Phosphate Solubilizing Microorganisms Research Articles

Management of soil phosphorous using phosphate solubilizing microorganisms: A sustainable approach

Phosphorus is crucial for plant growth and productivity, and its scarcity in soil negatively affects crop yields. A major portion of chemical phosphate fertilizer precipitates with soil minerals, making it unavailable for plant growth. Phosphate-solubilizing microorganisms play a pivotal role in enhancing phosphorus availability, facilitating better nutrient absorption, and ultimately boosting plant growth. This article presents a brief overview of the phosphorus status in Indian soil, discusses the various forms of phosphorus and its dynamics across different soil types, and analyses the factors involved, highlighting the importance of phosphorus management for sustainable agriculture. Physiological and molecular mechanisms of microbial phosphate solubilization provide deep insights into exploring PSMs for managing phosphorous in different soil types. It also provides a path for the necessity to explore the multifarious plant growth-promoting traits of PSMs underscoring its applicability for sustainable agricultural practices with viable economy. The mechanism of solubilization of phosphorus has been discussed to understand the role of microorganisms in different soils. The study highlights the role of significant microorganisms in developing tailored consortia of PSMs and other plant growth-promoting rhizobacteria (PGPR) based on the chemical composition of the soil, along with an integrated nutrient approach incorporating PSMs. This review offers valuable insights into harnessing PSMs and their practical applications, facilitating their broader adoption in agricultural systems to maintain soil health.

Using Bone Char as a Renewable Resource of Phosphate Fertilizers in Sustainable Agriculture and its Effects on Phosphorus Transformations and Remediation of Contaminated Soils as well as the Growth of Plants

AbstractRecycling slaughterhouse waste such as bone and converting it into bone char is a promising environmentally friendly, low-cost strategy in a circular economy and an important source of phosphorus. Therefore, this review focused on the impacts of bone char on the availability, dynamics, and transformations of phosphorus in soils as well as plant growth and utilizing bone char in remediating contaminated soils by heavy metals. Bone char is material produced through bone pyrolysis under limited oxygen at 300–1050 °C. Bone char applications to the soils significantly increased phosphorus availability and plant growth. Agricultural practices such as co-applying organic acids or sulfur or nitrogen fertilizers with bone char in some soils played an important role in enhanced phosphorus availability. Also, co-applying bone char with phosphate-solubilizing microorganisms enhanced plant growth and phosphorus availability in the soils. Applying bone char to the soils changed the dynamics and redistribution of phosphorous fractions, enhanced fertility, promoted crop growth and productivity, reduced heavy metals uptake by plants in contaminated soil, and decreased heavy metals bioavailability. Bone char has shown positive performance in remediating soils contaminated by heavy metals. Bone char proved its efficiency in sustainable agriculture and practical applications as an alternative source of phosphate fertilizers, it is safe, cheap and helps in remediating contaminated soils by heavy metals. Using bone char as a slow-release fertilizer is potentially beneficial because it reduces the hazard of excessive fertilizing and nutrient leaching which have negative impacts on the ecosystem.

The Role of Phosphate-Solubilizing Microbial Interactions in Phosphorus Activation and Utilization in Plant-Soil Systems: A Review.

To address the issue of phosphorus limitation in agricultural and forestry production and to identify green and economical alternatives to chemical phosphorus fertilizers, this paper reviews the utilization of phosphorus in plant-soil systems and explores the considerable potential for exploiting endogenous phosphorus resources. The application of phosphate-solubilizing microorganisms (PSMs) is emphasized for their role in phosphorus activation and plant growth promotion. A focus is placed on microbial interactions as an entry point to regulate the functional rhizosphere microbiome, introducing the concept of synthetic communities. This approach aims to deepen the understanding of PSM interactions across plant root, soil, and microbial interfaces, providing a theoretical foundation for the development and application of biological regulation technologies to enhance phosphorus utilization efficiency.

Response of Chickpea (Cicer arietinum L.) to Phosphate Solubilizing Microorganisms and Phosphorus Levels on Nutrient Availability, Uptake and Seed Yield in Inceptisol

Response of Chickpea (Cicer arietinum L.) to Phosphate Solubilizing Microorganisms and Phosphorus Levels on Nutrient Availability, Uptake and Seed Yield in Inceptisol

Microbial phosphate solubilization mechanisms in P solubilizing in andisol

Phosphate (P) nutrient plays a significant role in plant growth and yield. P is an essential element that plays an important role in photosynthesis and root development. Phosphate nutrient availability is deficient in some soil types due to retention, such as in Andisol soil types. High phosphate retention in Andisol soil types causes P nutrients to be unavailable to plants and can reduce crop yields. The availability of P in Andisol soils can be done, among others, by applying phosphate solubilizing microbes. Phosphate solubilizing microorganisms are soil microorganisms consisting of bacteria and fungi that can mineralize organic P, dissolve inorganic P minerals, and store large amounts of P to make it available to plants. This literature review aims to determine the mechanism of phosphate-solubilizing microbes in P dissolution in Andisol soil. The methods used in this systematic review are collecting data through the internet and utilizing recognized sources such as Science Direct, Research Gate, Google Scholar, and Web of Science. Content analysis was performed on the collected data, and the results were organized into thematic categories. Furthermore, the findings are presented descriptively with the help of tables to facilitate understanding. Since phosphate-solubilizing microorganisms can dissolve P in the soil through chemical and biological mechanisms, it can be concluded that phosphate-solubilizing microorganisms also have an important role in the soil P cycle. The implications of this literature review are to understand the retention of P nutrients in Andisols and how the dissolution mechanism works, as well as the use of microbes as a solution to increase phosphate dissolution so that it is available to plants.

Prospects of phosphate solubilizing microorganisms in sustainable agriculture.

Phosphorus (P), an essential macronutrient for various plant processes, is generally a limiting soil component for crop growth and yields. Organic and inorganic types of P are copious in soils, but their phyto-availability is limited as it is present largely in insoluble forms. Although phosphate fertilizers are applied in P-deficit soils, their undue use negatively impacts soil quality and the environment. Moreover, many P fertilizers are lost because of adsorption and fixation mechanisms, further reducing fertilizer efficiencies. The application of phosphate-solubilizing microorganisms (PSMs) is an environmentally friendly, low-budget, and biologically efficient method for sustainable agriculture without causing environmental hazards. These beneficial microorganisms are widely distributed in the rhizosphere and can hydrolyze inorganic and organic insoluble P substances to soluble P forms which are directly assimilated by plants. The present review summarizes and discusses our existing understanding related to various forms and sources of P in soils, the importance and P utilization by plants and microbes,, the diversification of PSMs along with mixed consortia of diverse PSMs including endophytic PSMs, the mechanism of P solubilization, and lastly constraints being faced in terms of production and adoption of PSMs on large scale have also been discussed.

Arbuscular Mycorrhizal Fungal Interacted with Biochar and Enhanced Phosphate-Solubilizing Microorganism Abundance and Phosphorus Uptake in Maize

In agricultural production, it is crucial to increase the availability of phosphorus (P) in cultivated soil to solve the P limitation. Arbuscular mycorrhizal fungi (AMF) have been proven to promote crop nutrient absorption effectively, while biochar can lead to improvements in soil properties. However, the possible synergistic effect of AMF and biochar on P uptake by crops as well as its underlying mechanisms are unclear. In this study, we conducted a pot experiment to explore the effects of biochar and AMF (Glomus etunicatum) on the community of rhizospheric phosphate-solubilizing microorganisms (PSMs) of maize (Zea mays L. Xianyu-335) using metagenomic methods. The experiment used 0 mg P2O5 g·kg−1 soil (P0) and 30 mg P2O5 g·kg−1 soil (P30) application rates. Each P application rate included 0 (NC), 20 g·kg−1 biochar (BC) addition, inoculation AMF, and without AMF treatments (NM) for a total of eight treatments. During the experiment, both the P uptake and the biomass of maize were measured. The study found that the combination of AMF and biochar significantly increased the mycorrhizal colonization rate of maize roots, regardless of P application level. It was observed that the P uptake by maize was significantly increased when exposed to a combination of AMF and biochar. The increase in P uptake in P0 treatments was 67% higher than the sum of the effects of biochar and AMF inoculation alone. The increase was only 35% higher in P30 treatments, demonstrating a substantially higher interactive effect under P0 than under P30 conditions. The AM-BC treatments significantly increased the abundance of Streptomyces, Bacillus, and Pseudomonas, genera that are known to contain PSMs. In addition, the abundance of genes related to P-cycling (gcd, phoD, and ugpQ) in PSMs increased significantly by 1.5–1.8 times in AM-BC treatments compared with NM-BC and AM-NC treatments under P0 conditions. This increase was significantly and positively correlated with the P uptake. Overall, the results suggest that biochar can help AMF colonize the roots, increasing the functional roles of PSMs in the rhizosphere, which in turn promotes P uptake and biomass in maize. This study provides a new way to improve P-use efficiency and reduce the need for P-fertilizer application in agricultural production.

A Sustainable Agriculture Method Using Biofertilizers: An Eco-Friendly Approach

Biofertilizers symbolize a promising and eco-friendly approach to increasing agricultural productivity while reducing the hazardous environmental impact of chemical fertilizers. Biofertilizers are compounds containing living microorganisms or their byproducts that, when applied to soil, enhance nutrient uptake and promote plant growth. These biological agents include nitrogen-fixing bacteria, mycorrhizal fungi, and phosphate-solubilizing microorganisms. Biofertilizers are well recognized for their composition, cost-effectiveness, and environment-friendly nature. These are safe substitutes for hazardous synthetic fertilizers. They contribute to soil health and biodiversity conservation by enriching the soil with beneficial microorganisms. This review provides an overview of biofertilizers, their significance in modern agriculture, and their potential to promote sustainable farming practices.

Performances of phosphate-solubilizing microorganisms on soil chemical properties under different soil characteristics: a meta-analysis

The addition of phosphate-solubilizing microorganisms (PSM) as biofertilizers can improve the quality of soil properties. A meta-analysis study was conducted to analyze the effect of PSM on soil properties. This meta-analysis has analyzed 20 research articles published between 1990 and 2023, which have reported the influence of PSM on soil properties. The value of effect size (ES) Hedges'd of available-P is 3.047 (p<0.001), ES of available K is 2.102 (p<0.001), ES of soil nitrogen (N) is 1.706 (p<0.001), ES of pH is -2.738 (p<0.001), ES of soil organic carbon (SOC) is 1.087 (p=0.004), ES of N-NH4 is 0.636 (p= 0.013), ES of N-NO3 is 2.643 (p< 0.001), ES of phosphatase is 5.001 (p< 0.001), ES of alkaline phosphatase is 22.956 (p<0.001), and ES of acid phosphatase is 23.104 (p<0.001). The results showed that in terms of phosphate solubility, PSM is more effective on alkaline soils with high SOC content, very high P availability, and a sandy loam texture. PSM is more effective for K solubility on acidic soils, with very high SOC content, high P availability, and a loamy texture. PSM is effective in increasing soil N with acid soil characteristics, low SOC content, moderate available P content, and clay texture. According to this study, the Penicillium fungus ranks second in the fungal group in terms of phosphate solubilization capacity after the genus Azotobacter. The genus Peronospora showed the greatest potential in increasing soil N. In contrast, Burkholderia showed the greatest effectiveness in solubilizing K.

Phosphate solubilizing microorganisms; the modern philosopher’s stone

AbstractThe search for the mediaeval philosopher’s stone and the search for effective phosphate solubilizing microorganisms are analogous. Both are based on an erroneous assumption about nature. Advocates for phosphate solubilizing microorganisms think that P is present in soils as discrete compounds of iron, aluminium, and calcium. This is not consistent with many observations. Rather, P is adsorbed on, and penetrates, into variable-charge surfaces. Further, phosphate solubilizing microorganisms often do not compete with microorganisms already present or produce acid under soil conditions. When responses do occur, they are more likely to be caused by effects of decreased pH on uptake of P by plant roots rather than on release of P by soil We are more likely to conserve resources and to decrease water pollution by understanding that previous applications have changed soil conditions so that subsequent applications are more effective, and much less phosphate is required.

Phosphate-Solubilizing Microorganisms Stimulate Physiological Responses of Perennial Ryegrass to Phosphorus Deficiency with Assistance of Straw Compost

Biofertilizers with phosphate-solubilizing microorganism (PSM) inoculations have been suggested to diminish the limitation of phosphorus (P) deficiency in plants. However, their applications in agriculture are restricted due to the inconstant effects of various PSMs. Proper carriers for the inoculations may overcome this shortcoming and improve PSMs’ effectiveness. The objective of this study was to investigate whether straw compost, a type of organic material, can act as a carrier for improving the efficiencies of phosphate-solubilizing bacteria and fungi named Acinetobacter sp. and Aspergillus niger, respectively, in soils. We monitored the growth and cellular physiological responses of one type of model plants, named perennial ryegrass (Lolium perenne L.), under four soil treatments, including non-fertilization, PSM inoculation alone, straw compost addition alone, and the combined applications of both PSMs and straw compost. We found the combined treatments significantly improved the growth by 14.7% for shoot height and 79.7% for shoot weight, respectively, on average. P and potassium (K) uptakes of ryegrass were also increased by 102.5% and 65.3%, respectively, after the application of both PSMs and straw compost. Furthermore, physiological properties, such as photosynthetic efficiency and P-transportation capacity, of ryegrass were also significantly improved under combined treatments when compared to other treatments, regardless of the types of PSM included. The piecewise structural equation model further indicated that PSM inoculation and straw compost input are synergistically contributing to the nutrient uptake of ryegrass through many direct and indirect ways. We propose that straw compost is a good carrier material for PSMs’ survival and would improve their plant growth promotion ability in soil. Our results provide valuable insights into the exploitation and utilization of P-biofertilizers in agriculture.

The Effects of Rhizobium Phaseoli and Phosphate-Solubilizing Microorganisms on Phaseolus Vulgaris Amended with Rock Phosphate and Biogas Spent Slurry

Phaseolusvulgaries seeds were inoculated with Rhizobium phaseoli, Phosphate solubilizing Microorganisms (PSM) with rock phosphate in plots containing poultry droppings slurry of biogas plant. This experiment was carried out in 4 treatments with control (T1, T2, T3, T4 and T0).The samples were collected at seedling, preflowering, blooming and end stages to learn the phenotypical nature, NPK and chlorophyll contents. Studies on microbes have also been conducted on plants at every stage of development. Comparing the plant supplied by R.phaseous PSM with rock phosphate to control and other application combinations, the results showed that the plant recorded the highest values in the morphological, biochemical, and microbiological features.From the seedling stage on, the plants' NPK content also rose. (1.262%, 0.28% & 0.26%) to the flowering stage. In the T4 treatment, there are likewise 36 nodules, and each nodule weighs 0.268 g. The weight is roughly 0.039g, and the lowest nodule number (07nos) was discovered in the control. The enriched manure that produced the best results was the combination of SPDS+PSM+RP+R.phaseoli (T4). The yield was 2.435tons/hectare and PSM+RP (T2), which produced 1.890 tons/hectare; PSM+RP (T3), 1.101 tons/hectare in inorganic manure (T1), and control (0.821 tons/hectare) (T0). The study report highlighted the critical roles that PSO, R. phaseoli, and rock phosphate played in P. vulgaries nodulation, nitrogen fixation, and good yield.

Study on the Effect of Trichoderma viride on Phosphate Solubilizing Microorganisms in Paddy Cultivation with the Combination of Chemical Fertilizer on soil Fertility Parameters

Trichoderma viride, biological control with Trichoderma viride is an eco-friendly and has potential approach for managing plant diseases. It also aids in phosphate solubilization. Phosphate Solubilizing Microorganisms are ubiquitous, whose number varies from soil to soil. The present work on, ‘Effect of Trichoderma viride on Phosphate Solubilizing Microorganism in Paddy cultivation” was conducted under lower gangetic alluvial region from 2016-2017(December to May) at Agricultural Experimental Station of Calcutta University, Baruipur, 24 Parganas (South), West Bengal. The Rice variety “Satabdi (IET-4786)” from the department of Genetics and Plant Breeding was sown and recommended fertilizer dose of 80:40:40 kg per hectare. The experiment was carried out with six treatments replicated four times. Out of the six treatments, T3 which received T.V and P.S showed highest Carbon, Phosphorus and Potassium content and T6 showed highest Nitrogen content in the soil

Response of green chiretta to different bio-fertilizers and their effect on phosphorus availability in the soil

When cultivating medicinal plants, the use of chemical substances such as pesticides and chemical fertilizers should be avoided, as these can be contaminated with hazardous substances. Bio-fertilizers are a good alternative for growing herbs, as they are produced from organic materials that contain fewer hazardous substances. The aim of this study was to investigate the effects of different bio-fertilizers on growth, yield, andrographolide content, nutrient accumulation, and different pigments in green chiretta. In addition, the effectiveness of bio-fertilizers on the convertible phosphorus content in the soil was investigated. The experimental design was a completely randomized design (CRD) with four treatments and four replicates. The details of the experiment were 1) control (no bio-fertilizer), 2) phosphate-solubilizing microorganisms (PSMs), 3) plant growth promoter, and 4) mycorrhiza. The findings revealed that the application of PSMs provided the highest leaf dry weight (yield) of green chiretta (20.8±3.58 g/plant). This treatment also gave the highest chlorophyll a, b and total chlorophyll content (699±70, 178±24, 880±94 mg/sqm, respectively) and andrographolide yield (0.38±0.06 g/plant). Regarding the phosphorus content in the soil, the PSMs application showed the highest available phosphorus and the highest phosphorus activation coefficient (PAC) in the soil, namely 52.0±4.76 mg/kg and 4.22±0.32 percent, respectively. These results indicate that the use of PSMs as a bio-fertilizer is most suitable for the cultivation of green chiretta, especially when this plant grows on acid sulfate soils.

The Attributes of Biofertilizer as an Alternative to Chemical Fertilizer: A Mini Review

Traditional soil management relies heavily on inorganic fertilizers, raising environmental and health concerns. A fertile soil requires a precise ratio of inorganic and organic components, with topsoil crucial for plant growth. Essential plant elements include macronutrients (nitrogen, phosphorus, potassium) and micronutrients (zinc, iron). Soil composition must balance minerals, air, water, and living matter. Macronutrients (nitrogen, phosphorus, potassium) are pivotal in plant growth. Potassium influences water regulation, root development, and crop resilience. Phosphorus, crucial for seed development, is essential for legume development. Nitrogen from nitrates, ammonium, and urea is indispensable for protein synthesis and overall plant growth. Biofertilizers, containing active microorganisms, offer an alternative to inorganic fertilizers. They enhance soil fertility, water and nutrient uptake, and plant tolerance to environmental variables. Nitrogen-fixing bacteria, phosphate solubilizing microorganisms (PSM), silicate solubilizing bacteria (SSB), plant growth-promoting rhizobacteria (PGPR), and arbuscular mycorrhizal fungi (AM fungi) are common groups of bacteria that play different specific roles in defining biofertilizer. Bacterial genera such as Rhizobium (a symbiotic nitrogen fixer known for forming nodules on legumes), Azotobacter (a free-living nitrogen fixer known for enhancing sugar content in crops), Azospirillum (a bacterium known for enhancing nitrogen content in non-leguminous plants) and Anabaena-Azollae (a symbiotic relationship between a cyanobacterium and lower plants known in fixing nitrogen and promotes growth in various crops). As agriculture continues to evolve, embracing biofertilizers represents a promising step toward a more sustainable and resilient future.

Effect of Phosphate Solubilizing Microorganisms and Phosphorus Levels on Growth Yield and Quality of Chickpea (Cicer arietinum L.) in Inceptisol

A field study was conducted to know the “Effect of phosphate solubilizing microorganisms and phosphorus levels on growth, yield and quality of chickpea (Cicer arietinum L.) in inceptisol.” The experiment was laid in Factorial Randomized Block Design (FRBD) with sixteen treatments, replicated thrice during rabi season of 2019-20 at the Department Research Farm of SSAC, College of Agriculture, Latur. The treatments comprises four main (absolute control, Bacillus megaterium, Aspergillus niger and Aspergillus awamori @ 10 ml kg-1 seed treatment) and four sub treatments (0,45,60 and 75 P2O5 kg ha-1). The results indicated that, the incorporation of phosphate solubilizing microorganisms viz. Aspergillius awamori @ 10 ml kg-1 seed in combination with soil application of 75 P2O5 kg ha-1 found to be effective in improving growth and yield attributing characters viz. number of root nodules, fresh and dry weight, chlorophyll content , grain yield and straw yield as compared to Aspergillus niger and Bacillus megaterium along with 60 P2O5 kg ha-1 and over control. Further results revealed that test weight and protein percentage was significantly influenced with the seed treatment of Aspergillius awamori @ 10 ml kg-1 seed in combination with application of 75 P2O5 kg ha-1.

Soil phosphorus transformation and plant uptake driven by phosphate-solubilizing microorganisms.

Phosphorus (P) is an important nutrient for plants, and a lack of available P greatly limits plant growth and development. Phosphate-solubilizing microorganisms (PSMs) significantly enhance the ability of plants to absorb and utilize P, which is important for improving plant nutrient turnover and yield. This article summarizes and analyzes how PSMs promote the absorption and utilization of P nutrients by plants from four perspectives: the types and functions of PSMs, phosphate-solubilizing mechanisms, main functional genes, and the impact of complex inoculation of PSMs on plant P acquisition. This article reviews the physiological and molecular mechanisms of phosphorus solubilization and growth promotion by PSMs, with a focus on analyzing the impact of PSMs on soil microbial communities and its interaction with root exudates. In order to better understand the ability of PSMs and their role in soil P transformation and to provide prospects for research on PSMs promoting plant P absorption. PSMs mainly activate insoluble P through the secretion of organic acids, phosphatase production, and mycorrhizal symbiosis, mycorrhizal symbiosis indirectly activates P via carbon exchange. PSMs can secrete organic acids and produce phosphatase, which plays a crucial role in soil P cycling, and related genes are involved in regulating the P-solubilization ability. This article reviews the mechanisms by which microorganisms promote plant uptake of soil P, which is of great significance for a deeper understanding of PSM-mediated soil P cycling, plant P uptake and utilization, and for improving the efficiency of P utilization in agriculture.

Phosphorus cycling in a subterranean estuary seepage face: A seasonal view on inventory composition and linkage with nitrate transformations

Seasonal field surveys (April 2018 to February 2019) were conducted in a subterranean estuary (STE) seepage face in Sanggou Bay (China) aiming to explore the transport and reactivity of phosphorus (P) and biogeochemical linkages with the cycling of nitrogen (N) prior to discharge. Porewater dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) together with different fractions of sedimentary P were analyzed in the upper, middle and lower intertidal covering the top 20 cm of sediment (1–4 cm, 5–8 cm, 9–12 cm, 13–16 cm and 17–20 cm depth). The accumulation of sedimentary organic P stimulated the growth of phosphate-solubilizing microorganisms and led to porewater DOP enrichment during spring. During summer, total P (TP), porewater DIP and DOP concentrations decreased, potentially due to enhanced mineralization driven by high ambient temperature. From autumn to winter, pelagic organic matter into the STE lowered, triggering a drop of TP standing stocks. Compared with the significant seasonality, sedimentary P storage was statistically identical along the intertidal. Such spatial homogeneity likely results from the rebalance driven by P adsorption dynamics and pelagic organic matter delivered by tide and wave setup. The vertical distribution of DIP, DOP, and sedimentary TP were linked to nitrate transformations. In the sediment layer with active mineralization and nitrification, concentrations of DOP, sedimentary redox and clay P increased. In the layer with active nitrate removal (2–5 cm depth), both DIP and DOP concentrations decreased. The sedimentary loosely-bound and organic P were also lower there. Notably, a substantial quantity of soluble P seeped out, acting as an important contributor to the dissolved P pool of the receiving waters. The spatial and temporal overlap of high concentrations of N and P in STEs adds variabilities and uncertainties in P out-drainage fluxes and nutrient stoichiometry balances, which should draw attention from coastal researchers and stakeholders.

Effect of Graded Levels of Phosphorus & Phosphorus Solubilizing Microorganisms on Growth and Yield of Green Gram (Vigna radiata L.)

The present investigation entitled "Effect of Graded Levels of Phosphorus and Phosphorus Solubilizing Microorganisms on Growth and Yield of Green gram" during kharif season of the year, 2022-2023 at the research farm of the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Latur. The experiment was layout in FRBD with three replications and a recommended variety of green gram BM 2003-2 as a test crop along with twelve treatments. The results in nutshell indicated that the growth and yield were significantly influenced by the application of 125% RDP, combined with Aspergillus awamori. The growth parameters viz., plant height, number of leaves & no. of nodules plant-1, significantly increased with application of 125 % RDP, combined with Aspergillus awamori. The combined approach of incorporating phosphate-solubilizing microorganisms, particularly Aspergillus awamori, with the application of 125% RDP, resulted in a noteworthy increase in the availability of nitrogen (N), phosphorus (P), and potassium (K) in the soil. This improvement was attributed to the enhanced solubilization of inorganic phosphorus and the secretion of organic acids, which facilitated an increase in the content of other essential nutrients in the soil. The nutrient content in both grain and straw exhibited significant increases due to seed inoculation with Aspergillus awamori in conjunction with the application of 125%RDP. This approach outperformed treatments involving Tricoderma viridae and Bacillus megaterium in combination with 100% RDP, and the control. The incorporation of phosphate-solubilizing microorganisms, particularly Aspergillus awamori, alongside the application of 125% RDP, proved to be significantly more effective than treatments involving a Tricoderma viridae with 100% RDP, as well as the control.

Enhancing phosphate-solubilising microbial communities through artificial selection

Microbial communities, acting as key drivers of ecosystem processes, harbour immense potential for sustainable agriculture practices. Phosphate-solubilising microorganisms, for example, can partially replace conventional phosphate fertilisers, which rely on finite resources. However, understanding the mechanisms and engineering efficient communities poses a significant challenge. In this study, we employ two artificial selection methods, environmental perturbation, and propagation, to construct phosphate-solubilising microbial communities. To assess trait transferability, we investigate the community performance in different media and a hydroponic system with Chrysanthemum indicum. Our findings reveal a distinct subset of phosphate-solubilising bacteria primarily dominated by Klebsiella and Enterobacterales. The propagated communities consistently demonstrate elevated levels of phosphate solubilisation, surpassing the starting soil community by 24.2% in activity. The increased activity of propagated communities remains consistent upon introduction into the hydroponic system. This study shows the efficacy of community-level artificial selection, particularly through propagation, as a tool for successfully modifying microbial communities to enhance phosphate solubilisation.