Journal Article

Comparing the yields of organic and conventional agriculture

Ramankutty, Navin, Foley, Jonathan A., Seufert, Verena

2012

Overview

A meta-analysis assessing the relative yields of organic and conventional agriculture shows that organic yields are on average lower, but that the magnitude of the difference is dependent on context. Crop yields compared There is much debate over the relative merits of conventional farming, which has a large environmental impact on the land it uses, and organic farming, which may require greater land use for the same yield. Central to this debate — and the subject of some controversy — are the relative yields of the two farming systems. Seufert et al . present a meta-analysis of the available scientific literature on organic-to-conventional yield comparisons, and conclude that organic yields are indeed lower, but that the difference varies substantially according to crop type, growing conditions and management practices. For instance, for perennials grown on favourable soils organic yields are just 5% lower than conventional yields, but the yield difference between the most comparable conventional and organic systems is as high as 34%. The authors conclude that the factors that limit organic yields need to be better understood to enable meaningful comparisons between the rival forms of agriculture. Numerous reports have emphasized the need for major changes in the global food system: agriculture must meet the twin challenge of feeding a growing population, with rising demand for meat and high-calorie diets, while simultaneously minimizing its global environmental impacts 1 , 2 . Organic farming—a system aimed at producing food with minimal harm to ecosystems, animals or humans—is often proposed as a solution 3 , 4 . However, critics argue that organic agriculture may have lower yields and would therefore need more land to produce the same amount of food as conventional farms, resulting in more widespread deforestation and biodiversity loss, and thus undermining the environmental benefits of organic practices 5 . Here we use a comprehensive meta-analysis to examine the relative yield performance of organic and conventional farming systems globally. Our analysis of available data shows that, overall, organic yields are typically lower than conventional yields. But these yield differences are highly contextual, depending on system and site characteristics, and range from 5% lower organic yields (rain-fed legumes and perennials on weak-acidic to weak-alkaline soils), 13% lower yields (when best organic practices are used), to 34% lower yields (when the conventional and organic systems are most comparable). Under certain conditions—that is, with good management practices, particular crop types and growing conditions—organic systems can thus nearly match conventional yields, whereas under others it at present cannot. To establish organic agriculture as an important tool in sustainable food production, the factors limiting organic yields need to be more fully understood, alongside assessments of the many social, environmental and economic benefits of organic farming systems.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 631/449/447 / Agricultural and farming systems / Agricultural Irrigation / Agriculture / Agriculture - methods / Agronomy. Soil science and plant productions / Alkaline soils / Animals / Biodiversity loss / Biological and medical sciences / Biomass / Confidence intervals / Conservation of Natural Resources - methods / Crops, Agricultural - classification / Crops, Agricultural - growth & development / Deforestation / Developed Countries / Developing Countries / Ecology / Ecosystem / Environmental aspects / Environmental impact / Farming systems / Food / Food production / Food supply / Food Supply - statistics & numerical data / Food, Organic - supply & distribution / Forestry / Fundamental and applied biological sciences. Psychology / General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping / General agronomy. Plant production / Generalities. Agricultural and farming systems. Agricultural development / Humanities and Social Sciences / Humans / Hydrogen-Ion Concentration / letter / Meta-analysis / multidisciplinary / Organic Agriculture - methods / Organic farming / Population Growth / Science / Science (multidisciplinary) / Soil - analysis / Soil - chemistry / Studies / Sustainable agriculture / Sustainable food systems / Sustainable production / Systematic review / Time Factors / Yield