Multi-species for multifunctional grassland: Evaluation of minor and novel forage species for temperate humid grasslands

One pillar of sustainable agriculture is grassland resilient and resistant to climate perturbation and capable of attaining multiple services. Novel or exotic and, so far, minor or underutilised plant species may become increasingly important against this background and exploration of such plant species seems of importance to maintain grassland functioning. We chose a set of 21 dicotyledonous plant species from seven botanical families. The set included 10 legumes, of which four were, so far, not used in temperate climate grassland and are named exotic henceforward. The other species are named minor as they are mostly not in widespread use. We evaluated different plant functions including herbage accumulation, herbage quality and functional traits in a pilot study under semi-controlled conditions under increased temperatures compared to ambient conditions. The factor species had a significant influence (p < .001, F-test) on all target variables, including the leaf dry matter content, the herbage biomass and the protein contents. All studied species had a high concentration of organic matter in the dry-matter, had low concentrations of neutral detergent fibre and reached relatively large protein concentrations. In addition, fibre-bound protein concentration was low resulting in pre-caecal digestible protein concentrations that meet the nutritional requirements of horses. In contrast, protein concentrations were often too low for intensive livestock feeding. Since no fertiliser N was applied, non-legumes accumulated on average 29% less herbage than legumes. The exotic legumes accumulated the highest herbage biomass on average while the minor legumes produced on average 22% less. Of the exotic legumes, Bituminaria bituminosa and Hedysarum coronarium were within the upper quartile for herbage accumulation. Plant functional traits of several species were in similar ranges showing potential for mixture design to follow traits rather than species. The study may pave the way for informed breeding of distinct plant species on the basis of relevant traits in order to improve herbage provision in the future under ongoing climate changes.