Unpacking the climatic drivers of US agricultural yields

Abstract

Understanding the climatic drivers of present-day agricultural yields is critical for prioritizing adaptation strategies to climate change. However, unpacking the contribution of different environmental stressors remains elusive in large-scale observational settings in part because of the lack of an extensive long-term network of soil moisture measurements and the common seasonal concurrence of droughts and heat waves. In this study, we link state-of-the-art land surface model data and finescale weather information with a long panel of county-level yields for six major US crops to unpack their historical and future climatic drivers. To this end, we develop a statistical approach that flexibly characterizes the distinct intra-seasonal yield sensitivities to high-frequency fluctuations of soil moisture and temperature. In contrast with previous statistical evidence, we directly elicit an important role of water stress in explaining historical yields. However, our models project the direct effect of temperature-which we interpret as heat stress-remains the primary climatic driver of future yields under climate change.

Combined influence of soil moisture and atmospheric evaporative demand is important for accurately predicting US maize yields

“…Underlying our statistical framework is the assumption that moisture availability influences yield variability similarly from May to July. Field-level studies have shown that certain growth stages (for example, tasselling and ear formation) are more sensitive to water stress 1,23 , although the general conclusions of this study do not change on the basis of the summertime months selected ( Supplementary Table 3).…”

“…The inference of moisture-mediated exposure to damage from temperature is consistent with previous studies. Exposure to high temperatures has been found to cause amplified yield damage under conditions of low water availability 13,18,23 . Conversely, well-irrigated fields show little sensitivity to high atmospheric temperature 8,12,[15][16][17] .…”

Corn Yield Dynamics and Weather Shocks: Climate Change Implications for the U.S. Corn Belt

“…Ortiz-Bobea et al (2019) similarly finds that somewhat drier late-season conditions are beneficial for corn. 12 Using Gibbs sampling across four parallel chains, convergence is achieved quickly and analyzed using theGelman and Rubin (1992) potential scale reduction factor.…”

“…One exception isOrtiz-Bobea et al (2019), who use detailed information on soil moisture from land surface model data from the North American Land Data Assimilation System. Their analysis of corn yields finds no statistically significant difference in mean climate change impacts between traditional models that use season-long temperature and precipitation and their proposed model of intra-seasonal temperature and soil moisture.…”

Heat stress during flowering in cereals – effects and adaptation strategies

“…However, to achieve the same going forward, we are faced with a two‐pronged challenge: (1) a plateauing rate of increase in grain yield across crops (Iizumi et al , ; Zhao et al , ); and (2) increasing intensity and frequency of harsh climatic conditions during the crop growth period (Zampieri et al , ; Pfleiderer et al , ). Among the climatic factors, a rapid increase in temperature is considered to be a primary factor affecting crop yields negatively (Ortiz‐Bobea et al , ). Temperatures above the critical threshold, termed as ‘heat stress’ can vary across crop growth and developmental stages, impacting different physiological processes ultimately reducing grain yield (Djanaguiraman et al , ).…”