Wednesday, January 17, 2018

Yes we can – feed 9 billion with organic agriculture

It is possible to feed more than 9 billion people with organic production methods with a small increase in the required crop acreage and with decreased greenhouse gas emission. But this assumes considerable reduction in food wastage and in the quantities of feed grown to animals.

Picture: Ann-Helen Meyer von Bremen
That is the conclusion in the paper Strategies for feeding the world more sustainably with organic agriculture in Nature communications by researchers from the Research Institute of Organic Agriculture in Switzerland, the Institute of Environmental Decisions in Switzerland. Food and Agriculture Organization of the United Nations (FAO) in Italy, Institute of Social Ecology Vienna in Austria and the Institute of Biological and Environmental Sciences in the UK.

The research builds on assumptions of a 25% reduction in yield with organic methods, the continued increase in global population up to more than 9 billion 2050 as well as different scenarios of impact of climate change on agriculture yields. The model doesn’t assume any change in the area used for grazing. The researchers acknowledge that different research show big variation in the ”yield gap” between organic and conventional. It is primarily research from Europe that shows big yield gaps, while other studies show much smaller gaps, if any. In general their assumptions are conservative and could hardly be accused of being biased in favour of organic.

Obviously, if consumption patterns are equal and yields are lower and population increases, more land would be needed with a large-scale conversion to organic agriculture. But if food waste is reduced with 50% and this is combined with a 50% reduction in the use of human-edible crops as animal feed, less land would be used compared to a reference scenario (the assumed population, consumption and production as per 2050 in FAO:s analysis) – still more than today though.

The biggest agronomic challenge for such a large scale conversion to organic would be the supply of nitrogen. On the up-side of that, the reactive nitrogen overload of the whole biosphere, one of the biggest changes in local and global biological cycles, would be reduced and gradually disappear. The researchers acknowledge that recycling of human waste and food waste into the agriculture system could reduce the nitrogen deficiency in agriculture, but they have not included that in the model.

The exclusion of synthetic fertilizers leads to big reductions of greenhouse gas emissions, as both the use and production of nitrogen fertilizers are major causes for emissions. Emissions from ruminants (cows, sheep and goats) will increase somewhat as their total numbers will increase (but less than the increase of population). Similarly, the greenhouse gas emissions from rice cultivation will increase because of more rice being produced.  

The combination of the lower yields and the increase of leguminous plants (beans etc) in order to fix nitrogen makes the availability of animal feed lower. So the decreased use of human-edible crops as feed for animals is rather a production necessity than something triggered by consumption changes. The reduction of animals will mainly be for monogastric animals such as pigs and chicken as they are the ones that mainly eat human-edible crops.

The results of the study coincides with similar results on a national and regional level. For instance, researchers from the Nordic countries concluded that it would be possible to feed between 31 and 37 million people (compared to the current 26 million) in the Nordic countries with organically produced food assuming substantial reduction in meat consumption.

One can claim that the results also show that you can’t convert the agriculture system to organic without increasing the cultivated lands considerably. Because, despite the conclusions of the authors, that is also a result from their scenarios. If nothing else is changed land demand will increase with 33%.  

Ultimately, all this modelling and scenario-building has limited value and the results are very much fixed by the assumptions and input data. The food system is a dynamic system where you can’t change just one or two parameters and keep the rest the same. But models and scenarios can still help us to identify certain critical conditions.

The choice of the authors to change food wastage and the proportion of food fed to animals is a rather reasonable choice and not taken out of the blue. One can assume that food will become more expensive with a large-scale conversion to organic and that will reduce waste considerably. Similarly, using human-edible food as feed for animals will be less interesting from a commercial perspective when they become more expensive. The dramatic increase of consumption of pig and chicken meat is as much a result of cheap grains and soy beans as of consumer demand.  The increased consumption of pulses to compensate for the reduction of meat coincide with a need to increase the cultivation of such crops to adjust to nitrogen shortages.

There are also other assumptions that could be included in models. The total calories produced under the scenarios are far above what people need to eat and as obesity is now a big global problem, one could have reduced calories available and thus be able to show even better results AND an improved health status of the world’s population. Improvements in the utilization of grasslands could also have been a parameter to consider.

Finally, the economic feedback loops are very important. There are several ways to increase yields in agriculture, of which the use of chemical fertilizers and pesticides are just two. They are admittedly important, but one can increase productivity by deploying more work, other nature resources (e.g. water), by switching crops or taking more crops per year. What is done is mainly determined by economic factors. Very few farms, organic or non-organic, produce at their maximum, but they produce what is optimal given prices of factors of production and output prices. In most cases, production per person has been much more important that production per unit of land. But in a world with limited land resources and 9 billion people, this will sooner or later change.

So yes, we can. If we want to.

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