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Forest fires are a complex disturbance linked to several factors, such as climate conditions, vegetation types and human activities. Their frequency and intensity/severity have increased in recent decades and this trend is projected to continue because of climate change. Particularly critical are wildfires that frequently affect natural areas. In 2020 across Europe about 131474 hectares of surface within the Nature 2000 Network (N2K) were burnt. In addition to causing damage to vegetation, fire can affect soil characteristics influencing the functioning of the whole forest ecosystem. Understanding the influence of fire on the soil system provides information on its resilience and can be a useful tool for supporting forest management.This research complements a larger multidisciplinary research project monitoring the conservation status, sensu Habitat Directive 92/43/EEC, of the Habitat of Priority Interest 2270*-Wooded dunes with Pinus pinea and/or Pinus pinaster, within the Special Areas of Conservation (SAC) IT9130006-Pinewoods of the Ionian Arch. Here, we explore the relationships between soil and vegetation as a function of different fire conditions considered capable of triggering multiple successional pathways, potentially leading to habitat degradation. In this context, the specific objective of this work was to evaluate the long-term effects of wildfires on the soil properties in two Aleppo pine stands within the “Romanazzi” and “Marziotta” sections of the SAC that have been influenced by fires between 1997-2006 and 2000-2012, respectively. In both stands, three sites were identified: double-fire, single-fire and unburnt (control) sites. In March 2021, a synchronic sampling across sites, covering a period of 9-24 years post-fires, was performed. In each of them, the weight and organic carbon content of the organic layer (O-layer) were measured alongside the physicochemical and biological properties of the underlying topsoil (0-10 cm depth, n=5).Our results show the absence of the O-layer in double-fire sites, indicating a loss of this organic carbon pool. On the contrary, in both single-fire sites, this layer had successfully recovered. Our data suggest that the recovery in the O-layer in single-fire plots might be independent of the time elapsed since the wildfire. Regarding soil properties, compared to control sites, both single and double-fire sites for each stand exhibited significant alterations in specific soil chemical properties, i.e., pH, electrical conductivity, content in total organic carbon (Corg), extractable organic carbon, nitric and ammoniacal nitrogen, as well as decreases in soil microbial biomass (Cmic), respiration, and Cmic/Corg ratio. Of particular interest was a significant alteration in the N-cycle with increased mineralization and nitrification rates in all burnt sites at both stands. Principal component analysis showed that the impact of multiple fires may not depend only on frequency or time since the last fire, but also on frequency-time interaction.In conclusion, the burnt sites have not recovered to control levels for many soil characteristics, especially for N-cycle processes. The increase in N mineralization, nitrification and, consequently, in N availability could induce shifts in the plant, fungi, and pedofauna community structure, thus affecting the successional pathways with consequences on the resilience of the target forest ecosystem.

Healthy soils are fundamental to support ecosystem functions and productivity and represent an adaptive fundamental condition to face climatic change extremes, like in Southern Mediterranean often characterized by land degradation, soil erosion and desertification risk. As part of the project LIFE16 CCA/IT/000011 Desert Adapt, since 2018 we have been working on agroforestry pastoral areas of Portugal to test more adaptive strategies, including changes in grazing cycles which can allow a better regeneration of the grass cover, higher protection of the soil and improvement of the overall soil functions that support pasture productivity. We present the first data set of soil monitoring from spring 2022 and we combine the evaluation of soil amelioration with a full integrated management view of the improved grazed system to underline the multiple beneficial environmental effects of soil protection within and beyond the soil system.

Soil quality is fundamental for ecosystem long term functionality, productivity and resilience to current climatic changes. Despite its importance, soil is lost and degraded at dramatic rates worldwide. In Europe, the Mediterranean areas are a hotspot for soil erosion and land degradation due to a combination of climatic conditions, soils, geomorphology and anthropic pressure. Soil organic carbon (SOC) is considered a key indicator of soil quality as it relates to other fundamental soil functions supporting crucial ecosystem services. In the present study, the functional relationships among SOC and other important soil properties were investigated in the topsoil of 38 sites under different land cover and management, distributed over three Mediterranean regions under strong desertification risk, with the final aim to define critical SOC ranges for fast loss of important soil functionalities. The study sites belonged to private and public landowners seeking to adopt sustainable land management practices to support ecosystem sustainability and productivity of their land. Data showed a very clear relationship between SOC concentrations and the other analyzed soil properties: total nitrogen, bulk density, cation exchange capacity, available water capacity, microbial biomass, C fractions associated to particulate organic matter and to the mineral soil component and indirectly with net N mineralization. Below 20 g SOC kg−1, additional changes of SOC concentrations resulted in a steep variation of all the analyzed soil indicators, an order of magnitude higher than the changes occurring between 50 and 100 g SOC kg−1 and 3–4 times the changes observed at 20–50 g SOC kg−1. About half of the study sites showed average SOC concentration of the topsoil centimetres

To analyze the relationship between the management of three forest stand plantations and soil quality in the Dimapur district of the Northeastern Himalayan region, India, three forest soil profiles, covered by different species stands, at three depths were tested for 13 physical and chemical variables. Only four of these variables (electric conductivity, bulk density exchangeable Mg and available P) were included in a minimum data set, after using a varimax rotation algorithm in a principal component analysis, and subsequently used to calculate a soil quality index (SQI). Results showed higher SQIs in the surface layers (0–20 cm depth) than in the deeper ones. Average weighed SQI varied significantly (P

In the context of global warming and increasing wildfire occurrence, this study aims to examine, for the first time, the changes in multi-level biodiversity and key soil features related to soil functioning in a burned Mediterranean beech forest. Two years after the 2017 wildfire, changes between burned and unburned plots of beech forest were analyzed for plant communities (vascular plant and cover, bryophytes diversity, structural, chorological, and ecological variables) and soil features (main chemical properties, microbial biomass and activity, bacterial community composition, and diversity), through a synchronic study. Fire-induced changes in the micro-environmental conditions triggered a secondary succession process with colonization by many native pioneer plant species. Indeed, higher frequency (e.g., Scrophularia vernalis L., Rubus hirtus Waldst. and Kit. group, and Funaria hygrometrica Hedw.) or coverage (e.g., Verbascum thapsus L. subsp. thapsus and Digitalis micrantha Roth ex Schweigg.) of the species was observed in the burned plots, whereas the typical forest species showed a reduction in frequency, but not in cover, except for Fagus sylvatica subsp. sylvatica. Overall, an increase in plant species and family richness was found in the burned plots, mainly in the herbaceous and bryophyte layers, compared to the unburned plots. Burned plots showed an increase in therophytes, chamaephytes, cosmopolites, steno-Mediterranean and Atlantic species, and a decrease in geophytes and Eurasiatic plants. Significant differences were found in burned vs. control soils for 10 phyla, 40 classes, 79 orders, 145 families, 342 genera, and 499 species of bacteria, with about 50% of each taxon over-represented and 50% under-represented in burned than in control. Changes in bacterial richness within several families (reduction in Acidobacteriaceae, Solibacteraceae, Rhodospirillaceae, and Sinobacteraceae, increase in Micrococcaceae, Comamonadaceae, Oxalobacteraceae, Pseudomonadaceae, Hymenobacteraceae, Sphingomonadaceae, Cytophagaceae, Nocardioidaceae, Opitutaceae, Solirubrobacteraceae, and Bacillaceae) in burned soil were related to fire-induced chemical changes of soil (pH, electrical conductivity, and cation exchange capacity). No evident effect of the wildfire was found on organic C content, microbial biomass (total microbial carbon and fungal mycelium) and activity, and microbial indexes (fungal percentage of microbial C, metabolic quotient, and quotient of mineralization), suggesting that soil functions remained unchanged in the burned area. Therefore, we hypothesize that, without an additional disturbance event, a re-establishment of beech forest can be expected but with an unpredictable time of post-fire succession.

Microbial diversity plays a crucial role in ecosystem processes, including organic matter decomposition and nutrient cycling. This research explores the effect of prescribed burning (PB) on soil microbial diversity, as well as biomass and activity in Mediterranean pine plantations. In burned and adjacent unburned plots of Pinus pinea and P. pinaster plantations of Southern Italy protected areas, the fermentation layer and the 5 cm thick layer of mineral soil underneath were sampled at intervals during the first year after PB. The experimental protocol encompassed measurements of total microbial abundance (Cmic and soil DNA), fungal mycelium, fungal fraction of Cmic, microbial activity, bacterial genetic diversity (16S rDNA PCR-DGGE), microbial metabolic quotient (qCO2), and C mineralization rate (CMR), as well as physical and chemical soil properties. PB caused only temporary (up to 3 h&ndash, 32 d) reductions in Cmic, DNA amount, fungal mycelium, respiration, and CMR in the P. pinaster plantation, and had no appreciable negative effect on the microbial community in P. pinea plantation, where fire intensity was lower because of less abundant litter fuel. In either plantation, PB did not generally reduce bacterial genetic diversity (evaluated as band richness, Shannon index, and evenness), thus, also accounting for the fast recovery in microbial growth and activity after high-intensity PB in P. pinaster plantation. While confirming PB as a sustainable practice to reduce wildfire risk, also supported by data on plant community obtained in the same plantations, the results suggest that an integrated analysis of microbial diversity, growth, and activity is essential for an accurate description of PB effects on soil microbial communities.

Truffles contribute both directly and indirectly to important dynamics in the soil web, being involved in a large number of ecological functions that are crucial for terrestrial ecosystems. Despite this, the interrelationships between true truffles, i.e. hypogeous ectomycorrhizal fungi producing valuable fruiting bodies, and other elements of the soil system are largely unknown. In this study, we aimed to shed new light on whether and how much Tuber aestivum affects soil microbial activities (evaluated as enzyme activities), abundance (assayed as soil DNA content) and bacterial genetic diversity along with soil chemical properties. We compared chemical and biological variables inside and outside brules (i.e. areas inhabited by truffles with scarce vegetation cover around host plants) in two seasons, namely spring and summer, using both a linear mixed model and a multivariate two-block partial least squares approach. The areas with truffle presence had higher pH but lower organic carbon and nitrogen content. Similarly, all enzyme activities were lower inside the brule than outside, with the exception of peroxidase. A soil quality index (i.e. AI3) based on three enzyme activities (β-glucosidase, acid phosphomonoesterase and urease) indicated a reduction in soil quality inside the brule. Overall, soil DNA content responded to an interaction of truffle presence/absence and season, while bacterial genetic diversity indexes were higher in spring. Despite the observational nature of this study, results point out that T. aestivum can be considered a key species in the soil where it is present as it was associated with changes in chemistry as well as microbial activity that were generally more conspicuous than mere seasonal effects, although the causative nature of these associations still needs to be confirmed.

Contamination of agricultural soils by trace elements is a recurrent hazard for human health because of the possibility of pollutants entering the food chain. Aim of this study was to assess the human health risk from consumption of the common leafy (Lactuca sativa L.) and fruit (Cucurbita pepo L.) crops, in an agricultural area of Southern Italy. Along with agricultural practices, a major pollutant source is recurrent flooding from the highly polluted Solofrana river. Soil samples and edible parts of crops from 14 sites (10 flooded and 4 not flooded) were analyzed for total amounts of As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn. The bio-accumulation factor (BAF) and Health Risk Index (HRI) were calculated for each element, crop and site and as average values of all sites (BAFmean and HRImean). Moreover, the Hazard Index (HI) was determined for each site, as the sum of HRI for all elements. Cr and Cu, mostly derived from river flooding and agricultural practices, respectively, were the only elements whose levels exceeded law thresholds and/or the natural background of the study area. Of the two considered crops, L. sativa accumulated more Cd, Cr and Ni, whereas C. pepo was a more effective bioaccumulator of Zn. Both HRImean (for As, Cd, Cr and Ni) and HI were higher for L. sativa than for C. pepo. A low health risk was associated to major soil pollutants (Cr and Cu) found in the study area; in contrast, combined data on soil pollution and plant bio-accumulation points to accumulation of Cd and As, mainly in lettuce, as a potential risk for human health. The results suggest that soil pollution data alone is not sufficient to assess health risk. Contamination of agricultural soils by trace elements is a recurrent hazard for human health because of the possibility of pollutants entering the food chain. Aim of this study was to assess the human health risk from consumption of the common leafy (Lactuca sativa L.) and fruit (Cucurbita pepo L.) crops, in an agricultural area of Southern Italy. Along with agricultural practices, a major pollutant source is recurrent flooding from the highly polluted Solofrana river. Soil samples and edible parts of crops from 14 sites (10 flooded and 4 not flooded) were analyzed for total amounts of As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn. The bio-accumulation factor (BAF) and Health Risk Index (HRI) were calculated for each element, crop and site and as average values of all sites (BAFmean and HRImean). Moreover, the Hazard Index (HI) was determined for each site, as the sum of HRI for all elements. Cr and Cu, mostly derived from river flooding and agricultural practices, respectively, were the only elements whose levels exceeded law thresholds and/or the natural background of the study area. Of the two considered crops, L. sativa accumulated more Cd, Cr and Ni, whereas C. pepo was a more effective bioaccumulator of Zn. Both HRImean (for As, Cd, Cr and Ni) and HI were higher for L. sativa than for C. pepo. A low health risk was associated to major soil pollutants (Cr and Cu) found in the study area; in contrast, combined data on soil pollution and plant bio-accumulation points to accumulation of Cd and As, mainly in lettuce, as a potential risk for human health. The results suggest that soil pollution data alone is not sufficient to assess health risk.

Greenhouse agriculture, a widespread practice in the Mediterranean basin, is prone to impoverishment in soil organic carbon because of crop removal and high decomposition rate. Open-field experimentation has shown that the addition of biochar, a product of thermochemical conversion of biomass, under a limited concentration of oxygen, increases the soil organic C pool, enhances crop productivity and improves C terrestrial sink. The present study investigates the effect of biochar amendment in a greenhouse environment in a Southern Italy organic farm. Two doses (10 or 20 t ha-1) of biochar from conifer pruning wastes were applied immediately before planting 1-week old plants of pepper (Capsicum annuum L.). Plant growth and crop yield were evaluated six months later, at the end of cultivation, in biochar-treated and in control (without biochar) plots. Soil samples were collected in the same plots immediately after biochar addition and six months later and were analyzed for the following parameters: bulk density, water-holding capacity, pH, electrical conductivity, organic carbon, mineral nitrogen, total microbial biomass and fungal mycelium contents, soil respiration, nitrogen mineralization, potential nitrification, soil suppressiveness to Rhizoctonia solani. A single biochar application caused no apparent damage to the crop; on the other hand, no improvement was observed in crop yield or soil suppressiveness to R. solani. In contrast, the single char application positively affected soil respiration, nitrogen mineralization and potential nitrification. These preliminary results suggest that soil amendment with biochar is a potentially useful practice in greenhouse agriculture, yet further experimentation is necessary to assess optimal amounts for better crop productivity and soil quality.

Wildfire has historically been a major disturbance in Mediterranean European ecosystems and prescribed burning is increasingly used here to mitigate possible damage and reduce hazard. This raises the issue of a possible negative impact on soil from repeated burning treatments. We investigated the effects of a single and repeated prescribed burning on total and extractable organic C, microbial biomass C, fungal mycelium, microbial activity, metabolic quotient and C mineralization rate in the fermentation layer (F-layer) and the 5-cm soil underneath of a Pinus halepensis Mill. plantation in the Cilento, Vallo di Diano e Alburni National Park, Southern Italy. Prescribed burning was sequentially applied in 2009 and 2014 and the measurements were performed during the first year following each burning treatment. The first treatment produced short-term effects on the microbial biomass and activity of the F-layer, whereas the soil layer underneath was virtually unaffected. Surprisingly, the second treatment had negligible effects on either layer, probably because of a reduction of the understory fuel load and changes in the stand structure after the first burning. Most remarkably, fire-induced changes in the soil parameters considered were generally smaller than over-time fluctuations.

This study attempts to assess the aquifer vulnerability in the northeastern sector of the Campania Plain (southern Italy). The area is a highly populated region with anthropic impacts caused by rapid urban growth, quarrying, agricultural and industrial activities and uncontrolled waste storage. The main geologic feature of this plain is the alternation of alluvial/transitional and volcaniclastic deposits of Late Pleistocene-Holocene age. The study was performed integrating different sets of geologic and environmental data to restore the stratigraphic architecture and to assess anthropic impacts on subsoil. The reconstruction of stratigraphic subsurface architecture was based on remarkable geodatabase, concerning well log stratigraphies. Specific insights have been delineated on the volcaniclastic lithofacies heteropies across the entire area of study to highlight the differences in lithification degree and permeability. The contribution of pedogenesis on the reconstruction of the stratigraphic setting was also considered for the relative implications on groundwater quality concerns, as paleosols are usually regarded as aquitards. All of this information has been managed into a GIS project to produce a detailed 3D geological reconstruction, integrated with hydrogeological information to provide a model of the aquifer under study, highlighting sites of greater vulnerability to pollution. The anthropic impacts on subsoil were assessed by evaluating land-uses and overlaying the ANHI (Agricultural Nitrate Hazard Index) Map. The integration of the above datasets has allowed to check the reliability of the previsional empirical model with respect to the hydrostratigraphic model based on a thorough stratigraphic model and to verify the real potential of contamination. © 2013 Springer-Verlag Berlin Heidelberg.

The study aimed to evaluate the impact of shifting cultivation on soil quality, in Wokha district of Nagaland, using weighted soil quality index (SQIw). Four forest sites and three sites under shifting cultivation were selected and physical (texture and bulk density) and chemical (pH, electrical conductivity, cation exchange capacity, organic carbon, available N, P, K, exchangeable cations) parameters were analyzed. The SQIw was calculated on a minimum data set selected by principal component analysis, followed by varimax rotation algorithm and through subsequent normalization of the parameters using the linear scoring function. Significant (P 0.70) for two forest soils (FS1 and FS2) and land under shifting cultivation (JH1), low quality (SQIw

Biochar has been recently proposed as a management strategy to improve crop productivity and global warming mitigation. However, the effect of such approach on soil greenhouse gas fluxes is highly uncertain and few data from field experiments are available. In a field trial, cultivated with wheat, biochar was added to the soil (3 or 6 kg m(-2)) in two growing seasons (2008/2009 and 2009/2010) so to monitor the effect of treatments on microbial parameters 3 months and 14 months after char addition. N(2)O, CH(4) and CO(2) fluxes were measured in the field during the first year after char addition. Biochar incorporation into the soil increased soil pH (from 5.2 to 6.7) and the rates of net N mineralization, soil microbial respiration and denitrification activity in the first 3 months, but after 14 months treated and control plots did not differ significantly. No changes in total microbial biomass and net nitrification rate were observed. In char treated plots, soil N(2)O fluxes were from 26% to 79% lower than N(2)O fluxes in control plots, excluding four sampling dates after the last fertilization with urea, when N(2)O emissions were higher in char treated plots. However, due to the high spatial variability, the observed differences were rarely significant. No significant differences of CH(4) fluxes and field soil respiration were observed among different treatments, with just few exceptions. Overall the char treatments showed a minimal impact on microbial parameters and GHG fluxes over the first 14 months after biochar incorporation.

The impact of different land use types on soil quality was evaluated by measuring several soil properties that are sensitive to stress or disturbance and by using two synthetic approaches, i.e. a numerical quality index and multivariate analysis. A Minimum Data Set of soil indicators was selected including physical (texture, bulk density and water holding capacity), chemical (pH, cation exchange capacity, electrical conductivity, organic carbon, total and mineral nitrogen, available K, Ca, Mg, P contents and total Cd, Cr, Cu, Pb and Zn contents) and biological (microbial biomass, fungal mycelium, soil potential respiration and potentially mineralizable nitrogen) parameters. These parameters were assayed on soil samples collected with seasonal frequency (except for physical parameters, determined only in autumn) in an area of Southern Italy under different land use types (i.e. permanent crops, grazing lands, shrublands, coniferous and mixed forests). Moreover, for most of the land use types, a further distinction on the basis of topographic position (hill, middle-hill and plain) was carried out. Annual means of the data (except for texture) were used to calculate a soil quality index (SQI) and elaborated by multivariate analyses (Cluster Analysis and Principal Component Analysis, PCA) in order to distinguish among different soil quality classes. Data indicated a clear difference in soil quality among the studied areas: low soil quality (SQI < 0.55) in almost all permanent crops; intermediate soil quality (0.55 < SQI < 0.70) in shrublands, grazing lands, coniferous forest and middle-hill olive grove (the only crop with an herb layer on the soil surface); high soil quality (SQI > 0.70) in mixed forests. Results suggested that the permanent crop management had generally a strong negative impact on soil quality, while the moderate grazing activity and the crop management that leaves an herb cover on the soil had a lower negative impact. Nevertheless, the abandonment of cultivated lands, with consequent development of shrublands, produced an improvement of soil quality suggesting a good recovery capacity in the studied soil. © 2009 Elsevier B.V. All rights reserved.

Soil microbial activities and chemical properties related to the N cycle were investigated in function of variations in plant cover type in a Mediterranean area of Southern Italy. Several biological (microbial biomass, soil respiration, protease activity, degradation of 7 amino acids, net N mineralization, net nitrification, potential net nitrification and denitrification) and chemical properties (water content, pH, organic C, total and mineral N, C/N ratio) were determined in soil samples collected in spring and early autumn under three plant cover types (high maquis, low shrub community and meadow) epitomizing distinct successional stages following disturbance. Water content, organic C and C/N ratio were higher in soil from high maquis than in soils from the other plant cover types; in contrast, no difference was generally observed between the three soil types as for total and mineral N content. Likewise, no clear-cut difference was recorded for most of the tested biological parameters if these were expressed per unit of soil dry weight, with the exception of protease activity and soil respiration, which were significantly higher in the high maquis. However, when biological data were expressed per unit of organic C, meadow soil showed higher values of microbial biomass, asparagine degradation (only in spring), net mineralization and net nitrification (only in autumn) compared to the other soils. Statistical analysis pointed to seasonal fluctuation of water availability as an important limiting factor for microbial biomass and activity, with the exceptions of net N mineralization, net nitrification, glutamine and glutamic acid degradation activities which appeared to be mainly driven by organic matter content in soils. Overall, the results suggest that, in the investigated Mediterranean environment, variations in plant community ranging from meadow to high maquis produce little changes in soil biological activities linked to the N cycle, these being primarily affected by the availability of water and soil organic matter during the annual cycle. © 2009 Elsevier B.V. All rights reserved.

Coumarins are a large family of plant secondary metabolites with allelopathic properties. Coumarin activity against weeds has been demonstrated in in-vitro conditions, but the effects of coumarin on weeds and other organisms in natural conditions have not been yet investigated. A necessary step before field study is represented by microcosm experiments where natural conditions can be partially simulated by using undisturbed soil cores and the effect of coumarin can be verified before application in field. This study evaluates the effects of coumarin (0, 100, 200, 300 mg kg1 dry soil) on a weed (wild oat), a crop (wheat), and microbial community in soil and soil þ plants microcosms. For each treatment and experimental system, we determined plant growth (length and mass of shoot and root), soil microbial biomass and activity, and bacterial and fungal genetic diversity. The results indicate that coumarin is a promising natural herbicide with potential application in sustainable agriculture, and point to doses in the range 100e150 mg kg1 dry soil for optimal harm-to-benefit compromise. Comparison with data from the literature reveals that responses to coumarin by plants and microorganisms in natural systems may significantly diverge from behaviours observed in vitro, probably reflecting multifaceted interactions of biotic and abiotic components. Coumarins are a large family of plant secondary metabolites with allelopathic properties. Coumarin activity against weeds has been demonstrated in in-vitro conditions, but the effects of coumarin on weeds and other organisms in natural conditions have not been yet investigated. A necessary step before field study is represented by microcosm experiments where natural conditions can be partially simulated by using undisturbed soil cores and the effect of coumarin can be verified before application in field. This study evaluates the effects of coumarin (0, 100, 200, 300 mg kg(-1) dry soil) on a weed (wild oat), a crop (wheat), and microbial community in soil and soil + plants microcosms. For each treatment and experimental system, we determined plant growth (length and mass of shoot and root), soil microbial biomass and activity, and bacterial and fungal genetic diversity. The results indicate that coumarin is a promising natural herbicide with potential application in sustainable agriculture, and point to doses in the range 100-150 mg kg(-1) dry soil for optimal harm-to-benefit compromise. Comparison with data from the literature reveals that responses to coumarin by plants and microorganisms in natural systems may significantly diverge from behaviours observed in vitro, probably reflecting multifaceted interactions of biotic and abiotic components. (C) 2015 Elsevier Ltd. All rights reserved.

Soil quality evaluation is a tool to improve soil management and land use system. A large number of different physical, chemical and biological properties of soil, known as soil quality indicators, are used to soil quality assessment. These properties, that are sensitive to stress or disturbance, are synthesized using numerical quality indices obtained by several different types of methods. The aim of this study was to compare two different methods for soil quality index calculation in agricultural lands of Qazvin Province, Iran. In particular, the Integrated Quality Index (IQI) and Nemoro Quality Index (NQI) models were applied using the indicator selection methods: Total Data Set (TDS) and Minimum Data Set (MDS). Ten soil quality indicators were included in TDS: pH, Electrical Conductivity (EC), Organic Matter (OM), Cation Exchange Capacity (CEC), percentage of equivalent CaCO3 (TNV), heavy metal content of cadmium (Cd), cobalt (Co), lead (Pb), chromium (Cr) and soil erodibility factor (K), while Principal Components Analysis (PCA) was used to select the indicators to include in MDS. The tested soil quality indices were appropriate to evaluate the effects of land management practices on soil quality. The results of the linear relationship as well as of the match analysis, among the approaches studied, identified better estimation of soil quality applying IQI index when compared to NQI index and higher values of agreement of TSD than MSD. However, also IQIMSD approach resulted in suitable evaluation of the effects of land management practices on soil quality. This latter result was particularly relevant in the area studied because the use of a limited number of indicators could allow to reduce the cost of the analysis and to increase the sampling density in order to obtain a more detailed evaluation of soil quality through a geostatistical approach. © 2013 Elsevier Ltd. All rights reserved.

Biochar is known to enhance soil fertility and C sequestration, but relatively little information is currently available about its effect on soil microbial community, a component of terrestrial ecosystems that plays a key role in nutrient cycling. This study tested the effects of soil amendment with two loads of wood-derived biochar (30 and 60 t ha(-1)) in a wheat crop in Tuscany (Italy). Soil samples were collected 3 and 14 months after treatments over two successive growing seasons, and analysed for pH, total organic C (C-org), extractable C (C-ext), microbial biomass-C (C-mic), 25 specific microbial activities, mean substrate-induced respiration (mSIR) for 25 substrates, functional microbial diversity and bacterial genetic diversity. No significant effect of biochar treatment was observed on C-org, C-ext, C-mic, microbial quotient (C-mic % C-org) or genetic diversity. An increase in mSIR, some specific microbial activities and soil pH, and a significant change in functional diversity were observed 3 months after treatment. In contrast, no effect of biochar was detected 14 months after treatment for the parameters considered, except for a small but significant increase in pH. Our data suggest that biochar addition stimulated soil microbial activity without causing any apparent disturbance, but this positive effect was very short-lived. (C) 2013 Published by Elsevier Masson SAS.

Concerns about groundwater contamination as well as pesticide residues in food and soil have fuelled vigorous debates about the sustainability of chemical-intensive agriculture. Search has been prompted for agronomic strategies with lower environmental hazards. In this multidisciplinary study we compared the characteristics of soils from 20 agricultural farms selected in five geographical areas of Southern Italy with different soil types. In each farm, fields with management regime classified as high-input (HIMR, intensive cultivation under plastic tunnels) or low-input (LIMR, tree orchards) were selected. Soil samples were analyzed for 31 parameters including physical and chemical properties (bulk density, water holding capacity, texture, pH, limestone, electrical conductivity, organic C to a depth of 0-20 and 20-40cm, total N, P2O5, Ca2+, Mg2+, K+, Na+, cation exchange capacity), enzymatic activities (dehydrogenase, arylsulphatase, β-glucosidase, phosphatase and urease) and microbiological features (potential respiration, functional diversity of microbial populations by BIOLOG EcoPlates™, microbial biomass, fungal mycelium, culturable actinomycetes, bacteria and fungi, pseudomonads and bacterial species richness by 16S rDNA-DGGE). Finally, a soil bioassay was performed in order to evaluate the plant growth of a biotest plant (Lactuca sativa) and soil suppressiveness of the Rhizoctonia solani-L. sativa pathosystem.Results showed that many soil properties were influenced by management regime more than by the sampling area. Compared to LIMR, HIMR soils consistently had reduced soil organic C (-24%), enzymatic activities, microbial biomass and fungal mycelium (-40% and -18%, respectively), functional diversity (-18%) and bacterial species richness (-14%). On the contrary, the same soils showed a remarkable increase in the values of the parameters related to the mineral soil fraction (electrical conductivity +370%; P2O5 +72%; Na+ +86%). Management regime did not affect cation exchange capacity, pH, limestone and soil texture. The lettuce bioassay showed a higher plant growth (+17%) in the LIMR compared to HIMR soils, despite the lower content of mineral nutrients. Suppression of R. solani was not influenced by management regime, but significant differences were recorded among farms. Differences among the assessed soil parameters indicate a trend of soil quality deterioration under the high-input management regime. © 2010 Elsevier B.V.

The relationship between pollution by heavy metals and soil microbial community was investigated in an area of Southern Italy mainly used for agriculture but also affected by industrial and extractive activities as well as vehicular traffic. Soil samples were seasonally collected in permanent crop fields (i.e. citrus and peach orchards, olive groves and vineyard) and uncultivated areas (coniferous and mixed forests, shrublands, grazing lands). Soil samples were analysed for chemical (water content, pH, cation exchange capacity, organic C, Cr, Cu, Zn, Pb and Cd contents) and biological properties (microbial biomass, fungal mycelium, soil respiration, potentially mineralizable nitrogen, metabolic quotient and carbon mineralization rate). The results showed that heavy metal contents in the studied soils generally fell within the limit values after Italian law, with the exception of soil from vineyard that generally exceeded the limit value for Cu, probably because of the large use of copper-containing fungicides. The soil Pb content was always above the values reported for typical unpolluted soils and sometimes the same was also observed for Cd and Cu. The data suggest that Cr, Cu and Zn mainly derive from agricultural activity, whereas Pb and Cd were mainly introduced by cement industry associated with extractive activity. The soil microbial community was negatively affected by increased Cr, Cu and Zn contents, but not by Pb and Cd. Among the heavy metals considered, Cr and Zn had the highest negative effect on soil microbial community. © by PSP.