Compensatory effect of supplementary irrigation on winter wheat under warming conditions

Global warming may exacerbate cropland soil drought, affect microbial systems, and decrease grain yield. However, the compensatory effects of supplementary irrigation on winter wheat yield and soil microbial communities under increased temperatures have not been fully studied. Here, a three-year field experiment was conducted, to verify the effects of warming treatments (WS: winter and spring warming; FF: flowering and filling period warming) and irrigation (W0: conventional irrigation; W1: supplemental irrigation) on crop-soil systems during the winter wheat growth stages. The results demonstrated that warming measures have significant negative effects on the net assimilation rate of flag leaves and yield formation, which led to a reduction of wheat yield by 14–40%. However, increasing irrigation can compensate for a yield of 9.7–15%. In addition, warming increases the soil temperature and decreases the soil water content, resulting in decreased soil microbial diversity. The effect size (β) = −0.23 to −0.53 for index of phylogenetic diversity (PD) under warming, while β= 0.16 under increased irrigation. The SEM model further showed that supplementary irrigation during anthesis to filling can improve the soil environment and extend the validity of photosynthetic to increase production, which was an important mitigation measure to adapt to the warming climate in wheat production.