Microalgae, soil and plants: A critical review of microalgae as renewable resources for agriculture

Authors: ALVAREZ, ADRIANA - University Of Minnesota; Weyers, Sharon; GOEMANN, HANNAH - Montana State University; PEYTON, BRENT - Montana State University; GARDNER, ROBERT - University Of Minnesota

Submitted to: Algal Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2021
Publication Date: 2/9/2021
Citation: Alvarez, A.L., Weyers, S.L., Goemann, H.M., Peyton, B.M., Gardner, R.D. 2021. Microalgae, soil and plants: A critical review of microalgae as renewable resources for agriculture. Algal Research. 54. Article 102200. https://doi.org/10.1016/j.algal.2021.102200.
DOI: https://doi.org/10.1016/j.algal.2021.102200

Interpretive Summary: Microalgae, including cyanobacteria, have potential to serve as both biofertilizers and soil structure enhancers, but further understanding of efficacy and impacts are needed to improve their implementation in agricultural systems. Researchers in Morris MN, from the University of Minnesota and USDA-ARS, and at Montana State University compiled a review of research investigating the use of various algae species, with particular emphasis on nitrogen-fixing cyanobacteria, and demonstrated benefits of soil inoculation to agricultural production due to positive influences on soil structure, nutrient delivery, and soil biota. This review provides a critical evaluation of research findings that suggest agricultural production will benefit from microalgae-based biofertilizers. This evaluation can be used by other researchers and policy makers to further develop and promote microalgae use as a renewable biofertilizer.

Technical Abstract: The tension between a growing global demand for food, rising environmental impacts of agricultural intensification, and the uncertainty of future changes in our global climate highlight a crucial need for sustainable alternatives to maintain and increase agricultural productivity. Microalgae, including cyanobacteria, are renewable resources with a broad range of options for applications in agricultural settings. This review incorporates fundamental and applied aspects of microalgae impacting critical agricultural needs such as biological nitrogen fixation, soil phosphorus cycling, effects on soil microorganisms, plant growth promotion either by soil nutrient cycling and/or phytohormones or root associations, biocontrol, and soil stabilization. In this context, the review summarizes progress on microalgal biofilms and consortia as platforms for technological improvement. To complete the review, research needs for future advances are outlined, including evaluations on different types of soil and agroecological regions, scaled production of inoculum and methods of deployment, and further developments on applications such as biostimulants and soil reclamation and restoration.