Search Results (406)

Microplastic (MP) and nanoplastic (NP) pollution has emerged as a pervasive and still insufficiently quantified pressure on terrestrial ecosystems, yet its consequences for wild herbivores remain incompletely understood. As key links between primary producers and higher trophic levels, wild herbivores occupy a critical ecological position and may serve both as exposed receptors and as biological vectors of plastic contamination. This manuscript presents a narrative review that synthesizes recent advances in understanding the physiological, behavioural, and ecological implications of MP and/or NP exposure in free-ranging herbivorous mammals, integrating evidence from field surveys, experimental studies, ecological modelling, and supportive mechanistic findings from livestock and experimental mammalian systems. Available evidence indicates that MPs and NPs are consistently detected in wild herbivores from both human-modified and protected landscapes, demonstrating widespread terrestrial exposure. Reported biological effects include oxidative stress, digestive dysfunction, inflammatory and immune responses, altered gut microbial communities, impaired nutrient assimilation, and organ-level damage, although much of the mechanistic evidence derives from controlled laboratory or livestock-based studies rather than direct wildlife investigations. Behavioural responses remain comparatively underexplored, particularly in large-bodied herbivores, with limited evidence for altered foraging, habitat use, and stress-related behaviours. At the ecosystem level, emerging studies suggest that herbivores may contribute to the landscape-scale redistribution of MPs and NPs through movement and faecal deposition, with potential downstream effects on soil processes, nutrient cycling, and plant–herbivore interactions. However, the current evidence base is constrained by major methodological and conceptual limitations, including the lack of standardized detection and reporting protocols, limited ecological realism in exposure studies, taxonomic and geographic biases, and poor resolution of long-term population-level and food-web consequences. Overall, the available literature indicates that MP and NP pollution represent a multifaceted and emerging risk to wild herbivores and the ecosystems they inhabit. Future research should prioritize standardized contamination-controlled monitoring, non-invasive faecal surveillance, ecologically realistic chronic exposure studies, and integrated conservation frameworks that recognize wild herbivores as sentinel species for terrestrial plastic pollution. Full article

Thismia species are non-photosynthetic plants entirely dependent on fungal partners for carbon and nutrients. While their arbuscular mycorrhizal associations are well-documented, bacterial symbiont roles remain unexplored. Using 16S rRNA gene amplicon sequencing, we investigated endophytic bacterial communities in T. gardneriana, T. javanica, and T. mirabilis from geographically distinct locations in Thailand. Despite geographic separation, Thismia spp. consistently harbored bacterial compositions taxonomically and functionally distinct from surrounding soil microbiomes. Root endospheres were significantly enriched in Pseudomonadota and Bacteroidota, particularly Puia, while showing reduced compositional dynamics of Acidobacteriota and Planctomycetota. Bacterial communities in Thismia roots were markedly distinct from surrounding soil, while root endosphere communities from geographically distinct habitats clustered together regardless of spatial separation. Mantel and partial Mantel tests confirmed that host species identity, not geographical location, was the primary predictor of root bacterial community structure. Functional prediction analyses suggested root-associated communities were enriched for nitrogen cycling pathways, particularly nitrogen fixation and nitrate reduction. The selective enrichment of Bacteroidota, known for nitrogen fixation and phosphate mobilization, suggests these bacteria provide critical nutritional support in nutrient-poor forest floor environments. Isolated root strains belonged exclusively to Bacillota, including Neobacillus with plant growth-promoting traits. Our findings highlight the importance of tripartite plant–fungal–bacterial interactions in Thismia nutritional ecology. Full article

The Ningxia Yellow River Irrigation District in China has long been influenced by flood irrigation and intensive fertilizer input under its particular geological and climatic constraints, and this region is characterized by low soil organic matter, poor nutrient status, low permeability, high pH, and widespread salinization. This cross-sectional field study compared the soil physicochemical properties and microbial communities among saline–alkali soil (SAS), straw-returning farmland (SR), and traditionally managed farmland (FM). EC was higher in SAS (approximately 4.21 dS·m⁻¹) than in SR and FM (approximately 0.23 and 0.30 dS·m⁻¹, respectively), whereas TOC and C/N were higher in SR (approximately 1.00% and 10.58, respectively) than in FM (approximately 0.78% and 8.69) and SAS (approximately 0.43% and 8.81). Bacterial and fungal communities showed different distribution patterns among the three farmland types. Compared with fungi, bacterial community structure and richness varied more clearly across soils differing in salinity and organic matter status. Variations in microbial community composition were accompanied by differences in soil salinity and carbon- and nitrogen-related properties. Acidobacteriota was positively correlated with soil carbon and nitrogen variables and negatively correlated with pH and EC, while Ascomycota was positively correlated with total carbon (TC) and TOC. These results show that straw-returning farmland differed from saline–alkali soil and traditionally managed farmland in both soil properties and microbial community characteristics, highlighting potential soil–microbe associations in saline-affected agricultural systems. Full article

Phosphogypsum (PG), a major by-product of the phosphate industry, has potential for improving acidic and nutrient-poor red soils, yet its agronomic benefits and heavy metal risks require systematic evaluation. A field experiment was conducted with five treatments, CK (soil only), GT (50% modified phosphogypsum, MPG), TT (40% MPG), ZT (50% phosphorite tailings), and DT (25% MPG + 25% lake sediment), to assess their effects on soil properties, enzyme activities, peanut growth, yield, quality, and heavy metal accumulation. All amendments improved soil structure, moisture retention, nutrient availability, and enzymatic activities. Peanut pod and kernel yields increased under all treatments, with DT achieving the greatest improvements (29.89% and 40.88%, respectively), whereas ZT showed the weakest response (1.91% and 6.26%). DT also achieved the highest soil quality index, and performed best in both yield improvement and root development. Although Cd accumulation increased under DT, heavy metal concentrations in peanut kernels remained below national food safety limits. Overall, DT was identified as the most effective amendment for enhancing red soil fertility and peanut productivity, while long-term monitoring of Cd bioavailability is recommended to ensure sustainable and safe application. Full article

Background: Phytolith-occluded carbon (PhytOC) is highly stable and constitutes an important long-term carbon pool in agroecosystems, particularly in nutrient-poor, sandy soils. Silicon (Si) uptake by plants is strongly associated with phytolith formation, with Si accounting for up to 90% of phytolith composition. However, the role of Si fertilization in enhancing PhytOC sequestration under field conditions remains insufficiently quantified. Integrated fertilization strategies supporting sustainable development in climate-resilient agriculture can enhance biological carbon sequestration by increasing phytolith formation and phytolith-occluded carbon accumulation, thereby improving the carbon sink potential of cereal-based agroecosystems. Methods: A field experiment was conducted to assess phytolith and PhytOC accumulation in barley biomass under different fertilization regimes, including foliar silicon application using the liquid immune stimulant Optysil and compost fertilization. Phytolith content was determined separately for grain and straw, and PhytOC stocks were converted into CO₂ equivalents to estimate annual sequestration potential. Results: Barley produced substantial amounts of phytoliths, with consistently higher concentrations in straw than in grain. Phytolith content ranged from 18.46 to 21.28 mg g⁻¹ DM in grain and from 27.89 to 38.97 mg g⁻¹ DM in straw. Depending on fertilization treatment, annual carbon sequestration through PhytOC ranged from 16.86 to 55.17 kg CO₂ equivalents ha⁻¹. Foliar silicon application increased PhytOC accumulation in barley biomass by up to threefold compared with treatments without Si. Conclusions: The results demonstrate that optimizing silicon fertilization can substantially enhance carbon sequestration in cropping systems via phytolith formation and PhytOC stabilization. Given the dominant role of cereals in crop rotations and their high phytolith-producing capacity as monocotyledonous plants, Si-mediated PhytOC sequestration represents a promising pathway for strengthening soil carbon storage and contributing to climate change mitigation. Full article

Livestock production systems are considered some of the most environmentally degrading due to greenhouse gas (GHG) emissions and their contribution to poor air, soil and water quality, amongst other impacts. Advanced manure treatment technologies are required in response to intensification of dairy production worldwide, and the considerably greater volumes of manure generated that require collection and management. Similarly, in Australian dairy systems cows spend more time off pasture, with increased collection of larger manure volumes from a range of contained housing facilities. Adoption of advanced treatment is required to capture nutrients at risk of loss, and ideally to valorise manure to support uptake of these technologies. This review describes the generation of manure and the manure sources found in commercial Australian systems, including grazing-based and intensive dairy farms, supporting zero grazing. The review draws on manure data from pasture-based industries elsewhere and summarises their properties for comparison with Australian systems. Manure treatments that recover and retain nutrients, water and energy are reviewed. These include additives, mechanical/chemical/membrane separation, thermochemical and biological treatments which produce organic and inorganic soil amendments, clarified or potable water, gases (N₂, H₂), biofuels and energy. The review describes the technical and operational details of the technologies, and where there are opportunities for the Australian dairy industry. Treatment technologies need to be validated for Australian systems based on the collated data of local manure properties, as differences with international manure data have been observed. The relative costs, technological maturity, and the benefits and challenges associated with adoption are discussed. Many advanced technologies are ready for adoption, but others are experimental or at pilot stage and relative costs range from low to very high. However, to accurately assess feasibility of manure treatments, environmental, and production benefits should be balanced against capital and operating expenses and account for costs associated with current management. For large intensive farms, implementing advanced manure technologies may be required to ensure approval to operate/expand and to meet regulatory compliance. Future research for the Australian industry should investigate nutrient retention and further develop separation treatments incorporating chemical and mechanical technologies. Bioconversion of manure through insect composting as well as investigating co-digestion opportunities to enhance biogas production would support famers currently using these systems. Full article

Nutrient inputs from human activities, such as agriculture and sewage discharge, influence algal blooms in water bodies. In Ecuador, the Daule River receives wastewater discharges. In addition, poor agricultural practices, including the unsuitable use of fertilisers in combination with soil erosion and surface runoff processes, increase the nutrient load to the river. Considering this, the objective of this study was to evaluate environmental and biological variables using statistical analysis to identify the parameters that influence algal blooms in the main stem of the Daule River. The methodology consisted of two phases: (i) data collection, including water sampling and laboratory work for the analysis of nutrients and phytoplankton, and (ii) statistical analysis, which includes univariate, bivariate, inferential and multivariate analysis (STATICO technique). The results showed that pH and dissolved oxygen were the main drivers of diatoms (Polymyxus coronalis and Aulacoseira granulate) and the charophyte Mougeotia sp. Similarly, ammonium-N was the main driver of the diatom Ulnaria ulna and the cyanobacteria Planktothrix cf. agardhii. The outcomes of this study identified the main environmental variables driving blooms of the five most abundant species, providing a basis for the development of ecological models in the context of land use and climate change. Full article

Approximately 20% of China’s land area is desertified or highly desertifiable, where loose sandy soil and low nutrient availability restrict plant growth. Microbial inoculants, as an emerging ecological restoration technology, play a key role in plant growth and soil nutrient activation in sandy regions. However, a systematic understanding of functional differences among microorganisms isolated from different stressed environments remains insufficient. Nine functional microbial strains from three stressed habitats, including sandy land, coastal saline-alkali soil, and heavy metal mining areas, were selected to conduct a three-month pot experiment, investigating their effects on soil nutrient activation, plant growth and microbial communities. Results showed that all inoculants increase plant biomass (by 4.15~25.59%), with KS-33, KS-36, SD-13 and SD-3 significantly promoting biomass in different plant parts (p < 0.05), and with YJ-15 remarkably enhancing root growth (root length increased by 70.83%, p < 0.01). Inoculation reduced bacterial Chao1 by 27.18~53.97%, but increased fungal Chao1 by 12.77~28.38% (except SD-30). Bacterial generalist species proportion increased from 61.12% to 83.78~93.99% after inoculation, higher than the variation degree of the fungal community. Mantel analysis revealed a reverse trend between soil nutrients, water content and plant growth. This may be associated with the increased consumption by plants and microorganisms. In summary, microbial inoculants enhance nutrient cycling processes and plant growth by reshaping soil microbial communities. Performance of microbial inoculants is more likely governed by their inherent ecological functions rather than being entirely determined by their original environments. Despite varying mechanisms, these inoculants can effectively enhance sandy soil microbial communities, providing a theoretical basis for regional ecological restoration. Full article

Apples in China are planted mainly in nutrient-poor mountain soil, and a large amount of fertilizer input results in resource waste and a decrease in nutrient utilization efficiency. Controlled-release fertilizer (CRF) has been shown to be environmentally friendly and increase crop yield, but nutrient release cannot be precisely synchronized with apple demand. Here, a suitable secondary fertilization method was established by a two-year apple field experiment with CRF and common compound fertilizer (CF) at various ratios under a 25% reduction in application. The application of CF and CRF changes the temporal and spatial distributions of soil NPK nutrients, decreasing NPK losses and NH₃ emissions. The NH₃ emissions under CF and CRF decreased by 17.98–44.86%, as N loss decreased by 11.59–29.81% and by 4.45–8.19%, with respect to those under CF alone, while the soil pH and electrical conductivity increased by 8.28–17.12% and 10.73–18.29%, compared with those under CF alone. The increase in soil P and K also decreased losses by 8.28–17.12% and 10.73–18.29%. The combined application of CF and CRF can increase soil microbial diversity and functional taxa and nutrient cycling genes, resulting in efficient nutrient transformation and supply for apple trees. The regulation of nutrients and microbes by the secondary application of CF and CRF drives an increase in apple yield of 23.71–54.32%, resulting in high economic benefits. In total, the application ratio of CF and CRF at 3:7 in March and July was an effective way to balance apple productivity and the soil ecological environment, providing a sustainable solution for mountainous orchard ecosystems globally. Full article

Coastal saline–alkali farmland typically experiences poor crop growth and low yields. Clarifying soil quality and identifying the primary constraining factors are crucial for improving productivity. This study systematically investigated the spatial heterogeneity and vertical distribution of soil physicochemical properties in a coastal reclamation area using large-scale field sampling. The results revealed that the plow layer soil in the coastal reclamation zone is characterized by typical saline–alkali conditions, low fertility, and weak nutrient-holding capacity, with a pH range of 8.0 to 9.2. Over 60% of the region had soluble salt (SS) content exceeding 2.0 g/kg, and soil organic matter (SOM), total nitrogen (TN), and cation exchange capacity (CEC) ranged from 7.2 to 24.9 g/kg, 0.45 to 1.42 g/kg, and 1.4 to 15.7 cmol⁺/kg, respectively. Correlation analysis showed significant positive correlations between SOM and TN, available potassium (AK), and CEC, while a strong negative correlation was found between pH and AP. Vertically, the soil demonstrated a notable risk of salt efflorescence and nutrient leaching. Soil salinity and alkalinity increased with depth, while SOM, TN, available phosphorus (AP), and nitrate content decreased. In conclusion, effectively suppressing soil salinization, lowering pH, and increasing organic matter content are essential strategies for improving soil structure, enhancing nutrient retention, and boosting the quality of coastal saline–alkali farmland. Full article

Background: Agriculture degrades soils, affects the delivery of ecosystem services, and contributes to climate change. Methods: This research examined nitrogen and sulfur recycling in soils under cropland expansion in Ghana at (a) reconnaissance scale in northern Guinea savannah (NGS), southern Guinea savannah (SGS), forest–savannah transition (FST), and semi-deciduous forest (SDF) agro-ecological zones (AEZs), and (b) farm level in rain Forest and the FST AEZs based on “duration of cultivation”. Fresh soils (20 cm depth) were incubated for 28 days at 28 °C, followed by the determination of mineralized nitrogen and sulfur at 14 and 28 days using standard methods. Results: Low nitrogen and sulfur contents led to predominant nitrogen and minor sulfur immobilizations, particularly in FST and savannah AEZs. Microbial biomass and pedogenic Fe controlled much of the nitrogen immobilization. At the farm level, dithionite Al and soil pH controlled nitrogen immobilization, particularly in relatively older farms, being pronounced in forest-related AEZs. Conclusions: Although the study is laboratory-based, it highlights the severe nature of soil degradation (SD) under cropland expansion in regions prone to poor nutrient budgets. Therefore, it calls for drastic measures to halt SD by adopting ecozone- and climate-driven sustainable soil management and agricultural systems. Full article

Soil provides essential ecosystem services and is pivotal for achieving multiple United Nations (UN) Sustainable Development Goals amid growing population pressures and resource demands. In arid to semi-arid regions such as Maio Island (Cape Verde), nutrient-poor soils and unsustainable land-use practices increase agricultural vulnerability, while volcanic geochemistry introduces elements that are not human friendly, further challenging environmental quality and long-term sustainability. Assessing soil (physical–chemical–biological) condition is therefore crucial for informed environmental and land-use planning. Here, Maio’s topsoil was evaluated using protocols adapted from Santiago, the largest Cape Verdean island. Estimated Background Values (EBVs) indicated naturally elevated V, Cr, Ni, Co, and Cu concentrations, consistent with mafic volcanic terrains. Robust Principal Component Analysis (rPCA) revealed geochemical groupings linked to volcanic–sedimentary units, with the dominant component (PC1) defined by Co–V–Cu–Mn–Ni versus As–Cd. Environmental Risk Indices (ERIs) and Multi-Element ERIs (ME–ERIs) quantified elemental enrichment relative to international land-use standards (residential and agricultural) and subsequently to Maio’s EBVs. The highest exceedances were observed for Cr, Co, Ni, V, and Cu, whereas As, Cd, Hg, Pb, and Zn fell within thresholds. The EBV-based assessment identified fewer exceedances than stricter international guidelines, though a few multi-element “hotspots” persist, highlighting potential land-use constraints and the need for preventive management. Overall, the integrated EBV/ERI/ME–ERI framework establishes an environmental geochemical baseline for Maio and offers a screening tool applicable across the entire archipelago. Full article

Water scarcity, poor soil, and low water and fertilizer utilization are major challenges on agricultural production in the tableland region of China’s Loess Plateau. Optimizing tillage patterns and improving soil nutrient status can improve crop yield and water and fertilizer utilization efficiency. A field trial was initiated in 2005 to assess the impacts of various tillage and fertilization practices on dryland agricultural production. A split-plot design was used, with tillage practices (traditional tillage and no tillage) as the main plot treatment and fertilization management (no fertilization (CK), mineral nitrogen (N), mineral phosphorus (P), composted cow manure (M), a combination of mineral nitrogen and phosphorus (NP), and a combination of mineral nitrogen, phosphorus, and composted cow manure (NMP)) as the split-plot treatment. An experiment was conducted from 2022 to 2024. The NMP treatment resulted in lower bulk density, a lower three-soil-phase index, and higher mean weight diameter, geometric mean diameter, soil water storage, total nitrogen, and soil organic matter than the CK. In the no-tillage treatment, the crop roots were less effective at extracting water from the deep subsoil, leading to greater residual moisture at depth (especially in the 120–200 cm soil layer) and lower yield and water use efficiency than in traditional tillage. The grain yield and water use efficiency were 9.2% and 8.4% lower, respectively, under no tillage than under traditional tillage. The NMP under traditional tillage exhibited lower surface soil bulk density and a higher three-soil-phase index, mean weight diameter, geometric mean diameter, soil organic matter, total nitrogen, and water use efficiency than the unfertilized control, resulting in higher grain yields. The NMP under traditional tillage is recommended to increase grain yield and water use efficiency in wheat–maize rotation systems in the tableland region of China’s Loess Plateau. Future studies should analyze the deep root architecture and the effect of weed competition on soil water depletion. Full article

The poor quality and scarcity of soil used for raising seedlings are key issues holding back the further development of the rice industry. Artificial humic substances (A-HS) and artificial soils are attracting increasing attention due to their cost-effectiveness and significant potential to improve rice cultivation. This study used native soil (NS), engineered soil (ES) and rice straw to create artificial substrates (AES and ANS) using humification–hydrothermal carbonization technology (24 h treatment of NS and ES with rice straw at 200 °C and 2 MPa). Experiments on cultivation of the rice seedlings were conducted using initial soils (ES and NS) and artificial soils with addition of A-HS (AES+A-HS and ANS+A-HS). This study examined the nutrient content and microbial environment of the seedling substrates as well as the changes in growth and development of the rice seedlings. The combination of rice straw biochar in artificial soils (AES and ANS) with A-HS significantly increased the content of soil organic carbon (SOC) and enhanced the nutrient levels, such as total nitrogen and available phosphorus. Furthermore, it enhanced the microbial diversity, and it increased the abundance of microorganisms such as Actinomycetota, Chloroflexota, and Basidiomycota, thereby improved the soil microbial environment. An enhanced soil nutrient content and improved microbial environment effectively promoted the rice seedling growth. Compared to the original soils (ES and NS), before transplanting to paddy fields, the stem width of the seedlings increased by 5.1% (AES+A-HS) and 10.2% (ANS+A-HS), and their height increased by 18.7% (AES+A-HS) and 4.5% (ANS+A-HS). The rice seedling emergence increased by 6.1% (AES+A-HS) and 3.9% (ANS+A-HS), and the transplant survival rate also increased by 4.1% (AES+A-HS) and 2.9% (ANS+A-HS). This study provides an effective approach to alleviating the scarcity of rice seedling substrates and improving the quality of rice seedlings, and it provides an effective foundation for increasing the yield of rice. Full article

Biochar, produced by pyrolyzing biomass under limited oxygen, can improve soil quality while supporting long-term carbon sequestration. This study compared two wheat-straw biochars (BC) made at 450 °C (BC1) and 600 °C (BC2), with a commercial hardwood biochar produced at 1280 °C (BC3) using lettuce in a sandy, nutrient-poor soil under a carbon capture, utilization, and storage (CCUS) perspective. Higher pyrolysis temperature increased fixed carbon, ash, and alkalinity and reduced volatile matter, indicating greater carbon stability (BC2 > BC1). Germination tests showed good compatibility, with BC1 performing best, likely because moderate temperatures retain more labile organic fractions. In growth-chamber trials (0.75% w/w), biochar boosted lettuce biomass and root development mainly when combined with mineral fertilization, with BC2 (25% and 59%, respectively) and BC3 (18% and 52%, respectively) yielding the strongest gains; unfertilized plants responded little, confirming that biochar is mainly a soil conditioner rather than a nutrient source. Biochar also stimulated soil enzymes linked to C, N, and P cycling and improved leaf chlorophyll, nitrogen status, and antioxidant capacity under fertilization. The nutrient profiles differed by biochar: BC1 increased K and nitrate, while BC2/BC3 lowered nitrate and BC3 enhanced Ca, Mg, and P uptake. Overall, agronomic outcomes depend on feedstock and pyrolysis temperature: mid-temperature biochars enhance productivity and soil biological activity, whereas high-temperature biochars maximize carbon permanence. Full article