative impact on biodiversity, because it means more deforestation or change from grass to crops. With conventional agriculture, the land use problem is not so big but the nitrogen and pesticide problems are important. Neither the organic nor the conventional strategies are sustainable by themselves.
What is necessary to make the food system sustainable?
Our key message is that to address sustainability in agriculture, we really have to look at the whole food system and not only food production alone. We also have to look at environmental impacts on a systemic level and not only by single efficiency indicators such as greenhouse gas emissions per kilograms of products or yield per hectare.
Many assessments that focus on efficiency measures claim that we need to reduce the impact per kilograms of product (sustainable intensification), which can also be a good thing in many aspects. But to really solve the question of sustainability, we need to reduce the whole size of the system, to produce less. To achieve that without reducing food security, we have to shift from resource-intensive animal products to more plant products that can be eaten directly, and to animal products that are based on resources that cannot be used for food production directly.
We basically have to decide which benefits of the system we trade-off against which drawbacks.
We also have to reduce wastage because it directly enlarges the food system without adding to food security to a certain extent. If the whole system is reduced, we gain the room to have production systems that are less efficient according to certain indicators. This is where the yield gap between organic and conventional agriculture becomes less relevant.
It comes down to a trade-off. If one only looks at land use, then it would be better to have conventional agriculture in combination with less food wastage and less animal products, because land use would still be lower than with organic agriculture. But if one looks at nitrogen and pesticide use, then the organic system is better. We basically have to decide which benefits of the system we trade-off against which drawbacks. It is really important to look at all the indicators at the same time and to find a combination of strategies that has overall a reasonably low level of environmental impact. The key is the combination of strategies that performs reasonably well on all indicators, as it will always be possible to find a system that works better on a specific indicator, while performing worse on the others.
What does this study bring on the nitrogen supply debate?
We find that nitrogen supply will indeed be a challenge for a fully organic system. But we are also quite conservative. For instance, we have not included the off-season legume crops, which is in a certain extent a source of nitrogen. We also discussed that we should work on recycling the nitrogen back into the system. Overall our study shows that solving the challenge of sufficient nitrogen supply is not an easy thing with organic agriculture but it is not such a huge problem according to our results.
How did you include the potential impact of climate change ?
We did some sensibility analysis on the impact of climate change and we addressed its impact on yields. Our basic scenario is based on the yield forecasts without climate change that the FAO uses. We then reduced those yield increases to 0 — that is the lower end of high climate change impact. According to some reviews, it is likely that the yields will not increase very much or not at all anymore for the big crops (wheat, rice, corn), depending on the scenarios. Some studies even say that the yields will come down on average. The land demand therefore increases a lot, both for conventional and organic agriculture. So the need to reduce on the consumption side is all the more important.
Were you surprised by the results of your research ?
The land use results were expected. For us, it was always clear that organic agriculture needs more land simply because of the yield gap. We did not know how it would perform regarding greenhouse gas emissions and that, in combination with other strategies, one does not really have to go to extremes to get a system with lower greenhouses gas emissions and lower nitrogen surplus. We knew in what direction the effect would go but we did not know how big it would be.
What is important to note is that to achieve sustainable food systems, we do not need to go for 100% wastage reduction or 100% reduction of concentrate feed livestock production. Going to 50% is already much better, although it would represent a big change. These consumption changes are quite drastic and we do not address how to achieve them. The aim was to point out that talking about sustainability in agriculture just does not make sense without addressing the consumption side.
How do you plan to develop this research further ?
We have rebuilt the model to add more details, for example on animal production systems and the off-season legumes for organic agriculture. We have applied this modeling to Switzerland to address what would be possible in this country. This is one case study where we have produced really detailed data.
One other thing we want to add to the global model is fisheries because there is currently no model that really integrate aquaculture from the animal production side. We captured this roughly in this research but it would be good to have it in more detail. We would also like to include bioenergy. There is a debate on land and water competition between biomass energy and food production but there are no measurements on the competition for nutrients. Basically, the biomass needs carbon to produce energy and agriculture needs nitrogen to fertilize. We would like to add that in detail to see how much bioenergy is possible when used in conjunction with a sustainable production system where mineral nitrogen fertilizers are reduced.
With other colleagues, I also did some work on what sufficiency could mean in a liberal society. It is an important concept that becomes more and more visible in governmental reports but nobody really knows how to implement it. We cannot prescribe people how much to eat or what to eat. I am convinced that this whole discussion really needs a fundamental debate on the values of our societies. It can sound a little bit naive and reminds of the discussion in the 1960s but I think if we really want to change something, we cannot avoid discussing sufficiency on this same fundamental level where we discuss aspects of individual freedom and justice.
I do not think these changes will be possible in the coming years. I see it more like a generation or two change. In our western and liberal societies, we do not have an intuition for our planet’s limits. Until now, our values and institutions deal with individual freedom, justice and the no-harm principle — individual freedom goes as far as it can before harming the other’s individual freedom. But we have no clue on how to react as a society to the global impact of climate change, because we do not really feel it directly and it does not relate to us as individuals as much as these core values. We really need to have a fundamental discussion on what it means to live as a society in a world where we have a global impact.