Algal compost - toward sustainable fertilization

In the present paper, the possibilities of the utilization of large amounts of beach-cast seaweeds are discussed. It is important to examine the methods of removing and processing algal biomass and find a manner of its cost-effective utilization in order to obtain a value-added product. A review of composting methods of algal biomass is presented. Compost from seaweeds can find several applications, for example, as an alternative to conventional fertilizers. Algae have been used for centuries as a natural fertilizer in many coastal areas because they are known to be rich in nitrogen, phosphorus, and potassium. Moreover, the biomass is characterized by the high content of trace elements and metabolites. There are different ways of management for algae for their use in agriculture. The most common is composting of algal biomass, for example, in piles. The advantages (i.e., high content of plant nutrients, organic components, etc.) and disadvantages (i.e., heavy metal content and salinity) of the composted biomass are presented. Finally, examples of the application of seaweed compost in plant cultivation are reported.