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Forest soils represent an important terrestrial organic carbon sink and the management practices could affect this C pool. The purpose of the present study was to investigate the effect of a forest restoration on the quantity and quality of the soil organic C (SOC). Since the widespread distribution of European chestnut (Castanea sativa Mill.) trees in European temperate forests, a 15 years old chestnut forest for timber production was selected on Northern Apennine chain (Italy) which was established on a clear–cut old chestnut stand. The soil sampling was performed in November 2004 (t0, before grafting), 2008 (t1) and 2019 (t2) through the digging of minipits down to 10 – 30 cm. In each minipit the surface and subsurface horizons were sampled and analysed for the determination of the total organic C content (TOC), and the C of fulvic acids (FA–C), humic acids (HA–C), humin (humin–C) and non–humic substances. Then, the total organic C stock (OCstock), the humification index (HI) and the humification rate (HR) were calculated. From t0 to t2 the mean thickness of subsurface horizon increased likely due both to the tree roots development and to the increased canopy cover due to tree growth which probably reduced the soil erosion. Generally, both TOC content and OCstock did not change over time. The FA–C and HA–C concentrations, instead, more sensitive to the change of management practises, generally reduced over time. This trend was also confirmed by the decline of HR. The humin–C content increased indicating an accumulation of the most recalcitrant SOC pool over time. Hence, the restoration of chestnut stands in mountainous areas, beyond to be a valid economic practice, has beneficial effects on the soil capacity to storage stable C., EQA - International Journal of Environmental Quality, Vol 40 (2020)

Among natural hazards, mud volcanoes can damage property and infrastructures and affect hillslope evolution at different spatial and temporal scales. The results of 10-year-long multidisciplinary investigations performed on a Roman-age archaeological site, La Rovina di Montegibbio, are presented, showing a peculiar example of mutual interplay between human settlement and geological forcing in the mud-volcanic environment. The site (350 m a.s.l.) lies at the termination of the upper Secchia River catchment, near the town of Sassuolo (Modena Province). Here, a 4-km-long mud volcano belt borders the Apennines chain front, comprising one of the most prominent mud volcanoes of Italy ( Salsa di Montegibbio), and the still-active chain hinge tectonics gives origin to gas and oil seeps. Based on geological, geoarchaeological, palaeobotanical, geochemical, geophysical records and analytical data, we unravel the onset, the evolution and the abandonment of the settlement in relation to the existence of a previously unknown mud volcano, belonging to the larger Montegibbio mud volcano system. The damages affecting the Roman-age buildings record the ground deformations in the context of mud volcano tectonics. In particular, the pattern of faults set buried under the archaeological site is shown and compared with that of the main mud volcano conduit. At least two Roman-age eruptive episodes have been recorded, whose ejected muds are geochemically characterized. The first recorded eruption must be regarded as the reason for the initial location and function of the sacred ancient settlement. The final site abandonment was because of subsequent severe ground deformations affecting the hillslope as a consequence of mud volcano activity.

Climate change, land use and management malpractices are increasing the areas of salt-affected soils, threatening soil health and economical sustainability of farms. The causes and processes are manifold and variable in space and time. There is the need to continuously update strategies to tackle salt-affected soils, finding solutions tailored at different scales. The aim of this article is to present a selection of case studies with high innovation potential and covering a range of farming systems and approaches. These include cases studies within irrigation scheduling, chemical and phytoremediation of sodic soils, agronomical and microbial management, and land-use changes. The reviewed cases cannot constitute a complete overview of techniques to counter salinisation, but they show the successful application of innovative practices and delineate further research and innovation projects to counter salt-affected soils.

Maintaining and improving the soil resource is crucial for the protection of the global environment, the sustainability issues, the human well-being, and the economic development. Soil is in fact a complex integrated system whose multitude of biotic and abiotic properties allows the provision of functions, which in turn deliver ecosystem services for human benefits. The most widespread agrarian, forest and food production systems may have negative impacts on soil, thus exacerbating its degradation processes. There is an increasing awareness that improper use or poor soil management, together with the most recent events related to climate change, jeopardize the proper functioning of soils. The need to protect the soil resource is thus widely shared internationally. One of the major challenges in the new growth EU strategy is to accomplish food security and to promote sustainable agricultural development, achieving the climate neutrality by 2050. Given the crucial role of soil for human activities, the Soil Thematic Group of the Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum - University of Bologna (Italy), states its position identifying the main challenges for the future growth of EU in: - The organic carbon loss; - Bio-technologies for agro-waste conversion into eco-efficient bio-based products; - Soil biodiversity: preservation and restoration; - The agroecological systems for supporting the farm to fork and ecosystems and biodiversity policies; - Towards a soil sustainable and suitable farm and food system; - Forest soil restoration; - Next generation policy instruments for soil conservation and carbon sequestration; - Soil as energy resource for sustainable rural facilities; - Novel methodologies and approaches to multi-criteria landscape analysis, monitoring and planning.

Soils are complex matrices and their geochemical investigation necessarily needs reliable Certified Reference Materials (CRMs), i.e. standards, to support analytical precision and accuracy. In particular, the definition of soil multi-element CRMs is particularly complex and involves an inter-laboratory program that employs numerous analytical techniques. In this study, we present the results of the inter-calibration experiment focused on the certification of two new soil standards named AMS-ML1 and AMS-MO1. The two soils developed on sandstone and serpentinite parent materials, respectively. The experiment involved numerous laboratories and focused on the evaluation of soil physicochemical parameters and geochemical analyses of major and trace elements by X-ray fluorescence (XRF) and Inductive Coupled Plasma techniques (ICP-OES and ICP-MS). The data was statistically elaborated. Three levels of repeatability and accuracy in function of the different analytical methods and instrumentation equipment was observed. The statistical evaluation of the results obtained by ICP-OES on Aqua Regia extracts (i.e., Lilliefors test for normally, Grubbs test for outliers, Cochran test for outliers in variances and ANOVA) allowed to computed some certified values for the two proposed soil standards. This preliminary study will represent the first step of a more thorough intercalibration ring-test involving a higher number of laboratories, in order to propose the investigated matrices as CRMs., EQA - International Journal of Environmental Quality, Vol 15 (2014)

In soil organic carbon (SOC) survey, the role of sampling approach is crucial andshould not be underestimated. In this sense, the appropriateness of soil sampling bypedogenic horizons (PGH) and fixed depth layers (FDL) in forest is still a field ofdebate. The present work aimed to: (a) study the spatial variability of SOC concentra-tions and C stocks through PGH and FDL samplings in uneven-aged sweet chestnut,European beech and Norway spruce forests of the Apennine chain (Italy); (b) clarifythe major advantages and drawbacks of sampling by PGH and FDL. In a representa-tive area (1818 m) of each forest, a soil profile was investigated and eight addi-tional sampling points were selected. The sampling was performed both by PGH andFDL (0–15 and 15–30 cm). For each forest, no SOC content and C stock differencesin 0–30 cm soil depth were found between PGH (58.8 ± 5.3 g kg1and 103±7gha1, respectively) and FDL (52.7 ± 4.3 g kg1and 117 ± 9 Mg ha1, respec-tively) sampling. However, under Norway spruce, PGH sampling pointed-out that Cwas mainly stored in Oe and Oa horizons (51.1 vs. 146 Mg ha1in the 0–30 cmlayer). The higher coefficient of variation obtained when soil horizons were consid-ered (from 19.2% to 72.8% for PGH and from 16.5% to 25.7% for FDL) suggestedthat PGH sampling preserved the information about the spatial variability within anecosystem. The information loss about SOC vertical and spatial distribution wouldindicate the inability of FDL sampling to support decision-making plans addressed forsustainable use of soil resource

Land capability and suitability maps are useful tools for soil resource conservation. This study aimed to build land capability and suitability maps using a multi-thematic approach by GIS in a salt-affected coastal area of Italy. Topographic, morphological, geological, pedological delineations and land cover maps, remote sensing image and climate data were acquired and the main physical and chemical properties, including electrical conductivity (EC) and available water capacity, were analysed on the soil samples collected in the study area. The acquired information were elaborated through QGIS software to obtain the land capability and suitability maps. The suitability map showed that most of the area (80%) is suitable for cultivation and, therefore, can be addressed for agricultural purposes without risk of degradation. In fact, the land capability map showed that 42% of the investigated area belongs to class I and II indicating that they can be used for a wide range of cultivations. While 44% of the investigated area clustered in class III and IV. In these latter the cultivation should be allowed to a limited range of crops due to the high sand content, which does not allow a good water retention, and due to a strong intrusion of sea water with consequent increase of the soil EC. In our study area, where agricultural productivity and environmental impact are in conflict, to classify the lands on base the land capability and suitability could help to define the best agricultural practices to apply in order to preserve soil functions.

Industrial farming without considering soil biological features could lead to soil degradation. We aimed to evaluate the biochemical properties (BPs) and biological fertility (BF) of different soils under processing tomato cultivation, estimate the BF through the calculation of a simplified BF index (BFIs), determine if the crop was affected by BP and BF. Three farms were individuated in Modena (MO), Ferrara (MEZ) and Ravenna (RA) provinces, Italy. Soil analysis included total and labile organic C, microbial biomass-C (Cmic) and microbial respiration measurements. The metabolic (qCO2), mineralization (qM) and microbial (qMIC) quotients, and BFIs were calculated. Furthermore, plant nutrient contents were determined. The low Cmic content and qMIC, and high qCO2 found in MEZ soils indicate the occurrence of stressful conditions. The high qMIC and qM, and the low qCO2 demonstrated an efficient organic carbon incorporation as Cmic in MO soils. In RA soils, the low total and labile organic C contents limited the Cmic and microbial respiration. Therefore, as confirmed by the BFIs, while MO showed the healthiest soils, RA soils had an inefficient ecophysiological energy state. However, no effects on plant nutrient contents were observed, likely because of masked by fertigation. Finally, BP monitoring is needed in order to avoid soil degradation and, in turn, crop production decline.

Maintaining multiple ecological functions (“multifunctionality”) is crucial to sustain viable ecosystems. To date most studies on biodiversity-ecosystem functioning (BEF) have focused on single or few ecological functions and services. However, there is a critical need to evaluate how species and species assemblages affect multiple processes at the same time, and how these functions are interconnected. Dung beetles represent excellent model organisms because they are key contributors to several ecosystem functions. Using a novel method based on the application of 15N-enriched dung in a mesocosm field experiment, we assessed the role of dung beetles in regulating multiple aspects of nutrient cycling in alpine pastures over appropriate spatial (up to a soil depth of 20 cm) and temporal (up to 1 yr after dung application) scales. 15N isotope tracing allowed the evaluation of multiple interrelated ecosystem functions responsible for the cycling of dung-derived nitrogen (DDN) in the soil and vegetation. We also resolved the role of functional group identity and the importance of interactions among co-occurring species for sustaining multiple functions by focusing on two different dung beetle nesting strategies (tunnelers and dwellers). Species interactions were studied by contrasting mixed-species to single-species assemblages, and asking whether the former performed multiple functions better than the latter. Dung beetles influenced at least seven ecological functions by facilitating dung removal, transport of DDN into the soil, microbial ammonification and nitrification processes, uptake of DDN by plants, herbage growth, and changes in botanical composition. Tunnelers and dwellers were found to be similarly efficient for most functions, with differences based on the spatial and temporal scales over which the functions operated. Although mixed-species assemblages seemed to perform better than single-species, this outcome may be dependent on the context. Most importantly though, the different functions were found to be interconnected sequentially as reveled by analyzing 15N content in dung, soil and vegetation. Taken together, our current findings offer strong support for the contention that the link between biodiversity and ecosystem functions should be examined not function by function, but in terms of understanding multiple functions and how they interact with each other.

Soil aggregation and organic matter (OM) conservation are important in the prevention of land degradation. Aggregation processes and OM turnover influence each other and depend on the characteristics of both minerals and organic pools. We assessed the relative importance of the organic and mineral phases at the macroaggregate and colloidal scale in two soils (CHL and SRP, chlorite and serpentine-rich, respectively) where Mg-silicates dominated, by incubating them with a relatively degraded and oxidized organic fraction, that is the humic acids (HAs) extracted from the organic horizons of both CHL and SRP. The HA from SRP were more aromatic and richer in phenolic groups, whereas HA from CHL were N-richer, more aliphatic and richer in carboxyl groups. The SRP soil formed larger amounts of macroaggregates, more stable than in CHL. At the colloidal scale, SRP was more flocculated and clay had a lower electrophoretic mobility than CHL. HA enhanced aggregate formation in both samples but improved aggregate stability only in CHL. In CHL, slight differences in electrophoretic mobility were visible, while in SRP, differences were more pronounced, with a point of zero charge at lower pH and larger hydrodynamic diameter. The abundance of Mg in SRP may have favoured the formation of weaker outer-sphere interactions and the release of clay-HA associations upon water dispersion, while in CHL Ca formed more stable bonds with HA. In SRP, ligand exchange reactions can be ruled out, conversely to the dominant bonding mechanism occurring in Al-silicate dominated soils, with important consequences on the release of OM-loaded clay particles. Copyright © 2016 John Wiley & Sons, Ltd.

Erosion is a relevant soil degradation factor in mountain agrosilvopastoral ecosystems that can be enhanced by the abandonment of agricultural land and pastures left to natural evolution. The on-site and off-site consequences of soil erosion at the catchment and landscape scale are particularly relevant and may affect settlements at the interface with mountain ecosystems. RUSLE (Revised Universal Soil Loss Equation) estimates of soil erosion consider, among others, the soil erodibility factor (K), which depends on properties involved in structure and aggregation. A relationship between soil erodibility and aggregation should therefore be expected. However, erosion may limit the development of soil structure; hence aggregates should not only be related to erodibility but also partially mirror soil erosion rates. The aim of the research was to evaluate the agreement between aggregate stability and erosion-related variables and to discuss the possible reasons for discrepancies in the two kinds of land use considered (forest and pasture). Topsoil horizons were sampled in a mountain catchment under two vegetation covers (pasture vs. forest) and analyzed for total organic carbon, total extractable carbon, pH, and texture. Soil erodibility was computed, RUSLE erosion rate was estimated, and aggregate stability was determined by wet sieving. Aggregation and RUSLE-related parameters for the two vegetation covers were investigated through statistical tests such as ANOVA, correlation, and regression. Soil erodibility was in agreement with the aggregate stability parameters; i.e., the most erodible soils in terms of K values also displayed weaker aggregation. Despite this general observation, when estimating K from aggregate losses the ANOVA conducted on the regression residuals showed land-use-dependent trends (negative average residuals for forest soils, positive for pastures). Therefore, soil aggregation seemed to mirror the actual topsoil conditions better than soil erodibility. Several hypotheses for this behavior were discussed. A relevant effect of the physical protection of the organic matter by the aggregates that cannot be considered in $K$ computation was finally hypothesized in the case of pastures, while in forests soil erodibility seemed to keep trace of past erosion and depletion of finer particles. A good relationship between RUSLE soil erosion rates and aggregate stability occurred in pastures, while no relationship was visible in forests. Therefore, soil aggregation seemed to capture aspects of actual vulnerability that are not visible through the erodibility estimate. Considering the relevance and extension of agrosilvopastoral ecosystems partly left to natural colonization, further studies on litter and humus protective action might improve the understanding of the relationship among erosion, erodibility, and structure.

Purpose This study investigated a Lateglacial to Holocene sedimentary sequence derived from a small catchment located at San Lazzaro di Savena in the surroundings of Bologna Emilia (Northern Italy), in which different buried soil horizons were investigated in order to delineate the physiographic evolution of the area. Materials and methods Several disciplinary/analytical approaches including pedostratigraphy, geochemistry, radiocarbon dating, archaeobotanical investigation and δ13 stable isotopes analyses were taken into account for the pedosequence characterization. Results and discussion This multidisciplinary approach allowed us to identify the main factors that affected the ancient environment over a prolonged time interval (ca12 ky); starting from 14 ky BP with a palaeosol ascribed to the Bølling period, cold-arid conditions characterized by a steppic vegetation gradually evolved toward a more humid (and slightly warmer) setting. This climatic change allowed the development of a forest constituted by abundant conifers at ca 10 ky BP. Humans also impacted on the environment, at least since 9 ky BP, as indicated by repeated traces of firing (plausibly for deforestation and land clearance). The data allow a comparison with findings provided by other neighbouring sites and contribute to the ongoing debate on the relationships between climatic and anthropogenic impacts on the landscape dynamic. Conclusions The human impact on the landscape has been effective from the Mesolithic, earlier than usually considered in previous studies. Anthropogenic activities caused geomorphological and hydraulic instabilities within the basin, accelerating soil erosion as indicated by the increase of the estimated sedimentation rates and change in the type of geochemical, mineralogical and textural properties of the studied soils.

The introduction of the “subaqueous soils” into the international classification system of the Soil Taxonomy (2010) gives a possibility to soil scientists to use the pedogenetic approach to investigate coastal soils in view of resource protection and valorization. Coastal areas, in fact, are complex and fragile ecosystems whose ecological value is worldwide recognized, but generally highly inhabited and affected by different erosion and pollution phenomena, and flooding problems. The soil science has a great opportunity to contribute to the correct management and protection of coastal soils, by recognizing the value of coastal soils and thus investigating the effect of the water table oscillation and ionic composition to the changes of soil properties and functionality. This work represent a first attempt to describe the soil continuum existing from hydromorphic to subaqueous environment, highlighting the evidence of some pedogenetic processes into subaquatic substrates and demonstrating the high ecological values of these pedons., EQA - International Journal of Environmental Quality, Vol 19 (2015)