“Beyond the Source of Bioenergy”: Microalgae in Modern Agriculture as a Biostimulant, Biofertilizer, and Anti-Abiotic Stress

Abstract

Microalgae are photoautotrophic organisms with high commercial potential. Extracts from microalgae are extensively used in crop cultivation, mainly because they possess growth-promoting properties, coupled with their enhancing impacts on the crop’s ability to withstand abiotic stresses viz. extreme temperatures, drought, salinity, and mineral deficiency. The chemical composition of microalgae extract includes carbohydrates, proteins, lipids, vitamins, micronutrients, macronutrients, and phytohormones (auxins, cytokinins, ethylene, abscisic acid, and gibberellins). This review aims to provide an update on the trending facts for a better understanding of growing microalgae, the production of biomass, the processing of microalgae extracts, summarizing bioactive compounds, and the chemical constituent of microalgae extracts. Furthermore, we review the supporting literature on the application of microalgae extracts as biostimulants and biofertilizers to enhance crop productivity and control abiotic stresses in crop cultivation.

Application of Cyanobacteria (Roholtiella sp.) Liquid Extract for the Alleviation of Salt Stress in Bell Pepper (Capsicum annuum L.) Plants Grown in a Soilless System

“…The application of microalgae as biostimulants and biofertilizers is gaining popularity as a potential and sustainable alternative to the inorganic fertilizer with a wider acceptance by farmers and agrochemical industries [ 17 ]. Interestingly, several studies have established that microalgae exhibits biostimulants properties that enhance the resistance of crops to the deleterious impacts of abiotic stress mostly salt stress [ 1 , 18 ]. Similarly, wastewater may be used as a source of raw material in microalgae production because of its richness in organic nutrients, consequently, minimizing the usual huge cost of production [ 3 , 19 ].…”

Impact of Compost Tea and Spirulina platensis Algae on Sugar Beet Grown under Different Levels of Inorganic Nitrogen Fertilizer

“…Total revenue/fed (L.E.) = Root yield/fed (ton)×Ton's initial price (10) Where: Tonʼs initial price of roots at 16% sucrose = L.E. 550 Sucrose incentive above 16% = L.E.…”

“…Spirulina platensis is a photosynthetic and multi-cellular blue-green micro-alga. Micro-algae extracts are mostly made up of natural bioactive materials rich in mineral elements, gibberellins, auxins, cytokinins, abscisic acid, proteins, carbohydrates and vitamins 10 . Foliar spray of algae-based biostimulants in crop production is a hopeful and advanced agricultural technique owing to its eco-friendly, with obtaining better crop production 11 .…”

Evaluation of Roholtiella sp. Extract on Bell Pepper (Capsicum annuum L.) Yield and Quality in a Hydroponic Greenhouse System

“…Consequently, to reduce these effects, there is a need for practicing modern agriculture as an alternative eco-friendly and sustainable technique. The discovery of green technologies that make use of bioresources such as biofertilizers and biostimulants is widely accepted as innovative options to improve crop growth and productivity (Calvo et al, 2014 ; Elzaawely et al, 2017 ; Van Oosten et al, 2017 ; Yakhin et al, 2017 ; Desoky et al, 2018 ; Bello et al, 2021a , b ).…”