European Journal of Soil Science最新文献

Food security and the sustainability of ecosystems are seriously threatened by land degradation, especially in the Indo-Gangetic Plains where soil erosion, salinization, and waterlogging are the main causes. This study integrated these three forms into a unified, versatile, and globally adaptable Land Degradation Index (LDI) for comprehensive land degradation assessment, using Sultanpur district, Uttar Pradesh, India as a case study. Soil erosion susceptibility was initially assessed using the Revised Universal Soil Loss Equation, whilst salinization and waterlogging were independently evaluated with a Frequency Ratio using 25 and 21 factors, respectively. The resulting susceptibility maps demonstrated high predictive accuracies, with Area Under the Curve (AUC) values of 97.3%, 94.5%, and 90.1%, respectively. LDI was subsequently calculated using these maps as inputs to integrate the three degradation processes into a unified index representing overall land degradation intensity. It identified and mapped the most severely affected areas, revealing that approximately 20% of the agricultural land in the study area was impacted by land degradation. This study also developed novel random forest regression models integrated with SHapley Additive exPlanations (SHAP)-based Game theory to examine the behaviour of conditioning factors in high and low susceptibility zones of Sultanpur district. The models fitted with MSE < 0.0046, RMSE < 0.07, MAE < 0.04, RMSLE < 0.05, and MRE < 0.04 and R² > 0.86. Soil salinization was found to be the primary driver of soil fertility loss in this study. This salinization is primarily driven by vegetation loss, changes in soil pH, overuse of nitrogen-rich fertilisers, and proximity to canals. Identifying the key drivers of land degradation and understanding their localised impacts provides vital insights for promoting sustainable agriculture and guiding evidence-based policymaking. These findings further highlight the broader global relevance of adopting site-specific land management strategies, particularly through vegetation restoration, balanced fertiliser use, and efficient irrigation, to sustain the productivity and resilience of agro-ecosystems like Sultanpur district.

Soil properties are significantly, but unevenly, conditioned by the landscape relief and/or bedrock. Here, we compare forest soil properties along toposequences between differently elevated areas of denuded Variscan mountain ranges and the alpine-fold Carpathians in the Czech Republic (Central Europe). Correlating soil properties were selected by multivariate analysis of granularity, physicochemical and chemical variables. Toposequences were defined from the selected soil properties through principal component analysis and vector overlays with relief and bedrock types. The relief or bedrock effects were compared by nonparametric tests of soil horizon properties between average values at the toposequences and weighted averages of the penetrating geological subdivision types. Eleven forest soil toposequence types were distinguished along wetland, lowland and highland conditions. Particular toposequences were characterised by different grain fractions, C_org, Al₂O₃ and P₂O₅ between soil horizons. The soil-forming effect of relief appeared to be more pronounced in flat areas, with marked transitions between rocks; on the other hand, the bedrock effect was more pronounced in geologically less structured fold areas. The different relief or bedrock effects on soil-forming conditions suggest specification of soil body assessment during terrestrial ecosystem classification.

Viruses are increasingly recognized as active agents in soil biogeochemistry, yet their responses to decades-long nutrient management remain poorly understood. Leveraging a 39-year, fully replicated field experiment in a double-rice system, we integrated virus-enriched metagenomics, 16S rRNA amplicon sequencing, and structural equation modelling (SEM) to unravel how long-term fertilization shapes virus–host dynamics and carbon cycling in paddy soil. Treatments (n = 5) comprised an unfertilized control, full chemical nitrogen fertilization (180 kg ha⁻¹ yr.⁻¹), and manure substitutions of 30%, 50% and 70%. Manure inputs significantly increased bacterial and viral abundances, mitigated the diversity loss caused by chemical fertilization, and enriched copiotrophic hosts. Caudoviricetes, Malgrandaviricetes, and Faserviricetes constituted the dominant viral taxa across all samples (3 treatments × 3 replicates). The viral community composition and lifestyle strategy shifted markedly along the fertility gradient. Manure amendments increased soil nutrient availability and host abundance and coincided with higher viral counts (causing an increase in virus-to-bacterium ratios), and we observed a shift toward predicted virulent lifestyles (69% in M50 vs. 61% in control). In contrast, the unfertilized nutrient-poor control contained the highest proportion of temperate phages and the greatest abundance of carbon-related auxiliary metabolic genes (AMGs), suggesting that the lysogenic conversion provided “metabolic rescue” to hosts by supplementing key metabolic functions under oligotrophic stress. SEM revealed that these viral community attributes, including lifestyle, diversity, and AMGs, were positively associated with microbial biomass carbon and soil organic carbon under manure amendment. By integrating viral ecology into the context of nutrient management and field-scale agroecosystem dynamics, our findings highlight viruses as an overlooked biological dimension in the design of fertilization strategies for sustainable agroecosystems.

Nonexchangeable potassium (neK) derived from micaceous minerals is a key K source in less-weathered granitic soils across the world, including Europe and eastern Asia. Plant use of neK may vary based on soil particle size, specifically coarse (> 20 μm) and fine (< 20 μm) fractions. This study quantified neK in both fractions of soils from different parent materials and evaluated its contribution to crop K uptake under varying K fertilization levels. In total, 55 soil samples were collected from vegetable fields with diverse soil groups or parent materials. Soils derived from granite and sedimentary rock, with high- and low-neK content, respectively, were used in pot experiments with sweetcorn under four K fertilizer rates of 10%, 40%, 70%, and 100%. Soils were fractionated into coarse (> 20 μm) and fine (< 20 μm) fractions, and neK was evaluated using hot HNO₃ extraction. Compared with neK in the fine fraction, neK in the coarse fraction exhibited a stronger linear relationship with total neK (< 2 mm), indicating its greater influence on overall neK content. Granite-derived soils showed relatively high neK levels, proportional to micaceous mineral content in the coarse fraction. In micaceous-rich granitic soils, neK in the coarse fraction of 1066 mg kg⁻¹ decreased by 8%, 9%, 11%, and 15% after the pot experiment under K fertilizer rates of 10%, 40%, 70%, and 100% (two-way analysis of variance, p < 0.05), whereas fine-fraction neK of 404 mg kg⁻¹ did not decrease significantly. The reduction (⊿neK_coarse) correlated positively with K balance in granitic soils. In contrast, sedimentary rock-derived soil had smaller neK levels (coarse- and fine-fraction neK; 31 and 200 mg kg⁻¹, respectively), with no decline in either fraction after the same pot experiment. These findings suggest that coarse micaceous minerals serve as a geologically controlled neK source in soils. In high-neK soils, the coarse fraction contained double the neK content of the fine fraction, leading to greater root accessibility and enhanced K release from neK through root uptake and exudates. In less-weathered granitic soils, promotion of root elongation by basal K fertilization improves accessibility to the coarse fraction and may replace K topdressing by utilizing neK in the coarse fraction.

This study investigates the dual role of biopolymer (via xanthan gum) in modulating soil compression dynamics and evaluates empirical models for parameterizing compression curves. Using uniaxial compression tests for two different soil types (fluvo-aquic and black soil) under varying bulk densities (1.3 and 1.6 g cm⁻³) and matric potentials (−0.06, −3, and −5 bar), we compared the performance of Gompertz, logistic, and lognormal functions in fitting the compression curves of xanthan-amended soils and their controls. Results revealed that the lognormal model outperformed the Gompertz and logistic functions in capturing soil compression characteristics, particularly residual porosity at high stresses. Our findings advocate for adopting lognormal models to advance soil mechanics parameterization, challenging the historical reliance on Gompertz functions. Moreover, xanthan addition induced a dual effect: while enhancing soil resilience through viscoelastic recovery as evidenced by elevated swelling index (C_s), it simultaneously reduced precompression stress (σ_p) and increased compaction susceptibility. This effect facilitates root penetration by improving initial compressibility and minimising radial growth resistance. Soil-specific responses highlighted greater σ_p reduction in fluvo-aquic than in black soil, modulated by bulk density and moisture. Overall, the study underscores biopolymers' evolutionary role as a self-optimising rhizosphere lubricant, balancing deformability and recovery to maximise root proliferation.

Soil aggregates are fundamental structural units that host spatially distinct microbial communities, which drive carbon (C) and nitrogen (N) stabilization through niche-specific biotic and abiotic processes. Yet, the mechanisms underlying microbial-mediated C/N stabilization across aggregate size fractions under different organic inputs remain poorly understood. Here, we conducted a long-term field experiment in a rice–oilseed rape rotation system with three treatments: chemical fertiliser alone (NPK), straw incorporation (NPKS), and biochar application (NPKB). Soil aggregates were fractionated into > 2 mm (large macroaggregates, LA), 0.25–2 mm (macroaggregates, MA), 0.053–0.25 mm (microaggregates, SA), and < 0.053 mm (silt + clay, XSA). Results showed that biochar preferentially enhanced C and N concentrations in finer fractions (< 0.053 mm), indicating enhanced long-term stabilization due to chemical recalcitrance and physical protection. In contrast, straw incorporation promoted complex microbial co-occurrence networks, enriched nitrogen fixation functions, and higher microbial diversity in microaggregates (0.053–0.25 mm), identifying this fraction as a microbial hotspot for dynamic C/N turnover. Moreover, the reduced abundance of chitin-degrading taxa and upregulation of nitrogen-conserving functions under NPKS implied a shift in microbial functional strategies under labile carbon input. These findings reveal contrasting pathways of aggregate-scale C/N stabilization driven by straw and biochar, underscoring the critical role of microaggregates as ecological interfaces linking microbial structure, function, and soil chemistry under organic amendments. These insights offer guidance for optimising organic input strategies to balance short-term nutrient activation and long-term carbon sequestration in sustainable agriculture.

In the contemporary discourse on sustainable development, reducing nitrogen (N) pollution is as critical as mitigating carbon dioxide (CO₂) emissions. Nitrogen is a vital macronutrient for plant growth, and its application in fertilizers has significantly enhanced crop yields. However, intensive and inefficient N fertilization has led to serious environmental consequences, including water eutrophication, biodiversity loss, and increased emissions of nitrous oxide (N₂O), a potent greenhouse gas for which agriculture is the main anthropogenic source. Stabilizing fertilizers with nitrification inhibitors (NIs) presents a promising strategy to improve N use efficiency and mitigate N losses. Despite their demonstrated benefits, NI-stabilized fertilizers still represent only a minor share of the global fertilizer market. This opinion article explores the key uncertainties that may be limiting their broader adoption from an economic and ecological perspective. We examine current knowledge gaps regarding the effects of NIs on soil health and microbial communities, the potential for resistance development among nitrifiers, and the context-dependent variability in their field performance. We also emphasize the need for full life cycle assessments to evaluate whether their environmental benefits outweigh the costs associated with production and application. Finally, we propose strategies to optimize both the use and design of NIs, such as soil-specific application approaches, decoupling NI dosage from N rates, and the discovery of more potent and selective inhibitors. By addressing these uncertainties and proposing strategies for further improvement of current and novel NIs, NI-stabilized fertilizers could become a central tool for sustainable N management in agriculture.