Search Results (4,983)

Soil mulching materials play an important role in regulating the greenhouse crop microclimate, as they influence light distribution, plant physiological activity, and crop yield. The aim of this study was to evaluate the effects of two plastic mulches (black polypropylene and white polyethylene mulch) on the microclimate, photosynthetic activity, crop development, yield, and fruit quality of sweet pepper (Capsicum annuum L.) grown under greenhouse conditions. The trial was developed during a spring–summer growing cycle in a single multispan greenhouse divided into two compartments (sectors) separated by a vertical polyethylene sheet. In the eastern sector of the greenhouse (control treatment), a black polypropylene agrotextile mulch with a thickness of 2500 μm was installed, while in the western sector, a white polyethylene plastic mulch (black on the inner side) with a thickness of 30 μm was used. The use of white polyethylene mulch resulted in slightly higher mean and maximum PAR inside the greenhouse by up to 3.7% compared with black polypropylene mulch, leading to slightly higher leaf-level PAR and net photosynthetic rate. Although no significant differences were observed in plant morphology or fruit quality parameters, marketable yield increased by 66% and total yield by 40% under white polyethylene mulch. Slight increases in internal air temperature were recorded without exceeding critical thresholds, while relative humidity remained largely unaffected. The use of reflective mulches may represent a promising low-cost and sustainable strategy to improve pepper yield and radiation-use efficiency in passively ventilated greenhouse systems under Mediterranean climatic conditions. Full article

The mixing of tree species influences soil microbial communities and ecosystem functioning, yet the underlying mechanisms remain inadequately understood. This study aimed to elucidate how different tree species mixtures regulate soil microbial community structure and ecological functions and to disentangle the relative roles of leaf functional traits, soil nutrients, and tree species identity in shaping bacterial and fungal assemblages. Leaf and soil samples were collected from 15 plots (20 m × 30 m) established in pure Larix principis-rupprechtii plantations (PL) and mixed Larix-Betula platyphylla (MLB) and Larix-Picea asperata (MLP) stands in the Saihanba Mechanical Forest Farm, China. Principal coordinate analysis, co-occurrence network analysis, and partial least squares path modeling were employed to assess changes in microbial community structure, network organization, and functional potential. Our results showed that the MLB stand mainly improved leaf nitrogen content (LNC), specific leaf area (SLA), and the concentrations of total nitrogen (STN) and phosphorus (STP) in the soil. The MLP stand preferentially promoted carbon and phosphorus accumulation in both leaves and soil. The MLB stand exhibited higher bacterial Chao1 richness, whereas the MLP stand showed reduced fungal diversity. The MLB supported a more complex bacterial network enriched with keystone taxa involved in nitrification and nitrate reduction, while MLP displayed a less complex bacterial network and a higher relative abundance of ectomycorrhizal fungi. Path analyses revealed that tree species mixtures shaped bacterial community structure largely via changes in leaf functional traits and soil conditions. Bacterial functional potential was primarily driven by improvements in soil nutrient availability. In contrast, fungal assemblage organization and functional expression were directly governed by the identity of the mixed tree species. These insights provide a foundation for improving soil fertility and nutrient cycling in managed forests via strategic species diversification. Full article

Precipitation pulses refer to discrete and intermittent precipitation events that significantly influence ecosystem carbon and nitrogen cycling processes. However, the mechanisms by which different vegetation types modulate the sensitivity of carbon dioxide (CO₂) and nitrous oxide (N₂O) fluxes to short-term rainfall pulses remain poorly elucidated. To address this knowledge gap, we conducted a controlled rainfall simulation experiment across four representative surface types (moss-dominated biological soil crusts, Artemisia-ordosica-dominated soil, Caragana-korshinskii-dominated soil, and bare sandy soil), applying two precipitation pulses (5 mm and 10 mm) to quantify soil CO₂ and N₂O flux responses. The results showed that: (1) CO₂ emissions increased significantly with precipitation intensity, with the 10 mm treatment producing higher mean fluxes than the 5 mm treatment. Emission peaks (1200–1600 mg m⁻² h⁻¹) occurred within 24 h after rainfall and returned to baseline levels within three days; (2) Surface cover exerted a strong regulatory effect on CO₂ emissions, with moss crust soils (~400 mg m⁻² h⁻¹) and A. ordosica soils (~350 mg m⁻² h⁻¹) exhibiting CO₂ fluxes 2.5–3 times higher than those of bare sandy soils (~120 mg m⁻² h⁻¹); (3) Structural equation modeling indicated that precipitation indirectly enhanced CO₂ emissions by increasing soil carbon availability, with total organic carbon emerging as the strongest direct driver. Together, these findings clarify the primary controls on precipitation-induced CO₂ emissions in restored desert systems and highlight the decoupled and weak short-term response of N₂O, providing critical insights for managing carbon–nitrogen processes under increasing precipitation variability. Full article

Salinity is an emerging constraint for Mediterranean coastal agriculture, where shallow groundwater, seawater intrusion, and summer evapo-concentration generate relevant intra-seasonal variability in soil electrical conductivity. Camelina [Camelina sativa (L.) Crantz] has been proposed as a diversification oilseed for constrained environments, but its field performance under realistic, dynamic salinity in Mediterranean soils remains unexplored. This two season on farm study compared three commercial camelina lines at an inland non-saline site and a coastal saline–sodic site in northeastern Italy, combining agronomic measurements with phenology aligned monitoring of soil saturated paste electrical conductivity (ECe). At the saline site, ECe increased from 1.8 dS m⁻¹ at the vegetative stage to 6.2 dS m⁻¹ at seed filling, while camelina completed its cycle earlier than at the inland site. Despite similar aboveground and root biomass yield at flowering across lines, performance diverged during the reproductive phase. Two lines maintained similar seed yields (1.30 Mg ha⁻¹) at the coastal site compared with the inland site, whereas one line declined from 1.45 Mg ha⁻¹ to 0.40 Mg ha⁻¹. Differences among lines in seed yield under salinity were accompanied by contrasting responses in seed oil composition. Oil yield at the saline site was more strongly associated with the increase in ECe from flowering to seed filling than with absolute ECe at seed filling. These results provide the first field-based evidence of line-specific salinity responses in camelina and highlight its potential to diversify moderately salt-affected Mediterranean coastal cropping systems, while emphasizing the need to account for temporal salinity dynamics in genotype selection and crop planning. Full article

Nanofertilizers have attracted increasing attention as an approach to improve the low nutrient use efficiency of conventional fertilizers, in which only a limited fraction of applied nitrogen, phosphorus, and potassium is ultimately taken up by crops. Beyond their capacity to minimize nutrient losses, nanofertilizers have attracted increasing attention for their possible role in addressing environmental issues, including soil eutrophication and the contamination of groundwater systems. Owing to their nanoscale characteristics, including large specific surface area and enhanced adsorption capacity, these materials enable more precise nutrient delivery to the rhizosphere and sustained release over extended periods, while also influencing soil–plant–microbe interactions. In this review, nanofertilizers are classified into six major categories—macronutrient-based, micronutrient-based, organic, controlled-release, composite, and nano-enhanced formulations—and representative examples and preparation routes are summarized, including green synthesis approaches and conventional chemical methods. The agronomic mechanisms associated with nanofertilizer application are discussed, with emphasis on enhanced nutrient uptake, modification of soil physicochemical properties, and shifts in microbial community composition. Reported studies indicate that nanofertilizers can increase crop yield across different crop species and formulations, while also contributing to improved nutrient cycling. Despite these advantages, several limitations continue to restrict their broader adoption. These include uncertainties regarding long-term environmental behavior, relatively high production costs compared with conventional fertilizers, and the absence of well-defined regulatory and safety assessment frameworks in many regions. Overall, this review highlights both the opportunities and challenges associated with nanofertilizer application and points to the need for further development of cost-effective formulations and standardized evaluation systems that account for their distinct environmental interactions. Full article

Thermoresponsive chitosan hydrogels hold significant promise for advancing biomedical technologies, yet their frequent reliance on petroleum-based polymers raises biosafety and environmental concerns. The present study utilized a molecular functionalization strategy to transform chitosan into thermoresponsive alkylated chitosan (ICS). The ICS was subsequently covalently crosslinked to construct a fully degradable, all-chitosan thermoresponsive hydrogel (TR-ICS_gel), showcasing the effective integration of structural design and functionality. By adjusting the ICS concentration, TR-ICS_gels with varying volume phase transition temperatures (VPTTs) were obtained. Above the VPTT, strengthened alkyl chain hydrophobic interactions triggered hydrogel dehydration and pronounced, reversible shrinkage–swelling. The hydrogel maintained a stable swelling response over 20 consecutive temperature-stimulus cycles. Further investigation was conducted on the effects of ionic strength and small-molecule solvents on the thermoresponsive behavior of TR-ICS_gel. Soil burial and buffer solution tests demonstrated that the hydrogel underwent almost complete degradation within 27 and 15 days, respectively, and the degradation rate could be regulated by the ICS concentration. The TR-ICS_gel’s all-chitosan framework ensured excellent biocompatibility, with cell viability maintained above 95%. This study presents a strategy for developing fully bio-based, degradable smart hydrogels, enhancing biosafety and environmental friendliness. Moreover, these results provide crucial performance data and theoretical support for their practical application. Full article

This study conducted laboratory model tests, integrated with Particle Image Velocimetry (PIV) technology, to investigate the evolution of the uplift bearing capacity of an under-reamed anchor group subjected to cyclic loading. The tests considered various working conditions, including different spacing ratios (S/D = 4, 5, 6, where S was the center-to-center spacing and D was the diameter of the under-reamed body), varying cyclic amplitude ratios (λ = 0.3, 0.5, 0.6, 0.7, 0.8) and different cycle times (M = 1, 5, 10, 30). PIV was utilized to observe the displacement field of the surrounding soil, revealing the group effect of the anchors and the variation in their uplift capacity under diverse cyclic amplitudes and cyclic times. The results indicated that the load–displacement curves could be delineated into three distinct stages: elastic, elastoplastic, and plastic. Notably, the group effect primarily initiated during the elastoplastic stage and developed significantly within the plastic stage. The cyclic amplitude ratio was identified as a key factor influencing the uplift capacity. Furthermore, compared to results from single pull-out tests, both the vertical displacement of the surrounding soil and the shear strength of the sidewall adjacent to the under-reamed body decreased following cyclic loading. Finally, the influence of the cyclic times depended on the occurrence of anchor failure; in the absence of failure, the anchor maintained satisfactory performance even after multiple cycles. Full article

Soil amendments are widely applied to improve soil fertility and structure, yet their performance in cold regions is constrained by low accumulated temperatures, frequent freeze–thaw (FT) cycles, and permafrost sensitivity. In this review, ‘cold regions’ refers to high-latitude and high-altitude areas characterized by long winters and seasonally frozen soils and/or permafrost. We screened the peer-reviewed literature using keyword-based searches supplemented by backward/forward citation tracking; studies were included when they assessed amendment treatments in cold region soils and reported measurable changes in physical, chemical, biological, or environmental indicators. Across organic, inorganic, biological, synthetic, and composite amendments, the most consistent benefits are improved aggregation and nutrient retention, stronger pH buffering, and the reduced mobility of potentially toxic elements. However, effectiveness is often site-specific and may be short-lived, and unintended risks—including greenhouse gas emissions, contaminant accumulation, and thermal disturbances—can offset gains. Cold-specific constraints are dominated by limited thermal regimes, FT disturbance, and the trade-off between surface warming for production and permafrost protection. We therefore propose integrated countermeasures: prescription-based amendment portfolios tailored to soils and seasons; the prioritization and screening of local resources; coupling with engineering and land surface strategies; a minimal cold region MRV loop; and the explicit balancing of agronomic benefits with environmental safeguards. These insights provide actionable pathways for sustainable agriculture and ecological restoration in cold regions under climate change. Full article

California sage scrub is an endangered, shrub-dominated, southern California ecosystem threatened by increasing fire frequencies and type-conversion to non-native grasslands. Once non-native grasses become established, their presence promotes more frequent fires, perpetuating grass dominance. To better understand how fire influences soil seed bank assemblages, we examined soil seed banks in burned and adjacent unburned sage scrub at the Robert J. Bernard Field Station (BFS) in two areas that burned in September 2013 and May 2017. In contrast to a previous soil seed bank study in California sage scrub, we found that unburned soil seed banks in sage scrub at the BFS were primarily composed of native seeds (88% of sprouts in unburned areas were native), highlighting that soil seed bank dynamics differ among California sage scrub sites. Despite burned areas supporting elevated densities of non-native seeds (the majority of which included Festuca myuros, a non-native grass), soil seed banks in our burned areas retained native seeds (21% of sprouts in burned areas were native), including native shrub species, suggesting that not all sage scrub habitats are primed to transition to non-native grasslands following disturbances. However, elevated densities on non-native seedlings in burned areas highlight the vulnerability of sage scrub to fire disturbances and the subsequent establishment of non-native grasses. Full article

As a critical aquatic–terrestrial ecological transition zone, the lake littoral zone exhibits steep biogeochemical gradients and plays a vital role in regulating submerged microbial communities and their functions. This study aims to reveal how multi-scale environmental gradients influence microbial succession processes along desert lake littoral zones, as well as the distribution patterns of functional genes involved in carbon (C), nitrogen (N), and sulfur (S) cycling. The results demonstrated that microbial alpha-diversity in the vadose zone exhibited significant individual variability horizontally, while showing pronounced inter-group differences vertically. Horizontally, a distinct functional succession was observed from the shore to the water’s edge, with microbial potential shifting progressively from aerobic oxidative types toward anaerobic reductive types. Vertically, the root-intensive layer fostered more complex co-occurrence networks through enhanced interspecific interactions, suggesting higher functional resilience compared to other layers. Further analysis identified soil moisture as the primary environmental filter driving microbial composition, explaining 27.7% of the variation. Structural equation modeling (SEM) further elucidated that pH and Total Organic Carbon (TOC) were the key regulators of carbon fixation and sulfur oxidation genes, while Total Nitrogen (TN) dominated the distribution patterns of nitrogen cycling genes. These findings deepen the mechanistic understanding of microbial-mediated element cycling in desert lakeshore zones and provide a theoretical basis and data support for maintaining the functions of these fragile ecosystems. Full article

Soil microorganisms are important components of forest ecosystems and play a key role in biogeochemical cycling. Bamboo is invasive due to its strong clonal expansion ability, which often leads to changes in plant communities and soil environments, thus affecting soil microorganisms. However, the existing research focuses on the response of moso bamboo (Phyllostachys edulis) and soil fungi and bacteria, and little attention is paid to other bamboo species and their impact on soil protists. In this study, we examined the effects of Bambusa emeiensis expansion on the soil microbial communities in subtropical evergreen broad-leaved forests. B. emeiensis expansion significantly reduced plant diversity and soil pH (p < 0.05). The expansion of B. emeiensis did not significantly change the relative abundance of dominant bacteria and fungi groups in the soil, but significantly changed the community composition of protists, including a significant increase in the relative abundance of Cercozoa, while the Evosea_X group and Ciliophora decreased significantly (p < 0.05). While α-diversity remained unchanged across all microbial groups, only protist community structure differed significantly (p = 0.026). The main driver of protist variation was identified as plant diversity decline by redundancy analysis (R² = 0.760, p = 0.032). These results can be interpreted within a bottom-up regulatory framework, in which plant diversity is linked to changes in protist community composition. Overall, protists are an important group of organisms that help us understand the impact of bamboo growth on the environment. Their role in nutrient cycling and soil fertility suggests that changes in protist communities may have broader implications for ecosystem sustainability. This study provides a scientific reference for the ecological management of regional B. emeiensis and highlights the potential impact of protist community shifts on soil health and ecosystem resilience. Full article

The field experiment was carried out in the fields of the Experimental Variety Testing Station in Chrząstów, belonging to the Central Research Centre for Cultivated Plants in Słupia Wielka. The aim of the present study was to determine the effect of residual nitrogen (N_res) remaining in the soil after cultivation of three varieties of common maize fertilized with different types of nitrogen fertilizers on nitrogen-use-efficiency indicators in subsequent crops of winter and spring common wheat. Nitrogen accumulation in both wheat cultivation systems showed a significant response to the interaction between maize varieties and the type of nitrogen fertilizer applied. Urea proved to be the most consistent source of nitrogen in the grain, regardless of the maize variety used as the preceding crop or the form of nitrogen applied. Variability in nitrogen accumulation under the U + N-Lock, Super N-46, and SG Stabilo treatments was primarily associated with a marked decrease in the SC maize variety. The SC + Roots Power maize variety left the soil in a condition highly favourable for nitrogen accumulation in wheat grain across two consecutive growing seasons. Maize variety was the primary factor influencing the proportion of fertilizer-derived nitrogen in the total nitrogen accumulated in the grain. The highest recovery of fertilizer nitrogen over the two-year production cycle was obtained in the SC + Roots Power treatment fertilized with SG Stabilo. Notably, urea demonstrated the strongest residual effect on nitrogen availability to winter wheat. Full article

Nanopesticides are pesticide formulations in which intentionally designed nanoscale carriers shape how an active ingredient (AIng) is deposited, transformed, and released. These systems can improve retention and efficacy, but carrier complexity introduces challenges: nanomaterials can transform in real soil–water matrices, reshaping exposure and risk. These processes are hard to quantify because test protocols and risk assessment frameworks for nanopesticides remain underdeveloped. In this review, we relate design choices across major carrier families—including polymer and lipid particles, nanoemulsions, porous inorganic carriers, and bio-based nanomaterials—to transformations in soil–water systems. We then connect these transformations to ecotoxicological evidence across key non-target taxa. We also address a central “measurement gap” in current risk assessment. Many standard tests were developed for dissolved chemicals. As a result, they do not capture (i) particle stability in realistic matrices, (ii) particle-bound versus dissolved (and ion-released) forms, or (iii) time-resolved exposure. Finally, we propose a Safe-and-Sustainable-by-Design roadmap that prioritizes low-hazard materials, predictable degradation, life-cycle thinking, and staged data generation to enable scalable, field-relevant adoption. Full article

In this study, phosphorus tailings sand (PTS) was ground into fine powder and incorporated with slag and fly ash to formulate a cementitious material composed solely of solid wastes. The current research aimed to promote the high-value utilization of local solid waste resources in Lianyungang and to explore their potential application in soil stabilization and ground improvement. Through optimization of component dosage and the proportions of alkaline activators, the effects on workability, mechanical properties, drying shrinkage, wet–dry cycles, microstructural evolution, and heavy-metal leaching behavior were comprehensively examined. The findings revealed that at the optimal ratio of PTS–slag powder–fly ash = 5:2.5:2.5, the developed cementitious material demonstrated a 28-day compressive strength of 33.8 MPa, along with 4.5 MPa flexural strength, and 168 mm flow spread. Moreover, the 28-day drying shrinkage reached a minimal value of 0.038%, with reduced mass loss of 6.7% after wet–dry cycling. Furthermore, under non-freezing conditions, the leaching content of Zn, Mn, Pb, and Cu from the PTS-based multi-solid-waste cementitious system remained below the permissible limits for non-hazardous discharge established by Chinese environmental regulations. These findings provide an innovative pathway for the resource-efficient application of phosphorus tailings sand and several solid wastes while offering technical guidance for silt stabilization and ecological restoration efforts in the Lianyungang region, highlighting promising engineering application prospects. Full article

Heat waves (HWs), characterized by periods of unusually high temperature, would inevitably affect the soil microenvironment and then soil respiration (Rs), which is considered to be the most active part of the global carbon cycle. An in situ spring and summer HWs simulation experiment combined with a locally common human disturbance (mowing) was conducted to separate Rs into autotrophic respiration (Ra) and heterotrophic respiration (Rh) on a natural Eurasian meadow steppe in 2018 and 2019. HWs significantly affected grassland Rs, Rh and Ra (p < 0.01) and also interacted with mowing, but the effect of spring HW and summer HW were different. During the summer HWs, daily Rs of the non-mowed plots increased by 1.07 μmol m⁻² s⁻¹ (11.71%) and increased in the mowed plots by 2.15 μmol m⁻² s⁻¹ (23.81%). During the spring HWs, daily Rs of the non-mowed plots decreased by 0.13 μmol m⁻² s⁻¹ (2.36%) and decreased by 0.52 μmol m⁻² s⁻¹ (9.02%) in the mowed plots. Rs, Rh and Ra were inhibited by spring HWs, but promoted by summer HWs. Our results indicated that the occurring time change in HWs would cause widely divergent influences on the ecosystem, and mowing would decrease the anti-interference ability of the ecosystem, which acted as an enhancement on both the positive and negative effects of HWs. These findings have important implications for accurate model prediction and carbon budget assessment. Full article