Differential grain yield strategies among four summer crops along a temperate aridity gradient

Context Dryland cropping systems in temperate subhumid and semi-arid regions confront increasing climate variability that threatens yield stability and long-term productivity. Optimizing crop choice and management requires understanding species-specific responses to environmental stress. Aims This study analyzed grain yield (GY) determination in four crop species (maize, sorghum, soybean, and peanut) that compete for land in temperate regions with contrasting water supply. Methods Field experiments were conducted over two seasons at three sites representing humid, subhumid, and semiarid conditions in Central Argentina, a major producing area of these crops. Early and late sowings were also evaluated. GY, shoot biomass, harvest index (HI), grain number (GN), and individual grain weight (GW) were measured and related to environmental variables. Key results GY declined with increasing aridity, higher vapor pressure deficit (VPD), and reduced water supply (WS). Biomass production was the primary GY driver, except in peanut, where HI was also critical. GN was strongly associated with crop growth rate and VPD during the critical period. GW contributed to GY variation in maize and soybean but not in sorghum and peanut. Sorghum exhibited resilience to elevated VPD and low WS, whereas peanut was sensitive to extreme aridity during the critical period and excess water or low temperatures during grain filling. Conclusions Species differed in yield formation strategies under stress. Sorghum was most resilient against dry conditions. Implications These findings emphasize the need for specific crop choice and management strategies aligned with local water regimes and evaporative demand to enhance yield stability in dryland systems.