European Journal of Soil Science最新文献

Grapevine (Vitis vinifera L.) is a traditional crop cultivated in Navarre (NE Spain). However, in some areas, it is grown without harnessing land suitability for its cultivation. This research was conducted to approach the pedological recognition of viticulture zoning (on the farm scale) in a traditional and distinct viticultural region: Olite (Navarre). As grape yield and grape quality in a given field are generally variable and do not coincide one way or another, 13 soil profiles were selected for pedological description and analysis in an attempt to recognise the importance of soil properties. For that purpose, 45 soil samples (corresponding to the different pedogenetic horizons of the 13 soil profiles) were collected to improve zonal vineyard estimations. The most notable characteristics of the studied soils were the presence of petrocalcic horizons, high stone fragments content, mainly loamy textures, high pH (between 8.24 and 9.24), high carbonate (between 19.1% and 90.0%), and active limestone contents (between 5.7% and 26.1%), and relatively low organic matter contents (<3.34%). Appreciable soil properties variability was detected from the results of this study and, therefore, variability in production and grape composition was expected. These results emphasise the spatial variability of the study area soils in a way that allows for the delineation of homogeneous viticultural zones. The results also provide the necessary information not only for viticultural zoning in the Navarre wine-growing region, but also in wine-growing regions with a Mediterranean continental climate. Hence, our findings will allow future viticultural management zones to be developed and specific practices to be implemented.

Rock fragments (RFs) are abundant soil constituents, but are routinely excluded from soil analyses. Hence, their contribution to soil properties, and in particular to the microbiome, is incompletely understood. Therefore, shifts in microbial colonisation along the rock-to-soil continuum of topsoils from three agricultural sites with different sedimentary parent rock materials were investigated with particular attention to RFs. Microbial biomass and community composition were quantified using phospholipid fatty acid (PLFA) analysis for unweathered and weathered parent rock materials, two RF fractions (8–16 mm and 2–8 mm) and the fine earth (FE; <2 mm). Trends in biogeochemical weathering, nutrient availability and soil organic matter (OM) development were assessed using mineralogical, geochemical and physical analyses. Actinobacterial PLFA was particularly abundant in parent rocks, where Actinobacteria likely contribute to rock weathering and the initiation of OM accumulation. Conversely, bacterial PLFAs were most abundant in the FE under nutrient- and OM-rich conditions. The integral role of RFs as a microbial habitat is demonstrated by a distinct fungal colonisation, which is enabled by the specific physical features of RFs in combination with the provision of inorganic nutrients. Our findings indicate that RFs are colonised by microbes and that differences in the community structure depend on mineralogical properties and chemical weathering status. We document that RFs are microhabitats with a significant potential to host microbial life in cultivated soils, and thus, could play an important role in biogeochemical cycling and the provision of soil functions in agroecosystems.

Despite the critical role of soil microbial communities in biomass production and ecosystem functioning, previous research primarily focussed on microbial structure without functional insights, especially for rare species. This study addresses this gap by exploring the functional potential of both abundant and rare bacterial communities across various land uses and soil groups in the Lower Namoi Valley, Australia. By integrating plant-beneficial bacteria (PBB) and Functional Annotation of Prokaryotic Taxa (FAPROTAX) databases, we show that rare species exhibited higher alpha diversity and multifunctionality than abundant species. Cropping enhanced the biodiversity of abundant functional bacteria in fine-textured soils, which promoted crop growth through increased PBB and carbon cycling. Conversely, rare functional bacteria exhibited consistently lower biodiversity in croplands. Random forest models and linear regression analyses identified land use as a significant factor influencing the biodiversity of rare functional bacterial communities, likely through plant–soil feedback systems. These findings underline the importance of land use in shaping bacterial community functionality and call for conservation strategies to protect soil biodiversity, especially rare species, to ensure sustainable soil ecosystems and support future food production.

The chemodiversity and thermodynamic stability of dissolvable organic matter (DOM) in paddy soil under different crop residue managements remain unclear. Using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) analysis, we explored the molecular composition of DOM in paddy soil 4 years following incorporation of maize residue in different forms (air-dried straw, manure and biochar). Compared to the control without amendments, manure increased the pool size of DOM but reduced its chemodiversity, while the straw and biochar amendments reduced the pool size but increased the chemodiversity of DOM by 0.22 and 0.05, respectively. Though approximately 60% of the compounds were shared among the treatments, those distinct among the treatments were shaped by residue-derived lignin-like compounds. Moreover, the nominal oxidation state of carbon (NOSC), which corresponds to the energy content in organic carbon, decreased with the maize residue amendments, regardless of the forms. Thus, crop residue amendments could lead to higher DOM persistence in the short-term, potentially slowing carbon turnover in paddy soil.

The local adaption of soil microbial communities to native litter inputs, the so-called home field effect (HFE), is well established, though this phenomenon has yet to be demonstrated for agriculturally relevant inorganic nutrient sources. Using compound-specific ¹⁵N-stable isotope probing of proteinaceous amino acids (AAs), we investigated if continuous long-term grassland fertilisation with either ammonium or nitrate resulted in preferential assimilation by the soil microbial community of the ‘home’ N fertiliser. Relative ammonium uptake was maximal in historic ammonium treated soils and previously unfertilised soil, confirming a general microbial preference for ammonium likely due to biochemical transformation efficiencies. Assimilation of nitrate and ammonium into AAs was comparable for the historic nitrate fertilisation, indicating that microbial adaptive processes governed by historical land use can dictate the immobilisation efficiency of different fertilisers. This is the first observation of the HFE in long-term fertilised grassland soils, with further work required to investigate abiotic or biotic mechanisms underpinning this phenomena.

Vegetation restoration processes significantly affect near-surface characteristics, thus affecting soil detachment. Existing research has primarily focused on analysing soil detachment via root morphological parameters and soil physical and chemical properties. However, few studies have focused on analysing the variation in soil detachment with restoration age from a mechanical parameter perspective. Natural, undisturbed soil samples were collected from five grasslands restored for 1–22 years and from one bare plot (0 years of restoration, employed as the control). The collected samples were subjected to flow scouring in hydraulic flume experiments under six stream powers. The relationship between the soil detachment rate (SDR) and the mechanical parameters of the root–soil composites, namely root cohesion and soil shear strength (τ₂₀₀), were quantified to reveal the mechanical mechanism underlying soil detachment during vegetation restoration. The results indicated that the SDR decreased, whereas root cohesion increased with increasing vegetation restoration age. The dominant factors influencing the SDR changed from hydrodynamics at the early restoration stage to the mechanical properties of the root–soil composites at the late stage. An SDR model with a high prediction accuracy (Nash–Sutcliffe efficiency = 0.96 and R² = 0.96) was developed based on mechanical parameters, and the fitting effect was greater than that of the SDR prediction model developed based on root morphological parameters and soil physical and chemical properties. This study aimed to analyse the SDR variation mechanism from the perspective of mechanics and could provide reference for the study of the erosion reduction effect of roots.

Straw return with chemical fertilizers is integral to improving soil quality and the sustainability of agricultural production. However, little is known about how straw return with chemical fertilizer application affects CO₂ emissions and carbon pools from the perspective of nutrient stoichiometry. We conducted a 2-year (2020–2021) field experiment in a wheat–maize rotation system in silty clay loam to study the effects of straw return and fertilizer application on CO₂ emissions, soil carbon pools and yields by applying stoichiometry. A split-plot experimental design was used (straw was main treatment, and fertilizer was the split-plot treatment). The treatments were no straw return + no fertilizer (S₀W), no straw return + mineral nitrogen fertilizer (S₀N), no straw return + mineral nitrogen and phosphorus fertilizer (S₀NP), straw return + no fertilizer (SW), straw return + mineral nitrogen fertilizer (SN) and straw return + mineral nitrogen and phosphorus fertilizer (SNP). The results indicated that, compared with S₀W, the SNP treatment significantly increased soil organic carbon (SOC) storage by 17% and 13% in the 0–20 cm and 20–40 cm soil horizons, respectively. Additionally, compared with S₀W, the SNP and SN treatments significantly increased the annual cumulative CO₂ emissions by 85% and 41%, respectively. Furthermore, the SNP and SN treatments significantly increased the annual yield by 61% and 38%, respectively, compared with S₀W. Our results indicated that straw and fertilizer inputs reduced the C:N_imbalance in the topsoil (0–20 cm), with fertilizer inputs showing a more pronounced effect. However, straw incorporation increased the C:N_imbalance in subsoil (20–40 cm). Redundancy analysis (RDA) and structural equation models (SEM) suggested that 0–20 cm carbon-phosphorus ratio (C:P) and nitrogen-phosphorus ratio (N:P) could be significant predictors of annual yield and CO₂ emissions. In conclusion, straw and fertilizers enhanced soil nutrient effectiveness and reduced carbon mineralization in favour of SOC storage. However, the input of exogenous materials (straw and fertilizers) disrupted the soil ecological stoichiometric balance and stimulated microbial activity, leading to increased CO₂ emissions. Overall, this study provides theoretical guidance and scientific support for the green development of agriculture.

Soil pH is a critical parameter influencing numerous soil properties including nutrient cycling, microbial activity, inorganic carbon and metal speciation and criteria for classifying acid sulfate soils and soils with reactive aluminium (Podzols and Andosols). Accurate measurement of soil pH is essential for effective soil assessment, management and crop production. This review of soil pH focuses on techniques and challenges for measurement and utilises insights from a comprehensive global soil dataset (n = 655,336). Soil pH has a global average of 6.36 with considerable regional variability. A Random Forest model of the global dataset identified total carbonate content, rainfall, evaporation, clay and organic carbon content as key drivers of soil pH (R² = 0.77, mean absolute error = 0.46 pH units). The advantages and limitations of various soil pH measurement methods (e.g., glass and solid-state electrodes, colorimetric and spectrophotometric methods, infrared spectroscopy, remote sensing and specialised field assessment methods) are discussed. Care should be taken in choosing appropriate pH measurement techniques depending on the purpose of the measurement and nature of the soils. The use of electrolytes (e.g., CaCl₂ and KCl) introduces variable changes in measured pH and, on average globally, pH measured in a 1:5 soil:0.01 M CaCl₂ extract is ~0.7 pH units lower than that measured in a 1:5 soil suspension. Although the use of electrolytes can help stabilise pH measurements in low ionic strength soils, their use requires careful consideration, as they do not eliminate all seasonal variability (which may also be important to assess) and they can introduce large pH perturbations in sodic-alkaline and acid sulfate soils. Varying soil-to-solution ratios have less influence on resultant pH values than electrolytes however the measurements at low soil-to-solution ratios (e.g., 1:1 soil:water) are preferable for accuracy. Perturbations from field pH conditions due to CO₂ outgassing and oxidation are likely when wet soils, acid sulfate soils and/or sub-soils are measured in the laboratory. These findings underscore the need for improved field measurement technology and further research on the measurement protocols to ensure accurate and reliable soil pH data, which are crucial for optimising agricultural practices and environmental management.

Soil forensics is not only a well-established research domain but has also been used in numerous successful international searches for burials and as trace evidence to help police and law enforcement in solving criminal, environmental and terrorism investigations. However, despite the confidentiality and legal constraints in case work in many parts of the world, some actual case studies using soil materials as evidence in court hearings have been published in international journals and books. This paper presents a case from the Campania region in Italy where soil analysis played a pivotal role. Employing a multiscale integrated approach encompassing soil microtomography, morphology, chemical analysis and geography, the study aimed to discern the origin of questioned soil residues found on a victim of crime. Results highlight the significance of considering spatial variability and an appropriate choice of analytical methods. The sequential and multiscale approach facilitated timely investigation without incurring unnecessary costs. Soil morphological and chemical analysis revealed inconsistencies between soil on the victim and soil at the suspected crime scenes, narrowing the investigative area down to approximately one square km. While detailed sampling did not yield statistically significant results, the evidence provided crucial insights, aiding investigators in working out what happened and helped in building a narrative around their case. The analysis indicated contact with a primary scene where the victim was likely dragged (over a Calcisol) and a final deposition site (over an Andosol) where the body was found. While potential murder sites were excluded, final guilt attribution remained inconclusive, and as in all trace evidence evaluation, it is not the role of the forensic soil scientist to consider the level of guilt, but to provide factual soil forensic evidence to assist the justice system. This study exemplifies the use of soil forensics in informing criminal investigations and highlights the complexities that can be involved in establishing comparability between soil samples.

Soil health refers to the capacity of soil to sustain ecosystem functions and provide a favourable environment for soil organisms and plants. However, it is challenging to quantitatively determine soil health by assessing its ecosystem functions. Here, we constructed a multifunctional soil health assessment method based on five soil functions including plant productivity (PP), water regulation (WR), nutrient cycling (NC), carbon storage (CS), and biodiversity preservation (BP), with soil acidification rate and soil erodibility factor as restrictive indicators. The entropy weight coefficient method was used to calculate the indicator weights, and the minimum data set (MDS) was established using random forest modelling. The impact of organic manure treatments on the five soil functions and the soil health index (SHI) was calculated using a long-term fertilization experiment. Our results showed that manure application significantly promoted the five soil functions and SHI, and the SHI was significantly positively correlated with soil fertility index (SFI) and soil quality index (SQI). Random forest modelling showed that the five soil functions contributed similar proportions to the variation in SHI. SHI based on the total data set and minimum data set was positively associated with maize characteristics, including root weight, shoot weight, and grain yield. In conclusion, the multifunctional soil health assessment method is crucial for elucidating the relationships of management practices with soil health and crop yield, enabling the achievement of healthy management and sustainable development for ferric acrisol farmland.