Dear Friends and Colleagues
Organic Farming Can Feed the World, But Only If We Cut Meat Consumption and Food Waste
A new study, published in the journal Nature Communications, (Item 1) takes a food systems approach that goes beyond a focus on production, yields and environmental impacts per unit output of specific commodities. It measures the impacts of a conversion to organic agriculture on a range of environmental and production indicators, and complements this scenario with two additional changes to the food system, namely (a) reductions of livestock feed from arable land (i.e. food-competing feed) with corresponding reductions in animal numbers and products supply (and thus human consumption) and in related natural resource use and environmental impacts; and (b) reductions of food wastage, with correspondingly reduced production levels and impacts. The key aim was to find out whether producing a certain total amount of food, in terms of protein and calories, with organic agriculture would lead to higher, or lower, impacts than producing the same amount of food with conventional agriculture.
The results show that adoption of organic agriculture by itself increases land demand with respect to conventional production, but it has advantages in terms of other indicators, such as reduced nitrogen surplus, and pesticide use. However, when combined with the production of adequately high proportions of (nitrogen-fixing) legumes, and with significant reductions of food-competing feed use, livestock product quantities and food wastage, organic agriculture can feed more than 9 billion people in 2050, sustainably, and without vastly increasing the current land acreage under agriculture. Specifically, this translates to cutting food waste by half and eliminating competing feed sources for livestock altogether. Increasing organic yields and production, reducing food wastage, and reducing animal numbers and animal product consumption need not be implemented singly at maximal coverage. All could be implemented at partial coverage only and in combination, to achieve the improvements needed to increase sustainability of the global food system.
Since cutting down on meat drastically may be challenging for some, lead author Adrian Muller suggests the option where organic crops make up about 50% of crops, food waste is cut by half, and crops grown for livestock are cut by half (allowing for more acreage to grow human food); and putting an extra "nitrogen tax" on producers so that the environmental cost of excess fertilizer becomes an economic one (Item 2).
Organic production can also reduce greenhouse gas emissions. The role of land management in preventing dangerous levels of climate change has often been overlooked. A separate study, published in the Nature journal Scientific Reports, shows that there is great potential for the sequestration of carbon dioxide through changing the way soils are protected, through better farming methods that can also help to preserve declining soil fertility (Item 3).
STRATEGIES FOR FEEDING THE WORLD MORE SUSTAINABLY WITH ORGANIC AGRICULTURE
Muller, Christian Schader, Nadia El-Hage Scialabba, et al.
Organic agriculture is proposed as a promising approach to achieving sustainable food systems, but its feasibility is also contested. We use a food systems model that addresses agronomic characteristics of organic agriculture to analyze the role that organic agriculture could play in sustainable food systems. Here we show that a 100% conversion to organic agriculture needs more land than conventional agriculture but reduces N-surplus and pesticide use. However, in combination with reductions of food wastage and food-competing feed from arable land, with correspondingly reduced production and consumption of animal products, land use under organic agriculture remains below the reference scenario. Other indicators such as greenhouse gas emissions also improve, but adequate nitrogen supply is challenging. Besides focusing on production, sustainable food systems need to address waste, crop–grass–livestock interdependencies and human consumption. None of the corresponding strategies needs full implementation and their combined partial implementation delivers a more sustainable food future.
ORGANIC AGRICULTURE CAN HELP FEED WORLD, BUT ONLY IF WE EAT LESS MEAT AND STOP WASTING FOOD
Agriculture could go organic worldwide if we slashed food waste and stopped using so much cropland to feed livestock, a new study finds.
The analysis, published in the journal Nature Communications, shows that it will take several strategies operating at once to feed the growing human population in a more sustainable way - and some of those strategies may require people to shift their dietary patterns, too.
The world's population is expected to hit 9.8 billion by 2050, which means an extra 2 billion or so mouths to feed. This will require increasing agricultural output by an additional 50 percent, the study authors wrote - which is made an even greater challenge as dietary patterns have been changing and the demand for meat has been rising. (Raising livestock leaves a large carbon and water footprint relative to growing plant-based foods.) All of this puts an additional strain on an already taxed environment.
"It is, therefore, crucial to curb the negative environmental impacts of agriculture, while ensuring that the same quantity of food can be delivered," the study authors wrote.
Experts have thrown out several strategies to deal with the impending food security problem, without coming to a clear agreement on which one would be best. Among the options: improving efficiencies in producing crops and using resources; reducing food waste; cutting down the animal products we eat; or resorting to more organic agriculture.
"Organic agriculture is one concrete, but controversial, suggestion for improving the sustainability of food systems," the study authors wrote. "It refrains from using synthetic fertilizers and pesticides, promotes crop rotations and focuses on soil fertility and closed nutrient cycles."
Regardless of whether organic fruits, vegetables and other crops are better for you, there's evidence showing they may be better for the environment. Since organically grown crops can't use synthetic nitrogen fertilizer, it means that less excess nitrogen acidifies the soil and ends up in waterways, or escapes into the air as a greenhouse gas. It also means no man-made pesticides, meaning fewer chemicals in the local environment and less risk to insect biodiversity - which is important because many insects are crucial players in their local ecosystems.
But those benefits are offset somewhat by what's known as the yield gap: the idea that organic crops require more land because their yields are lower than the fertilizer-fed, pesticide-protected conventional crops - potentially resulting in some extra deforestation. Still, could organic crops allow future food needs to be met with less environmental impact?
"Because of the yield gap, there are opposing voices that say it's not possible ... (and) there are proponents that say this yield gap is not really important and one could overcome it," said lead author Adrian Muller, an environmental systems scientist at the Research Institute of Organic Agriculture in Switzerland. "We just wanted to look at it from a food-systems perspective, because we think only looking at the yield gap is not enough. It is important to really look at production and consumption together and to see what organic agriculture can contribute on such a food-systems level."
To find out, Muller and colleagues developed models based on data from the Food and Agriculture Organization of the United Nations, looking at the effects that going organic would have under different scenarios, modulating the severity of climate change, the amount of food waste and the share of crops used to feed livestock instead of people, for example.
The researchers found that the human population's needs could be fully met by all-organic agriculture - but only if food waste was cut in half and the competing feed sources for livestock were eliminated altogether. Since that would seriously scale back the amount of livestock, that might be a hard sell with today's meat-filled diets.
Muller said a more feasible solution might be one where organic crops make up about 50 percent of crops, food waste is cut by half, and the competing feed sources are cut by half (allowing for more acreage to grow human food).
"We need to utilize all the potential strategies we have, without supporting one extreme and leaving out other approaches," he said.
Getting to that point may still be a challenge. Organic crops make up a tiny fraction of agriculture overall, nowhere near that 50 percent target. But there are some things that can be done now, Muller pointed out, such as putting an extra "nitrogen tax" on producers so that the environmental cost of excess fertilizer becomes an economic one.
"I think we are moving in the right direction," Muller said, "and as an optimist I think, yeah, somehow, it will work."
SWITCHING TO ORGANIC FARMING COULD CUT GREENHOUSE GAS EMISSIONS, STUDY SHOWS
Converting land from conventional agriculture to organic production could reduce greenhouse gas emissions, the run-off of excess nitrogen from fertilisers, and cut pesticide use. It would also, according to a new report, be feasible to convert large amounts of currently conventionally farmed land without catastrophic harm to crop yields and without needing huge amounts of new land.
The study, published in the journal Nature Communications, found that by combining organic production with an increasingly vegetarian diet, ways of cutting food waste, and a return to traditional methods of fixing nitrogen in the soil instead of using fertiliser, the world’s projected 2050 population of more than 9 billion could be fed without vastly increasing the current amount of land under agricultural production.
This is important, as converting other land such as forests, cerrado or peatlands to agricultural use would increase greenhouse gas emissions from the land. The authors found that an increase in organic farming would require big changes in farming systems, such as growing legumes to replenish nitrogen in the soil.
However, other scientists were cautious over endorsing the report’s findings, pointing out that the size of the world’s agricultural systems and their variability, as well as assumptions about future nutritional needs, made generalisations about converting to organic farming difficult to make.
Sir Colin Berry, emeritus professor of pathology at Queen Mary, University of London, said: “As for all models, assumptions have to be made and what weight you attach to which item can greatly change outcomes. The assumption that grassland areas will remain constant is a large one. The wastage issue is important but solutions, not addressed here, to post-harvest- pre-market losses will be difficult without fungicides for grains. Some populations could do with more protein to grow and develop normally, despite the models here requiring less animal protein.”
Les Firbank, professor of sustainable agriculture at Leeds University, said: “One of the question marks about organic farming is that it can’t feed the world. [This paper] concludes organic farming does require more land than conventional methods, but if we manage the demand for food by reducing waste and reducing the amount of crops grown as animal feed, organic farming can feed the world.”
He warned: “[These] models can only be viewed as a guide: there are many assumptions that may not turn out to be true and all these scenario exercises are restricted by limited knowledge [and] are fairly simplistic compared to real life, but realistic enough to help formulate policy. The core message is valuable and timely: we need to seriously consider how we manage the global demand for food.”
Even without converting to organic production, however, the US, India, China and Russia – four of the world’s biggest greenhouse gas emitters – could turn into some of the biggest absorbers of carbon, through better management of their agricultural land.
A separate new study shows that these countries have the greatest potential for the sequestration of carbon dioxide through changing the way soils are protected, through better farming methods that can also help to preserve declining soil fertility.
Scientists said the potential of using soil as a carbon sink was equivalent to taking between 215m and 400m cars off the road, even if only small changes are made, of a kind which should be achievable on all farms. The study, published on Tuesday in the Nature journal Scientific Reports, and conducted by experts from the Chinese Academy of Science, the Nature Conservancy NGO, and the International Centre for Tropical Agriculture, found that farming crops differently could make a big contribution to achieving the goals of the Paris agreement on climate change.
Today’s intensive agricultural methods, involving frequent tilling of soils and the excessive use of chemical fertilisers, could be replaced with the revival of older methods such as the increased use of manure, cover cropping, mulching and growing trees next to cropland. However, the role of land management in preventing dangerous levels of climate change has often been overlooked at the talks, where discussions over the burning of fossil fuels have dominated. This is partly because of the urgency of switching away from fossil fuels, and partly because land management is a diffuse and diverse problem spread across the globe from small farmers to agri-industrialists, whereas fossil fuel sources tend to be larger and more monolithic, such as coal-fired power plants.
The results will be presented to delegates at the UN COP23 climate talks in Bonn on Wednesday. Nations at the talks are discussing ways to increase the commitments on emissions reductions made alongside the Paris agreement, and which scientists say are currently inadequate to hold the world to no more than 2C of warming, the binding target under the landmark 2015 accord.