Crop modeling defines opportunities and challenges for drought escape, water capture, and yield increase using chilling‐tolerant sorghum

Abstract

Many crop species, particularly those of tropical origin, are chilling sensitive, so improved chilling tolerance can enhance production of these crops in temperate regions. For the cereal crop sorghum ( Sorghum bicolor L.), early planting and chilling tolerance have been investigated for >50 years, but the potential value or tradeoffs of this genotype × management change have not been formally evaluated with modeling. To assess the potential of early planted chilling‐tolerant grain sorghum in the central US sorghum belt, we conducted CERES‐Sorghum simulations and characterized scenarios under which this change would be expected to enhance (or diminish) drought escape, water capture, and yield. We conducted crop growth modeling for full‐ and short‐season hybrids under rainfed systems that were simulated to be planted in very early (April), early (May 15), and normal (June 15) planting dates over 1986–2015 in four locations in Kansas representative of the central US sorghum belt. Simulations indicated that very early planting will generally lead to lower initial soil moisture, longer growing periods, and higher evapotranspiration. Very early planting is expected to extend the growing period by 20% for short‐ or full‐season hybrids, reduce evaporation during fallow periods, and increase plant transpiration in the two‐thirds of years with the highest precipitation (mean > 428 mm), leading to 11% and 7% increase grain yield for short‐ and full‐season hybrids, respectively. Thus, in this major sorghum growing region, very early and early planting could reduce risks of terminal droughts, extend seasons, and increase rotation options, suggesting that further development of chilling‐tolerant hybrids is warranted.

Crop modeling suggests limited transpiration would increase yield of sorghum across drought-prone regions of the United States

“…Management practices need to be considered to enhance the performance of LT sorghum. Shifting planting dates can change the frequency of water deficit environments ( Chenu et al., 2011 ; Raymundo et al., 2021 ) ( Supplementary Figure S3 ) by increasing grain yield in early planting dates, especially in Kansas ( Figure 4B ). Higher yields in early spring resulted from the synchronization of planting dates with the onset of precipitation, which increased the frequency of WW environments ( Supplementary Figure S3 ).…”

Precise colocalization of sorghum’s major chilling tolerance locus with Tannin1 due to tight linkage drag rather than antagonistic pleiotropy

“…Improving crop adaptation to climatic stressors, such as drought, heat, and cold, is important to safeguard agricultural productivity and food security (Maggio et al 2015 ). Development of more chilling tolerant crops can improve agricultural sustainability by increasing crop yields by facilitating early planting, increasing yield through a lengthened growing season, and better-aligning crops’ evapotranspirative needs with precipitation and temperature patterns (Long and Spence 2013 ; Raymundo et al 2021 ). Early planting of chilling tolerant crops can also minimize nitrogen loss via runoff and emissions during fallow periods (Mosier et al 1998 ).…”

Adapting to heat stress by sowing summer grain crops early in late winter: Sorghum root growth, water use, and yield

“…Agronomy could mitigate heat stresses during flowering, and terminal drought stresses, by advancing flowering dates so that the overlap between times of the year of the high likelihood of the stresses and sensitive crop stages could be avoided. Sorghum crops sown in late winter or early spring will develop during periods of the year of lower atmospheric demand and flower before yield-limiting summer heat waves, reducing the impact of heat and terminal water stresses (Raymundo et al 2021). However, sorghum is affected by cold temperatures early in the season (Marla et al, 2019).…”