Foliar Fertilization: The Facts and the Fiction

Foliar fertilization is an important tool for the sustainable and productive management of crops, however, current understanding of the factors that influence the ultimate efficacy of foliar applications remains incomplete. Here we provide provide an integrated analysis of the principles, both physico-chemical and biological, known to influence foliar absorption and utilization by the plant, and review the available laboratory and field experimental results to provide insights into the factors that ultimately determine the efficacy of foliar applications. Advancement in this field will require a sound understanding of the physical, chemical, biological, and environmental principles that govern the absorption and utilization of foliar applied nutrients.