Organic agriculture has a history of being contentious and is considered by some as an inefficient approach to food production. Yet organic foods and beverages are a rapidly growing market segment in the global food industry. Here, we examine the performance of organic farming in light of four key sustainability metrics: productivity, environmental impact, economic viability and social wellbeing. Organic farming systems produce lower yields compared with conventional agriculture. However, they are more profitable and environmentally friendly, and deliver equally or more nutritious foods that contain less (or no) pesticide residues, compared with conventional farming. Moreover, initial evidence indicates that organic agricultural systems deliver greater ecosystem services and social benefits. Although organic agriculture has an untapped role to play when it comes to the establishment of sustainable farming systems, no single approach will safely feed the planet. Rather, a blend of organic and other innovative farming systems is needed. Significant barriers exist to adopting these systems, however, and a diversity of policy instruments will be required to facilitate their development and implementation.
Organic agriculture has a history of being contentious. Emblematic of this, and representing the prevailing attitudes of many farmers and scientists in the 1970s and 1980s, are the unsympathetic words uttered in 1971 by then US Secretary of Agriculture Earl Butz: “Before we go back to organic agriculture in this country, somebody must decide which 50 million Americans we are going to let starve or go hungry”1. At the turn of the twenty-first century, sceptics considered organic agriculture to be ideologically driven and inefficient2,3. They argued that organic agriculture relies on more land to produce the same amount of food as conventional agriculture and that adopting organic agriculture on too large a scale could potentially threaten the world's forests, wetlands and grasslands2,3. They also asserted that organic agriculture has too many shortcomings and poor solutions to agricultural problems2,4. Organic agriculture is still considered by some critics as being an inefficient approach to food security5,6 and a farming system that will become less relevant in the future6.
Yet the number of organic farms, the extent of organically farmed land, the amount of research funding devoted to organic farming and the market size for organic foods have steadily increased7. Sales of organic foods and beverages are rapidly growing, increasing almost fivefold between 1999 and 2013 to US$72 billion (ref. 7; Fig. 1); this 2013 figure is projected to double by 2018. Moreover, recent international reports recognize organic agriculture as an innovative farming system that balances multiple sustainability goals and will be of increasing importance in global food and ecosystem security8,9,10.
Here, we review the performance of organic farming systems in the context of sustainability metrics and global challenges, and examine some of the barriers to the adoption of organic farming systems and the policies needed to overcome them.
Organic practices and certification
Organic agriculture, sometimes called biological or ecological agriculture, combines traditional conservation-minded farming methods with modern farming technologies. It emphasizes rotating crops, managing pests naturally, diversifying crops and livestock, and improving the soil with compost additions and animal and green manures (Fig. 2). Organic farmers use modern equipment, improved crop varieties, soil and water conservation practices, and the latest innovations in feeding and handling livestock. Organic farming systems range from strict closed-cycle systems that go beyond organic certification guidelines by limiting external inputs as much as possible to more standard systems that simply follow organic certification guidelines.
Rudolf Steiner's 1924 course on biodynamic agriculture sparked the evolution of organic agriculture in Europe1. Organic agriculture was established in its own right in the 1930s and 1940s, being developed in Britain by Lady Eve Balfour and Sir Albert Howard, in Switzerland by Hans Mueller, in the United States by J. I. Rodale and in Japan by Masanobu Fukuoka1. By the 1970s, organic foods had grown in popularity, prompting the first organic certification standards to be drafted in Europe and the United States, and commencing an ongoing evolution of certifiers that now includes 283 organic certification bodies worldwide operating in 170 countries7. This proliferation of certifiers reflects both a complex history of sometimes competing independent standards and the demand for access to certifiers around the world.
Many farms in both developed and less-developed countries implement organic practices but are not certified organic. However, growers are increasingly turning to certified organic farming systems as a way to provide verification of production methods, decrease reliance on non-renewable resources, capture high-value markets and premium prices, and boost farm income. Although requirements vary slightly between certifying agencies, they promote soil quality, crop rotations, animal and plant diversity, biological processes, and animal welfare, while generally prohibiting irradiation, sewage sludge, genetic engineering, the prophylactic use of antibiotics, and virtually all synthetic pesticides and fertilizers. Standards continue to evolve with changing technologies and socioecological conditions; some requirements are based on scientific evidence, whereas others are driven by ideology.
As most certification standards originated in temperate developed countries, they are not always applicable in other regions, especially in less-developed countries. High demand for organic foods in Europe and North America has resulted in the import of organic foods from large farms in less-developed countries7. Although premium prices for exported foods may be beneficial to farmers, the inaccessibility of many of these foods to local consumers raises questions about food security and social equity. Participatory guarantee systems, which rely on local stakeholder verification, have emerged as a more locally focused alternative to traditional certification7, and could lead to the development of more locally relevant visions for the production and consumption of organic foods.
Sustainability of organic agriculture
About 38% of Earth's land cover is occupied by agriculture11. Although agriculture provides growing supplies of food and other products, it is a major contributor to greenhouse gases, biodiversity loss, agrochemical pollution and soil degradation12,
According to a US National Academy of Sciences report10, any farm, be it organic or conventional, can only be deemed sustainable if it produces adequate amounts of high-quality food, enhances the natural-resource base and environment, is financially viable, and contributes to the wellbeing of farmers and their communities. With the rise of organic farming in the past two decades, hundreds of research studies comparing different aspects of organic and conventional farming systems have been published. This section focuses on assessing such comparison studies across these four sustainability areas.
Production. Production includes crop and animal yield and their quality. Numerous individual studies have compared yield differences between organic and conventional systems. These data have been synthesized in several meta-analyses or reviews; according to these studies, yield averages are 8 to 25% lower in organic systems15,
Although meta-analysis is a great tool that can describe broad patterns not immediately visible in primary field research19,20, it must also be treated with caution, because no single farming system or practice works best everywhere. Still, these studies15,
Whereas organic systems yield less food, organic foods have significantly less to no synthetic pesticide residues compared with conventionally produced foods25,
At least 15 reviews or meta-analyses26,27,32,
Environment. Reviews and meta-analyses generally support the perception that organic farming systems are more environmentally friendly than conventional farming systems45,
As organic agriculture uses virtually no synthetic pesticides, there is little to no risk of synthetic pesticide pollution of ground and surface waters46. With respect to nitrate and phosphorous leaching and greenhouse gas emissions, organic farming systems score better than conventional farming when expressed per unit production area46,49,51,57,58; however, given the lower land-use efficiency of organic farming in developed countries, this positive effect is less pronounced and in some cases reversed when expressed per unit product49,57,58. In a meta-analysis of environmental quality parameters, organic farms were found to have lower nitrate leaching, nitrous oxide emissions and ammonia emissions per unit of field area, but higher leaching and emissions per unit product48. Severe degradation of freshwater and marine ecosystems around the world is linked to excessive use of nitrogen and phosphorous fertilizers12,59, leading to eutrophication of freshwater and the production of hypoxic zones in coastal waters. Lower nutrient pollution from organic compared with conventional systems can be illustrated by differences in their nitrogen cycling and losses (Fig. 3).
Organic systems are usually more energy efficient than their conventional counterparts46,
Economics. Whether organic agriculture can continue to expand globally will primarily be determined by its financial performance compared with conventional agriculture17,60. The main factors that determine the profitability of organic agriculture include crop yields, labour and total costs, price premiums for organic products, the potential for reduced income during the organic transition period (usually three years), and potential cost savings from the reduced reliance on non-renewable resources and purchased inputs61.
To the best of our knowledge, only one meta-analysis has analysed the financial performance of organic and conventional agriculture20. The analysis combines findings from 40 years of studies covering 55 crops grown on five continents. When actual price premiums (higher prices awarded to organic foods) were included, organic agriculture proved significantly more profitable (22 to 35% greater net present values) and had higher benefit/cost ratios (20 to 24%) than conventional agriculture. When organic premiums were taken away, net present values (−27 to −23%) — net returns accounting for the time value of money — and benefit/cost ratios (−8 to −7%) of organic agriculture were significantly lower than conventional agriculture20.
Although price premiums were 29 to 32%, breakeven premiums necessary for organic profits to match conventional profits were only 5 to 7%, even with organic yields being 10 to 18% lower. The size of organic premiums awarded, and the difference between organic premiums and breakeven premiums, were consistent during the 40-year study period. The fact that organic premiums were significantly higher than breakeven premiums suggests that organic agriculture can continue to expand even if premiums decline. The study also found that total costs were not significantly different, but labour costs were significantly (7 to 13%) higher with organic farming practices20. Although one of the successes of conventional agriculture has been its ability to produce more with less labour, some have found the extra labour of organic agriculture to be beneficial in providing rural employment and development opportunities62,63.
Few economic studies have accounted for negative externalities (such as environmental costs) or positive externalities (such as ecosystem services), with associated monetary values, in organic and conventional comparison studies. Putting a price on the negative externalities caused by farming, such as soil erosion or nitrate leaching into groundwater, would make organic agriculture even more profitable, given that its environmental impact is less than that of conventional agriculture45,
A number of studies (for example, refs 65,66) have compared ecosystem services in organic and conventional farming systems. A few of these studies have accounted for the monetary value of ecosystem services; these studies generally show that conventional practices decrease the ability of farms to provide some economically significant ecosystem services relative to organic practices67,
Wellbeing. How well organic, conventional and other farming systems are performing in areas such as social equity (for instance, issues of gender, race, ethnicity and class) and quality of life for farm families and communities remains unclear due to limited research. Available data indicate that both organic and conventional farming systems need to make significant progress to meet social sustainability goals10. However, organic farming has been shown to have some sociocultural strengths, such as positive shifts in community economic development, increased social interactions between farmers and consumers71,72, and greater employment of farm workers and cooperation among farmers62,63.
Although organic farming often requires additional manual work on the farm, it reduces the exposure of farm workers to pesticides and other chemicals. Such exposure can be particularly problematic in less-developed countries, where illnesses and death have resulted from occupational and accidental exposure (due in part to the fact that it is impractical and expensive for workers to use safety equipment)73,74.
Organic certification programmes have adopted social wellbeing goals. Guidelines of the International Federation of Organic Agriculture Movements (IFOAM) stipulate that organic farmers should be able to support themselves and other workers with fair incomes, while maintaining safe and dignified working conditions75. Furthermore, organically certified animals must be raised humanely under conditions that allow for the expression of their natural behaviours and needs75. For example, European Union, US and Japanese rules on organic production require livestock to have access to open air or grazing whenever possible, and that sick animals be treated as needed, even with the use of antibiotics if required76,
Organic farming can improve food security by diversifying on-farm crop and livestock operations, which diversifies income sources and improves variety in diets79. Organic farming necessitates diverse crop and livestock rotations, encourages the integration of multiple farm enterprises and encourages the use of leguminous crops for biological nitrogen fixation. By growing a higher diversity of more nutrient-rich (such as vegetables) and more protein-rich (such as legumes and meats) foods, whether for export or subsistence, a farmer has access to at least a portion of these foods. For example, following 840 small organic and non-organic farms in the Philippines, researchers found the increase in vegetable and protein consumption from 2000 to 2007 to be two to three times greater for the more diversified organic farmers than conventional farmers80.
Balancing sustainability metrics. Some argue that significantly scaling-up organic land area may increase nitrogen and other nutrient limitations on yields17, and question whether the greater land area required by organic agriculture to maintain yields counteracts its environmental gains2,3. Probably the biggest criticism of organic agriculture is its lower yields compared with conventional agriculture4,5, a particularly salient challenge given the task of feeding a growing world population without further agricultural expansion13. Conversely, some contend that the environmental advantages of organic agriculture far outweigh the lower yields, and that increasing research and breeding resources for organic systems would reduce the yield gap16,17,24,81. Others suggest that multifunctional farming systems, such as organic, coupled with more plant-based diets and reduced food waste, are necessary elements of a more sustainable food system16,54,65. Sometimes excluded from these arguments is the fact that we already produce adequate kilocalories of food to more than feed the world but do not provide adequate access to all individuals82. Globally, 1.9 billion adults are overweight and of these 600 million are obese83, while 793 million people are undernourished and more than 28% of children under the age of five are stunted due to malnourishment82,84.
Debates aside, although yield is an important sustainability metric, the issue is more complicated than kilograms of food per hectare. Mainstream conventional farming systems have provided growing supplies of food and other products but often at the expense of the other three sustainability goals. Environmental degradation, public health problems, loss of crop variety and genetic biodiversity, and severe impacts on ecosystem services have not only accompanied conventional farming systems but have often extended well beyond their field boundaries. Such negative externalities are not accounted for.
The performance of organic farming systems in the context of sustainability metrics indicates that they better balance multiple sustainability goals than their conventional counterparts (Fig. 4). Based on present evidence, we argue that although organic farming systems produce lower yields compared with conventional agriculture, they are more profitable and environmentally friendly, and deliver equal or more nutritious foods with less to no pesticide residues. In addition, initial evidence indicates that organic agriculture is better at enhancing the delivery of ecosystem services, other than yield, as well as some social sustainability benefits. Importantly, the body of research studies has been heavily biased towards developed countries, whereas studies in the less-developed world, especially in tropical and subtropical climates, need to be greatly increased.
With only 1% of global agricultural land in organic production7, and with its multiple sustainability benefits, organic agriculture can contribute a larger share in feeding the world. Yet, significant barriers to farmers adopting organic practices remain in both developed and less-developed countries.
Barriers and policies
Obstacles to farmers adopting organic agriculture include powerful vested interests and existing policies, a lack of information and knowledge, weak infrastructure and other economic challenges, and misperceptions and cultural biases (Fig. 5). Global and national agribusiness corporations, agrochemical industries, commodity groups and food companies have a strong vested interest in the conventional agroindustrial model, command ever-greater market power in the food system and have heavily influenced public policy to favour this model10,85. The consolidation of industries, the concentration of market power, and many past and current agricultural policies have led to decreased agricultural diversity10 and have disincentivized agricultural innovation81.
Considerably less public and private funding has been put towards research and development for organic systems than towards conventional systems worldwide; this has resulted in a lack of crop and livestock breeding for organic farming conditions and a dearth of knowledge and information resources supporting organic farmers17,19. Historically, public funding for research on organic systems has been higher in Europe than in the United States7. Moreover, research on organic agriculture in less-developed countries represents only a small fraction of the overall scientific literature on the topic17,19,52.
Some farmers face infrastructure and economic barriers, which include certification costs and access to markets, loans and insurance. Many areas, especially rural regions and less-developed countries, lack access to additional labour, markets for organic foods, infrastructure for storage and distribution, or appropriate certification requirements86,87. Finally, strong cultural biases against the connotations of organic agriculture, and conventional mindsets held by some individuals and organizations, limit the spread of organic practices86,87.
With these obstacles in mind, governments should focus on creating an enabling environment for the development and adoption of not just organic but also other innovative and more sustainable farming systems88. These efforts must be targeted at improving agricultural performance in all four areas of sustainability and will require a diversity of knowledge-based, legal and financial policy instruments89.
Knowledge-based policy instruments are needed to create an enabling environment for agricultural innovation, education and outreach. Specifically, policy instruments must: ensure farmer and scientist engagement in research and development decision-making; improve farmer knowledge and capacity through effective extension and outreach infrastructure, such as the use of farmer field schools and communication technologies; and enhance women's educational and leadership opportunities90.
Legal instruments must play a stronger role in ensuring open and competitive markets, limiting commercial influence in government and increasing transparency in the food production system. In addition, they are needed to reduce food waste, to improve the security of land tenure for farmers, and to develop national targets for trade policies that promote food and ecosystem security.
Financial instruments are needed to give monetary value to the externalities that arise from agricultural practices and to empower farmers through access to capital, infrastructure and competitive markets88. In developed countries, direct and indirect crop subsidies and biofuel incentives should be replaced by targeted agro-environmental incentives, such as payments for biodiversity protection and soil conservation. Some policy organizations have found that raising the costs of fossil fuels, irrigation water and other limited resources strongly encourages more efficient farming systems91. In less-developed countries, targeted input subsidies and investment in rural infrastructure are key financial instruments. For example, subsidizing organic nutrient inputs alongside mineral fertilizer inputs for the poorest farmers can be an effective strategy for increasing yields and building soils92.
More than 40 years after Earl Butz's comment, we are in a new era of agriculture, as reflected in the words of current US Secretary of Agriculture Tom Vilsack: “Organic agriculture is one of the fastest growing segments of American agriculture and helps farmers receive a higher price for their product as they strive to meet growing consumer demand”93. Moreover, organic agriculture has been able to provide jobs, be profitable, benefit the soil and environment, and support social interactions between farmers and consumers.
Although organic agriculture has an untapped potential role in global food and ecosystem security, no one farming system alone will safely feed the planet. Rather, a blend of organic and other innovative farming systems, including agroforestry, integrated farming, conservation agriculture, mixed crop and livestock, and still undiscovered systems, will be needed for future global food and ecosystem security. For example, integrated farming systems that blend mostly organic with some conventional practices have been shown to be more sustainable than conventional farming systems94,95 and are likely to play a central role. Achieving global food and ecosystem security requires more than just achieving sustainable farming systems worldwide. We need to reduce food waste, improve food distribution and access, stabilize the human population, eliminate the conversion of food into fuel, and change consumption patterns towards a more plant-based diet.
Equal adherence to all four sustainability goals of production, environment, economics and social wellbeing does not limit but encourages farmers and researchers to innovate. The challenge facing policymakers is to create an enabling environment for scaling-up organic and other innovative farming systems to move towards truly sustainable production systems. This is no small task, but the consequences for food and ecosystem security could not be bigger. To make this happen will require mobilizing the full arsenal of effective policies, scientific and socioeconomic advances, farmer ingenuity and public engagement.
J.M.W. is supported by NSF-IGERT (0903714) and USDA-NIFA (230470).