Prospects for diversifying temperate pasture systems in south-eastern Australia with serradella (Ornithopus spp.)

There is potential for the wider use of serradella (Ornithopus spp.) in south-eastern Australian permanent pastures where the legume component has historically been based on subterranean clover (Trifolium subterraneum L.). Serradella is a genus of annual legumes native to the Mediterranean region and central and north-western Europe. Cultivar development in Australia has largely focused on the yellow (O. compressus L.) and French serradella (O. sativus Brot.) species, with slender (O. pinnatus (Mill.) Druce) and common birds-foot (O. perpusillus L.) serradella of minor importance. Serradellas have been shown to be productive on deep, sandy, acidic soils in Mediterranean climates where they have demonstrated equal or higher production than has subterranean clover. Recent research has highlighted a broader adaptation zone for serradella, including the cooler regions of the temperate pasture zones of south-eastern Australia with acidic, duplex soil types. Diversifying the feedbase with serradellas offers benefits, including low incidence of pest and disease, improved drought resilience, low bloat risk, low oestrogenic activity, and tolerance of acidic and P-deficient soils with the potential to reduce P fertiliser inputs for pastures by 30%. Key challenges for broad-scale adoption of serradellas in these new environments includes selection and commercialisation of cultivars with appropriate flowering and seed traits, effective introduction of serradella rhizobia and improved options for controlling weeds. This paper reviews the traits of serradellas that make them a viable legume option for south-eastern Australia, along with progress in cultivar and agronomic development.