Soil Inoculation with Cyanobacteria: Reviewing Its’ Potential for Agriculture Sustainability in Drylands

Abstract

In the last decades, there has been a huge expansion of intensive agriculture crops to attend the enormous demand of food needs with increasing population. Intensive agriculture is highly dependent on chemicals, which has caused numerous environmental problems such as contamination of aquifers, soils and air, with serious consequences on human health. A challenge in the next decades will be the development of economically viable methods to enhance productivity, at the same time that conservation of natural resources, protection of environment and production of healthy agricultural products are ensured. Sustainable agriculture requires management of a healthy living soil. Use of microorganisms such as cyanobacteria appears as a real alternative to achieve more sustainable managements. In this review, we briefly discuss the roles of cyanobacteria in the improvement of soil stability, soil nutrient and moisture status, organic matter content, microbial activities, and the growth and productivity of crops. Application of cyanobacteria is especially promising in croplands from dryland regions where high tolerance of these organisms to harsh environmental conditions converts them into viable alternatives or complements to more widespread conservation practices based on vegetation covers.

Soil Photosynthetic Microbial Communities Mediate Aggregate Stability: Influence of Cropping Systems and Herbicide Use in an Agricultural Soil

“…Photosynthetic microorganisms such as eukaryotic algae and prokaryotic cyanobacteria are ubiquitous pioneer colonizers of topsoil surfaces (Booth, 1941; Metting, 1981). They have been extensively studied in dryland ecosystems, where they play key roles in the formation of biological soil crusts and soil ecological processes (Evans and Johansen, 1999; Belnap and Lange, 2003; Chamizo et al, 2018), and in rice field ecosystems, where they are important to soil fertility (Singh et al, 2011). Far less is known about the communities and functions of soil algae and cyanobacteria living in mesic agricultural croplands (Büdel, 2001; Bérard et al, 2004; Zancan et al, 2006; Langhans et al, 2009; Peng and Bruns, 2019b), located in areas with temperate oceanic climates (Cw, Cfb, or Cfc) or mesic continental climates (Dfa or Dfb) (Peel et al, 2007).…”

Cyanobacteria as a Nature-Based Biotechnological Tool for Restoring Salt-Affected Soils

“…These features underline the possibility of using phytoremediation (i.e., the use of living plants for in situ removal, degradation, and containment of contaminants in soils) coupled with cyanobacteria (through inoculation) to improve salt-affected soils remediation [41,131]. Even though there are a vast amount of laboratory studies available, little research has been conducted under field conditions [41], much needed for the next large-scale applications [132,133]. The successful use of cyanobacteria in agricultural salt-affected soils remediation extends to several soil types and climatic conditions [41], which could support the up-scale of cyanobacteria culturing and application for salt-affected soil restoration, both in managed and natural ecosystems.…”

“…Selection of suitable cyanobacteria isolates for artificial crust formation is crucial for the success of restoration [49,150]. Both primary and applied research are needed to upscale from laboratory or indoor conditions to field-scale applications [133]. The exposure of the cyanobacteria inoculum to harsh conditions prior to their transfer to the field (preconditioning) has shown positive results in the establishment and recovery rates of biocrusts [151,152].…”

Applying biostimulants boosts forage productivity without affecting soil biotic and abiotic parameters on a Central Coast California rangeland

“…These expectations are supported in part by decades of research on the use of microbial inoculants and humic products to improve crop productivity and quality (reviewed in Hart & Forsythe 2012; Kong et al 2018; Jindo et al 2020). For example, research has shown that inoculants have the potential to improve nutrient availability and plant uptake through the addition of specific microbial taxa with, for example, capabilities to fix atmospheric nitrogen (N2), solubilize phosphorus, or stimulate root growth and elongation (Hamdali et al 2008; Halpern et al 2015; Chamizo et al 2018). Inoculation with putative plant growth promoting (PGP) microorganisms can also alleviate plant environmental stress and prevent infections by phytopathogens through the synthesis of targeted enzymes, signaling molecules, and other compounds such as siderophores (reviewed in Khatoon et al 2020; Arora et al 2020).…”