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In semiarid environments, the total inorganic carbon (TIC) in soil may contribute to the total carbon (C) pool more than the total organic C pool (TOC), thus playing a key role in storing atmospheric CO2. However, due to the different origin pathways of soil carbonates, not all of the TIC pool can be accounted for CO2 sequestration. Indeed, the inorganic C can be accounted for a net sink of CO2 only when calcium (Ca2+) forming carbonates originate from non-carbonate minerals (atmogenic inorganic C, AIC). The aim of this study carried out in a gypsiferous area is to investigate the dissolution of Ca2+ that comes from gypsum (CaSO4·2H2O) in the formation of soil atmogenic carbonates and to quantify the different forms of inorganic C pools to understand their role in storing CO2 in comparison to the TOC pool. To this end, five soil profiles were studied along a hillslope in a gypsiferous afforested area. Soil samples were analysed to determine their main chemical properties, as well as Ca2+, Sr2+, and the 87/86Sr isotopes ratios in different soil fractions. Ca2+ that comes from gypsum, which contributes to the formation of atmogenic carbonates, ranged from 0% to 63%; the remaining percentage resulted from the parent material or other sources (e.g., aeolian dust). The distribution of Ca2+ in soils depended on the relief and the distance of the soils from gypsum outcrops. The accumulation of AIC in soil developed on Holocene deposits reached a maximum accumulation of 16 kg m−3 in the first meter of depth. The average Sr2+/Ca2+ ratio in primary carbonates was 0.333, whereas it was 0.192 in secondary carbonates, thus suggesting that different sources contribute to Ca2+ in both carbonate types. Consequently, the Sr2+/Ca2+ ratio of soil carbonates could be a useful indicator of the presence of secondary carbonates. Overall, results suggest that gypsum plays a key role in the net accumulation of inorganic C in the soil, contributing to store atmospheric CO2. Finally, considering that the AIC pool was lower than the organic C pool, the latter was by far the most important element in fixing atmospheric CO2 in the soils of the semiarid Mediterranean environment that were surveyed.

We investigated the organic carbon pools and the microbial diversity and activity in anthropogenic terraced soils in a desert area of Southern Peru to highlight how the introduction of agriculture influences carbon evolution and storage and genetic and functional diversity of soil microbiota over time. Five sites were selected considering soils cultivated since 5, 15, 20, 35 and 65 years, sampled along the profile depth (0–20 and 20–40 cm layer). Soil and microbial parameters comprised by organic carbon pools, microbial respiration, microbial community physiological profile (CLPP) and microbial diversity (PCR-DGGE) were determined. The results showed that the highest C concentrations were reached after a long cultivation time (P65), at both depths. In this site Corg was mainly composed by chemically not extractable C, considered the most stabilized fraction. The remaining extractable C fraction decreased with the depth and was mainly made up of highly mineralizable compounds. Data showed that human transformations has affected organic carbon pools only after several decades of cultivation, whereas the activity and structure of the microbial community changed gradually over time, showing the major differences between the most ancient (65 years) and the most recent (5 years) anthropized soils.

This study provides results of an ecological restoration activity performed in the Kokdzhon phosphate mining of the Zhambyl region (a semi-desert mining area of Kazakhstan). The test area was made by a quarry-hole, about 1.25 hectares wide, that was preliminarily filled with the earthy material of a dump and, subsequently, levelled. The total volume of human transported material (HTM) used was 700 tonnes. Soil samples were taken from 0 to 30 cm depth at 23 sampling sites and several soil quality parameters were determined. In the test area 750 tree species were planted in suitable dug holes: (150 seedlings of Russian Olive; 150 seedlings of Black Saxaul); 150 seedlings of Androsov Elm; 150 seedlings of Salt Cedar; 150 seedlings of Russian Salt Tree). In addition, a mixture of cereal and legume seeds (in equal amount of weight for each species) was seeded in 4 furrows, in between the tree lines. The results of this preliminary activity show a low engraftment of the plants used for the ecological restoration over one year. This could reasonably be due to the unfavourable soil characteristics of the test area that can be regarded as a human transported material (HTM), on which the action of the soil genetic factors, particularly, the biotic one, has yet to play out fully.

Technosols are soils developed on non-traditional substrates and containing large quantities of materials mostly due to intensive human industrial activity, such as artefacts. The increasing number of sites affected by Technosols and their impact on the environment as growing media for plants or as source of pollutants require an understanding of their functioning and evolution, above all the knowledge on the transport of toxic substances from contaminated technogenic soils to groundwater. A case study on properties, remediation and evaluation of Technosols made up by vitrified fly ash and glass–ceramics in Italy was carried out. Original technogenic soils, classified as Spolic Technosols (ecotoxic), were pedotechnically in situ remediated by adding smectitic marlstone and Ca(OH)2. Chemical analysis on samples from piezometers showed the presence of harmful heavy metals in groundwater. By means of boreholes and soil profiles the new soils generated, after remediation, were physically and chemically characterized and classified as Spolic Technosols (calcaric). Analysis on soil toxicity and leaching tests showed the effectiveness of the remediation and the mobility reduction of some potentially harmful elements according to the environmental Italian regulation.

Since ancient times Humans and Soil have experienced interwoven links. Nowadays soil scientists continue to stress such links highlighting the importance of soil in: i) satisfying the ever growing Human demand for food, water and energy, and ii) providing ecosystem services that mitigate climate changes, influence human health and improve biodiversity. Pedotechniques are recently used to generate soils suitable for table grape cultivation in order to increase productivity and grape quality, thus to get substantial financial returns. We show one emblematic study case of pedotechniques applied in Sicily (Italy). Aims of the investigation were: i) stressing threats to soil security derived by the generation of anthropogenic soils, ii) assessing the economic sustainability of pedotechniques and table grape production, taking into consideration only the internal factors and excluding the external economic contributions that are allocated to social sustainability and iii) stressing the role of soil science to focus on “economic value” to the soil ecosystem services and degradation processes. Results highlight that soil transformations allow for considerable investment costs. The highest productivity and the consequent higher profitability of the cultivation amortize the start-up costs. From the other side transformations could trigger considerable deterioration of both soil ecosystem services and environmental quality. In order to stress this last aspect and to define the relationships between pedotechnique application and soil security we have considered the five soil security dimensions (i.e. capability, condition, capital, connectivity and codification).

This paper assesses the distribution of soil phenolic matter (SPM) in soil environments from a pedological perspective, with particular emphasis on soil horizonation and its involvement in pedogenic processes. The study was conducted on 15 soil profiles (Andosols, Calcisols, Cambisols, Lixisols, Phaeozems, Podzols, Umbrisols) covering five distinct ecosystems. Although the ecosystems were virtually homogeneous in and of themselves, they represented strongly contrasting climates, geolithology and morphology, land use and vegetation cover (intensive agriculture, chestnut grove, alpine pasture, woody reforestations, and natural woods). Three main SPM fractions were categorised: (i) “total” (SPMt), (ii) “soluble” and/or “labile” (SPMs), and (iii) the fraction with a “high” (SPMh) affinity for the soil body. The SPMh and SPMs contents varied significantly, averaging 2.84 ± 0.52 g kg − 1 and 0.07 ± 0.02 g kg − 1 , respectively. Thus, these fractions appear to belong to different soil organic matter (SOM) pools. Indeed, the SPMs fraction was characterised by transitional, ephemeral low-weight molecules, which continuously reached the soil through both plant metabolism/decay and SOM degradation and were subsequently transformed into larger materials (humic matter, organo-mineral complexes) and/or lost by leaching and mineralisation. The SPMh fraction is likely involved in pedogenic processes that are primarily driven by the transport/translocation of colloidal phases under the following conditions: (i) in the early stages of horizon differentiation or, more specifically, in transport processes from the overlying A horizons and (ii) in cheluviation phenomena leading to the formation of spodic horizons. Moreover, SPMh also appears to be involved in early “in situ” alteration of cambic horizons. This involvement may result from the strong etching/complexing activity of soluble polyphenols from the overlying horizon, which promotes “in situ” weathering of the parent material. The total amount of SPM in a given environment greatly depended on the environmental conditions, which ranged from 0.02 g kg − 1 in an intensively cultivated Haplic Cambisol to 13.14 g kg − 1 in an Andic Cambisol under natural downy oak cover. Additionally, the SPMh/SPMs and SPMt/SOM% ratios decreased significantly from natural woods to intensive agriculture systems and may therefore indicate the extent of different anthropic impacts, such as soil cover/land use, in different ecosystems.

In Latin America countries, competition for access to natural resources among different groups has been a major reason for the outburst of violence over the last decades. One of the main aims of the political ecology concerns the understanding of the environmental conditions that can underlies the social conflict among people. Such understanding needs to be based on a detailed investigation of the natural resources of the landscape, mainly the soils. Few years ago the Italian Ministry for Foreign Affairs financed a soil survey with a humanitarian purpose: the development of a peace plan between Peru and Ecuador by improving the socio-economic conditions of the rural populations living in the areas close to the border. To achieve such goal, the construction of an irrigation canal was planned to irrigate few hundred hectares in the province of Ayabaca, on the border between Peru and Ecuador. To be soundly planned and designed, the canal project was obviously based on a preliminary soil survey that is essential to assess the irrigation suitability of the land. In this work, the authors illustrate the soil characteristics within the study area, their suitability for irrigation and the key aspects for future land uses, highlighting the philosophy followed in applying the land evaluation system which took into consideration the social, cultural and humanitarian purposes of the soil survey. Results proved the feasibility of the financed project and the potential increase of the living conditions of the rural people.

This paper takes into consideration the influence of human activities on the loss of pedodiversity in a Mediterranean area due to large scale farming. In particular it examines the quantitative and qualitative soil changes in a period of 53 years (from 1955 to 2008) evaluating the loss of soil diversity at soil subgroups level of the USDA Soil Taxonomy system. The following indices were used: richness; Shannon’s diversity index; Simpson diversity index; Shannon’s evenness index; Simpson’s evenness index. In this case study, considering what we observed in time, the human intervention in soil transformation could increase the diversity in the landscape in an initial phase, but forwarding by large scale farming the result is a huge loss of pedodiversity in time, as diversity indices remarkably have shown. This analysis enabled identification of disappeared soil types, with their unique history of formation. In our opinion this strongly reflects a sort of “genetic erosion” of the soil types, resulting in a substantial weakening of the whole pedo-ecosystem.

Anthropogenic soils created ex novo by land-us e change in large scale farming are, from a pedogenetic point of view, catastrophic events that bring the soils to time zero and change the natural pattern of the soilscape, remarkably, in some cases. The qu antitative aspects of pedodiversity of a soilsc ape in South-East Sicily, where some types of soils, in recent decades, have suffered a consistent reduction due to the transformations by large scale farming, are considered. The evolution of pedodiversity over a 53-year period (1955 to 2008 ) is examined using a dedicated statistical method and a space – time model based on Markov analysis and cellular autom ata in order to predict the evolution of the soilscape pattern in the next 42 years (i.e. until 2050). Soil subgroups, using the USDA Soil Taxonomy and a classi fi cation proposal, were considered and the followi ng indices were used: richness; Shannon's diversity index; Simpson diversity index; modi fi ed Simpson 's diversity index; Shannon's evenness index; Simpson's evenness index and m odi fi ed Simpson 's evenness index. These indices measured over time, show, quantitatively, a decrease in pedodiversity that highlights the effect of the human intervention in modifying the natural order of the soilscape

This study examined the chemical and structural properties of humic substances and microbiological activity in order to verify differences in carbon dynamics along soil profiles in two Vertisols (Typic Haploxerert and Xeric Epiaquert) and two Alfisols (Mollic Haploxeralf and Ultic Haploxeralf) developed under Mediterranean climate in Italy. Humification parameters, thermal methods, including differential scanning calorimetry (DSC) and thermogravimetry (TG), together with Fourier transform infrared (FT-IR) and fluorescence spectroscopies were used to characterize humic acids (HA). Microbiological activity of soils was assessed by basal respiration, metabolic quotient (qCO2) and Cmic:Corg ratio. FT-IR spectra and thermal analysis DSC/TG of HA extracted from the upper horizons showed a higher aliphatic character, whereas HA extracted from the lower horizons had a higher content of aromatic structures and polysaccharides. Moreover, the fluorescence index of the HA (HIXflu) showed a higher degree of aromatic polycondensation in the subsoils. The Cmic:Corg ratio was negatively correlated with the HIXflu of HA (Pb0.05), while qCO2 was positively correlated with the labile components of HA (Exo1/(Exo2+Exo3)) (Pb0.05). These results suggest reduced C availability in deep horizons where HA structures resulted in complex and thermally more stable molecules. Following discriminant function analysis all the chemical and microbiological properties with the exception of labile thermal fraction of HA and soil pH largely varied between B and the upper horizons. In deep horizons of both Vertisols and Alfisols the microbial biomass was nutritionally stressed with a low efficiency in C turnover. No correlation was found between specific soil processes, such as argilliturbation or clay illuviation and humic substances properties or soil microbial biomass and activity.

To investigate man's role in the creation and evolution of soils in areas of large scale farming, and to investigate the main morpho-descriptive aspects of the related soils, a survey was carried out in south eastern Sicily, Italy, where, as common to other regions of the Mediterranean basin, there are wide areas with anthropogenic soils due to large scale farming activity. The complex genesis pattern of these anthropogenic soils, which shows a double sequence of man-made horizons, sideways oriented to the soil surface, does not allow their classification as Technosols, because their composition is not dominated or strongly influenced by artefacts or human-made materials as is the case for Technosols. According to the principles of the WRB (World Reference Base for Soil Resources), these soils should be regarded as being within the Anthrosols reference soil group (RSG). For their classification, the “geomiscic” horizon, not listed among the diagnostic horizons of the WRB, is proposed as a new diagnostic horizon for the Anthrosols RSG. The geomiscic horizon can be succinctly defined as “a horizon that develops when a layer, at least 30 cm thick of different kinds of earthy materials, is added to the soil using earthmoving equipment. For farming purposes this layer is subsequently deeply mixed into the underlying soil using heavy machinery. Its colour is related to the source materials and generally the layer is not parallel to the surface of the soil”.

Due to anthropic pressure, many areas of the world are affected by a process of soil “entisolization” that leads to the formation of “anthropogenic soils”. In order to investigate Man's role in soil evolution, a survey was carried out in Southeastern Sicily (Italy), where, for years, there have been wide farming areas with anthropogenic soils. A chronosequence of anthropogenic soils in a vineyard area, cultivated for 22 years, was investigated. The first stage of the chronosequence was made by the original soils which, in the study area, had been undisturbed till the 1980's. These soils, classified as Entic Haploxerolls under the American Soil Taxonomy (ST) or Calcaric Kastanozem according to the World Reference Base (WRB) system, were used for almond groves and/or grazing and showed an A–C or A–Bw–C profile. In 1982 these soils were subjected to trenching in order to establish a vineyard and resulted in a complete mixing of the original soil horizons and the formation of soils classifiable as Haplic Xerarents (ST) or Aric Regosols (WRB). After 20 years, in 2002, the vineyard was removed and the surface of the Entisol/ Regosol was covered by a 50÷70 cm thick layer of transported parent material, composed of soft “marly limestone”. In July 2004 these soils were mixed once again by deep ploughing (∼100 cm deep) to establish a new vineyard. These deeply disturbed soils, were surveyed again and tentatively classified. These newly created soils show a double sequence of artificial horizons at an oblique angle to the soil surface. Their complex genesis pattern does not allow their classification as Arents (ST) or Regosols (WRB), so a tentative classification is proposed following both the ST and the WRB rules, as Miscic Geofragmexerants and Geomiscic Anthrosols, respectively. © 2007 Elsevier B.V. All rights reserved.