Systems management strategies for increasing alfalfa use in warm-humid regions

Alfalfa use(Medicago sativa L.;“lucerne”)in warm,humid regions of the world represents a potential area of expansion for the alfalfa industry.The objective of this review paper is to demonstrate how alfalfa forage breeding and systems research efforts have identified opportunities for increasing alfalfa contributions in these regions,along with potential pathways for seed industry and farming operations to increase adoption.Our review draws primarily on reports from the Southeast United States and Argentina.Significant technological advancements in plant screening and selection have identified alfalfa plant populations that are more adapted to the growing conditions experienced in these regions,which are often characterized by mild temperature,long growing seasons,and multiple other abiotic and biotic stressors.Management systems research conducted in the United States and Argentina has demonstrated the use of alfalfa for conserved forage,grazing,or dual-purpose use in monoculture or mixtures with warm-season grasses such as bermudagrass(Cynodon spp.).These trials report increased forage production,nutritive value,and ecosystem services of alfalfa–grass mixtures when compared with traditionally N-fertilized warmseason grass-based systems.Grazing-based alfalfa systems in Argentina have demonstrated methods for utilizing alfalfa as part of beef,dairy,and finishing systems.Some approaches for expanding alfalfa production in the region include targeted marketing efforts for adapted varieties and demonstrating alfalfa applications within existing farming frameworks.This includes educational programming efforts and on-farm demonstrations to promote alfalfa use as a component of the livestock diets,integration into grass-based systems,crop rotations,and wildlife use.Continued emphasis on a systems approach to alfalfa inclusion represents an opportunity for improved forage and livestock production in warm,humid regions of the world.