Effect of four plant species on soil 15N-access and herbage yield in temporary agricultural grasslands

Background and aims We carried out field experiments to investigate if an agricultural grassland mixture comprising shallow- (perennial ryegrass: Lolium perenne L.; white clover: Trifolium repens L.) and deep- (chicory: Cichorium intybus L.; Lucerne: Medicago sativa L.) rooting grassland species has greater herbage yields than a shallowrooting two-species mixture and pure stands, if deep-rooting grassland species are superior in accessing soil 15 N from 1.2 m soil depth compared with shallow-rooting plant species and vice versa, if a mixture of deep- and shallow-rooting plant species has access to greater amounts of soil 15 N