Can Impacts of Climate Change and Agricultural Adaptation Strategies Be Accurately Quantified if Crop Models Are Annually Re-Initialized?

Bruno Basso,David W. Hyndman,G. Philip Robertson,Anthony D. Kendall,Peter R. Grace,Pieter Spanoghe

doi:10.1371/journal.pone.0127333

Bruno Basso, David W. Hyndman + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0127333

Copy DOI

Abstract

Estimates of climate change impacts on global food production are generally based on statistical or process-based models. Process-based models can provide robust predictions of agricultural yield responses to changing climate and management. However, applications of these models often suffer from bias due to the common practice of re-initializing soil conditions to the same state for each year of the forecast period. If simulations neglect to include year-to-year changes in initial soil conditions and water content related to agronomic management, adaptation and mitigation strategies designed to maintain stable yields under climate change cannot be properly evaluated. We apply a process-based crop system model that avoids re-initialization bias to demonstrate the importance of simulating both year-to-year and cumulative changes in pre-season soil carbon, nutrient, and water availability. Results are contrasted with simulations using annual re-initialization, and differences are striking. We then demonstrate the potential for the most likely adaptation strategy to offset climate change impacts on yields using continuous simulations through the end of the 21st century. Simulations that annually re-initialize pre-season soil carbon and water contents introduce an inappropriate yield bias that obscures the potential for agricultural management to ameliorate the deleterious effects of rising temperatures and greater rainfall variability.

Highlights

Sustainable food production under a changing climate is among the most important international research priorities [1,2]
We examine climate and soils for a representative region that is well suited for maize production in the Northern High Plains (NHP), USA
Because appropriate soil management can enhance the carryover of carbon and water, simulations that annually re-initialize pre-season soil carbon and water contents introduce a yield bias that obscures the potential for soil management to ameliorate the deleterious effects of rising temperatures and greater rainfall variability

Summary

Introduction

Sustainable food production under a changing climate is among the most important international research priorities [1,2]. We demonstrate the importance of simulating crop yields using a continuous model that accounts for annual carryover of soil water, nutrients, and carbon over long time periods, such as in climate change impact and adaptation studies. This allows for a more realistic assessment of management factors, such as tillage practice that might exacerbate or attenuate climate change impacts on yields and yield stability, and thereby provide insights into long-term adaptation strategies. We use the continuous model to evaluate the most likely adaptation strategy to select different cultivars, shift planting dates, and alter plant densities

Methods

Results and Discussion

Conclusions