Plants Production with Microalgal Biostimulants

In order to ensure food security worldwide in the face of current climatic changes, a higher quality and quantity of crops is necessary to sustain the growing human population. By developing a sustainable circular economy and biorefinery approaches, we can move from a petroleum-based to a bio-based economy. Plant biostimulants have long been considered an important source of plant growth stimulants in agronomy and agro-industries with both macroalgae (seaweeds) and microalgae (microalgae). There has been extensive exploration of macroalgae biostimulants. A lack of research and high production costs have constrained the commercial implementation of microalgal biostimulants, despite their positive impact on crop growth, development and yields. The current knowledge on potential biostimulatory compounds, key sources and their quantitative information from algae is summarized in the present review. Our goal is to provide a brief overview of the potential for microalgal biostimulants to improve crop production and quality. A number of key aspects are discussed, including the biostimulant effects caused by microalgae extracts, as well as the feasibility and potential for cocultures and coapplication with other biostimulants and biofertilizers. This article also discusses the current knowledge, recent developments and achievements in extraction techniques, types of applications, timings of applications. Ultimately, this review highlights the potential for microalgal biostimulants for sustainable agricultural practices, the algal biochemical components contributing to these traits, and finally bottlenecks and involved prospects in commercializing microalgal biostimulants.