Climate‐risk assessment for winter wheat using long‐term weather data

Abstract

Temperature and water deficit stresses cause large year-to-year yield variability, and matching crop phenology with periods less prone to stresses can improve yield stability. We used 30 years of daily weather data from 69 stations in the U.S. Great Plains to quantify the risk of water deficit and temperature stresses for winter wheat (Triticum aestivum L.) cultivars differing in maturity, and to evaluate whether the selected variables explained variability in yield and area abandonment. Crop phenology was estimated using a simple temperature-based model based on 282 field observations. A difference between the 15-d running sums of reference evapotranspiration (ET o ) and precipitation greater than 40% of the soil's available water holding capacity (AWHC) determined atmospheric water deficit (AWD). Heat and freeze stresses occurred when maximum temperatures >27 • C and minimum temperatures <0 • C occurred around heading. Probabilities of AWD in the spring was greater in the west and in the south; however, latitudinal AWD gradients dissipated when crop maturity was considered.The day of year (DOY) for last freeze increased from south to north and from east to west; and the DOY for onset of heat stress increased from south to north but did not follow a longitudinal gradient. Early maturing varieties avoided heat and AWD stresses during heading but were more likely to experience freezing conditions. Regional yield decreased and area abandonment increased with early onset of spring AWD and heat stresses. This conceptual framework for evaluating the risk of environmental stresses can be applied to other regions and cropping systems. 2132wileyonlinelibrary.com/journal/agj2 Agronomy Journal. 2020;112:2132-2151.

Soft winter wheat outyields hard winter wheat in a subhumid environment: Weather drivers, yield plasticity, and rates of yield gain

“…Our results also suggested that water deficit stress was rarely a yield‐limiting factor; instead, excessive grain fill precipitation tended to restrict wheat yield for both wheat classes. These findings agree well with a recent climate‐risk assessment for winter wheat in the region (Lollato et al., 2020). This excessive precipitation may contribute to increased incidence and severity of fungal diseases that limit wheat yield (de Oliveira Silva, Slafer, Fritz, & Lollato, 2019; Jaenisch, de Oliveira Silva, DeWolf, Ruiz‐Diaz, & Lollato, 2019; Kelley, 2001; Lollato et al., 2019).…”

Genotype‐specific nitrogen uptake dynamics and fertilizer management explain contrasting wheat protein concentration

“…Two winter wheat genotypes with similar yield performance but contrasting GPC histories, exposed to different N rates and N timings under a range of environments, revealed N management and genotypic opportunities to increase wheat grain yield and GPC simultaneously, disrupting the commonly reported negative relationship between both variables. The range of environmental conditions evaluated is representative of the long‐term weather in the region (Lollato et al., 2020b; Torres, Lollato, & Ochsner, 2013) and the negative yield–GPC relationship is detrimental to global food security (Simmonds et al., 1995), possibly leading to GPC below market standards and influence the value of the wheat grain (Dick, Thompson, Epplin, & Arnall, 2016).…”

Wheat nitrogen, phosphorus, potassium, and sulfur uptake dynamics under different management practices

“…Moreover, the additional N application in our study increased N concentration in the stem and grain for IM relative to the SM ( p < .05 , data not shown), and may explain why the N dilution curve for the IM was above the critical dilution curve of SM (i.e., under luxury consumption of N). This difference among dilution curves for IM as compared to SM also suggests that intensifying management can help to increase crop nutritional status even when water is limited, which is a common yield‐limiting factor in the U.S. southern Great Plains (Lollato et al., 2020). Similar to our findings, Reussi et al.…”