title: Do maize models capture the impacts of heat and drought stresses on yield? Using algorithm ensembles to identify successful approaches.
abstract: Stresses from heat and drought are expected to increasingly suppress crop yields, but the degree to which current models can represent these effects is uncertain. Here we evaluate the algorithms that determine impacts of heat and drought stress on maize in 16 major maize models by incorporating these algorithms into a standard model, the Agricultural Production Systems sIMulator (APSIM), and running an ensemble of simulations. Although both daily mean temperature and daylight temperature are common choice of forcing heat stress algorithms, current parameterizations in most models favor the use of daylight temperature even though the algorithm was designed for daily mean temperature. Different drought algorithms (i.e., a function of soil water content, of soil water supply to demand ratio, and of actual to potential transpiration ratio) simulated considerably different patterns of water shortage over the growing season, but nonetheless predicted similar decreases in annual yield. Using the selected combination of algorithms, our simulations show that maize yield reduction was more sensitive to drought stress than to heat stress for the US Midwest since the 1980s, and this pattern will continue under future scenarios; the influence of excessive heat will become increasingly prominent by the late 21st century. Our review of algorithms in 16 crop models suggests that the impacts of heat and drought stress on plant yield can be best described by crop models that: (i) incorporate event-based descriptions of heat and drought stress, (ii) consider the effects of nighttime warming, and (iii) coordinate the interactions among multiple stresses. Our study identifies the proficiency with which different model formulations capture the impacts of heat and drought stress on maize biomass and yield production. The framework presented here can be applied to other modeled processes and used to improve yield predictions of other crops with a wide variety of crop models.
authors.affiliation: Department of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Zhenong
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Department of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette, IN, 47907, USA.|Department of Agronomy, Purdue University, West Lafayette, IN, 47907, USA.|Purdue Climate Change Research Center, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Qianlai
authors.initials: Q
authors.lastname: Zhuang
authors.affiliation: Department of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Zeli
authors.identifier: 0000-0001-5958-2584
authors.initials: Z
authors.lastname: Tan
authors.affiliation: Purdue Climate Change Research Center, Purdue University, West Lafayette, IN, 47907, USA.|Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, 47907, USA.|Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Dukes
authors.affiliation: CSRIO Agriculture, Queensland Bioscience Precinct, 306 Carmody Road, St. Lucia, Qld, 4067, Australia.
authors.forename: Bangyou
authors.initials: B
authors.lastname: Zheng
authors.affiliation: The Marine Biological Laboratory, The Ecosystems Center, Woods Hole, MA, 02536, USA.
authors.forename: Jerry M
authors.initials: JM
authors.lastname: Melillo
mesh_terms: D000465:Algorithms; D018556:Crops, Agricultural; D055864:Droughts; D006358:Hot Temperature; D003313:Zea mays
keywords: Agricultural Production Systems sIMulator; crop model comparison; drought stress; heat stress; maize; yield