These days, one of the main issues preventing agricultural development is salinized soils. Potassium fulvic acid (PFA) not only regulates plant growth, but also improves the soil nutrient content and physical structure, which makes it a soil conditioner worth promoting. Nevertheless, the research conducted thus far on the subject of PFA with regard to plant growth and inter-root microbial communities remains somewhat limited in scope. In this study, a pot experiment was conducted to simulate both the normal environment and salt stress environment. The objective of this experiment was to verify the effect of PFA on the growth of blueberry (Vaccinium corymbosum L.) as well as its effect on the soil physical and chemical indices and the soil microbial community structure. The findings demonstrated that the implementation of potassium fulvic acids exhibited a minimal impact on the growth of blueberry plants under standard environmental conditions. However, it was observed to exert a substantial effect on enhancing various physiological parameters, including plant height, root activity, and chlorophyll synthesis, particularly in response to salt stress. PFA led to a substantial augmentation in the soil organic matter content, alongside a notable rise in the alkali-hydrolyzable nitrogen (AN) and available potassium (AK) content. Concurrently, PFA caused a notable escalation in the activities of soil urease, sucrase, acid phosphatase, and catalase (p < 0.05) in the salt-stressed environment. PFA increased the abundance of Acidobacteria, Myxococcota, Ascomycota, and Fungi_phy_Incertae_sedis under salt stress, which was mainly related to the decrease in electrical conductivity (EC) values and increase in soil acid phosphatase (S-ACP) activity. It is evident that the implementation of PFA is advantageous in enhancing the saline environment, mitigating the impact of salt damage on blueberries and establishing a foundation for the expansion of cultivated areas and the sustainable cultivation of blueberries.

Addressing saline soil issues while ensuring agricultural productivity requires innovative technologies. This study investigated the impact of adding an innovative remediation preparation, specifically leguminous compost containing 50 g (LCT+CS-1), 100 g (LCT+CS-2), or 150 g of corn silk kg-1 (LCT+CS-3), to saline soil (ECe = 11.05 dS m-1) on soil characteristics and fenugreek plant performance during the 2022/2023 and 2023/2024 seasons. All organic supplementations significantly improved soil organic matter content, nutrient levels, and enzyme activities (urease, acid and alkaline phosphatase, and catalase) while reducing soil pH and Na+ content compared to the control. These results reflected decreased Na+ content, oxidative stress indicators (hydrogen peroxide and superoxide radicals), and oxidative damage (leaf electrolyte leakage and malondialdehyde levels) in fenugreek plants. On the other hand, leaf integrity (chlorophyll and carotenoid contents, membrane stability index, and relative water content) and nutrient contents improved. Furthermore, K+/Na+ ratio, osmoregulatory compounds (soluble sugars and proline), antioxidant levels (glutathione, ascorbate, phenols, and flavonoids), and antioxidant activity increased notably. Thus, notable increases in plant growth and yield traits and seed quality (trigonelline, nicotinic acid, total phenols, and flavonoids) were achieved. LCT+CS-2 was the most effective treatment for saline soil (ECe = 11.05 dS m-1), alleviating salinity effects and improving fenugreek growth, yield, and seed quality traits.

AimsPecan (Carya cathayensis Sarg.) is an important forest trees in China, the application of chemical pesticides for disease control has caused severe damage to the soil, including reduced fertility and disruption of microbial communities. Although Trichoderma treatment has been shown to promote plant growth and improve soil quality, its effects on the growth promotion of pecan and the impact on soil microbial communities and physicochemical properties remained unclear.MethodsIn this study, we investigated the impact of T. asperellum TCS007 spore suspension and its fermented crude extract on the growth and development of pecan seedlings. We also explored the effects of TCS007 treatment on the nutrients, enzyme activities, and microbial diversity in the rhizosphere soil of pecan seedlings during their three main growth stages.ResultsTreatment with TCS007 spore suspension or crude extract promoted the growth of pecan seedlings, with significantly higher levels of leaf hormones and defense enzyme activity compared to the control (CK). Moreover, the content of soil organic matter and ammonium nitrogen, as well as the activity of soil enzymes such as catalase and urease, were all significantly higher than CK after treatment, and the soil pH shifted from slightly acidic to slightly alkaline. The results indicated that TCS007 treatment significantly increased the richness of beneficial fungi and bacteria in the soil.ConclusionThe results demonstrated that TCS007 treatment significantly promoted the growth of pecan plants, increased enzyme activity and nutrient content in the soil, and improved the soil micro-ecological environment.

Nitrogen fertilizers have a significant impact on the growth of rice. The overuse and inappropriate application of nitrogen fertilizers have resulted in environmental pollution, in addition to subjecting both humans and livestock to negative health hazards. Finding a viable substitute for traditional nitrogen fertilizers is crucial and essential to help improve crop yield and minimize environmental damage. Nano-nitrogen fertilizers offer a possible alternative to traditional fertilizers due to a slow/controlled release of nitrogen. The present work aimed to study the effect of a slow-release urea nanofertilizer on soil ammonical (NH4-N) and nitrate-N (NO3-N) content, culturable soil microflora, and soil enzyme activities in three different soil samples procured from Ludhiana and Patiala districts through a soil column study. Seven treatments, including 0, 50 (75 kg/ha N), 75 (112.5 kg/ha N), and 100% (150 kg/ha N) of the recommended dose (RD) of conventional urea and nano-urea fertilizer were applied. The leachate samples collected from nano-urea treatment exhibited NH4-N for the first two weeks, followed by NO3-N appearance. The higher NH4-N and NO3-N contents in the leachate were recorded for light-textured soil as compared to medium- and heavy-textured soil samples. The soil microbial counts and enzyme activities were recorded to be maximum in light-textured soils. Therefore, this slow-release formulation could be more useful for light-textured soils to decrease applied N-fertilizer losses, as well as for improving the soil microbial viable cell counts and soil enzyme activities. The effect of urea nanofertilizer on the growth and yield of direct-seeded rice (Oryza sativa L.) was also evaluated under field conditions. Both studies were performed independently. Numerically, the highest shoot height, fresh and dry shoot weight, and significantly maximum total chlorophyll, carotenoid, and anthocyanins were recorded in the T2 (100% RDF through nano-urea) treatment. The yield-attributing traits, including the number of filled grains and thousand-grain weight, were also recorded to have increased in T2 treatment. A numerical increase in NPK for plant and grain of rice at 100% RDN through nano-urea was recorded. The soil application of the product exhibited no negative effect on the soil microbial viable cell count on different doses of nano-urea fertilizer. The soil nitrogen fixer viable counts were rather improved in nano-urea treatments. The results reflect that nano-urea fertilizer could be considered as a possible alternative to conventional fertilizer.

Nitrogen deposition and drought significantly influence plant growth and soil physicochemical properties. This study investigates the effects of nitrogen deposition and water stress on the growth and physiological responses of Quercus dentata, and how these factors interact to influence the overall productivity. Two-year-old potted seedlings were selected to simulate nitrogen deposition and water stress. Nitrogen was applied at rates of 0 kgha-1year-1 (N0) and 150 kgha-1year-1 (N150). The levels of water stress corresponded to 80% (W80), 50% (W50), and 20% (W20) of soil saturation moisture content. High nitrogen (N150) significantly increased stem elongation and stem diameter by enhancing photosynthetic parameters, including P n (W80) and G s (W50), and maintained higher water use efficiency. Under drought conditions, nitrogen enhanced leaf water content, stabilized electrical conductivity, regulated antioxidant enzyme activity, and increased the accumulation of proline. However, under severe drought, nitrogen did not significantly improve biomass, highlighting the critical role of water availability. Additionally, increased nitrogen levels enhanced soil enzyme activity, facilitated the uptake of crucial nutrients like K and Zn. Mantel tests indicated significant correlations between soil enzyme activity, water use efficiency, and leaf Fe content, suggesting that nitrogen deposition altered nutrient uptake strategies in Q. dentata to sustain normal photosynthetic capacity under water stress. This study demonstrates that nitrogen deposition substantially enhances the growth and physiological resilience of Q. dentata under W50 by optimizing photosynthetic efficiency, water use efficiency, and nutrient uptake. However, the efficacy of nitrogen is highly dependent on water availability, highlighting the necessity of integrated nutrient and water management for plant growth.

Riparian soils, together with vegetation, play a crucial role in supporting biodiversity and driving biogeochemical processes within river ecosystems. Conservation of riparian soils and artificial planting are essential for river ecosystem recovery following land degradation. Researchers focus on examining soil nutrients, microbial biomass, and organic acid metabolism in the interactions between plants and soil along riverbanks. However, the seasonal responses of riparian soils to artificial plantations have been infrequently reported in the existing literature. This study investigates the influence of seasonal variations on soil conditions and the growth of artificially planted species in the riparian zones of the Three Gorges Dam Reservoir (TGDR) in China. The species sampled include Cynodon dactylon, Hemarthria altissima, and Salix matsudana. These species provide valuable insight into soil properties along riparian zones, assessing interactions across different seasons: T1 (spring), T2 (summer), and T3 (autumn). The results demonstrated significant seasonal changes in soil organic matter, ammonium nitrogen, nitrate nitrogen, and other indicators between T1 and T3. Apart from invertase activity in H. altissima soil, enzyme activity peaked during T1. Dominant soil bacteria were examined using high-throughput 16S rDNA sequencing, revealing that the available bacteria belong to 62 phyla and 211 classes. Among the most abundant were Proteobacteria and Actinobacteria, averaging over 60 % across all soil samples. Principal component analyses accounted for 62.81 % (T1), 50.57 % (T2), and 54.08 % (T3) of the variation observed in the study, indicating that soil properties were predominantly influenced by the different seasonal phases, assuming all other factors remained constant. Pearson correlation analysis (p < 0.05) identified strong positive correlations between physical properties and all three plant species during T1 (r <= 0.94), as well as significant negative correlations with bacterial communities in T2 and T3 (r <= -1.00). These findings suggest that the selected plant species are well-suited to cultivation in the riparian zone of the TGDR. This study enhances our understanding of seasonal dynamics in riparian environments, offering practical insights into their management.

Di(2-ethylhexyl) phthalate (DEHP) is perceived an emerging threat to terrestrial ecosystem, however, clear and accurate studies to fully understander ecotoxicity and underlying mechanisms of DEHP on the soil fauna remain poorly understood. Therefore, this study conducted a microcosm experiment of two earthworm ecotypes to investigate the ecological hazards of DHEP from multiple perspectives. The results showed that DEHP significantly increased the 8-hydroxy-deoxyguanosine (8-OHdG) content both in Eisenia foetida (13.76-133.0%) and Metaphire guillelmi (11.01-49.12%), leading to intracellular DNA damage. Meanwhile, DEHP negatively affected the expression of functional genes (ATP-6, NADH1, COX), which may be detrimental to mitochondrial respiration and oxidative stress at the gene level. The two earthworm guts shared analogous dominant bacteria however, the incorporation of DEHP drastically suppressed the homogeneity and diversity of the gut microbes, which further disrupted the homeostasis of the gut microbial ecological network. The keystone species in the gut of E. foetida decreased under DEHP stress but increased in the gut of M. guillelmi. Moreover, DEHP presented detrimental effects on soil enzyme activity, which is mainly associated with pollutant levels and earthworm activity. Collectively, the findings expand the understanding of soil ecological health and reveal the underlying mechanisms of the potential exposure risk to DEHP.

Simple Summary Microorganisms and their enzymes are crucial to ensuring soil quality, health, and carbon sequestration. Their numerous reactions are essential for biogeochemical cycles. However, a comprehensive review is lacking to summarize the latest findings in agricultural and enzymatic research. Although the relationships between soil enzyme activities and different soil ecosystems, such as arctic and permafrost regions, tropics and subtropics, tundra, steppes, etc., have been intensively investigated, particularly in the context of climate changes, only a few reviews summarize the impact of climate change on soil enzyme activity. This review aims to highlight the main groups of microbial enzymes found in soil (such as alpha-glucosidases and beta-glucosidases, phosphatases, ureases, N-acetyl-glucosaminidases, peptidases, etc.), their role in the global nutrient cycles of carbon, nitrogen, phosphorus, sulfur, carbon sequestration, and the influence of intensive agriculture on microbial enzymatic activity, and the variations in enzyme activity across different climate zones and soil ecosystems. Furthermore, the review will emphasize the importance of microbial enzymes for soil fertility and present both current challenges and future perspectives.Abstract The extracellular enzymes secreted by soil microorganisms play a pivotal role in the decomposition of organic matter and the global cycles of carbon (C), phosphorus (P), and nitrogen (N), also serving as indicators of soil health and fertility. Current research is extensively analyzing these microbial populations and enzyme activities in diverse soil ecosystems and climatic regions, such as forests, grasslands, tropics, arctic regions and deserts. Climate change, global warming, and intensive agriculture are altering soil enzyme activities. Yet, few reviews have thoroughly explored the key enzymes required for soil fertility and the effects of abiotic factors on their functionality. A comprehensive review is thus essential to better understand the role of soil microbial enzymes in C, P, and N cycles, and their response to climate changes, soil ecosystems, organic farming, and fertilization. Studies indicate that the soil temperature, moisture, water content, pH, substrate availability, and average annual temperature and precipitation significantly impact enzyme activities. Additionally, climate change has shown ambiguous effects on these activities, causing both reductions and enhancements in enzyme catalytic functions.

The use of engineered nanomaterials (NMs) as novel antimicrobial agents has garnered significant attention in agriculture. The antimicrobial properties of 5 mg/kg metal oxide (copper oxide and zinc oxide nanoparticles, CuO and ZnO NPs)- and carbon (reduced graphene oxide and multiwalled carbon nanotubes, rGO and MWCNT)-based NMs on two soil-borne fungal pathogens, Fusarium oxysporum f.sp. lactucae (F.o.lact) and Fusarium oxysporum f.sp. lycopersici (F.o.lyco), were evaluated over a 21-day incubation period. Both metal- and carbon-based NMs reduced the dehydrogenase activity (DHA) in Fusarium-infested soil by more than 40% relative to the infested controls; the efficacy of antifungal efficacy was CuO NPs > ZnO NPs > rGO > MWCNT. Similar decreases in the soil activities of urease (UE), sucrase (SC), acid phosphatase (ACP), and polyphenol oxidase (PPO) suggest that NMs could effectively inhibit Fusarium growth in soil over time. The total available metal fractions, including acid extractable fraction, Fe/Mn oxidation state, and the fraction bound to organic matter, were increased by 5.99-7.29% with metal-based NM compared to the infested controls. The Shannon index of microbial communities in the infested soils with metal-based NMs was increased by 12.2-23.5% relative to infested controls. Similarly, carbon-based NMs increased the Shannon index of the fungal community by 10.18-29.86%. Importantly, the relative abundance of Fusarium was decreased with both metal- and carbon-based NMs. These NMs also increased the relative abundance of beneficial microorganisms in infested soil, such as Pseudomonas, which was increased by 29.7-96.2% with metal-based NMs relative to the untreated controls. These findings demonstrate that NMs at appropriate doses could inhibit the Fusarium abundance and subsequent crop damage while simultaneously fostering the development of beneficial microorganisms in soil.

Microplastics (MPs) have distributed in agricultural soil. However, the effects of MPs on the growth of tobacco remain unclear. In this study, a pot experiment was conducted to evaluate the effects of linear low-density polyethylene (LLDPE) MPs at four different concentrations (0 mgkg-1 as control, 10 mgkg-1, 100 mgkg-1, and 1000 mgkg-1) on soil enzyme activity, physiological characteristics, and tobacco growth. The results showed that compared with the control, the treatments of 100 and 1000 mgkg-1 significantly inhibited the activities of soil catalase (S-CAT) and soil sucrase (S-SC). Compared with the control, the 1000 mgkg-1 treatment significantly altered root morphology, inhibited tobacco growth, and water content, resulting in a significant decrease in chlorophyll a content, catalase (CAT) and superoxide dismutase (SOD) activities in tobacco leaves, thereby incited a significant increase in malondialdehyde (MDA) content and peroxidase (POD) activity. Interestingly, the 10 mgkg-1 treatment stimulated the activity of soil urease (S-UE) and root biomass. Overall, this study highlights the significant impact of MPs on soil enzymes, oxidative damage to tobacco, and inhibition of tobacco growth and development. It emphasizes the environmental risks of MPs pollution in soil, particularly for commercial crops like tobacco, and provides insights for controlling MPs abundance in the environment. Further research is needed to investigate the underlying mechanisms of MPs' effects on metabolism and genes in the soil-tobacco-microbial system.