Meta‐analysis reveals globally sourced commercial mycorrhizal inoculants fall short

New Phytologist, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 21, 2024

Several researchers have highlighted the potential of microbial inoculants to advance sustainable agriculture (Elnahal et al., 2022; O'Callaghan 2022). Among inoculants, arbuscular mycorrhizal (AM) fungi garnered attention for their ability enhance soil health and plant fitness. AM can increase growth through enhanced access limiting resources, improve defense against herbivores pathogens, tolerance drought salinity stress, carbon sequestration (Reynolds 2006; Bennett 2009; Ji & Bever, 2016). With this promise, commercial market is rapidly growing, approaching 995 million USD globally (Mordor Intelligence, 2024). often referred as 'endomycorrhizal' on product labels, are easily widely available in many regions world. Despite optimism surrounding global studies revealed inconsistencies with products, including instances crop mortality, unlabeled fertilizers, nonviability (Corkidi 2004; Tarbell Koske, 2007; Faye 2013; Duell M. Salomon Koziol The benefits products be limited by narrow inclusion same four five species, containing a single fungus Rhizophagus genus (Basiru 2020), despite evidence that more diverse fungal consortium may (Magnoli 2023), nutrient uptake 2006), other benefits. Concerns regarding mislabeling contamination pathogens further highlight risks associated these (Tarbell Vahter 2023). lack accountability viability compounded scientific assessments do not report identities, although some (Wiseman making it challenge both inoculant industry users informed quality concerns. Regulatory frameworks remain (Carrazco 2024; J. 2022), exacerbating challenges related identity products. United States fully lacks regulations import/export or control, having 25% share industry, representing 249 annually Moreover, transport present risk future invasion non-native microbes (Schwartz Hart 2017). While there multiple causes concern, date no synthesis efficacy inocula. To comprehensively assess we collected published comparisons analyzed them using meta-analyses, mixed models, categorical comparisons. Inoculants were assessed impact viability. avoid positive publication bias, only assessing included. This approach accounts high likelihood selecting nonviable certain (M. Studies evaluating fewer an increased bias happened select viable inoculant, skewing results. In total, analysis encompassed 302 trials, 7 field 28 laboratory-grown 17 added sterilized controls, 250 trials symbiotic associations among seven species. Only half observations reported names tested. Of names, tested across publications, but used experiments within another context (e.g. different crops assessed). pool 94 unique, sourced evaluated. contrast which propagation control practices research (henceforth laboratory-grown) meticulously evaluated peer-reviewed experiments. process involves comprehensive documentation propagation, additions, storage, handling, application methods, viability, responses. Therefore, data presented provided controls compare transparent frameworks. A literature review was conducted Web Science May 2024 find papers response root colonization inoculants. Abstract search terms mycorrhiza* inocula* (462 publications identified) product* (132 identified). An additional in-press article also included due relevance (Koziol For meta-analysis, had meet criteria: (1) Experiments must follow full-factorial design, noninoculated controls; (2) Responses measured non-AM growing media; (3) Crop mean biomass and/or presented; (4) Commercial publicly products; (5) rationale behind criterion stemmed from previous indicating particularly where probability could reach 70–80% Consequently, few might on, increasing chance would introducing favoring studies, inoculant. implemented address issue ensure integrity meta-analysis Using criteria, six continents identified. names. those reporting (i.e. media). either identified field-collected soils, controls. unique Seven species utilized corn (Zea mays), tomato (Solanacea lycopersicum), Leek (Allium ampeloprasum), Sorghum (Sorghum bicolor), Sweetbay magnolia (Magnolia virginiana), carrot (Daucus carota subsp. sativus), lettuce (Lactuca sativa). As experimental details each study, 76% acquired typical customer purchase channels, 19% obtained directly companies, 5% acquisition strategies unreported. Interestingly, 20 management framework covered biotechnology, far outnumbering number effect several Variance calculated SE (Hoeksema 2010). Six estimates given variance 0.004, overestimate variance, because they rounded 0.00 (IDs 179, 180, 182, 184, 185, 188). Ten removed set mortality all receiving comparative purposes, second resulting complete (n = 10). these, CGR middle value observed harmful (−0.62) average group. Analyses R metafor package (Viechtbauer, 2010), publication, random effects. Specifying statistically nonindependence repeated use individual visualize extent observation categorized based (Table 1). category cutoffs conservative toward producers maximizing return investment (ROI). ROI vary prices crops, cost producing inoculum, well advantages symbioses specific such decreased inputs (Benami 2020). outcomes will very year (Ceballos Hijri, 20% improvement growth, likely result adoption biotechnology. Twenty-six colonization, 13 percent hyphae arbuscules proc SAS (SAS, 2013), type (control, soil, products), study year, fixed predictors, if than one experiment arbuscules, categorically 2). figures, 'Insufficient, Negligible' lumped 'None' error bars overlapping zero (mean hyphal infection: 1.6, SE: 2.1). Olpidium sp. marked absent Analyzing encompassing 298), significant differences types (Fig. 1a). showed less 9%, significantly lower (39%) (41%; Fig. Research resulted arbuscule levels 23%, while at near Study predictor (F5,259 3.7, P 0.003). 8.7% oldest (2004) 2.3% newest (2024). Approximately 3% 10) excluded 1b). Notably, 84% minimal 189 out 226), 85% 22 26) 7) sufficient Around 6% 58% displayed potential, characterized greater 25%. 81% negligible 59), crucial exchange plant–microbe symbiosis, 67% elicited 1c, n 14). Regarding contamination, microscopy indicated 11 occurrences pathogen soils two occurrence, respectively 1d). exact unclear, occurred various spanned decades trials. Meta-analysis between (Qm (df 2), 37.5, < 0.0001), demonstrated effectiveness compared 2a). Both (+38%, 0.0001) (+19%, 0.03) estimate performance overrepresents 10 therefore 2b; c. products). When substituting median dataset, reduced marginally larger S1; +13%, 0.06). Overall, 74% over 53% 40% > 2b). Further dataset 199) most necessarily linked Categorizing (> +5% −5% decrease growth), 48% found beneficial 2c). 12% 19) simultaneously suggesting largely unrelated symbiosis. By contrast, adequately colonized (63%). 41 (25%) addition highlighting negative impacts carrier media, amendments, unknown elements 70% information propagules applied per pot manufacturer's labels laboratory spore extraction (field inoculants) 211). propagule 25.7, 165.2, 1163.0 laboratory-grown, respectively. 400 6). Analysis 30 highest (792 81 455) lowest (0.4 50) numbers similar averaging 80% closely matched overall pattern previously. label correlated (P 1.0) 0.7). Mycorrhizal positively 199, R2 0.40, 0.0001). Here, studied nine colonization. indicates rarely need produce viable, substantial proportion contrasting higher rates supports findings largest presence exchange, Past work has correlation benefit 2015), illustrating importance structures benefited 63% (19 observations), labeled additions additives (Duell Given controlled fertilizer when 2024), should consider adding relevant paired accurately discrepancy raises concerns about establish relationships host plants. suggested insufficient abundance incorrect storage reasons failed However, 790) least (< similarly low observations. suggests rather primary concern. It noted disclosure form how determined add uncertainty, governing bodies allow counting others (CDFA, Considering purchasing possible approximately once reaches customer. Furthermore, Olpidium, highlights stringent measures production 2007). Although needed. comparing ectomycorrhizal concern (Karlsen-Ayala Paired recent contain claimed support inocula assessment improvement, been previously recommended (Gianinazzi Vosátka, emphasizes ensuring purity ecto- endomycorrhizal throughout packaging distribution until end users. spanning families biofuels, grains, vegetables, ornamentals, fruits, leafy greens). broad agronomic sector, demonstrating its applicability wide range agricultural practices. sheds light sector. nearly suggest 88% ineffective promoting lacked 876 spent wasted. Encouragingly, did benefitted biotechnology – issues addressed. consistent difference infection driven transparency reporting. Unlike undergo rigorous scrutiny experiments, necessitating detailed application, response. adopt standards methodology reliability Additionally, occur stream commerce, reflect use. adhering standards, effects effectively harnessed ecological purposes. summary, recommendations independently place 2004). Based yet commit improving continue show 10% (2024), that, even time. pressing mandatory regulation control. Such regulatory enforcement, along independent assessments, incur costs consumers estimated 836 extrapolated market. Funding: funded National Foundation (DBI-2027458, DBI-2120153, DTIP 2016549), University Kansas General Fund Allocation 2302053, Malone Family Land Preservation Perennial Agricultural Project. funders role design study; collection, analyses, interpretation data; writing manuscript; decision publish Liz owner MycoBloom LLC. participate study. LK conceptualized designed performed analysis, interpreted JDB formal analysis. TPM contributed collection drafted original manuscript. LK, reviewed edited visualized data. administered project funding. All authors read agreed version Dataset S1. S1 Second figure description. Please note: Wiley responsible content functionality any Supporting Information supplied authors. Any queries (other missing material) directed New Phytologist Central Office. publisher supporting content) corresponding author article.

Language: Английский

---

Positive response to inoculation with indigenous arbuscular mycorrhizal fungi as modulated by barley genotype

Agronomy for Sustainable Development, Journal Year: 2025, Volume and Issue: 45(2)

Published: March 28, 2025

Abstract Climate change-driven extreme events are reducing barley productivity. The high use of mineral fertilizers, combined with low nutrient efficiency, leads to environmental and economic concerns. Indigenous arbuscular mycorrhizal fungi (AMF) inoculants offer a sustainable alternative, especially in intensive farming systems where AM colonization diversity low. However, poor adaptation local conditions limits inoculant success. Few studies have tested indigenous AMF inoculated on field crops, limited research barley. No has yet explored how genotype environment modulate inoculation outcomes terms crop Key factors such as fungal abundance community structure shifts remain unidentified. This study evaluated the agroecological effects an consortium three varieties (Atlante, Atomo, Concerto) over 2 years. In 2020, Atomo Concerto responded positively root colonization, grain yield increases 64% 37%, respectively. 2021, only showed enhanced while increased by 78% 134% Atlante. Multivariate analysis revealed strong impact productivity, significant third-order interaction among AMF, genotype, environment. Inoculation slightly altered composition but strongly influenced structure, particularly at different plant growth stages. Root was correlated length containing arbuscules being best predictor. Changes rather than composition, drove response, Glomus Septoglomus , present inoculum, main players. These findings support for biofertilization highlight importance selecting genotypes stable response across environments. Our results disclose first time role stage host preference without inoculants.

Language: Английский

---

Realising the promise of arbuscular mycorrhizal fungal biofertilisers through more applied research

New Phytologist, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 23, 2024

'To truly harness the potential of AMF biofertilisers in sustainable agriculture, we must bridge gap between conceptual studies and practical applications.' Overall, findings Koziol et al. (2024b) are sobering, highlighting fundamental quality issues with commercial inoculants. At most basic level, these products often ineffective from onset due to insufficient numbers viable propagules by time they reach consumers. This lack viability means that many inoculants fail establish any symbiotic arbuscular mycorrhizal relationship through colonisation plant roots, which is critical for realisation expected benefits. found application 84% resulted (< 5%) root colonisation. Ten observations complete opposite desired effect product — crop mortality following application. Despite decades biofertiliser being marketed, shortcomings have persisted, pointing a systemic failure their production, assurance retail. also points absence clear guidelines frameworks, contributing persistence (Salomon al., 2022). However, it not impossible produce effective highlighted laboratory-produced demonstrated successful colonisation, as small number products. highlights indeed possible align closer expectations. The implications substantial extend beyond academic world various other considerations around agriculture sustainability. end-user left do fulfil promises, resulting economic losses unrealised environmental estimated if 88% either unable colonise or at promoting yields, then $876 million USD wasted globally primary producers. ongoing presence market undermines trust this biotechnological tool, making harder genuine be identified accepted. These failures only affect agricultural practices but risk tarnishing reputation research itself. As result, seen missed opportunities progress over several decades. A 'chicken egg' dilemma remains who responsible advancing applied research, where both academia industry could deflect responsibility onto other. Advocating an standpoint, one argue meaningful requires proactive efforts, well-positioned initiate changes. science behind advanced point producers can no longer justify persistent knowledge. Achieving goal demands shift scientific focus. For decades, countless explored effects on soil systems, concluding soils should managed boost natural communities inoculation species enhance outcomes. significant knowledge gaps hinder our ability realise suggestions. To applications. community move merely advocating use, instead address challenges limit effectiveness real-world settings. few newer studies, such Lutz (2023), worked direction predicting establishment after broad range soils. just area seems long overdue been prioritised ago. Many foundations remain underdeveloped, still relying heavily preliminary decades-old research. Based current state industry, very directives urgently needed (Fig. 1 summary). One biggest during storage. Research examine how different production methods, storage conditions, carrier materials impact propagule viability. Also, understanding spores, compared infected pieces hyphal fragments, improving quality. Another key aspect determining optimal spore density required per square meter ensure growth promotion. combined testing identify reliable water agar germination metabolic staining, help predict Additionally, evaluating whether persist multiple growing seasons factors management (especially fallow periods, fungicide application), rotations (that may include nonhost crops canola) climate (rainfall, temperature) overall functionality. It essential consider risks associated biofertilisers, displacement native unintended introduction pathogens (Schwartz 2006; 2024a). necessitates conducting genetic analyses inoculated well inoculum assess compatibility, risks, biosecurity. Such will model establishment, providing foundational framework integrated further example, functional traits community. What might initially seem like trivial tasks complicated significantly influence behaviour. conducted across diverse systems build robust body similar what has done areas its nutrition. Although debates regarding concepts previously termed 'mutualism–parasitism continuum' (Bennett & Groten, 2022), largely reached consensus common modes action when comes aim achieve strong base more closely related biofertilisers. advocate undertake does need so alone. towards well-suited collaboration partnerships regulatory agencies, parties benefit shared resources solutions. We look rhizobia inoculant exemplar bioinoculants researched applied. Symbiotic nitrogen fixation legume roots bacteria shares same principles promises AMF. Yet, contrast regulated, thus benefited rigorous control frameworks science-based development programs improve bacterial strains methods field-based (Bullard 2005). reliably nodulate host confer benefits yield nutrition, while increasing mineral N reduce fertiliser researchers AMF, there currently window opportunity us capitalise momentum recent (2024b), others. With pressure institutions collaborate with, solicit funding from, partners, poised prioritise supports global, systematic improvements ultimate furthering practice. successfully involve establishing ethical transparent collaborations bioinoculant willingness work releasing societal impacts leading right researchers, growers alike. SJW-W acknowledges Australian Council Discovery Early Career Researcher Award (DE210100908). New Phytologist Foundation neutral regard jurisdictional claims maps institutional affiliations.

Language: Английский

---

Microbial inoculants as a means of improving soil and crop yields

Scientific Horizons, Journal Year: 2024, Volume and Issue: 27(10), P. 79 - 90

Published: Aug. 27, 2024

The article presented the results of studies influence microbial inoculants Rhizobium japonicum and Azospirillum brasilense on growth development soybean (Glycine max) at initial stages its development. study was conducted three experimental plots: a control plot without treatment, with inoculum inoculum. main indicators were evaluated: plant height, number leaves, root system total biomass different growth, as well laboratory analysis nitrogen content in tissues. showed that had significant impact all measured parameters compared to plot. In particular, plants 50% higher system, which confirmed by formation nodules responsible for fixation. also improved development, but effect less pronounced japonicum. Nitrogen 45% tissue plot, indicating effective treated brasilense, 25% higher, nodule formation, pronounced. aim evaluate effectiveness improving early vegetation, investigate their productivity, uptake biomass, determine optimal conditions maximising agricultural conditions. emphasised importance using increase productivity resistance application provided greater assimilation, makes this inoculant more than

Language: Английский

---

The Importance of Mycorrhizal Fungi and Their Associated Bacteria in Promoting Crops’ Performance: An Applicative Perspective

Horticulturae, Journal Year: 2024, Volume and Issue: 10(12), P. 1326 - 1326

Published: Dec. 11, 2024

Agricultural systems are particularly impacted by global climate change (CC), responsible for the introduction of multiple environmental stressors negatively affecting plant growth. Soil microbial communities crucial in agricultural practices, influencing crop performance and soil health. Human activities CC threaten biodiversity, leading to quality degradation decreasing health productivity. Among plant-beneficial microorganisms, mycorrhizal fungi widespread terrestrial ecosystems, including agroecosystems, they play a key role enhancing plants’ fitness resilience both abiotic biotic stresses. Therefore, exploring symbiosis sustainable agriculture has become increasingly critical. Moreover, application bioinoculants could reduce dependence on inorganic fertilizers, enhance yield, support plants overcoming This review, after briefly introducing taxonomy, morphology mechanisms supporting establishment, reports roles their associated bacteria improving nutrition mitigating CC-induced stresses such as drought salinity, also giving specific examples. The focus is arbuscular (AMF), but ericoid (ErM) considered promising microorganisms model. New emerging concepts illustrated, AMF hyphosphere acting preferential niche host growth-promoting potential ErM improve Ericaceae non-host plants, behaving endophytes. Finally, limitations mycorrhizal-based discussed possible alternatives chemical-based products. To this aim, ways overcome problems use proper formulations, systematic check propagule viability suitable agronomical practices field.

Language: Английский

---