MendelNet 2019; 108-112

Interactive effects of elevated CO₂ concentration, drought and nitrogen nutrition on malting quality of spring barley

Jan Simor, Karel Klem, Vratislav Psota

Elevated CO₂ concentration [EC] generally leads to increased rates of photosynthesis, increased formation of assimilates and finally to storing them in the grain. Increased storage of starch
in the grain, however, leads to an unbalanced proportion to the proteins, and their relative content decreases. This is particularly apparent in the conditions of nitrogen deficiency. The interactive effects of EC, nitrogen nutrition and reduced water availability are, however, not yet sufficiently understood. Within the manipulation experiment in open top chambers (Domanínek near Bystřice nad Pernštejnem) that allow simulation of EC (expected by the end of this century – 700 ppm) and  drought, the effect
of these interactions on protein content, and other quality parameters of spring barley grain was studied. EC reduced grain protein content, increased extract, Kolbach index and also summary Malting quality index. Such effect was more pronounced under higher nitrogen dose, which generally worsened malting quality parameters. Reduced water availability slightly enhanced all malting quality parameters
and also showed slight synergistic effect to EC. No clear interactive effects on malting quality were found for nitrogen nutrition and water availability.

Keywords: malting barley, greenhouse gases, nitrogen fertilization, reduced water availability