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In this study, the effectiveness of an inoculant containing a nitrogen (N)-fixing microorganism (Methylobacterium symbioticum) was evaluated on maize (Zea mays L.) grown both in the field (silage maize) and in pots over two years (2021 and 2022). The field trial included the following two treatments: with (Yes) and without (No) the inoculant. The pot experiment was designed as a factorial arrangement with two factors: the application of the inoculant (Yes and No) and N applied to the soil (0, 0.4, 0.8, and 1.6 g pot−1). In the field, total dry matter yield (DMY) did not differ significantly between treatments, although the average DMY was higher in the inoculant treatment. In pots, the total DMY varied significantly across all N rates but was only significantly affected by the inoculant application in 2022. N fixation estimates in the field were 58.8 and 14.5 kg ha−1 for 2021 and 2022, respectively, representing 23.7% and 9.1% of the N recovered in the aboveground plant parts. In pots, the estimated fixed N values were −49.2 and 199.2 mg pot−1 in 2021 and 2022, respectively, which corresponded to −5.2% and 18.5% of the N found in the aboveground plant parts. Considering the average values obtained across the four cultivation conditions, there was a positive outcome for the treated plants. However, these values cannot be considered significant when compared to nitrogen removal in maize crops. A commercial product should provide an unequivocal and quantitatively relevant contribution to plant nutrition, which did not appear to be the case. Thus, for this inoculant to provide reliable guarantees of positive outcomes for farmers and become a useful tool in promoting more sustainable agriculture, further studies appear necessary. These studies should aim to determine in which crops and under what cultivation conditions the application of the inoculant is truly effective in enhancing N fixation and improving crop productivity. [ABSTRACT FROM AUTHOR]

Introduction: There is a need to rebuild soil health by implementing regenerative agricultural practices across cropping systems dependent on agrochemicals, such as in United States corn production. One increasingly utilized regenerative practice is the application of biostimulants, or microbial inoculants that can rebuild soil health and productivity. In this study, we describe results from a multi-year corn trial conducted to quantify the impact of Re-Gen, a biostimulant invented to recycle plant biomass and increase nutrient bioavailability in the soil. Methods: Re-Gen was applied across four fields (VA01, BH01, VA04, and LA05) at a dairy cattle farm in Ferrisburgh, VT. Results: Over the two consecutive years (2022-2023) of the trial, Re-Gen application on corn stover and cover crop residues increased ear corn yield by 24% and corn silage yield by 12.5-30%, depending on the field. Analysis of soil nutrients and plant tissues showed increased nutrients, particularly in field LA-05. Multi-year Re-Gen application increased yield and generated additional economic value, indicating that the effects of Re-Gen do not diminish with multiple applications. The increased corn silage yield correlated to increased potential milk yield from cows fed silage grown in Re-Gen-treated fields. Further investigation into the mechanism suggests that increased phosphatase production Re-Gen could contribute to increased phosphorus bioavailability in the soil and uptake in the tissue, potentially increasing yields. Discussion: These results highlight the potential for Re-Gen to foster regenerative agriculture processes on cropland and livestock farms while also increasing corn and milk yield and, therefore, revenue for corn farmers in the United States and for similar cropping systems worldwide. [ABSTRACT FROM AUTHOR]

Distilled grain waste (DGW) is rich in nutrients and can be a potential resource as animal feed. However, DGW contains as much as 14% lignin, dramatically reducing the feeding value. White-rot fungi such as Pleurotus ostreatus could preferentially degrade lignin with high efficiency. However, lignin derivatives generated during alcohol distillation inhibit P. ostreatus growth. Thus, finding a new strategy to adjust the DGW properties to facilitate P. ostreatus growth is critical for animal feed preparation and DGW recycling. In this study, three dominant indigenous bacteria, including Sphingobacterium thermophilum X1, Pseudoxanthomonas byssovorax X3, and Bacillus velezensis 15F were chosen to generate single and compound microbial inoculums for DGW composting to prepare substrates for P. ostreatus growth. Compared with non-inoculated control or single microbial inoculation, all composite inoculations, especially the three-microbial compound, led to faster organic metabolism, shorter composting process, and improved physicochemical properties of DGW. P. ostreatus growth assays showed the fastest mycelial colonization (20.43 μg·g-1 ergosterol) and extension (9 mm/d), the highest ligninolytic enzyme activities (Lac, 152.68 U·g-1; Lip, 15.56 U·g-1; MnP, 0.34 U·g-1; Xylanase, 10.98 U·g-1; FPase, 0.71 U·g-1), and the highest lignin degradation ratio (30.77%) in the DGW sample after 12 h of composting with the three-microbial compound inoculation when compared to other groups. This sample was relatively abundant in bacteria playing critical roles in amino acid, carbohydrate, energy metabolism, and xenobiotic biodegradation, as suggested by metagenomic analysis. The feed value analysis revealed that P. ostreatus mycelia full colonization in composted DGW led to high fiber content retention and decreased lignin content (final ratio of 5% lignin) but elevated protein concentrations (about 130 g·kg-1 DM). An additional daily weight gain of 0.4 kg/d was shown in cattle feeding experiments by replacing 60% of regular feed with it. These findings demonstrate that compound inoculant consisting of three indigenous microorganisms is efficient to compost DGW and facilitate P. ostreatus growth. P. ostreatus decreased the lignin content of composted DGW during its mycelial growth, improving the quality of DGW for feeding cattle. [ABSTRACT FROM AUTHOR]

Background and Objectives Biofertilizers play major role in sustainable agriculture and are inoculants containing useful microorganisms which are used as solid, liquid and/or encapsulated formulations. Different materials can be used as liquid carriers. Increasing inoculant longevity by using different materials is the main purpose in production of liquid inocula. These additives are carbon-based materials and could reduce environmental stresses. In this study the effectiveness of liquid inocula of Enterobacter cloacae S16-3 on oil content, fatty acids composition and nutrient uptake of rapeseed in a sterile sandy loam soil were evaluated. Nine liquid inocula of S16-3 (F1-F9) were prepared using different amounts of materials including glycerol, polyethylene glycol (PEG), trehalose, carboxymethylcellulose (CMC), Arabic gum (AG), polyvinylpyrrolidone (PVP), glucose and starch, in different combinations. Then, the effect of liquid inocula on growth of rapeseed (Brassica napus L.) cultivar Hyola 308 was investigated. Methodology The experiment was carried out in greenhouse conditions based on completely randomized design (CRD) with three replications. The treatments were 9 liquid inocula (F1-F9). In all treatments, 70% of NPK was added to the soil in each pot, since we assumed that S16-3 is able to supply only 30% of these elements, one control treatment without adding any bacteria and fertilizer (negative control), and two positive controls (using NPK equal to 70% and 100% of fertilizer recommendation). Germinated seedlings of rapeseed were planted and inoculated with inocula in each pot. Except for NPK elements, micronutrients were provided based on soil test; however, in the case of nitrogen, phosphorus and potassium that were the main objective of this experiment, no chemical fertilizer or bacteria were used in negative control treatment. In positive control (100NPK), based on the soil test and previous experiments, 100% of the recommended amount of fertilizer, equivalent (56.5 mg N/kg soil, from Urea), (13 mg P/kg soil, from triple superphosphate) and (31.3 mg K/kg soil, from potassium sulfate) were used, moreover, for other positive control treatment (70NPK), 70% of the above values were added to the pots. During the growth period, irrigation was performed with sterile water and the moisture content of the pots was maintained by weighing in a moisture range 0.7 - 0.8 FC. At harvest, characteristics such as dry weight of roots, shoots and seed, seed oil percentage and fatty acids composition, uptake of nitrogen, phosphorus, potassium, iron, zinc, manganese and calcium by root and shoot were measured. Findings The results showed that the dry weight of root, shoot and seed, seed oil percentage and fatty acids, uptake of nitrogen, phosphorus, potassium, iron, zinc, manganese and calcium by root and shoot of rapeseed were significantly influenced by the presence of E. cloacae bacteria (in the form of nine inocula) and 100NPK and 70NPK treatments. The highest percentage of seed oil (47.02%) and the highest amount of oleic acid (53.1%) was obtained by F9 (glycerol, glucose, AG, PEG) treatment, and oil quality was affected by bacterial inoculation. The highest amount of saturated fatty acids, such as stearic acid (4.5%) and palmitic acid (5.6%) was recorded in negative control. Element analysis in dry tissue of plant showed that 100NPK treatment had the highest N, K, Fe, Zn and Ca uptake, and among liquid inocula treatments (F1-F9), the highest uptake of these elements belonged to the F5 (AG, starch, PEG). The highest amount of total P in F1 treatment (glycerol, trehalose, CMC) and F4 (trehalose, AG, PEG) and highest Mn uptake by plant were obtained in F5 treatment. Conclusion In most measured indices, the effects of liquid inocula had higher performance than without inoculation treatment (negative control). From the nutritional point of view, F5 (AG+ starch+ PEG) liquid inoculant was better than the other inocula. F9 treatment had a significant effect on quantitative and qualitative characteristics of rapeseed oil. [ABSTRACT FROM AUTHOR]

Straw‐decomposing microbial inoculants (MIs) have been increasingly applied to straw‐amended soils. However, the interactive effects and underlying microbial mechanisms of straw and decomposing MIs on nitrous oxide (N2O) emissions remain unclear. Here, a pot experiment with an Aquic Inceptisol was conducted to determine soil N2O emissions and the abundance and composition of microbial functional genes under six amendments: wheat straw (W), Bacillus subtilis MI (B), Streptomyces rochei MI (S), a combination of straw and B. subtilis MI (WB), a combination of straw and S. rochei MI (WS), and a control without wheat straw or MI (C). Compared with the control, the amendments of straw, decomposing MIs, and their combinations decreased soil N2O emissions by 43%, 22–30%, and 46–60%, respectively. Mechanistically, the positive relationship between ammonia‐oxidizing bacteria (AOB) and soil potential nitrification rate (PNR), along with decreased AOB abundance (−36%) following straw and decomposing MI amendments, further suggested that AOB predominated soil nitrification and was responsible for the suppressed nitrification. In addition, straw amendment increased nirK gene abundance (by 48%) and potential denitrification rate (by 11%), while the increase in nosZI gene abundance (+25%) involved in N2O consumption contributed to the decrease in N2O emissions. Overall, the additive effect of straw and decomposing MIs on soil N2O emissions was associated with two amendment‐induced changes in the abundance and composition of AOB and straw‐stimulated the abundance of the nosZI gene. Our results revealed the potential for mitigating N2O emissions following the amendments of straw and MI by influencing soil N2O‐related microbial groups. [ABSTRACT FROM AUTHOR]

Chemical pesticides and fertilizers are used in agricultural production worldwide to prevent damage from plant pathogenic microorganisms, insects, and nematodes, to minimize crop losses and to preserve crop quality. However, the use of chemical pesticides and fertilizers can severely pollute soil, water, and air, posing risks to the environment and human health. Consequently, developing new, alternative, environment-friendly microbial soil treatment interventions for plant protection and crop yield increase has become indispensable. Members of the filamentous fungal genus Trichoderma (Ascomycota, Sordariomycetes, Hypocreales) have long been known as efficient antagonists of plant pathogenic microorganisms based on various beneficial traits and abilities of these fungi. This minireview aims to discuss the advances in the field of Trichoderma-containing multicomponent microbiological inoculants based on recent experimental updates. Trichoderma strains can be combined with each other, with other fungi and/or with beneficial bacteria. The development and field performance of such inoculants will be addressed, focusing on the complementarity, synergy, and compatibility of their microbial components. [ABSTRACT FROM AUTHOR]

Plant growth-promoting bacteria (PGPB) have growth-promoting and disease-resisting effects and can be used as new types of plant growth promoters. This study was conducted to determine the plant growth-promoting traits of five strains and follow a 2-year field trial to evaluate their effects on grape growth and fruit quality. The five PGPB were combined with two organic fertilizers (cow dung fertilizer and distillers' grain fertilizer) for application on grape fields; the control group only received the corresponding organic fertilizer. The five strains showed different growth promoting abilities, as indicated by their differing production of indole acetic acid (IAA) and siderophores and ability to dissolve phosphorus and potassium, fix nitrogen, and resist saline and alkali. During the field trial, vine growth and fruit quality were significantly better in the distillers' grain fertilizer (high nutrient content) alone treatment than in the cow dung fertilizer (low nutrient content) alone treatment. However, after the two fertilizers were inoculated with the five different PGPB, only the five treatments with cow dung fertilizer inoculated with PGPB showed significant improvement. The five treatments of cow dung fertilizer inoculated with PGPB exhibited varied impacts on plant growth and fruit quality. And the promotion effects persisted significantly after two consecutive years. Among the PGPB, Bacillus velezensis 18, B. velezensis 20, and Rahnella aquatilis 5 emerged as consistently effective performers over the two-year period, demonstrating stable and commendable outcomes. These strains are recommended for prolonged application in grape cultivation to optimize growth and yield. This study provides a theoretical reference and an experimental basis for organic fertilizer inoculated with PGPB to improve grape production. [ABSTRACT FROM AUTHOR]

ABSTRACT Over-application of chemical fertilizers and continuous cropping obstacles seriously restrict the sustainable development of tobacco production. Localized fertilization of beneficial microbes has potential advantages in achieving higher productivity, but the underlying biological mechanisms of interactions between rhizospheric microorganisms and the related metabolic cycle remain poorly characterized. Here, an integrative analysis of microbiomes with non-targeted metabolomics was performed on 30 soil samples of rhizosphere, root surrounding, and bulk soils from flue‐cured tobacco under continuous and non-continuous monocropping systems. The analysis was conducted using UPLC-MS/MS platforms and high-throughput amplicon sequencing targeting the bacterial 16S rRNA gene and fungal ITS gene. The microbial inoculant consisted of Bacillus subtilis, B. velezensis, and B. licheniformis at the ratio of 1:1:1 in effective microbial counts, improved the cured leaf yield and disease resistance of tobacco, and enhanced nicotine and nitrogen contents of tobacco leaves. The bacterial taxa Rhizobium, Pseudomonas, Sphingomonadaceae, and Burkholderiaceae of the phylum Proteobacteria accumulated in high relative abundance and were identified as biomarkers following the application of the microbial inoculant. Under continuous monocropping, metabolomics demonstrated that the application of the microbial inoculant significantly affected the soil metabolite spectrum, and the differential metabolites were significantly enriched to the synthesis and degradation of nicotine (nicotinate and nicotinamide metabolism and biosynthesis of alkaloids derived from nicotinic acid). In addition, microbes were closely related to the accumulation of metabolites through correlation analysis. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments.IMPORTANCEThis study elaborated on how the microbial fertilizer significantly changed overall community structures and metabolite spectrum of rhizospheric microbes, which provide insights into the process of rhizosphere microbial remolding in response to continuous monocropping. we verified the hypothesis that the application of the microbial inoculant in continuous cropping would lead to the selection of distinct microbiota communities by establishing models to correlate biomarkers. Through correlation analysis of the microbiome and metabolome, we proved that rhizospheric microbes were closely related to the accumulation of metabolites, including the synthesis and degradation of nicotine. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments.

IntroductionThere is a need to rebuild soil health by implementing regenerative agricultural practices across cropping systems dependent on agrochemicals, such as in United States corn production. One increasingly utilized regenerative practice is the application of biostimulants, or microbial inoculants that can rebuild soil health and productivity. In this study, we describe results from a multi-year corn trial conducted to quantify the impact of Re-Gen, a biostimulant invented to recycle plant biomass and increase nutrient bioavailability in the soil.MethodsRe-Gen was applied across four fields (VA01, BH01, VA04, and LA05) at a dairy cattle farm in Ferrisburgh, VT.ResultsOver the two consecutive years (2022-2023) of the trial, Re-Gen application on corn stover and cover crop residues increased ear corn yield by 24% and corn silage yield by 12.5-30%, depending on the field. Analysis of soil nutrients and plant tissues showed increased nutrients, particularly in field LA-05. Multi-year Re-Gen application increased yield and generated additional economic value, indicating that the effects of Re-Gen do not diminish with multiple applications. The increased corn silage yield correlated to increased potential milk yield from cows fed silage grown in Re-Gen-treated fields. Further investigation into the mechanism suggests that increased phosphatase production Re-Gen could contribute to increased phosphorus bioavailability in the soil and uptake in the tissue, potentially increasing yields.DiscussionThese results highlight the potential for Re-Gen to foster regenerative agriculture processes on cropland and livestock farms while also increasing corn and milk yield and, therefore, revenue for corn farmers in the United States and for similar cropping systems worldwide.

In this study, the effectiveness of an inoculant containing a nitrogen (N)-fixing microorganism (Methylobacterium symbioticum) was evaluated on maize (Zea mays L.) grown both in the field (silage maize) and in pots over two years (2021 and 2022). The field trial included the following two treatments: with (Yes) and without (No) the inoculant. The pot experiment was designed as a factorial arrangement with two factors: the application of the inoculant (Yes and No) and N applied to the soil (0, 0.4, 0.8, and 1.6 g pot−1). In the field, total dry matter yield (DMY) did not differ significantly between treatments, although the average DMY was higher in the inoculant treatment. In pots, the total DMY varied significantly across all N rates but was only significantly affected by the inoculant application in 2022. N fixation estimates in the field were 58.8 and 14.5 kg ha−1 for 2021 and 2022, respectively, representing 23.7% and 9.1% of the N recovered in the aboveground plant parts. In pots, the estimated fixed N values were −49.2 and 199.2 mg pot−1 in 2021 and 2022, respectively, which corresponded to −5.2% and 18.5% of the N found in the aboveground plant parts. Considering the average values obtained across the four cultivation conditions, there was a positive outcome for the treated plants. However, these values cannot be considered significant when compared to nitrogen removal in maize crops. A commercial product should provide an unequivocal and quantitatively relevant contribution to plant nutrition, which did not appear to be the case. Thus, for this inoculant to provide reliable guarantees of positive outcomes for farmers and become a useful tool in promoting more sustainable agriculture, further studies appear necessary. These studies should aim to determine in which crops and under what cultivation conditions the application of the inoculant is truly effective in enhancing N fixation and improving crop productivity.

Currently, there is a noticeable scarcity of applications that harness composite microbial inoculants to stimulate straw decomposition, nitrogen fixation, and crop growth. This study addresses this gap by selecting and coculturing three bacterial strains to create a composite microbial inoculant named HY-1. This innovative inoculant exhibits multifunctional capabilities, including nitrogen fixation, straw decomposition, and crop growth promotion. Furthermore, we aimed to explore its impact on soil microbial communities. The results showed that the optimal preparation conditions for the compound microbial inoculant HY-1 were 28.5 ± 0.6 °C, pH = 7.34 ± 0.40, and bacteriophage ratio 1:2:1 (Microbacterium: Streptomyces fasciatus: Bacillus amyloliquefaciens). Compared to single strains, the combination exhibited higher levels of cellulose-degrading and nitrogen-fixing enzyme activity, increased the straw degradation rate by 37.91% within 180 days, and significantly promoted the growth of corn seedlings. Under the condition of straw return, the compound bio-fungicide HY-1 effectively improved the soil microbial diversity. At that time, the soil had the highest number of unique bacterial operational taxonomic units (166), and the abundance of Proteobacteria in the soil increased by 7.24%, while that of Acidobacteriota decreased by 2.27%. The biosynthetic function of the cell wall/membrane/periplasm and the metabolic function of transporting inorganic ions were significantly enhanced. In this study, we discovered that employing coculturing techniques to produce the composite microbial inoculant HY-1 and applying it in the field effectively compensates for the limitations of single-strain inoculants, which often exhibit fewer functions and less pronounced effects. This approach demonstrates significant potential for enhancing the quality of agricultural soils. [ABSTRACT FROM AUTHOR]

For a long time, microbial applications in crop production focused primarily on the symbiosis between mycorrhizal fungi and plants and the relationship between N2-fixing rhizobia and legumes. However, plant-associated microorganisms and microbiomes in general have lately gained immense attention, and the available information on the ecology and functions of microbiomes in the soil and plant environment exploded in the last decade. With this understanding, researchers as well as the industry have realized the vast potential of microorganisms to be used in agriculture and most importantly, to make farming more sustainable. Microorganisms have been shown to be applicable for plant protection and to improve plant nutrition. As a consequence, microbiome management can help to replace agrochemicals and increase environmental and human health. Furthermore, agriculture is facing various challenges related to climate change such as drought or emerging pathogens. Also, for these scenarios, microorganisms may find application to alleviate various abiotic and biotic stresses. [Graphic: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Soil salinity is a limiting factor in crop productivity. Inoculating crops with microorganisms adapted to salt stress is an alternative to increasing plant salinity tolerance. Few studies have simultaneously propagated arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSF) using different sources of native inoculum from halophyte plants and evaluated their effectiveness. In alfalfa plants as trap culture, this study assessed the infectivity of 38 microbial consortia native from rhizosphere soil (19) or roots (19) from six halophyte plants, as well as their effectiveness in mitigating salinity stress. Inoculation with soil resulted in 26–56% colonization by AMF and 12–32% by DSF. Root inoculation produced 10–56% and 8–24% colonization by AMF and DSF, respectively. There was no difference in the number of spores of AMF produced with both inoculum types. The effective consortia were selected based on low Na but high P and K shoot concentrations that are variable and are relevant for plant nutrition and salt stress mitigation. This microbial consortia selection may be a novel and applicable model, which would allow the production of native microbial inoculants adapted to salinity to diminish the harmful effects of salinity stress in glycophyte plants in the context of sustainable agriculture. [ABSTRACT FROM AUTHOR]

The present study evaluated germination, production, and morphological composition of Urochloabrizantha intercropped with corn and sorghum; and silage fermentation losses and aerobic stability of intercrop silage using microbial inoculant. Twenty experimental parcels (5.0 × 3.6 m) were used in a blocked randomized design to evaluate four treatments obtained from a 2 × 2 factorial arrangements: I) crop material (corn vs. sorghum) and II) Brachiaria (U. brizantha) establishment (present vs. absent). Corn- and sorghum-brachiaria integrated systems showed similar brachiaria germination, forage yield, and morphological composition. There was no crop and brachiaria interaction effect on the variables related to corn and sorghum plants and the total productivity. Brachiaria decreased the stem diameter and increased the population of maize and sorghum plants. However, it did not affect systems productivity. Microbial inoculation did not affect corn silage effluent losses and reduced sorghum silage effluent losses. In corn silage, brachiaria did not affect gas losses, while in sorghum silage, brachiaria increased the gas losses. Total losses were higher in sorghum silage than in corn silage, which resulted in a lower DM recovery. The treatments did not affect the pH of the silage after aerobic exposure. However, brachiaria increased silage temperature evaluated at 32 and 40 hours after aerobic exposure. Thus, corn or sorghum consortium has similar brachiaria morphological composition and productivity. Moreover, in intercropped silage, brachiaria increases effluent losses and reduces silage aerobic stability. [ABSTRACT FROM AUTHOR]

Objective This study investigated the effects of corn silage as a source of microbial inoculant containing antifungal and carboxylesterase-producing bacteria on fermentation, aerobic stability, and nutrient digestibility of fermented total mixed ration (FTMR) with different energy levels. Methods Corn silage was used as a bacterial source by ensiling for 72 d with an inoculant mixture of Lactobacillus brevis 5M2 and L. buchneri 6M1 at a 1:1 ratio. The corn silage without or with inoculant (CON vs MIX) was mixed with the other ingredients to formulate for low and high energy diets (LOW vs HIGH) for Hanwoo steers. All diets were ensiled into 20 L mini silo (5 kg) for 40 d in quadruplicate. Results The MIX diets had lower (p

This research was conducted to assess the influence of microbial inoculant (EM.1®) on the initial oviposition and developmental pattern of two prevalent necrophagous flies (Chrysomya megacephala and Chrysomya rufifacies) in Malaysia. Nine rabbit carcasses were equally divided into control and two treated groups. The control carcasses were sprayed with deionized water (about 100 mL), whereas the two other treated groups were individually sprayed with two concentrations of EM.1® at 1:500 and 1:100, respectively. Results revealed that the single application of EM.1® on both treated carcasses did not statistically impede oviposition by both necrophagous species, as well as their subsequent developmental patterns (P > 0.05) when compared with that of controls. Therefore, estimating the minimum post-mortem interval (mPMI) using empirical baseline data for the control animal model would remain appropriate for estimating mPMI in cases involving carcasses with a single application of EM.1®

Rye (Secale cereale L.) is a valuable annual forage crop in Korea but there is limited information about the impact of chemical and biological additives on fermentation characteristics of the crop. This experiment was conducted to investigate fermentation dynamics of wilted forage rye treated with the following six additives; control (no additive), sodium diacetate applied at 3 g/kg wilted forage weight (SDA3), 6 g/kg wilted forage weight (SDA6), inoculations (106 CFU/g wilted forage) of Lactobacillus plantarum (LP), L. buchneri (LB), or LP+LB. The ensiled rye sampled at 1, 2, 3, 5, 10, 20, 30, and 45 days indicated that the acidification occurred fast within five days of storage than the rest of the storage period. The microbial inoculants decline the pH of ensiled forage, more rapidly than the control or SDA treated, which accompanied by the decrease of water-soluble carbohydrates and increase of lactic acid. Compared with the control silage, all treatments suppressed ammonia-nitrogen formation below to 35 g/kg DM throughout the sampling period. Suppression of total microbial counting occurred in SDA6, LP, and LP + LB. The lactic acid production rates were generally higher in microbial inoculation treatments. Acetic acid concentration was lowest in the LP-treated silage and highest in the SDA- and LB-treated silages. The in vitro dry matter (DM) digestibility and total digestible nutrients were the highest in the silage treated with SDA (6 g/kg) at day 45 of ensiling. Based on lower ammonia-nitrogen concentrations and higher feed value, ensiling forage rye treated with SDA at 6 g/kg is promising through enhanced silage quality.

Objective: This study investigated the effects of corn silage as a source of microbial inoculant containing antifungal and carboxylesterase-producing bacteria on fermentation, aerobic stability, and nutrient digestibility of fermented total mixed ration (FTMR) with different energy levels. Methods: Corn silage was used as a bacterial source by ensiling for 72 d with an inoculant mixture of Lactobacillus brevis 5M2 and L. buchneri 6M1 at a 1:1 ratio. The corn silage without or with inoculant (CON vs MIX) was mixed with the other ingredients to formulate for low and high energy diets (LOW vs HIGH) for Hanwoo steers. All diets were ensiled into 20 L mini silo (5 kg) for 40 d in quadruplicate. Results: The MIX diets had lower (p<0.05) acid detergent fiber with higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber compared to the CON diets. In terms of fermentation characteristics, the MIX diets had higher (p<0.05) acetate than the CON diets. The MIX diets had extended (p<0.05) lactic acid bacteria growth at 4 to 7 d of aerobic exposure and showed lower (p<0.05) yeast growth at 7 d of aerobic exposure than the CON diets. In terms of rumen fermentation, the MIX diets had higher (p<0.05) total fermentable fraction and total volatile fatty acid, with lower (p<0.05) pH than those of CON diets. The interaction (p = 0.036) between inoculant and diet level was only found in the immediately fermentable fraction, which inoculant was only effective on LOW diets. Conclusion: Application of corn silage with inoculant on FTMR presented an antifungal effect by inhibiting yeast at aerobic exposure and a carboxylesterase effect by improving nutrient digestibility. It also indicated that fermented feedstuffs could be used as microbial source for FTMR. Generally, the interaction between inoculant and diet level had less effect on this FTMR study. [ABSTRACT FROM AUTHOR]

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Purpose: Recent agricultural policies require the complementary use of area-based and product-based environmental indicators to assess agricultural system transitions because both alleviating productivity-environment trade-offs and increasing food value chain sustainability are crucial in successful policy decisions. However, there is a dilemma due to the exclusiveness between representing trade-offs in the transition paths and connecting the calculated results to the assessment of downstream food products. Here, this paper proposes a procedure to resolve the dilemma. Methods: The dilemma-resolving procedure is to partition product footprint changes into yield and environmental improvement effects in the same unit as the product footprint. After specifying a typology of transition toward agricultural sustainability, the partitioning procedure was developed on the basis of mapping from a two-dimensional space (area-based indicators) to a one-dimensional space (product-based indicators). To demonstrate the effectiveness and performance of the partitioning procedure, this paper applied it to the three categories of agricultural system transitions, including those to organic agriculture, integrated production, and production systems involving new agricultural inputs such as microbial inoculants and biostimulants, using the cases of the impact category of global warming (carbon footprint). The transition dataset (matched pairs) was constructed using a bibliographical survey. Results and discussion: The results indicate that the partitioning procedure is effective and has good performance: (1) it was able to apply to all the cases in the dataset and to classify all the cases into six specified transition types; (2) it was differentiable between the three transition categories; and (3) it was able to explain the features of each transition category. These results imply that the perspective on agricultural system transitions can be integrated with the perspective on food value chains. Therefore, productivity-environment trade-offs during the research and development phase of agricultural technologies can be linked to environmental mitigation practices along the food value chains. Conclusions: The results imply that, by applying the partitioning procedure, the recent agricultural policy framework contained two exclusive perspectives can be explained consistently. Every stakeholder related to agricultural policy making should be explicit about product-environment trade-offs during agricultural system transitions, as well as about food value chain sustainability. The partitioning procedure facilitates such stakeholder practices. [ABSTRACT FROM AUTHOR]

Microbial inoculants can be used to restore abandoned mines because of their positive effects on plant growth and soil nutrients. Currently, soils in greenhouse pot studies are routinely sterilized to eradicate microorganisms, allowing for better inoculant colonization. Large-scale field sterilization of abandoned mining site soils for restoration is difficult, though. In addition, microbial inoculants have an impact on plants. Plants also have an impact on local microbes. The interactions among microbial inoculants, native microorganisms, and plants, however, have not been studied. We created a pot experiment utilizing the soil and microbial inoculant from a previous experiment because it promoted plant growth in that experiment. To evaluate the effects of the plants, native microorganisms, and microbial inoculants, we assessed several indicators related to soil elemental cycling and integrated them into the soil multifunctionality index. The addition of the microbial inoculant and sterilizing treatment had a significant impact on alfalfa growth. When exposed to microbial inoculant treatments, the plant and sterilization treatments displayed radically different functional characteristics, where most of the unsterilized plant treatment indices were higher than those of the others. The addition of microbial inoculant significantly increased soil multifunctionality in plant treatments, particularly in the unsterilized plant treatment, where the increase in soil multifunctionality was 260%. The effect size result shows that the positive effect of microbial inoculant on soil multifunctionality and unsterilized plant treatment had the most significant promotion effect. Plant and native microorganisms amplify the positive effects of microbial inoculant. [ABSTRACT FROM AUTHOR]

Plant growth-promoting bacteria (PGPB) have growth-promoting and disease-resisting effects and can be used as new types of plant growth promoters. This study was conducted to determine the plant growth-promoting traits of five strains and follow a 2-year field trial to evaluate their effects on grape growth and fruit quality. The five PGPB were combined with two organic fertilizers (cow dung fertilizer and distillers’ grain fertilizer) for application on grape fields; the control group only received the corresponding organic fertilizer. The five strains showed different growth promoting abilities, as indicated by their differing production of indole acetic acid (IAA) and siderophores and ability to dissolve phosphorus and potassium, fix nitrogen, and resist saline and alkali. During the field trial, vine growth and fruit quality were significantly better in the distillers’ grain fertilizer (high nutrient content) alone treatment than in the cow dung fertilizer (low nutrient content) alone treatment. However, after the two fertilizers were inoculated with the five different PGPB, only the five treatments with cow dung fertilizer inoculated with PGPB showed significant improvement. The five treatments of cow dung fertilizer inoculated with PGPB exhibited varied impacts on plant growth and fruit quality. And the promotion effects persisted significantly after two consecutive years. Among the PGPB, Bacillus velezensis 18, B. velezensis 20, and Rahnella aquatilis 5 emerged as consistently effective performers over the two-year period, demonstrating stable and commendable outcomes. These strains are recommended for prolonged application in grape cultivation to optimize growth and yield. This study provides a theoretical reference and an experimental basis for organic fertilizer inoculated with PGPB to improve grape production.

Composting is an effective method of recycling organic solid waste, and it is the key process linking planting with recycling. To explore the reuse of agricultural organic solid waste as a resource in the Yellow River Delta, the effects of microbial inoculant and different additives (calcium superphosphate, biochar, tomato straw, rice husk, and sugar residue) on pile composting of cow dung were studied to obtain the best composting conditions. The results showed that microbial inoculant and additives all played positive roles in the process of aerobic composting, and the experimental groups outperformed the control groups without any additives. For discussion, the microbial inoculant promoted rapid pile body heating more than the recovery materials alone, and the effects on aerobic composting were related to the organic matter of substrates and biochar. After being composted, all the materials were satisfactorily decomposed. Degradation of additives into humic acid might serve as electron shuttles to promote thorough organic matter decomposition. These results provide a scientific basis data for industrial composting of organic solid waste processed by onsite stacking, and provide a reference for researcher and practitioners for studying the applications of microbial inoculant on aerobic composting. [ABSTRACT FROM AUTHOR]

Biostimulants have been identified as an alternative to chemical fertilizer to increase crop production in sustainable farming. The aim of the study was to investigate the effects of two commercial biostimulants (protein hydrolysate (PH) Trainer® and microbial inoculant Europlus®) on the growth, yield and quality of oriental tobacco. The field experiment was conducted in 2020 and 2021 at Tobacco and Tobacco Products Institute, Markovo, Bulgaria on Rendzic Leptosol. The experimental design was a randomized complete block replicated three times. The doses of both biostimulants were used based on the manufacturer's recommendations. The plants were sprayed two times with PH Trainer four and six weeks after transplanting. The microbial product Europlus was incorporated in the top soil layer three weeks after transplanting. The control plants were not treated with biostimulants. The application of microbial inoculant Europlus and PH Trainer improved the yield of tobacco by 5.5% and 6.7%, respectively, in comparison with untreated plants. The enhancement of the yield of sun-cured leaves was mainly due to the higher leaf area. Biostimulant treatments had no significant effect on macro and micronutrient concentrations in tobacco leaves. The application of PH Trainer and microbial inoculant Europlus increased the N, P, and K concentrations in leaves. The concentration of Ca, Mn, Zn and Cu were slightly higher than the control treatment when microbial inoculant Europlus was applied. The addition of protein hydrolysate Trainer and microbial inoculant Europlus increased nicotine content by 13.5% and 8.6%, respectively, compared to the control. The reducing sugars/nicotine ratio was better in tobacco from treatments with biostimulants compared to non-treated control. The results indicated that the use of biostimulants (microbial inoculant and protein hydrolysate) in sustainable tobacco farming was effective in increasing the yield of oriental tobacco and the quality of cured leaves. [ABSTRACT FROM AUTHOR]

This research was conducted to assess the influence of microbial inoculant (EM.1®) on the initial oviposition and developmental pattern of two prevalent necrophagous flies (Chrysomya megacephala and Chrysomya rufifacies) in Malaysia. Nine rabbit carcasses were equally divided into control and two treated groups. The control carcasses were sprayed with deionized water (about 100 mL), whereas the two other treated groups were individually sprayed with two concentrations of EM.1® at 1:500 and 1:100, respectively. Results revealed that the single application of EM.1® on both treated carcasses did not statistically impede oviposition by both necrophagous species, as well as their subsequent developmental patterns (P > 0.05) when compared with that of controls. Therefore, estimating the minimum post-mortem interval (mPMI) using empirical baseline data for the control animal model would remain appropriate for estimating mPMI in cases involving carcasses with a single application of EM.1®. [ABSTRACT FROM AUTHOR]

Peat is typically used as a carrier for microbial inoculants; however, due to its non-renewable nature alternatives need to be identified as reliable and renewable carriers for mineral-solubilizing inoculants. In pot experiments, solid microbial inoculants were comprised of peat (P), biochar (BC), and spent mushroom substrates (SMS) using Medicago sativa L. as experimental materials, and the purpose of this study is to assess the effect of solid microbial inoculants on soil multifunctionality and plant growth. The results revealed that the SMS microbial inoculant had the greatest positive impact on plant biomass and significantly stimulated soil multifunctionality which is typically managed or assessed based on various soil functions or processes that are crucial for sustaining productivity, in contrast to the peat microbial inoculant, particularly at a supply level of 100 g/pot. There was no significant correlation between soil multifunctionality and bacterial/fungal microbial diversity. However, according to the co-occurrence network of bacteria and fungi, soil multifunctionality was intimately correlated with the biodiversity of the main ecological clusters (modules) of bacteria and fungi, rather than to the entire soil microbial community structure. The keystone species of module hubs and connectors play critical roles in maintaining the stability of ecological clusters of microbial co-occurrence networks and linkages between ecological clusters. Soil pH is a major predictor of changes in plant biomass, and leads to changes therein by affecting the major ecological clusters of bacterial and fungal co-occurrence networks. These results suggested that SMS may serve as a good alternative to peat as a carrier of mineral-solubilizing microorganisms to maintain soil multifunctionality and promote plant growth. [Display omitted] • Microbial inoculants using spent mushroom substrates enhance soil multifunctionality. • There is no significant correlation between soil microbial diversity and multifunctionality. • Soil multifunctionality is linked to the biodiversity of Bacterial module 1 and Fungal module 1. [ABSTRACT FROM AUTHOR]

The high content of recalcitrant lignocellulose in green waste (GW) makes composting and degradation challenging. Conventional GW composting typically employs single-strain microbial inoculants (MIs) with limited enzyme production capabilities, resulting in low composting efficiency and suboptimal compost product quality. In this study, Bacillus amyloliquefaciens (J1), Clonostachys rogersoniana (B2), and Streptomyces thermoviolaceus (J3) was utilized to optimize cultivation conditions and strain ratios based on enzyme activity indicators. The aim was to develop a potent three-strain lignocellulose-degrading MIs and test the hypothesis that its performance is superior to that of single-strain and two-strain MIs in terms of lignocellulose degradation and compost maturation. The results indicated that, the optimal treatment was T7, which was inoculated with a three-strain MIs composed of the spore suspensions of J1, B2, and J3 with a volume ratio of 3:3:2. Specifically, compared to the control (without MI), T7 increased the content of particle size between 0.25 and 2.00 mm and humic acid by 17% and 291%, respectively. Furthermore, T7 enhanced the degradation rates of cellulose, hemicellulose, and lignin by 197%, 145%, and 113%, respectively, and increased the activities of laccase, manganese peroxidase, lignin peroxidase, and carboxymethyl cellulase by 605%, 269%, 180%, and 228%, respectively. Additionally, T7 increased the relative abundance of bacteria (e.g. Pseudomonas) and fungi (e.g. Parascedosporium) that facilitated lignocellulose degradation, enhanced the alpha diversity index and promoted the formation of a microbial community structure characterized by prominent dominant species and greater diversity. Remarkably, the inoculation with the three-strain MI yielded high-quality compost within 32 days. [Display omitted] • Adding a three-strain microbial inoculant (MI) optimized green waste composting. • The efficiency of three-strain MI was superior to single-strain or two-strain MI. • Inoculation with a three-strain MI reduced the composting time to 32 days. • The degradation rates of lignocelluloses were the highest with the three-strain MI. • Inoculation with three-strain MI boosted the relative abundance of Actinobacteria. [ABSTRACT FROM AUTHOR]

Co-composting with exogenous microbial inoculant, presents an effective approach for the harmless utilization of livestock manure and agroforestry wastes. However, the impact of inoculant application on the variations of viral and antibiotic resistance genes (ARGs) remains poorly understood, particularly under varying manure quantity (low 10 % vs. high 20 % w/w). Thus, employing virome and metagenomic sequencing, we examined the influence of Streptomyces - Bacillus Inoculants (SBI) on viral communities, phytopathogen, ARGs, mobile genetic elements, and their interrelations. Our results indicate that SBI shifted dominant bacterial species from Phenylobacterium to thermotropic Bordetella , and the quantity of manure mediates the effect of SBI on whole bacterial community. Major ARGs and genetic elements experienced substantial changes with SBI addition. There was a higher ARGs elimination rate in the composts with low (∼76 %) than those with high manure (∼70 %) application. Virus emerged as a critical factor influencing ARG dynamics. We observed a significant variation in virus community, transitioning from Gemycircularvirus - (∼95 %) to Chlamydiamicrovirus -dominance. RDA analysis revealed that Gemycircularvirus was the most influential taxon in shaping ARGs, with its abundance decreased approximately 80 % after composting. Collectively, these findings underscore the role of microbial inoculants in modulating virus communities and ARGs during biowaste co-composting. [Display omitted] ● Co-composting with microbial inoculant suppressed ARGs and pathobiome risks. ● Widely-existed phytopathogens significantly decreased following co-composting. ● Inoculants and manure quantity modulates virus communities and ARGs. ● Virus was a significant positive factor influencing ARGs. ● Gemycircularvirus was the most influential taxon in shaping ARGs changes. [ABSTRACT FROM AUTHOR]

Silage has been the preferred method of forage conservation in many regions of the world, primarily due to frequent rainfall during the period of maximum forage growth and limited opportunities to preserve forage as hay. Corn and sorghum are the main forages conserved as silage, but cultivation of annual summer crops is costly and may be risky due to variable climactic conditions. Therefore, livestock producers have relied on perennial grasses as a source of forage for conservation as silage. However, most grasses have undesirable characteristics that reduce the potential of achieving satisfactory fermentation and conservation, such as limited dry matter concentration, and morphological and chemical characteristics. Several management practices have been developed with the objective of improving grass silage fermentation and nutritive value, and microbial inoculants have been among the most used management practices. Nonetheless, most microbial inoculants have been tested and developed for corn silage and later recommended to grass silage with limited scientific evidence for the efficacy of the specific inoculant. The most used grasses as forages are divided into cool- (C3) and warm-season (C4) perennial grasses with notorious differences between them. Cool-season grasses have greater water-soluble carbohydrates and lesser structural carbohydrates concentrations than warm-season perennial grasses, which are desirable traits for better silage fermentation and positive microbial inoculant effects. Warm-season perennial grasses have greater accumulation of starch as non-structural carbohydrate, which does not directly contribute to silage fermentation. In addition to the limitations mentioned previously, warm-season perennial grasses have decreased dry matter concentration and nutritive value, reducing the likelihood of achieving desirable fermentation. A literature review was conducted to evaluate the effects of microbial inoculant on nutritive value and fermentation characteristics (pH, lactic acid, acetic acid, butyric acid, and ammonia concentrations) of grass silage. In addition, the effect of different microbial inoculants (homofermentative vs. heterofermentative) was evaluated. Lastly, results from current research projects testing the effects of microbial inoculants on silage microbiome and gas production were presented. [ABSTRACT FROM AUTHOR]

Warm-season perennial grasses are the main forage sources preserved as silage or haylage by livestock producers in subtropical and tropical regions; however, the nutritive value and silage fermentation parameters are often less than desirable. Microbial inoculants have been used to improve grass silage nutritive value and fermentation characteristics with inconsistent results. The objective of this study was to investigate the effects of a microbial inoculant on nutritive value and fermentation parameters of ‘Gibtuck’ limpograss (Hemarthria altissima) silage. Treatments were silage treated with SiloSolve FC (68.1 billion CFU/g, Lactobacillus lactis and Lactobacillus buchneri) or control (no microbial inoculant) distributed in a complete randomized design with 10 replicates. The inoculant level used was 0.5 g/ Mg of forage. The experiment was conducted in Ona, FL in May 2023. Twenty 4 × 4 m plots of established limpograss were harvested at 15-cm stubble height with 58-d regrowth interval. The forage was chopped to a particle size ranging from 10 to 18 mm, placed into mini-silos (PVC pipes with rubber), and sealed immediately. The inoculant was applied with a hand sprayer before ensiling. The silos were opened after 60 d for analysis. There was no difference (P > 0.05) between the inoculant and control treatments on DM concentration (25%), DM recovery (96%), NDF (67%), and NFC concentrations (14%); however, silage treated with inoculant had greater CP (8.5 vs. 8.0%; P = 0.03), IVTD (56 vs. 54%; P = 0.01), and NDFD (53 vs. 51%, P = 0.02) and lesser ADF concentrations (38 vs. 40%; P = 0.02) than control. The inoculant did not affect (P > 0.05) silage pH (4.2) and lactic acid concentrations (1.5%) but resulted in greater acetic acid (2.5 vs. 2.0%; P = 0.01), propionic acid (1.6 vs. 1.0%, P < 0.01), and total acid concentrations (5.6 vs. 5.0%; P = 0.04), and decreased butyric acid (0 vs. 0.2%; P < 0.01), isobutyric acid (0.1 vs. 0.4%; P < 0.01), and NH3-N concentrations (4.4 vs. 5.3% N; P < 0.01). Aerobic stability (140 h), mold (1.1 log cfu/g) and yeast (2.2 log cfu/g) count were not affected (P > 0.05) by the inoculant treatment. At the genus level, there was no difference (P > 0.05) in relative abundance of Lactobacillus (85%), Enterobacter (4.0%), Enterococcus (1.8%), and Weissella (0.2%) between inoculant and control, but silage treated with inoculant had less Clostridium (1.0 vs. 2.3%, P = 0.04), Pediococcus (0.2 vs. 0.3%, P = 0.03) and greater relative abundance of Lactococcus (2.8 vs. 0.5%, P < 0.01) and Bacillus (0.2 vs. 0.1%, P = 0.01). At the species level, the inoculant was effective to increase the relative abundance of Lactococcus lactis (from 0.02 to 0.48, P = 0.002) and Lactobacillus buchneri (from 1.4 to 1.9, P = 0.03). SiloSolve FC is a promising microbial inoculant to be used in warm-season grass silage in subtropical and tropical regions. [ABSTRACT FROM AUTHOR]

Plant seeds harbor numerous beneficial endophytes that can be vertically transmitted across generations, positively influencing plant growth. This study aimed to enhance our understanding of the functions of endophytes in Eucommia ulmoides seeds and investigate their potential mechanisms for promoting E. ulmoides seedling growth. Preliminary screening for seed endophytes that increase E. ulmoides seedling growth was conducted using microbe–seedling co-culture experiments. Subsequently, the two strains with the most pronounced growth-promoting effects were tested in pot experiments. The mechanism underlying their effects on E. ulmoides growth was elucidated through high-throughput sequencing analysis of rhizosphere soil. The bacterium Cytobacillus gottheilii B7 and the fungus Cladosporium halotolerans Z27 had the most significant growth-promoting effects on E. ulmoides seedlings. Inoculation of these strains into the soil led to substantial improvements in physiological indicators in E. ulmoides. Notably, strain B7 showed a superior effect compared to strain Z27. Although strain B7 inoculation reduced rhizosphere bacterial α-diversity, it strengthened the network interactions among rhizosphere microorganisms and selectively recruited specific rhizosphere microbial taxa, including Ilumatobacter , Algoriphagus and OLB13, while inhibiting the growth of Subulicystidium and Symmetrospora. Functional annotation suggested that strain B7 inoculation enhanced plant nitrite respiratory metabolism and inhibited plant pathogen. Similarly, strain Z27 inoculation recruited genera such as Flavihumibacter , Pseudoxanthomonas , and Myriococcum , while inhibiting Symmetrospora. These results provide scientific data for a comprehensive analysis of seed endophytes in the future and valuable resources for the development and application of microbial inoculants. • Inoculation of endophytes promoted E. ulmoides growth and stress resistance. • Inoculation of endophytes changed the structure and function of E. ulmoides rhizosphere microbiota. • Inoculation of endophytes recruited beneficial microorganisms and inhibited plant pathogen in the rhizosphere. [ABSTRACT FROM AUTHOR]

ABSTRACT: The present study evaluated germination, production, and morphological composition of Urochloabrizantha intercropped with corn and sorghum; and silage fermentation losses and aerobic stability of intercrop silage using microbial inoculant. Twenty experimental parcels (5.0 × 3.6 m) were used in a blocked randomized design to evaluate four treatments obtained from a 2 × 2 factorial arrangements: I) crop material (corn vs. sorghum) and II) Brachiaria (U. brizantha) establishment (present vs. absent). Corn- and sorghum-brachiaria integrated systems showed similar brachiaria germination, forage yield, and morphological composition. There was no crop and brachiaria interaction effect on the variables related to corn and sorghum plants and the total productivity. Brachiaria decreased the stem diameter and increased the population of maize and sorghum plants. However, it did not affect systems productivity. Microbial inoculation did not affect corn silage effluent losses and reduced sorghum silage effluent losses. In corn silage, brachiaria did not affect gas losses, while in sorghum silage, brachiaria increased the gas losses. Total losses were higher in sorghum silage than in corn silage, which resulted in a lower DM recovery. The treatments did not affect the pH of the silage after aerobic exposure. However, brachiaria increased silage temperature evaluated at 32 and 40 hours after aerobic exposure. Thus, corn or sorghum consortium has similar brachiaria morphological composition and productivity. Moreover, in intercropped silage, brachiaria increases effluent losses and reduces silage aerobic stability.

While large inputs of synthetic nitrogen fertilizers enable our current rate of crop production and feed a growing global population, these fertilizers come at a heavy environmental cost. Driven by microbial processes, excess applied nitrogen is lost from agroecosystems as nitrate and nitrous oxide (N 2 O) contaminating aquatic ecosystems and contributing to climate change. Interest in nitrogen-fixing microorganisms as an alternative to synthetic fertilizers is rapidly accelerating. Microbial inoculants offer the promise of a sustainable and affordable source of nitrogen, but the impact of inoculants on nitrogen dynamics at an ecosystem level is not fully understood. This review synthesizes recent studies on microbial inoculants as tools for nutrient management and considers the ramifications of inoculants for nitrogen transformations beyond fixation. Nitrogen-fixing microbial inoculants are widely studied as alternatives to synthetic nitrogen fertilizers. Some microbial inoculants may aid in mitigating nitrous oxide (N 2 O) emissions from agriculture. However, other inoculant formulations can exacerbate N 2 O emissions, further contributing to greenhouse gas emissions. Although nitrate leaching from agroecosystems poses a serious environmental threat, whether inoculants mitigate or exacerbate nitrification is poorly understood. Microbial inoculants can have off-target effects, including disruption of resident microbial community structure and increased nitrogen losses. [ABSTRACT FROM AUTHOR]

Bio-formulation technologies have a limited impact on agricultural productivity in developing countries, especially those based on plant growth-promoting rhizobacteria. Thus, calcium alginate microbeads were synthesized and used for the protection and delivery of three beneficial Bacillus strains for agricultural applications. The process of encapsulation had a high yield per gram for all bacteria and the microbeads protected the Bacillus strains, allowing their survival, after 12 months of storage at room temperature. Microbead analysis was carried out by observing the rate of swelling and biodegradation of the beads and the released-establishment of bacteria in the soil. These results showed that there is an increase of around 75% in bead swelling on average, which allows for larger pores, and the effective release and subsequent establishment of the bacteria in the soil. Biodegradation of microbeads in the soil was gradual: in the first week, they increased their weight (75%), which consistently results in the swelling ratio. The co-inoculation of the encapsulated strain TRQ8 with the other two encapsulated strains showed plant growth promotion. TRQ8 + TRQ65 and TRQ8 + TE3T bacteria showed increases in different biometric parameters of wheat plants, such as stem height, root length, dry weight, and chlorophyll content. Thus, here we demonstrated that the application of alginate microbeads containing the studied strains showed a positive effect on wheat plants. [ABSTRACT FROM AUTHOR]

Paenibacillus mucilaginosus is a typical plant growth-promoting rhizobacterium. However, the relevant molecular mechanisms remain obscure. This study investigated the effect of Paenibacillus mucilaginosus PM12 on tomato growth and uncovered the bacterium's physiological processes. A greenhouse experiment was conducted, which included the PM12 group (3.2*108 cfu/pot) and the control group (inoculated with the same amount of sterilized suspension). The metabolomics of the centrifuged supernatant of the fermentation broth of Paenibacillus mucilaginosus was studied by LC-MS, and the metabolite composition of the functional bacteria and its metabolic pathway were determined. PacBio+Illumina HiSeq sequencing was used to complete map sequencing of the samples. Indepth analysis of the functional genes related to the secretion of these substances by functional bacteria was conducted. PM12 significantly promoted the tomato growth, early flowering time and increased fruiting. Extracellular metabolite composition analysis showed that PM12 secreted organic acids to dissolve phosphorus, capsular polysaccharides to dissolve potassium, and auxin. The complete genome sequence indicated that the strain comprised one circular chromosome with 8,660,710 bases containing 58.51% GC content and 85.67% coding regions. Four genes (pyk, ackA, gltA and aroK) were related to organic acid secretion, four genes (pelA, pelD, pelf and pelG) were related to capsular polysaccharide secretion, and four genes (trpA, trpB, trpS and idi) were related to auxin secretion. The molecular biological mechanism of the extracellular secretion of organic acids to dissolve phosphorus, capsular polysaccharides to dissolve potassium and auxin to promote the growth of the PM12 strain was elucidated. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the effects of chitosan instead of microbial inoculants on fermentation profile, losses, chemical composition, in vitro degradation, and aerobic stability of sugarcane silage (SS). Forty experimental silos (PVC tubes with 28 cm i.d., 25 cm height) were used in a randomized block design to evaluate the following treatments: (I) Control (CON): SS with no additive; (II) LB: SS ensiled with 5.0 × 105 colony forming units (CFU) of Lactobacillus buchneri (NCIM 40788)/g as-fed; (III) LPPA: SS ensiled with 1.6 × 105 CFU of L. plantarum and 1.6 × 105 CFU of Pediococcus acidilactici /g as-fed; and (IV) Chitosan (CHI): SS ensiled with 6 g/kg dry matter (DM) of chitosan. Microbial inoculation of SS reduced (P ≤ 0.05) silage pH relative to CON and CHI treatment. The LPPA decreased ammonia-nitrogen and LB decreased (P ≤ 0.05) ethanol content and increased acetic acid content relative to other treatments. The LPPA-silos had higher (P ≤ 0.05) gas losses and lower (P ≤ 0.05) DM recovery than other treatment silos. Consequently, LPPA reduced (P ≤ 0.05) DM and non-fibre carbohydrates and increased (P ≤ 0.05) neutral detergent fibre (NDF) silage content compared to other treatments. Treatments did not affect (P ≥ 0.212) DM and NDF in vitro degradation and silage pH after aerobic exposure. However, LB reduced silage temperature after aerobic exposure. Thus, LB reduces alcoholic fermentation and improves SS aerobic stability. Inoculation of LPPA reduces DM recovery and negatively affects SS chemical composition. Although CHI positively affects SS conservation relative to CON, it shows higher gas losses and decreased SS temperature after aerobic exposure compared to LB. [ABSTRACT FROM AUTHOR]

The silage process is an efficient way of storing nutrients for animal nutrition. Our hypothesis was that the Baru pulp can be preserved in the form of silage, regardless of the use of additives to aid the process. Silages of Baru pulp containing different additives were evaluated through in vitro analysis, fermentation parameters, and composition and thermal analysis including differential scanning calorimetry and thermogravimetry. The treatments consisted of (1) silage with Baru pulp (BP) in natura without additive; (2) BP in natura with acetic acid; (3) BP in natura with formic acids; and (4) BP in natura added with microbial inoculums in a randomized experimental design with three replications per treatment and analyzed in duplicate. The ensiled material was kept in anaerobic conditions for a period of 30 days. BP before and after the silage process presented averages of 67.31 and 66.24% for in vitro digestibility of DM (IVDMD). Microbial inoculant additive was the most effective in reducing pH, followed by acetic acid and formic acid. There were effects of additives on silages for all degradation parameters in ruminal liquid in vitro. It was observed that BP before ensiling had the highest A fraction (7.9 mL gas/100 mg DM), without differing from the silage treated with formic acid (7.1 mL gas/100 mg DM). Similar effects were observed on mass loss (TG) and heat flux (DSC) between the silages. Our findings suggest that Baru pulp with formic acid is more efficient in the conservation and preservation of fermentable carbohydrates as well as in silage production. [ABSTRACT FROM AUTHOR]

Strain TSO9 was isolated from a commercial field of wheat (Triticum turgidum L. subsp. durum) located in the Yaqui, Valley, Mexico. Here, the genome of this strain was sequenced, obtaining a total of 5,248,515 bp; 38.0% G + C content; 1,186,514 bp N50; and 2 L50. Based on the 16S rRNA gene sequencing, strain TSO9 was affiliated with the genus Priestia. The genome annotation of Priestia sp. TSO9 contains a total of 147 RNAs, 128 tRNAs, 1 tmRNA, and 5512 coding DNA sequences (CDS) distributed into 332 subsystems, where CDS associated with agricultural purposes were identified, such as (i) virulence, disease, and defense (57 CDS) (i.e., resistance to antibiotics and toxic compounds (34 CDS), invasion and intracellular resistance (12 CDS), and bacteriocins and ribosomally synthesized antibacterial peptides (10 CDS)), (ii) iron acquisition and metabolism (36 CDS), and (iii) secondary metabolism (4 CDS), i.e., auxin biosynthesis. In addition, subsystems related to the viability of an active ingredient for agricultural bioproducts were identified, such as (i) stress response (65 CDS). These genomic traits are correlated with the metabolic background of this strain, and its positive effects on wheat growth regulation reported in this work. Thus, further investigations of Priestia sp. TSO9 are necessary to complement findings regarding its application in agroecosystems to increase wheat yield sustainably. [ABSTRACT FROM AUTHOR]

The application of microbial inoculants holds promise for the sustainable restoration of abandoned mine sites by affecting soil nutrients and microbial communities. However, the responses of plant microbial communities to microbial inoculants in mine restoration remain largely unknown. To bridge this knowledge gap, we conducted a 4-year field experiment at an abandoned carbonate mine site to assess the impacts of microbial inoculants on the soil-plant microbiome. Our findings revealed that microbial inoculants significantly changed roots, fine root bacterial and fungal communities. Further, no significant correlations were observed between the soil-plant nutrient content (Z-score) and microbial alpha diversity. However, a significantly positive correlation was found between the relative abundance of the keystone ecological cluster (Module #1) and soil-plant nutrient content. The application of microbial inoculants also increased complexity, albeit decreased stability of plant microbiome networks, alongside a reduction in stochastic assembly. Conversely, they decreased the complexity but increased the stability of soil microbiome networks, accompanied by an increase in stochastic assembly. Notably, the number of specifically enriched microbiome functional traits of roots and root nodules under the microbial inoculant treatments surpassed that of the control. In summary, our findings underscored the potential of microbial inoculants to enhance soil-plant functionality at abandoned mine restoration sites., (© 2024 John Wiley & Sons Ltd.)

Soil salinity is a limiting factor in crop productivity. Inoculating crops with microorganisms adapted to salt stress is an alternative to increasing plant salinity tolerance. Few studies have simultaneously propagated arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSF) using different sources of native inoculum from halophyte plants and evaluated their effectiveness. In alfalfa plants as trap culture, this study assessed the infectivity of 38 microbial consortia native from rhizosphere soil (19) or roots (19) from six halophyte plants, as well as their effectiveness in mitigating salinity stress. Inoculation with soil resulted in 26–56% colonization by AMF and 12–32% by DSF. Root inoculation produced 10–56% and 8–24% colonization by AMF and DSF, respectively. There was no difference in the number of spores of AMF produced with both inoculum types. The effective consortia were selected based on low Na but high P and K shoot concentrations that are variable and are relevant for plant nutrition and salt stress mitigation. This microbial consortia selection may be a novel and applicable model, which would allow the production of native microbial inoculants adapted to salinity to diminish the harmful effects of salinity stress in glycophyte plants in the context of sustainable agriculture.

In this study, it was aimed to determine the effect of microbial inoculants and molasses on the quality and in vitro digestibility of the silages ensiled from the cultivation of different proportions of ryegrass-Hungarian vetch mixtures grown in Central Anatolian conditions. For this purpose, 5% molasses and 10 g/ton (1.25 x 1011 CFU/g) inoculant were added to silages of ryegrass (Lolium multiflorum L.) containing 20%, 40%, 60%, and 80% Hungarian vetch (Vicia pannonica L.), under laboratory conditions. The prepared silages were opened at the end of 60 days and their physical analysis, chemical contents, fermentation parameters, in vitro digestibilities using rumen inocula obtained from cannulated Holstein cow, and energy levels were determined. In the study, it was determined that the microbial inoculant increased the lactic acid level significantly (p < 0.05). In vitro digestibility of organic matter and energy values increased in silages containing 60% HV compared to other silages and with both additives (p < 0.05). The neutral detergent fiber levels increased in mixtures containing 40% and 60% Hungarian vetch (p < 0.05). The increase in the vetch ratio affected the external appearance of the silages negatively (p < 0.05), and the physical properties were adversely affected by the inoculant (p < 0.05). As a result, it was determined that Hungarian vetch can be mixed with ryegrass up to 80% with and without inoculant and molasses additive to obtain high-quality silage. But the highest digestibility values were obtained when Hungarian vetch was mixed at a 60% level. It would be more appropriate to prefer molasses to avoid undesired changes in physical properties. [ABSTRACT FROM AUTHOR]

Although straw-decomposing microbial inoculants (SDMI) are capable to generally promote the fertility of straw-amended soils, their impact on the release of individual soil major nutrients remains controversial. Additionally, the combined effects of SDMI and environment/management on various forms of nutrients remain poorly documented. To fill these research gaps, we conducted a meta-analysis study using 1214 paired observations from 132 field trials in China. Our results showed that SDMI significantly increases the total and available concentrations of nitrogen, phosphorus, and potassium in soil (p < 0.05), although increases in nutrients varied with different conditions. Moreover, mean annual precipitation (MAP) had significant correlations with the effects of SDMI-amended straw on soil total nitrogen (p = 0.008) and available nitrogen (p = 0.0006). The effect of SDMI-amended straw on soil total phosphorus and soil available potassium was mainly correlated with soil organic matter (p = 0.032) and MAP (p = 0.049), respectively. Our findings indicate that SDMI-amended straw can have a measurable impact on the status of soil major nutrients. In particular, the application of SDMI-amended rice straw with an initial C/N ratio of ≤15 to neutral soils in temperate and subtropical monsoon climates is a promising strategy. [ABSTRACT FROM AUTHOR]

This study investigated the effect of a microbial biostimulant (Effective Microorganisms-1) on growth and flowering of a native forb (Pycnanthemum verticillatum (Michx.) Pers. var. pilosum (Nutt.) Cooperr. [Lamiaceae, whorled mountainmint]) grown under different irrigation and fertilizer levels and in presence or absence of organic soil amendment. Plant height, width, and number of main stems were unaffected, while the number of inflorescences were significantly higher in plants treated with the biostimulant. Plants exhibited slightly enhanced growth (plant width and number of main stems) under higher supplemental irrigation (3.81 cm [1.5 in] water per week as opposed to 2.54 cm [1 in] per week); however, plants had more inflorescences under lower supplemental irrigation. Plants grown in unamended soil were wider than plants grown in amended soil, but no other morphometrics were affected by that cultural factor. Whorled mountainmint attracted a diverse population made up of arthropods: pollinating (19+ families and 2 genera), beneficial (11+ families), and herbivorous (15+ families). Anthesis significantly augmented number of pollinating insects but it did not affect number of predatory and (or) other beneficial arthropods, nor plant-feeding arthropod taxa. Effective Microorganisms-1 biostimulant may be utilized to enhance establishment and flowering to further boost arthropod visitation and successfully grow whorled mountainmint with low inputs. [ABSTRACT FROM AUTHOR]