Aim This study makes quantitative global estimates of land suitability for cultivation based on climate and soil constraints. It evaluates further the sensitivity of croplands to any possible changes in climate and atmospheric CO2 concentrations.
Location The location is global, geographically explicit.
Methods The methods used are spatial data synthesis and analysis and numerical modelling.
Results There is a cropland ‘reserve’ of 120%, mainly in tropical South America and Africa. Our climate sensitivity analysis indicates that the southern provinces of Canada, north‐western and north‐central states of the United States, northern Europe, southern Former Soviet Union and the Manchurian plains of China are most sensitive to changes in temperature. The Great Plains region of the United States and north‐eastern China are most sensitive to changes in precipitation. The regions that are sensitive to precipitation change are also sensitive to changes in CO2, but the magnitude is small compared to the influence of direct climate change. We estimate that climate change, as simulated by global climate models, will expand cropland suitability by an additional 16%, mainly in the Northern Hemisphere high latitudes. However, the tropics (mainly Africa, northern South America, Mexico and Central America and Oceania) will experience a small decrease in suitability due to climate change.
Main conclusions There is a large reserve of cultivable croplands, mainly in tropical South America and Africa. However, much of this land is under valuable forests or in protected areas. Furthermore, the tropical soils could potentially lose fertility very rapidly once the forest cover is removed. Regions that lie at the margins of temperature or precipitation limitation to cultivation are most sensitive to changes in climate and atmospheric CO2 concentration. It is anticipated that climate change will result in an increase in cropland suitability in the Northern Hemisphere high latitudes (mainly in developed nations), while the tropics will lose suitability (mainly in developing nations).
The objective of this study was to identify and describe soil structural patterns and rooting behavior in reclaimed minesoils. The soil chosen for this study consists of approximately 0.4 m of topsoil (A horizon) material placed on approximately 1.5 m of a blend of B horizon, mixed paleoloesses, Sangamon paleosol, and Illinoian till. Four soil pits were excavated, exposing root systems of the corn test crop. Detailed soil and root pattern descriptions were made in each pit. Root patterns were depicted using the profile wall method. An outline of soil structural pattern was superimposed over the root pattern to provide a pictorial relationship between the two. Differences in the physical condition of subsoils were distinguished on the basis of the soil descriptions and statistical analysis of the root length determinations. An artificial soil structure was characterized and attributed to particular mining and reclamation practices. The structural arrangement consists of rounded aggregates loosely compressed together, that fall within the size classes currently used for blocklike and polyhedral aggregates. Plant rooting was distinctly more profuse where this structure was present than where the soil material was massive and compact. It is proposed that structural differences among newly constructed soils are of such significance that they should be carefully characterized and described, and where appropriate used for series level separations. Operations using a mining wheel in combination with belt transportation favor the formation of the more desirable fritted structure, whereas operations using scrapers exclusively favor the formation of the less desirable massive physical condition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.