Global Response Patterns of Major Rainfed Crops to Adaptation by Maintaining Current Growing Periods and Irrigation

• Published in: Earth's future Vol. 7; no. 12; pp. 1464 - 1480
• Main Authors: Minoli, Sara, Müller, Christoph, Elliott, Joshua, Ruane, Alex C., Jägermeyr, Jonas, Zabel, Florian, Dury, Marie, Folberth, Christian, François, Louis, Hank, Tobias, Jacquemin, Ingrid, Liu, Wenfeng, Olin, Stefan, Pugh, Thomas A. M.
• Format: Journal Article Web Resource
• Language: English
• Published: Goddard Space Flight Center John Wiley & Sons, Inc 01-12-2019; American Geophysical Union; American Geophysical Union (AGU); Wiley
• Subjects: Adaptation; Agricultural practices; Agricultural production; Agronomy; Arid regions; Arid zones; Climate change; Continental interfaces, environment; Crop evapotranspiration; crop model; Crop production; Crop yield; crop yields; Crops; Cultivars; Earth and Related Environmental Sciences; Earth sciences & physical geography; Environmental Sciences; Evapotranspiration; Geosciences (General); Geovetenskap och miljövetenskap; growing period; Heat; Irrigation; Irrigation systems; Mathematical functions; Miljövetenskap; modelling; Natural Sciences; Naturvetenskap; Ocean, Atmosphere; Phenology; Physical, chemical, mathematical & earth Sciences; Physiology; Physique, chimie, mathématiques & sciences de la terre; Productivity; Respiration; Sciences de la terre & géographie physique; Sciences of the Universe; Temperature effects; temperature increase; Temperature rise; Temperature trends; Tropical environments; Water scarcity; Wheat
• ISSN: 2328-4277; 2328-4277
• DOI: 10.1029/2018EF001130

Increasing temperature trends are expected to impact yields of major field crops by affecting various plant processes, such as phenology, growth, and evapotranspiration. However, future projections typically do not consider the effects of agronomic adaptation in farming practices. We use an ensemble of seven Global Gridded Crop Models to quantify the impacts and adaptation potential of field crops under increasing temperature up to 6 K, accounting for model uncertainty. We find that without adaptation, the dominant effect of temperature increase is to shorten the growing period and to reduce grain yields and production. We then test the potential of two agronomic measures to combat warming-induced yield reduction: (i) use of cultivars with adjusted phenology to regain the reference growing period duration and (ii) conversion of rainfed systems to irrigated ones in order to alleviate the negative temperature effects that are mediated by crop evapotranspiration. We find that cultivar adaptation can fully compensate global production losses up to 2 K of temperature increase, with larger potentials in continental and temperate regions. Irrigation could also compensate production losses, but its potential is highest in arid regions, where irrigation expansion would be constrained by water scarcity. Moreover, we discuss that irrigation is not a true adaptation measure but rather an intensification strategy, as it equally increases production under any temperature level. In the tropics, even when introducing both adapted cultivars and irrigation, crop production declines already at moderate warming, making adaptation particularly challenging in these areas.