Elevated atmospheric [CO₂] can dramatically increase wheat yields in semi‐arid environments and buffer against heat waves

Abstract

Wheat production will be impacted by increasing concentration of atmospheric CO 2

Can additional N fertiliser ameliorate the elevated CO2‐induced depression in grain and tissue N concentrations of wheat on a high soil N background?

“…The Australian Grains Free Air CO 2 Enrichment (AGFACE) facility is located on an experimental farm managed by the Victorian State Government, near Horsham, Victoria, Australia (36°45′07″S, 142°06′52″E, 127 m above sea level), and described in detail in previous papers (Fitzgerald et al., ; Mollah, Norton, & Huzzey, ). In brief, the experimental plots are on a 7.5‐ha field on heavy Vertosol clay soil (~35% clay at the surface and 60% in 1.4 m depth).…”

“…Detailed weather data for the seasons in question (2007–2009 growing seasons) were recorded by an on‐site automatic weather station and are given in Fitzgerald et al. ().…”

“… a,b These data were reported as 159 and 207 mm of in‐season rainfall, respectively, in Fitzgerald et al. () but are corrected here. …”

“…() and more details on experimental design, agronomic treatments and weather data in Fitzgerald et al. ().…”

“…Importantly, undisturbed soil processes are present in such a system. The Australian Grains Free Air CO 2 Enrichment (AGFACE) facility is globally unique in that it operates in a water‐limited wheat cropping agro‐ecosystem and is on a site where the soil N supply is generally high and adequate to meet demand for crop yield (Fitzgerald et al., ). This enabled the present study to address the question whether N application above the level normally recommended for growth and yield response in current CO 2 environments can ameliorate the e[CO 2 ]‐related decline in biomass and grain [N] of wheat.…”