European Journal of Soil Science最新文献

Land use type is the key factor affecting wind erosion and organic carbon level. However, the independent contribution of wind erosion to soil organic carbon (SOC) change and the combined effects of land use and wind erosion on SOC are still unclear. In this study, the relationship between land use and wind erosion, as well as their effects on organic carbon, was studied by using radionuclide tracer and spectral techniques in grassland, woodland and farmland in the western Songnen Plain. The results showed that the land use type had a significant influence on the wind erosion rate, and the wind erosion rates of grassland, woodland and farmland were 74.06, 124.98, 226.98 t·ha⁻¹·yr.⁻¹, respectively. The SOC in 0–10 cm was the highest in grassland (26.63 g·kg⁻¹), followed by woodland (17.73 g·kg⁻¹), and the lowest in farmland (7.46 g·kg⁻¹). Wind erosion significantly reduces the stability of SOC. Variance partitioning analysis (VPA) showed that 0–10 cm surface SOC was mainly influenced by the independent contribution of wind erosion (10.39%) and the combined effect of wind erosion, land use and soil properties (60.56%). SOC content in the 10–40 cm deep layer was mainly affected by land use (41.58%) and soil properties (53.48%). According to the partial least squares path model (PLS–PM), the effect of wind erosion on SOC is direct (−0.24*), while the effect of land use type on SOC is indirect. These results indicated that maintaining grassland cover and implementing windbreaks in agricultural areas could effectively mitigate SOC loss. The quantified wind erosion–SOC relationships provide concrete targets for land management policies in arid regions, particularly for carbon sequestration initiatives and wind erosion prevention and control.

The incorporation of crop straw creates decomposition hotspots, and the microscale variability of pH in soil-straw hotspots is a critical driver of microbial activity and nutrient cycling. However, little is known about the pH dynamics at the soil–straw interface, particularly under conditions of fluctuating moisture. In this study, we applied high-resolution planar optode imaging to monitor in situ microscale pH dynamics at the straw–soil interface in a typical fluvo-aquic soil during three consecutive drying–rewetting cycles. Two straw incorporation patterns—heterogeneous (patch) and homogeneous (uniform)—were compared to assess their effects on localized pH variations. The heterogeneous straw treatment induced pronounced acidification hotspots (pH < 6.6) concentrated around straw patches. During wetting, the acidic zones expanded radially outwards, accompanied by a progressive steepening of the pH gradient (up to 0.10 units mm⁻¹). Upon drying, water limitation caused these zones to contract inwards as the pH gradient flattened. In contrast, the homogeneous treatment exhibited dispersed, less intense acidification (pH 6.7–6.9) with smaller spatial and temporal fluctuations. Repeated drying–rewetting cycles promoted cyclic accumulation and depletion of formic and acetic acids at the straw–soil interface. The magnitude of both acidification and cation release (Ca²⁺, Mg²⁺, and K⁺) diminished across successive cycles, indicating the progressive depletion of labile straw components. These findings highlight the importance of straw spatial arrangement in shaping microscale soil acidification under moisture fluctuations, offering valuable insights for optimizing crop residue management and predicting soil biogeochemical responses.

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.