Land-use change shapes arbuscular mycorrhizal fungi diversity and soil health in the Caldenal semi-arid ecosystem

Phosphorus (P) limitation is prevalent in terrestrial ecosystems. Plants can improve soil P availability through the exudation of organic acids and symbiotic interactions with microorganisms. However, associations between different plant functional groups and phosphorus cycling in P limited karst ecosystems remain poorly understood. To investigate this, the exudation rates of oxalic, citric and acetic acids from fine roots, the contents of carbon, nitrogen, and P in leaves and fine roots, and the contents of oxalic, citric and acetic acids, total P, available P (AP), and microbial biomass P in rhizosphere soils were measured across different plant functional groups in a karst ecosystem in southwestern China. Additionally, the activities of acid and alkaline phosphatases were also analyzed, as well as the relative abundance, community structure, diversity, and co-occurrence network patterns of arbuscular mycorrhizal fungi (AMF) and alkaline phosphatase-encoding (phoD) gene-harboring bacteria. The results showed that both the exudation rates and the contents of organic acids and AP were highest in the tree group, followed by the shrub and grass groups. The AP content of the legume group was significantly higher than that of the non-legume group. The exudation rates of oxalic acid were significantly greater than those of citric and acetic acids. AMF diversities were highest in the shrub and legume groups. The diversities of phoD-harboring bacteria decreased from the tree group to the shrub group and then to the grass group, yet there were no significant differences between the legume and non-legume groups. The communities of both AMF and phoD-harboring bacteria exhibited significant differences among these plant functional groups. The prevalent genera of phoD-harboring bacteria across all groups were Pseudomonas and Halomonas, with Halomonas being particularly prevalent in the legume group. The AMF community was dominated by Glomus, which attained its highest relative abundance in the tree and legume groups. Furthermore, the increased exudation rate and content of oxalic acid were associated with higher relative abundances of Glomus in AMF and Pseudomonas and Bacillus among phoD-harboring bacteria. Structural Equation Model (SEM) analysis demonstrated that plant-exuded organic acids, especially oxalic acid, were positively associated with P availability indirectly through their linkages with the diversity and abundance of AMF and phoD-harboring bacteria. The crucial role of oxalic acid was particularly prominent in the tree and legume groups. Our findings suggest that screening AMF and phoD-harboring bacteria with highly efficient P transformation activity and inoculating them into the rhizosphere of plants with high oxalic acid exudation could help improve plant resilience to P limitation and support sustainable restoration in karst ecosystems.

Arbuscular mycorrhizal fungi (AMF) support critical ecosystem services including plant resource acquisition and productivity. AMF functional traits such as relative biomass investment in root vs soil colonization or drought tolerance are thought to be evolutionarily conserved within AMF lineages and might influence AMF community responses to climate change. In a long-term field experiment, six coexisting native shrub species were exposed to 9 yr of simulated climate warming (2°C), rainfall reduction (30%) or their combination in a semiarid shrubland. Photosynthesis and aboveground plant biomass growth were reduced by warming combined with rainfall reduction, while both AMF biomass and diversity in soil increased markedly. In particular, the richness of virtual taxa of the Glomeraceae lineage increased steeply with topsoil desiccation, resulting in overwhelming dominance over other AMF lineages under warming combined with rainfall reduction. Higher AMF biomass and diversity in soil under warming combined with rainfall reduction suggests increased carbon investment in mycorrhizal fungi by climatically stressed host plants. High tolerance to soil drying appears to be widespread across the Glomeraceae, which may enable AMF in this lineage to buffer the impacts of a drier climate on host plants through effective phosphorus acquisition from dry soil and enhanced plant water use efficiency.

Arbuscular mycorrhizal fungi (AMF) are key drivers of plant growth and nutrition, shaping the relationship between plant diversity and ecosystem productivity. In agroecosystems, AMF generally benefit crops but often have neutral or even negative effects on weeds, yet the mechanisms underlying these contrasting interactions remain poorly understood. In this Viewpoint, we propose a plant community-level framework to investigate interactions between multiple crop and weed species and diverse AMF taxa, focusing on chemically mediated communication via root exudates, particularly flavonoids (FLVs) and strigolactones (SLs). These compounds can act as 'cry for help' signals that recruit beneficial soil microorganisms to alleviate environmental stress. We found that their composition varies widely among plant families, with crops typically producing more diverse and functionally distinctive FLV profiles than weeds. Similar patterns, though less documented, appear for SLs. Different FLV subclasses elicit contrasting AMF responses, influencing spore germination, hyphal growth, and root colonization. Notably, FLVs with stronger positive effects on AMF are more common in crops, whereas those with neutral effects tend to dominate in weeds. Our results are consistent with the idea that such molecular cues may shape AMF recruitment and could potentially feed back into plant community dynamics, although this hypothesis should be explicitly tested.

Optimal stimulation of rhizosphere nutrient mobilization and grassland plant growth by intermediate but not by high diversity of arbuscular mycorrhizal fungi

An investigation was conducted from 2022 to 2024 examined native arbuscular mycorrhizal (AM) fungi in the saline wetland rice ecosystems of the Aghanashini and Kagal regions in the Uttara Kannada district, Karnataka, India. Between the two sites, Aghanashini recorded higher AM fungal diversity across all diversity indices, including the Shannon-Wiener diversity index, Margalef’s species richness index and Simpson’s dominance index. Three efficient AM fungal isolates–UASDAMFAG8 (Acaulospora mellea), UASDAMFAG10 (Glomus macrocarpum) and UASDAMFAG28 (Glomus aggregatum)–were selected based on their superior performance in phosphorus uptake, total dry biomass production and peroxidase activity in rice grown under salinity levels of 6 and 8 dS m-1 respectively. These isolates were evaluated individually and in combination under controlled microcosm conditions. The AM fungal consortium (G. macrocarpum + A. mellea + G. aggregatum) significantly enhanced plant growth parameters, mycorrhizal root colonization, total glomalin content, relative chlorophyll content, proline accumulation, phosphorus uptake and soil enzyme activities compared to the uninoculated control (UICNotably, the consortium increased proline content in rice to 13.47 and 14.06 μmol g-¹ fresh weight (FW) under 6 and 8 dS m-¹ salinity respectively. Among individual inoculants, G. macrocarpum showed the most pronounced effects across all measured parameters. The statistical interaction between AM fungi and salinity stress revealed that the AM fungal consortium effectively mitigated the adverse effects of salinity at both levels. These findings suggest that native AM fungal isolates, particularly in consortium form, can be exploited for enhancing salt tolerance and promoting sustainable rice cultivation in saline wetland ecosystems.

Soil physicochemical properties and rhizosphere conditions are key determinants of arbuscular mycorrhizal fungi (AMF) diversity, spore production, and symbiotic functioning. This study investigated AMF diversity, spore abundance, and root colonization across six contrasting land-use systems in Southern Nigeria, with particular emphasis on previously unreported host plant species. Pronounced variations in soil physicochemical properties occurred among sites. All soils were coarse-textured and sand-dominated, with pH values ranging from strongly to moderately acidic (3.54 – 5.19) and clear nutrient gradients across ecosystems. Dumpsite soils contained the highest levels of total nitrogen (0.67), organic carbon (1.18) and available phosphorus (107.27), followed by cropland and mangrove soils. Electrical conductivity varied widely, from 29 mmho cm⁻¹ in the derived savanna to 2,897 mmho cm⁻¹ in mangrove soils, reflecting land-use intensity and tidal influence. Six AMF taxa were identified using spore morphology. Acaulospora spp. dominated all ecosystems, followed by Rhizophagus and Glomus spp., whereas Gigaspora and Funneliformis spp. were sparsely distributed. Total spore abundance peaked in cropland (384 spores 100 g⁻¹ dry soil), mangrove (378), and dumpsite (368) soils, and was lowest in freshwater swamp soils (298). Root colonization was evaluated in 28 plant species across multiple families, revealing widespread AMF associations. Colonization levels were highest in dumpsite and lowland forest soils (28-30%), intermediate in derived savanna and mangrove ecosystems (24-27%), and lowest in freshwater swamp and cropland systems (10-24%). All values fell within ranges reported for tropical ecosystems (10 - 40%). Overall, this study provides a first integrated assessment of AMF patterns across land-use systems in Nigeria.

Abstract Multiple global change factors (GCFs) co‐occurring may weaken the positive effects of high biodiversity on ecosystem multifunctionality. Arbuscular mycorrhizal fungi (AMF) play a crucial role in determining ecosystem functionality, yet it remains unclear whether high AMF diversity alleviates the negative impact of multiple GCFs on ecosystem multifunctionality. In this study, we conducted a microcosm experiment using Triticum aestivum (wheat) to examine the effects of AMF diversity on ecosystem multifunctionality and individual functions under 0, 1 and 6 GCFs. We found that, under 0 GCF and 1 GCF treatments, ecosystem multifunctionality in the high AMF diversity treatment was significantly higher than that in the low diversity and non‐AMF treatments. However, when 6 GCFs occurred simultaneously, AMF diversity had no impact on ecosystem multifunctionality. Notably, AMF diversity simultaneously promoted plant growth and net photosynthetic rate. High AMF diversity had limited effects on soil functions and did not consistently outperform treatments with lower AMF diversity under multiple GCFs. Despite six GCFs strongly reduced the development of AMF, the high‐diversity AMF still exhibited the highest root colonization and soil hyphal length density. Synthesis. Our results suggested that the simultaneous occurrence of multiple GCFs diminished the benefits of high AMF diversity on ecosystem multifunctionality. However, high AMF diversity consistently improved plant growth under all conditions, possibly due to plants' selective association with mycorrhizal partners. These findings indicate that reducing global change stressors is essential for maintaining ecosystem functioning. Meanwhile, sustaining AMF diversity remains important for supporting plant productivity in the rapidly changing world.

Climate change poses a major threat to ecosystems worldwide, including Iran's ecologically important Zagros oak forests. These forests are experiencing accelerating decline due to climate-related stress and intensified human pressures, despite their key role in sustaining regional biodiversity. Soil health and the crucial symbiotic partnership between oak trees and arbuscular mycorrhizal fungi (AMF) are crucial for resilience in drought-prone Mediterranean environments. Due to a lack of comprehensive studies, this research aimed to analyze the root-associated microbiome of Persian oak (Quercus brantii) across western and southwestern Iran, specifically focusing on AMF diversity and their ecological role. Our study employed Illumina high-throughput sequencing of ITS and 18S rRNA V4 markers of root-associated fungal communities to assess taxonomic composition and diversity of 160 trees across eight different sites. Analyses revealed dominant fungal groups, including key AMF taxa like Glomeraceae and Claroideoglomeraceae, with significant spatial variation in diversity and community structure, likely influenced by regional and abiotic factors. In addition, the findings highlight the important ecological function of the Persian oak canopy in creating a favorable microclimate and the essential symbiotic partnership with AMF for drought tolerance and nutrient uptake. However, our study ultimately concludes that despite this crucial symbiosis, the Zagros oak forests remain highly vulnerable to increasing pressures from agricultural expansion and the escalating impacts of climate change, seasonal wildfires, and declining groundwater levels, which pose significant threats to their long-term survival.

ABSTRACT Glomalin‐related soil proteins (GRSPs) play a vital role in the stabilization of soil organic carbon (SOC); however, their long‐term dynamics under intensive cultivation remain poorly understood in citrus orchard ecosystems. In this study, we studied GRSP contents and arbuscular mycorrhizal fungi (AMF) communities in natural forest soils and citrus orchards cultivated for 10, 20, and 30 years. The results showed that natural forest soils had the highest content of total GRSP (T‐GRSP), significantly exceeding that in citrus orchard soils irrespective of planting duration. AMF Shannon and Simpson indices in the 20‐ and 30‐year‐old citrus orchard soils were markedly lower than that in the 10‐year‐old orchards and natural forest soils. Hierarchical clustering further indicated a distinct gradient in AMF community composition across different land‐use types and cultivation years, with the AMF community in natural forest soils being clearly separated from that in citrus orchards. Paraglomus and Glomus dominated the AMF genera, showing opposite trends of variation with increasing planting years. The relative abundance of Paraglomus increased significantly with planting duration and stabilized in the 20‐ to 30‐year‐old soils, whereas Glomus was more abundant in the 10‐year‐old soils than in the older orchards. Variation partitioning analysis revealed that T‐GRSP content was jointly regulated by AMF and basic soil properties. Soil factors (pH and SOC) alone explained 29.3% of the variation in T‐GRSP, while AMF diversity, community composition, and the dominant genus Paraglomus and Glomus together explained 21.6%. These findings highlight the pivotal role of T‐GRSP in enhancing SOC storage and stabilization under long‐term, intensive citrus cultivation. Moreover, this integrative study provides new insights into the ecological mechanisms driving AMF community assembly and their functional contributions to soil carbon processes.

Black wattle (Acacia mearnsii) was introduced to southern Brazil in the 1930s without any documented history of microbial inoculation. This study tested the hypothesis that black wattle introduction does not harm indigenous arbuscular mycorrhizal fungi (AMF) communities or reduce soil AMF inoculum potential, probably because the species readily associates with a diverse range of native AMF. Soil samples were collected from areas with different land uses (native forest fragments, native pasture and black wattle plantations) and used in two greenhouse experiments. Experiment 1 assessed the inoculum potential of soils from different land uses by evaluating AMF root colonisation in Brachiaria (Urochloa brizantha) seedlings. Experiment 2 used Brachiaria and black wattle seedlings as trap plants to assess AMF spore diversity in the soil samples. AMF species were identified based on spore morphotypes. Results indicated that black wattle plantations did not significantly alter soil inoculum potential or AMF spore diversity, except in cases where soil P content was substantially affected by the plantation. Black wattle readily formed symbioses with diverse AMF communities upon introduction to a new environment. The most frequently observed AMF morphotypes in the black wattle rhizosphere were Claroideoglomus etunicatum and Rhizoglomus clarum, followed by Archaeospora trappei, Acaulospora colombiana, Acaulospora mellea, and two unidentified Glomus species. These findings align with the observation that black wattle has successfully adapted to the AMF diversity of southern Brazilian ecosystems.

Plant and arbuscular mycorrhizal (AM) fungal diversity are both positively linked to ecosystem productivity across diverse ecosystems. However, given their high sensitivity to climate extremes such as extreme drought, the persistence and adaptability of these diversity-productivity relationships under rapid climate changes remain poorly understood. To address this, we established a grassland experiment at two proximate sites with distinct natural plant and AM fungal communities, imposing two contrasting extreme drought regimes (intense and chronic), each exceeding a 20-year recurrence interval based on site-specific precipitation records. We show that AM fungal diversity consistently outperforms plant diversity in predicting plant aboveground/net primary productivity (ANPP/NPP), as well as compositional shifts in plant species productivity, despite pronounced drought sensitivity in both communities. Notably, enhanced drought resistance in plant productivity was primarily associated with the stability of AM fungal richness rather than plant richness, highlighting their mutual dependence under extreme drought. Structural equation modelling confirmed that AM fungal richness buffered drought effects on ANPP, NPP and plant richness, with stronger effects on ANPP and NPP than those of plant richness and soil properties. These results suggest that AM fungal diversity may play a greater role than plant diversity in buffering plant communities against climate extremes. While causality remains to be fully resolved, these findings shed light on the adaptive significance of this ancient symbiont in sustaining ecosystem functioning under rapid climate change.

Land use change and agricultural expansion threaten biodiversity yet the effects on soil life remain poorly understood, especially for microbes. Arbuscular mycorrhizal (AM) fungi are microbes that form associations with most plant species and are essential for plant nutrient uptake. The diversity of these fungi is also sensitive to both land use change and regional climatic conditions. We therefore asked whether variation in AM fungal diversity is driven by land use change, and whether these effects are further influenced by interactions with temperature and precipitation gradients. To test this, we quantified AM fungal biodiversity in cultivated and adjacent uncultivated soils across a 1700 m elevational gradient (temperature: 7.7°C-16.5°C and precipitation: 1000-3500 mm). We found that conversion of uncultivated soils to agriculture reduced AM fungal richness by 80%, on average. Richness in uncultivated soils increased with the temperature gradient, while richness in farms declined. A similar but inverted trend was found for precipitation, where richness in uncultivated sites declined as precipitation increased. Uncultivated soils contained approximately three-fold more unique AM fungal species compared to cultivated soils. Our findings demonstrate that interactions between climate and land use strongly influence AM fungal biodiversity patterns in tropical mountain ecosystems. Incorporating both factors into conservation and sustainable agriculture strategies will be critical to preserving belowground biodiversity under global change.

The rhizosphere is a biodiversity hotspot, shaped by intricate interactions between plants and soil microorganisms. Drought events increasingly threaten agroecosystems by negatively impacting both plant productivity and associated microbial communities. Mutualistic interactions with arbuscular mycorrhizal fungi (AMF), rhizobia, and plant growth‐promoting microorganisms enhance plant tolerance to abiotic stressors while supporting water and nutrient uptake. One approach to disentangling the role of soil microbes in plant biomass production is to compare sterilized and untreated soils. In this study, we used steam sterilization to reduce microbial load while preserving soil structure, thereby allowing us to isolate microbial contributions to plant performance under recurrent drought. We investigated the diversity and dynamics of AMF, Rhizobium root nodule bacteria, and soil microbial communities (fungi and bacteria) in the rhizosphere of Trifolium pratense (red clover) exposed to two consecutive drought events in both steam‐sterilized and untreated soil. Steam sterilization significantly increased plant biomass under both wet and dry conditions. Contemporarily, we observed reduced pathogen pressure (e.g., Fusarium and Ilyonectria ) and not severely affected abundances of AMF and rhizobia. Drought consistently induced higher AMF abundance and compositional changes, notably stimulating Funneliformis mosseae , regardless of soil treatment. Fungal communities responded more strongly to drought than bacterial communities, particularly in sterilized soils. Our findings demonstrate that steam sterilization is a valuable tool for promoting plant productivity and resilience. This has practical implications for sustainable agriculture in drought‐prone environments.

Mycorrhizal fungi are vital components of agroecosystems, enhancing nutrient uptake, improving soil structure, and supporting plant robustness.This study compared the natural diversity of arbuscular mycorrhizal fungi (AMF) in Castor (Ricinus communis L.) and Cotton (Gossypium hirsutum L.) fields at seedling and mature stages in Mahobatpara village, Kutiyana Taluka, Porbandar District, Gujarat.Forty Soil samples were collected (10 per crop per stage) and analyzed for AMF spore density, species diversity, and soil parameters (pH, organic carbon, organic matter, available phosphorous).Results showed that spore density in castor fields increase markedly from 733-1332 spores/100 g soil at seedling stage to 1097-1997 at maturity, while cotton fields exhibited a general decline 1271-1662 at seedling to 1055-1578 at maturity.Soil pH remained neutral to slightly alkaline (6.5-7.8 in castor; 7.69-8.63 in cotton), and organic carbon, organic matter content was stable (organic carbon: 0.5-1.5%;organic matter: 0.87-2.9%).Available phosphorous showed a decreasing trend in both crops, more pronounced in cotton (seedling: 10-110 kg/ha; maturity: 18-106 kg/ha).Overall, castor supported higher AMF diversity with Glomus species dominating, while cotton showed relatively more large spored genera (Gigaspora, Scutellospora).These findings emphasize crop-specific influences on AMF communities and reinforce the role of AMF in sustainable agriculture, suggesting their potential application as biofertilizer to improve soil fertility and crop productivity in semi-arid regions.

Agroecology is increasingly shaped by the convergence of traditional knowledge, farmers’ lived experiences, and scientific research, fostering a plural dialog that embraces the ecological and socio-political complexity of agricultural systems. Within this framework, soil biodiversity is essential for maintaining ecosystem functions, with soil microbiology, and particularly arbuscular mycorrhizal fungi (AMF), playing a pivotal role in enhancing soil fertility, plant health, and agroecosystem resilience. This review explores the synergy between agroecological practices and AMF by examining their ecological, economic, epistemic, and territorial contributions to sustainable agriculture. Drawing on recent scientific findings and Latin American case studies, it highlights how practices such as reduced tillage, crop diversification, and organic matter inputs foster diverse and functional AMF communities and differentially affect their composition and ecological roles. Beyond their biological efficacy, AMF are framed as relational and socio-ecological agents—integral to networks that connect soil regeneration, food quality, local autonomy, and multi-species care. By bridging ecological science with political ecology and justice in science-based knowledge, this review offers a transdisciplinary lens on AMF and proposes pathways for agroecological transitions rooted in biodiversity, cognitive justice, and territorial sustainability.

Arbuscular mycorrhizal fungi (AMF), which significantly enhances the absorption capacity of plant roots, forms a mutually beneficial symbiotic relationship with plants and is known as the “underground internet of plants”. To explore the community characteristics, environmental driving factors, and growth-promoting effects of AMF on maize in saline–alkaline habitats, this research attempts a survey of the rhizosphere soil of saline–alkali maize fields in four areas of northern Xinjiang (20 samples). High-throughput sequencing and morphological methods were used to analyze the diversity of AMF, and the correlation analyses of Mantel and Pearson were used to explore the relationship between AMF and soil environmental factors. The results showed that eleven genera of AMF belonging to three orders and seven families were identified in the rhizosphere soil of maize in Xinjiang, and Glomus was the absolute dominant group. The relationship analysis of the environmental factors and diversity of AMF shows that total nitrogen, total potassium and acid phosphatase are the main factors affecting the community structure of AMF. Through spore isolation and pot experiments, Rhizophagus intraradices, Acaulospora denticulata and Glomus melanosporum were successfully screened and identified. Among them, Rhizophagus intraradices, which can effectively improve the plant biomass, promote the root growth and enhance the absorption of phosphorus and potassium nutrients, promoted the growth of maize remarkably. This study systematically revealed the diversity of AMF as an environmental driving mechanism as well as plant growth promoter, establishing it as a candidate for application in the maize rhizosphere in northern Xinjiang. This provides a theoretical basis for AMF resource development and agricultural application in this saline–alkali area.

Recent studies have tested the sensitivity of Microbial-Based Indicators (MBIs), such as Arbuscular Mycorrhizal Fungi (AMF), for monitoring changes in soil properties across a wide range of environments. However, the direction and magnitude of AMF responses depend on contextual factors such as land use, vegetation type, geography, and environmental variables. Thus, there is still no consensus about whether AMF show a consistent response to changes in certain soil properties. Likewise, a better understanding of how interactions among different aspects of the microbial community can modify the influence of soil properties on AMF responses is needed. Based on data compiled across a wide geographic range, this study analyzes the responses observed in several aspects of AMF to soil properties across different land uses. A Dependency Network Analysis (DEPNA) was performed within a correlation network constructed using average correlation coefficients to evaluate the strength of relationships between soil properties and different MBIs while controlling the effect of another MBI. Average correlation coefficients were estimated via meta-analysis to account for experimental heterogeneity. The total Influence Degree (TID), computed from partial correlations, suggests strong dependencies between MBIs (related to AMF diversity, mycorrhizal colonization rate, and Glomalin Soil Proteins) and soil properties (Pb concentrations, soil structural features, and nutrient stocks). The results suggest that AMF emerge as robust microbial indicators of soil condition, reflecting both fertility enhancement and degradation. Partial correlation and dependency network analyses show that soil effects on AMF and GRSP are largely mediated by microbial biomass, respiration, and diversity, explaining responses across land uses and stress gradients.

Arbuscular mycorrhizal fungi (AMFs) are well known to establish symbiotic associations with plant roots, and assist to enhance nutrient uptake and contribute to improve soil structure and fertility. This study investigated the AMF diversity and physiochemical properties of rhizosphere soil associated with three ethno-medicinal plants— Inula racemosa, Saussurea costus (cultivated), and Hyoscyamus niger (wild) from cold desert areas of Himachal Pradesh, India. Results showed that soil samples were moderately alkaline (pH 7.17–8.23), with low to medium levels of organic carbon, nitrogen, phosphate, and potassium. Cultivated soils showed higher macronutrient levels than noncultivated lands. Principal component analysis indicated a positive correlation between root colonization and pH, organic carbon, and phosphorus, while a negative correlation was found with electric conductivity, nitrogen, and potassium. Root colonization varied across medicinal plants, with Glomus and Acaulospora being the dominant AMF genera. A total of 14 arbuscular mycorrhizal fungal species from 6 genera were identified. The study indicates a potentially rich diversity of AMFs in cold desert ecosystems, particularly within the Glomeraceae family. Utilizing these AMFs in off site cultivation and conservation efforts, through single spore cultures or AMF consortia, could be beneficial for promoting sustainable growth of these valuable plants.

Reclaimed water (RW), which is treated municipal wastewater suitable for beneficial reuse, is increasingly recognized as a viable option for agricultural irrigation worldwide due to its numerous benefits. However, RW contains various contaminants whose fate in soils is variable and not fully understood. These contaminants may accumulate in soils, degrade, be taken up by plants and microbes, leach into groundwater, or be transported to surface waters via runoff. This review examines the impacts of RW contaminants on soil microbial communities, which play critical roles in nutrient mineralization, cycling, enzyme activities, and overall soil function. Evidence from literature is mixed: some studies report reductions in total bacterial and archaeal populations and decreased diversity of arbuscular mycorrhizal fungi, whereas others indicate enhanced microbial proliferation and enzyme activity due to increased availability of microbial growth substrates. These variable effects suggest that the impact of RW contaminants on soil microbial communities and their functions depends on soil properties (e.g., pH, organic matter content, texture, and mineralogy), the type and concentration of contaminants, and the wastewater treatment methods applied. Further research across diverse soil types and environmental conditions is needed to better understand how RW contaminants influence microbial communities, enzyme activities, and overall soil health.