Climate Change and Maize Yield in Iowa

PLoS One. 2016 May 24;11(5):e0156083. doi: 10.1371/journal.pone.0156083. eCollection 2016.

Abstract

Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output from six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10-20% by the end of the 21st century.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Agriculture / methods*
  • Climate Change
  • Ecosystem
  • Iowa
  • Linear Models
  • Zea mays / growth & development*

Grants and funding

This study was funded in part by the U.S. Department of Energy Award Number DE-EE0004397 (science.energy.gov/ber/) and U.S. Department of Agriculture's Agriculture and Food Research Initiative Competitive Grant No. 2011-68005-30411 (nifa.usda.gov). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.