Mind the gap: how do climate and agricultural management explain the 'yield gap' of croplands around the world

• Published in: Global ecology and biogeography Vol. 19; no. 6; pp. 769 - 782
• Main Authors: Licker, Rachel, Johnston, Matt, Foley, Jonathan A., Barford, Carol, Kucharik, Christopher J., Monfreda, Chad, Ramankutty, Navin
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.11.2010; Blackwell Publishing Ltd; Blackwell Publishing; Blackwell
• Subjects: Agricultural land; Agricultural management; agricultural system; Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; climate; Climatic zones; Corn; Crop ecology; Crop production; crop yield; cropland; Crops; Energy crops; Food crops; Fundamental and applied biological sciences. Psychology; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; General aspects; Generalities. Agricultural and farming systems. Agricultural development; global; global land use; land management; Sustainable agriculture; Synecology; yield gap; World; Climate; Agricultural system; yield gap; Biogeography; Farmland; Ecology; global; Agricultural land; Environmental management; Land use; crop yield; global land use; Land management; Agriculture; Yield; cropland; Land development
• ISSN: 1466-822X; 1466-8238
• DOI: 10.1111/j.1466-8238.2010.00563.x

As the demands for food, feed and fuel increase in coming decades, society will be pressed to increase agricultural production - whether by increasing yields on already cultivated lands or by cultivating currently natural areas - or to change current crop consumption patterns. In this analysis, we consider where yields might be increased on existing croplands, and how crop yields are constrained by biophysical (e.g. climate) versus management factors. This study was conducted at the global scale. Using spatial datasets, we compare yield patterns for the 18 most dominant crops within regions of similar climate. We use this comparison to evaluate the potential yield obtainable for each crop in different climates around the world. We then compare the actual yields currently being achieved for each crop with their 'climatic potential yield' to estimate the 'yield gap'. We present spatial datasets of both the climatic potential yields and yield gap patterns for 18 crops around the year 2000. These datasets depict the regions of the world that meet their climatic potential, and highlight places where yields might potentially be raised. Most often, low yield gaps are concentrated in developed countries or in regions with relatively high-input agriculture. While biophysical factors like climate are key drivers of global crop yield patterns, controlling for them demonstrates that there are still considerable ranges in yields attributable to other factors, like land management practices. With conventional practices, bringing crop yields up to their climatic potential would probably require more chemical, nutrient and water inputs. These intensive land management practices can adversely affect ecosystem goods and services, and in turn human welfare. Until society develops more sustainable high-yielding cropping practices, the trade-offs between increased crop productivity and social and ecological factors need to be made explicit when future food scenarios are formulated.