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

Abstract

Aim 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.Location This study was conducted at the global scale.Methods 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' . ResultsWe 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.Main conclusions 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.

The representation of landscapes in global scale assessments of environmental change

“…The common 0.5°pixels classified by their dominant land cover are insufficient and can be replaced by units with a higher resolution. Many global studies now aim at a 5 arcminute (*10 9 10 km) spatial resolution consistent with many recent datasets (Monfreda et al 2008;Licker et al 2010;Neumann et al 2010;. This higher resolution leads to a much better representation of the variation in land cover and especially to a better representation of the smaller land cover types that are hardly ever dominant at the 0.5 degree resolution.…”

Solutions for a cultivated planet

“…The best places to improve crop yields may be on underperforming landscapes, where yields are currently below average. Recent analyses 57,58 have found large yield variations across the world, even among regions with similar growing conditions, suggesting the existence of 'yield gaps' (Supplementary Fig. 4a).…”

Association between Grain Size and Shape and Quality Traits, and Path Analysis of Thousand Grain Weight in Iranian Bread Wheat Landraces from Different Geographic Regions

“…With increasing world population, it has been estimated that the global demand for wheat will increase by a further 60% by 2050 (Licker et al, 2010). It is a huge challenge to ensure global food security through sustainable wheat production for the projected population with the increasing adverse impact of climate change (Palm et al, 2010).…”