Effects of Multi-Species Microbial Inoculants on Early Wheat Growth and Litterbag Microbial Activity

Abstract

The use of microbial consortia (MC) with complementing features is considered to be a promising method of sustainable crop intensification, potentially trumping the limited performance of single-strain applications. We assessed the effect of two novel MC on early wheat growth and litterbag microbial activity in heated and unheated soil. Pot experiments were carried out in duplicate in a greenhouse over 63 days using a completely randomized design with six replications. A range of parameters of plant growth and nutrient uptake were regularly assessed and statistically analyzed by ANOVA. The litterbag-NIRS method was used to trace the microbial activity. Averaged over both trials, soil heating resulted in a significant increase in shoot biomass (+53%) and subsequent nitrogen uptake (+307 mg N pot−1) but strongly reduced root development (−46%) compared with unheated soil. The application of MC had no effect on wheat growth in the heated soil. By contrast, in the unheated soil, shoot (+12%) and root (+15%) biomass and shoot nitrogen uptake (+11%) were significantly increased after double inoculation with MC compared with autoclaved MC. The litterbag-NIRS method confirmed clear effects of soil heating on microbial activity. Differences between MC application and the control were noted, indicating a buffering effect of MC.

A Metagenomic and Gene Expression Analysis in Wheat (T. durum) and Maize (Z. mays) Biofertilized with PGPM and Biochar

“…The high cargo capacity of char was utilized and demonstrated in this work. The microbial consortia chosen for the experiments were the MC-B and MC-C [ 40 , 41 ], previously tested on wheat T. aestivum [ 41 ] but not on wheat T. durum nor Z. mays . First, it was evaluated whether the microbes could colonize the char surface and functionalize it and the extent to which this was achieved.…”

Testing plant growth promoting microorganisms in the field - a proposal for standards

“…Missing effects of PGPM application may also be due to a masking effect resulting from high nutrient availability either in pots ( Hett et al., 2022 ) or in the field ( Hett et al. 2023 ) and limited impact of stress factors.…”

“…However, a wide range of other physiological mechanisms may affect crop growth as well. According to Hett et al. (2022) , the potential functions of PGPM include (i) the facilitated acquisition of water and nutrients (primarily N, P, and Fe); (ii) the modulation of phytohormonal balances by changing the levels of auxins, cytokinins, gibberellins, abscisic, jasmonic and salicylic acids, mediating, inter alia, stimulation of root growth and modifications of plant development; (iii) the release of volatile organic compounds and siderophores with functions in stress priming and nutrient mobilization and (iv) the reinforcement of resistance against abiotic stress factors ( Vessey, 2003 ; Martínez-Viveros et al., 2010 ; Glick, 2012 ; Glick, 2014 ; Vejan et al., 2016 and Table 2 ).…”

“…However, a wide range of other physiological mechanisms may affect crop growth as well. According to Hett et al (2022), the potential functions of PGPM include (i) the facilitated acquisition of water and nutrients (primarily N, P, and Fe); (ii) the modulation of phytohormonal balances by changing the levels of auxins, cytokinins, gibberellins, abscisic, jasmonic and salicylic acids, mediating, inter alia, stimulation of root growth and Vessey, 2003;Martıńez-Viveros et al, 2010;Glick, 2012;Glick, 2014;Vejan et al, 2016 and Table 2). Furthermore, in non-axenic soil systems, introduced PGPM interact directly (e.g.…”

Multispecies Bacterial Bio-Input: Tracking and Plant-Growth-Promoting Effect on Lettuce var. sagess

“…The design and formulation of multispecies bio-inputs might be advantageous over first-generation bio-inputs (single-strain), because: (1) microorganisms most probably act in a cooperative manner by providing nutrients, removing inhibitory products, and stimulating beneficial physiological traits; (2) such a diverse array of organisms might improve adaptation to a wide range of environmental conditions; (3) provision of more than one PGPB with equal or different modes of action might improve the ability of a bacterial community to promote plant growth [ 9 ]. In this way, several PGPB co-inoculation studies with promising results have been reported in crops such as soybean, maize, potato and wheat, among others [ 11 , 12 , 13 , 14 , 15 , 16 ]; however, there are few reports regarding the use of such tools on studies on horticultural crops [ 9 , 17 , 18 ]. Also, despite the enormous potential of microorganisms to promote plant growth either alone or in a mixture, the reproducibility of their beneficial effects in the field varied too much, which is frequently related to a failure of the inoculated microorganisms to colonize and establish within new environments [ 4 , 16 ].…”