Modern agricultural science has changed food production systems in dramatic ways, and this green revolution has yielded much to be grateful for. Globally, crop yields have increased dramatically over the past 50 years. We’ve also seen a steady decline in global hunger and undernutrition, despite the fact that the human population doubled between 1950 and 1987.
Despite its many gains, the agricultural revolution of the mid 20th century was far from perfect. There were, for example, geographic disparities in the degree to which the positive impacts of the green revolution were felt. Improvements in agricultural production were concentrated in areas that are already well-suited to agriculture, with marginal agricultural areas benefiting much less. And today the problem of hunger is still nowhere near solved – an estimated 11% of our global human family, over 820 million people, remain undernourished, with women and children experiencing the greatest suffering.
The intensification of agricultural production has also come with very serious environmental costs, as I outlined in my third blog, and those environmental impacts undermine the ability of agricultural lands to be productive at the same rates as they have in the past. Climate change is already impacting agricultural yields globally due to increased flooding and droughts, and it is also exacerbating the already serious problem of soil erosion which puts at risk our ability to grow many of the crops we rely on.
We need a new green revolution – one that is focused not only on optimising crop yields and nutrition to feed a growing population, but also on decreasing the environmental impacts and resource consumption of food production systems to levels that can be sustained within the planet’s biophysical limits. Scientists and farmers around the world are working hard to figure out just what this new revolution will look like, but many questions remain. The tricky truth is that solutions will look very different at different geographic scales and across different crops and growing conditions, and debates between different research and farming communities can be quite bitter and entrenched. Add to this uncertainty the machinations of global agri-food corporate behemoths, and the picture begins to look very muddy indeed.
One alternative production system that emerged in reaction to the conventional agricultural systems of the green revolution is organic agriculture. Organic agriculture rejects many industrial agricultural practices, in favour of a system that addresses toxicity (human and ecological) as well as soil and water quality, and on-farm biodiversity conservation. Organic agricultural standards restrict the use of synthetic fertilizers and pesticides, GMOs, and nano technologies. They also prohibit the full confinement of livestock. Certain alternative farming practices are encouraged, including the use of composted animal and plant matter, as well as green manure, for fertilizer, extensive crop rotations for pest control and soil health, buffer zones between agricultural activity and water ways to protect water quality, buffer zones between organic farms and non-organic operations, humane treatment of animals (access to exercise, grazing, sun, fresh air, etc.), and diversified agro-ecological landscape.
Organic agriculture’s share of the global agriculture market and total agricultural land is small, but it is growing steadily. Concern among both producers and consumers about the impacts of conventional agriculture is driving this growth, and many consumers believe that organic foods are more healthy and more environmentally sustainable.
But is organic agriculture really the answer? Can we scale up organics now, feed the ten billion people expected to be alive by 2050, and see to it that the environmental ills of conventional agriculture are addressed? Systematic analyses of the environmental performance of organic systems as compared to their conventional counterparts are attempting to answer that very question. Their findings show that organics performs quite well with respect to some impacts, but not necessarily others, and concerns are being raised about whether organic agriculture provides an easy solution for a sustainable food future.
A recently published systematic review examining the costs and benefits of organic agriculture provides an important and balanced assessment of how organic agriculture systems are performing across a number of social, economic, and environmental dimensions. They find that organic systems are consistently better performing in addressing human and environmental toxicity, soil quality and structure, and improving on-farm biodiversity. They also find, however, that when impacts are expressed per unit of food output, total greenhouse emissions of organic systems tend to be comparable or higher than their conventional counterparts. Similarly, nutrient losses are sometimes lower but are often higher when expressed per unit of food output. This leaching pollutes waterways with excess nutrients, causing algal blooms and frequently leading to dead zones devoid of oxygen, also referred to as eutrophication. It should be noted that greenhouse gas and nutrient emission data for both conventional and organic production systems are highly variable and uncertain, because these emissions to soil, air, and water are highly impacted by climate, soil type, and management practices.
A recent study that modelled a scenario scaling up organic production to supply the country of Sweden found that scaling up organics in Sweden was likely to result in lower toxicity, but that GHG emissions would likely be similar, and the amount of land use and eutrophication would likely increase.
Another study modelled the potential impacts of a wholesale conversion to organic agriculture in England and Wales. On the one hand, they found that large scale conversion to organics would likely result in local benefits, including greater carbon storage in soils and increased on-farm biodiversity. On the other hand, this study suggests that a wholesale conversion to organics England and Wales could result in a net global increase in GHG emissions, due to the expansion of agricultural production in other regions to make up for lower domestic yields under organic management. They also caution that conversion to organic agriculture would likely result in greater land use, putting biodiversity at greater risk due to habitat loss.
The reason that organic agricultural systems are potentially not performing as well with respect to climate change impacts, eutrophication, and land use can be traced back to a single issue that continues to plague organic production systems; organic systems consistently produce smaller yields than their conventional counterparts. Yields under organic management are on average 19-25% lower, with significant variability across different crop types, plant types and crop species.
Figure source: Seufert, V., Ramankutty, N., & Foley, J. (2012). Comparing the yields of organic and conventional agriculture. Nature, 485: 229-234.
Lower yields means that more land is needed to produce food under organic management. The organic yield gap also means total GHG and nutrient emissions are likely to be higher in lower yield organic systems than conventional systems, when these impacts are expressed per unit of food output. Proponents of organic agriculture have argued passionately that measuring the environmental impacts of organic systems per unit of food produced does not sufficiently reflect the benefits of organic farms as biodiverse landscapes. I am sympathetic to these arguments, to a point, because I share their concerns about toxic pollution, soil losses and the many other ills of conventional agriculture, and in many ways organic agriculture has provided important insights into addressing agriculture’s impacts. That said, I feel just as strongly that if we are going to assess the fitness of agricultural systems to help mitigate environmental issues (especially climate change and biodiversity), while also meeting the goal of feeding our entire human family, then we must model agricultural landscapes as existing first and foremost for the purpose of food production. If we agree with this argument, then production yields matter very much indeed.
Examining the case of organics illustrates nicely that creating a production system that focuses narrowly on just a couple of impacts can miss important trade-offs occurring elsewhere. Organic agriculture exists to mitigate local toxic impacts, and impacts to soil and on-farm biodiversity, but a massive scaling up of organic production could result in trade-offs impacting the climate and biodiversity at a global scale.
Just as food is not only nourishment but also a rich expression of culture, so too is the art and science of food production. Many brilliant and creative ideas for shifting food production to be more sustainable are being explored, trialed, and advocated for, and passions are running high. Among the many possible alternatives to conventional production, I’ve chosen to use this space to explore some of the costs and benefits of organic agriculture, but many other alternatives are being proposed. Modelling agricultural systems involves contending with many complexities and uncertainties, but it is nonetheless clear that there are many questions that need to be answered in order to determine whether organic production, and other alternative systems, can be scaled up to meet the needs of a growing population. Can enough food be produced? Is the yield gap likely to increase or decrease? If the yield gap cannot be overcome, would we see greater biodiversity losses due to greater land requirement? And higher rates of greenhouse gas emissions and nutrient leaching?
It seems to me that, if neither conventional nor organic agriculture satisfies all of our criteria for sustainable agriculture, we are perhaps asking the wrong questions in comparing conventional and organic systems. In tackling bigger, more complex questions about what the next green revolution and the future of agriculture should look like, we need to learn lessons from many different contemporary production systems. Solutions will need to be applied according to what works well in a local context, but we must also then assess these solutions based on their contribution to both local and global scale impacts. And at all times we must remember: every human deserves to get enough to eat, and we must address our failure to feed our entire human family. It’s a massive challenge that requires open-mindedness, creativity, ingenuity, and the cooperation of a global network of concerned scholars, farmers, consumers, and politicians.
Photo by Heiko Janowski on Unsplash
