Modern plant breeding has yielded crop genotypes that need precise anthropogenic chemical control, thereby largely neglecting that the rhizosphere microbiome can protect against diseases and promote plant nutrient availability and uptake. In the project, we will evaluate plant-microbiome interactions in six barley cultivars of barley (three modern and three ancient) and investigate how different microbiomes affect plant nutrient uptake. We will investigate to which extent modern varieties have lost the ability to interact with the microbiome with focus on plant/bacteria/protozoan interactions. We expect that systems with only bacteria will support plant growth more poorly than systems with both bacteria and protozoa. We will sequence the microbiome and perform multielement analyses to capture the dynamics of the interactions. Our results will be a significant contribution to the understanding of the role of the microbiome in modern plant production.