Gilles Billen, researcher at Pierre and Marie Curie University and member of CNRS, the French scientific research agency, and his colleagues claimed to have calculated a way for Europe to free itself from dependency on imports, reduce greenhouse gases, and curb nitrogen losses, all by 2050. They suggested three points of attack:
- Change the European diet of 601 million people to low-protein intake, consisting of 45 percent cereals, 10 percent legumes, 15 percent fruits and vegetables, and 25 percent animal, and five percent seafood. The European diet has ranged from 45 percent to 55 percent animal protein (and five to six percent seafood), since the 1960s.
- Adopt organic crop rotation practices throughout the European community, focusing on “long crop rotations” of over five years, with “two or three years of temporary sown grassland, such as clover, alfalfa or mix grass and legumes preceding cereal crops.” This would also involve expanding organic crop cover systems, currently used in eight percent of the EU’s agricultural area. Synthetic nitrogen fertilizers would not be used. Instead, the “savings” from these practices would preserve nitrogen. In addition, nitrogen could be recovered by recycling 70 percent of human excrement.
- Feed livestock with local grass and feed (reducing imports). Raise livestock and crops closer together, and coordinate to use manure for growing grass and cropland to produce a nitrogen surplus and avoid synthetic fertilizers. Current practices are, the authors say, “often disconnected and concentrated in ultra-specialized regions.”
Billen’s approach would be a dramatic pivot from current EU policies, which is, he and his colleagues write, “still characterized by a logic of intensification on reduced cropland areas and specialization of activities in the most suitable territories, denying the advantages of their possible complementarity and resulting in huge environmental losses of reactive nitrogen.”
For dietary changes, a reduction to 30 percent animal products would reduce nitrogen consumption to 5 kg of nitrogen per capital per year (kg/N/cap/year), down from about 6 kg/N/cap/year. Reducing demand for animals would in turn reduce the number of livestock on grazing land.
Organic crop rotation practices (which ban any use of synthetic fertilizers) would involve five year crop rotations (currently practiced in western and central Europe, but not in other regions), with two or three years of clover, alfalfa, mixed grass or legumes throughout the EU. This approach would show nitrogen fixation ranging from 20 to 100 kg of nitrogen per hectare per year (kg/N/hec/year). The authors also assume nitrogen input could come from recycling human excrement, which is about “80 percent of nitrogen excretion.”
For “crop-livestock reconnection,” animals must feed locally with no imports, and their manure would be spread on nearby crop- and grassland. This would also eliminate the need for synthetic sources of nitrogen fertilizer–up to 20 percent of nitrogen deposits current come from animals in grazing-dense areas of Europe. Livestock then, “influences cropland productivity by enabling a strategic recirculation of manure nitrogen, and thereby the capacity to locally provide food and feed,” the researchers write. This rewrite of crop-animal raising would also have a maximum nitrogen surplus of 35 kg nitrogen/hec/year, to maintain water quality.
All this, the researchers write, adds up to a difference between current usage of 63 kg nitrogen/hec/year (if current conditions continue) and their scenario, which only produces 30 kg nitrogen/hec/year. It also would cut livestock density by nearly one half.
A CNRS press release declared that these changes would keep Europe fed, aid in exporting from Europe and reduce pollution:
According to this scenario, it would in this way be possible to reinforce Europe’s autonomy, feed the predicted population in 2050, continue to export cereals to countries which need them for human consumption, and above all substantially reduce water pollution and greenhouse gas emissions from agriculture.
The authors correctly name issues facing European agriculture. Climate change is indeed changing what can be grown and raised in different regions of the continent. It is a net importer of proteins, including protein-containing crops for feeding livestock, and reducing this need for imports would reduce pressure on other areas of the world, like South America, to clear forests and grow crops for European consumption. Further, excess nitrogen that’s currently produced through the Haber-Bosch process adds to greenhouse gases and requires a great deal of energy (still often from fossil fuels) to produce nitrogen. Currently, “food systems” (which includes transport, processing and delivery of post-harvest food) account for one-third of greenhouse gas emissions. “The success of the Haber-Bosch process and the Green Revolution was such that, for a long time, very little resources were invested in the development of more sustainable agro-ecological options,” the authors conclude.
These issues are very real, not just for Europe but largely for the world. But how realistic are Billen’s solutions? Not very, experts say. Even the study authors admit the human waste recycling idea “would imply that the current prohibition of human excreta in the European organic farming regulation would be lifted.” Nonetheless, the authors conclude that “a fundamental agroecological transformation of European agro-food systems is biophysically possible.”
While nobody argues that eating less meat would reduce the need for animal production, and a plant-based diet would probably be healthier overall (assuming that the animal is of the fat-containing kind), swaying public opinion and behavior about food consumption is a daunting, in some cases impossible challenge. Moreover, the ability of agroecology methods to reduce Europe’s heavy import needs is far-fetched, scientists say.
Stuart Smyth, professor of agricultural and resource economics at the University of Saskatchewan, observed several instances in which Billen’s team left out certain data that would have contradicted their findings and ignored current issues with organic food production.
In the paper’s first figure (1c, below), the authors claim that crop yields followed a rising curve, correlating with nitrogen application from 1960 until about 1985. Then, starting in the 1990s, yields kept rising even as nitrogen use decreased. This, Billen and his colleagues write, indicates a higher theoretical crop yield even with less nitrogen (encouraging then, the use of agroecological practices such as rotation and heavier manure use). Changing the crop mix and eschewing external nitrogen inputs, then, would increase yields with less nitrogen. However, Smyth observed that the authors did not account for total increase in the use of EU crop land. “Yields can appear to increase as the total amount of land producing crops increases. This figure is incomplete without the perspective to total crop production land.”
In addition, the third proposal, bringing crop and livestock land closer together (and using manure on cropland), is probably not feasible in most parts of Europe. “The majority of land presently used for livestock cannot be used to produce crops, due to problems with erosion and soil composition that is unsuitable to crop production,” Smyth wrote. He continued:
The article fails to acknowledge the massive amounts of nitrogen intensive corn production. Corn is required for livestock feed and the EU has imported in excess of 12 million metric tons of corn for most of the past decade.
As for increased yields from agroecology practices (which incorporate organic farming methods like avoiding synthetic pesticides and fertilizers, tilling, crop rotation and cover plants), “The authors fail to incorporate the staggering yield lags for organic production, which average 33% and can be over 50% for some vegetable crops,” Smyth wrote. The table below shows significant yield gaps (overall) between organic and conventional production.
Cover crops are fairly uncontroversial, and are used throughout Europe (and the United States). In this study, the authors called for longer crop rotations (over five years), currently practices in western and central Europe, to be “generalized” throughout the continent. However, in southern Europe, which has less rainfall and scarcer sources of water, growing cover crops (clover, alfalfa, or legumes, for example) is not possible, and may be less possible in the coming decades. To this end, the authors recommended “simple fallow, with ample spontaneous development of weeds,” or irrigation of alfalfa and other covers. All of these decisions come at a cost.
Finally, even if human excrement were available and crops could possibly grow nearer grazing land, the resulting manure would provide more nitrogen. However, as Smyth pointed out, “the spreading of manure or use of green manure requires tillage, which increases GHG emissions and reduces CO2 sequestration. Both contribute to unsustainable agriculture production.” While manure and nitrogen-fixing legumes do not require the energy of the Haber-Bosch process, both still produce greenhouse gases (in this case, methane).
For Andre Heitz, retired agricultural engineer and former director of the World Intellectual Property Organization, the study struck an all-too-familiar chord:
The paper is no doubt yet another reincarnation of an old story: a spreadsheet Kriegsspiel (war game) or number-crunching exercise, which sets out a foretold conclusion, assembles the necessary assumptions and concludes that the desired result is — more precisely ‘may be’ or ‘could be’ — achievable.”
The paper did not account for reducing food losses and waste, which are significant factors when calculating yields and land use. But the paper follows other previous formulas: “These scenarios usually include a change in dietary patterns, and the reshaping of the agricultural landscape. One would have to see whether the equations are plausible, which would be a monumental task.”
Two numbers that didn’t add up caught Heitz’ attention:
- The study authors claim in a chart with the CNRS press release that 80 kg/year of nitrogen would be recovered in France alone from nitrogen fixation. “That alone is surprising. Soybeans would leave 30-40 kg post-harvest. Other crops would release more, but that would not meet the claimed average of +80kg/year. The land would also be unavailable for cash/food crops.”
- Nitrogen fixation is set at lower levels in other countries. Those levels seem incompatible with a reasonable yield of the cash crop(s).
For Marcel Kuntz, plant biotechnologist at CNRS in Grenoble, Switzerland, the paper (and its attendant publicity) is another example of “virtue signaling.” CNRS, for its part, does not influence researchers to follow any certain direction. But the agency does get selective on what research it wants to promote.
For example, while CNRS issued a press release on the OneEarth study promoting the virtues of organic and agroecology practices in this case, they ignored other studies showing how European use of CRISPR gene editing in agricultural technology is losing ground to China and the United States because of the European Union’s strict stands, essentially equating it with transgenic “GMO” technology and restricting its use enough to be prohibited within European borders.
But it’s biotechnology, and not sweeping dietary changes and crop rotations and combined grazing/growing lands, actually could make a significant dent in European food and feed supply. Matin Qaim, Professor of International Food Economics and Rural Development at the University of Göttingen, Germany, recently presented figures showing clear yield increases, pesticide and fertilizer reduction and reforestation possibilities arising from the adoption of certain genetically modified crops (his presentation is in the first 17 minutes of the video below). Meanwhile, under current regulations, imports to the European Union is responsible for 16 percent of tropical deforestation (where the exports come from), and 33 million tons of carbon dioxide have been emitted, thanks to the EU’s refusal to adopt GM and gene edited drops.
For long-time agricultural consultant and former CEO of the California Strawberry Board Rodger Wasson, the best fit for fixing Europe’s import and nitrogen use problem is more of a mix. For him, these goals could be met, or at least start moving in a less nitrogen-intensive direction. “From this they could still suggest more genetic engineering, integrated livestock (and natural N) production, Integrated Pest Management, cover crops, rotations and necessary limiting of feed imports from places that aren’t destroying rain forests,” he wrote.
Andrew Porterfield is a writer and editor, and has worked with numerous academic institutions, companies and non-profits in the life sciences. See his bio here. Follow him on Twitter @AMPorterfield