For the assessment of the environmental and sanitary risks deriving from contamination of agricultural soils, it is crucial to identify and characterize the contaminants and study the soil chemical ...properties influencing their mobility and bioavailability. This information is essential for the selection of the best site remediation and securing strategy. The study site of this work is agricultural land of 6 ha in the province of Naples (Italy) subject to the past illegal burial of industrial wastes, principally from tanneries. With the aim of identifying the contaminants and assessing their mobility and bioavailability, the soil of the site was characterized for the main chemical and physical properties and for the concentration of potentially toxic elements and hydrocarbons. The readily and potentially bioavailable fractions of the main metal contaminants and their distribution in the soil geochemical fractions were determined by extraction in 1 M of NH4NO3, 0.05 M of ethylenediaminetetraacetic acid (EDTA) pH 7, and European Community Bureau of Reference (EU-BCR) sequential fractionation. Further, the speciation of heavy hydrocarbons and chromium was carried out. The agricultural soil was widely contaminated by chromium, zinc, and heavy hydrocarbons (up to 4487, 1846, and 1800 mg/kg, respectively). In some sub-areas, contaminations by cadmium, lead, and copper (up to 283, 417, and 1183 mg/kg, respectively) were also observed. The chromium was found to be scarcely mobile and bioavailable and was mainly associated with the oxidizable, residual, and reducible fractions of the soil (on average 56%, 25%, and 19% of the total, respectively). However, chromium speciation revealed the presence of a significant amount of highly toxic Cr(VI) (above the legal threshold of 2 mg/kg), despite the low oxidizing power of the soil. Zinc was more mobile and bioavailable than chromium and was mainly distributed among the acetic acid-extractable and reducible fractions of the soil (on average 28% and 47% of the total, respectively). Cadmium was found to be very mobile and bioavailable, and was mainly distributed in the acetic acid-extractable and reducible fractions of the soil (on average 40% and 45% of the total). The speciation of heavy hydrocarbons showed that they consist almost entirely of long-chain aliphatic hydrocarbons, considered not very toxic and immobile. These results suggest that the use of not-edible plant coverage might be the best securing and remediation action for the study site, with the potential to preserve the soil ecosystem services, contain the risk of soil erosion and particle dispersion, and phytoextract the bioavailable metals.
Aims
Data about woody debris (WD) decomposition are very scarce for the Mediterranean basin. The specific aim of this work is to explore the relationships between WD traits with the decay rate.
...Methods
We carried out a three-year litterbag decomposition experiment using ten WD types incubated in two plant communities (i.e. shrubland and woodland) and in laboratory conditions. WD was characterized for 31 chemical and anatomical traits, including macro- and micronutrients, lignin, and cellulose as well as organic chemistry by Solid-state Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (
13
C CPMAS NMR) and Fourier transform infrared spectroscopy/ Attenuated Total Reflection (FT-IR/ATR spectroscopy).
Results
WD decay rate was negatively associated with di-O-alkyl, lignin/N and C/N ratios, but positively with N concentration. Less consistent but positive correlations were recored for K, Mn, and Na concentration. The alkyl C and carboxylic C regions, associated with aliphatic and amide compounds, was positively correlated with WD decomposition. Conversely, di-O-alkyl C and O-alkyl C fractions, largely associated with cellulose and hemicellulose, were negatively correlated with WD decay rate. Finally, the positive correlation between Na concentration and WD mass loss in field conditions suggest a role of this neglected micronutrient for wood decomposition. WD specific density and anatomical features, have a minor capability to explain decomposition rate.
Conclusions
Our findings demonstrate a major role of WD chemical traits in explaining the variability of decomposition in Mediterranean ecosystems.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Phytoextraction of potentially toxic elements (PTEs) is eco-friendly and cost-effective for remediating agricultural contaminated soils, but plants can only take up bioavailable forms of PTEs, thus ...meaning that bioavailability is the key for the feasibility of this technique. With the aims to assess the phytoextraction efficiency on an agricultural soil contaminated by Cr, Zn, Cd, and Pb and the changes induced by plants in PTE bioavailability and in human health risk due to dietary exposure, in this work we carried out a mesocosm experiment with three successive croppings of Brassica juncea, each followed by Rocket salad as bioindicator. Brassica juncea extracted more Zn and Cd than Cr and Pb, significantly reducing, after three repeated croppings, the bioavailable element concentrations in soil as a result of plant uptake and soil pH changes. For Cd, this reduction did not bring the bioavailable amounts obtained by soil extraction with NH4NO3 below the trigger value of 0.1 mg kg−1 set by some European countries. Nevertheless, the Hazard Quotient for Cd in Rocket salad decreased across three repeated croppings of Brassica juncea. This indicated the beginning of a re-equilibration process between soil PTE forms of different bioavailability, that are in a dynamic equilibrium, thus stressing the need to monitor the possible regeneration of the most readily bioavailable pool.
A research was carried out in southern Italy in order to evaluate the effects of two farming systems (open field, greenhouse) and five transplanting times (27 September, 11 October, 25 October, 8 ...November, 22 November) on plant growth, harvest precocity, fresh pod yield and seed quality of organic faba bean. Crop biomass and root expansion were higher in open field than in greenhouse. The fourth planting time resulted in the highest crop biomass, whereas the second crop cycle showed the highest leaf area index. Greenhouse crops showed higher precocity than the open field ones by about two weeks, as well as the first transplant; the delay in harvest beginning increased from the second to the fourth planting time. Both fresh pod and seeds yield were significantly higher in open field than under protected environment with the third and fourth planting times. Seed fiber and protein content showed higher values in greenhouse compared to open field and increased with the transplant delay. Seed polyphenols attained higher concentration in open field and with the two earliest planting times. Overall, 25 October to 8 November planting times in open field best fitted the southern Italy growing conditions in terms of pod yield, but the 27 September to 11 October planting times resulted in the highest harvest precocity, remarkably enhanced under greenhouse growing, whereas seed quality was controversial.
The long-term use of Cu-based fungicides at doses of several kilograms per hectare stimulated a wide debate about the human health and environmental risks of the progressive accumulation of Cu in ...agricultural soils. Here, the health risks due to copper accumulation in agricultural soils were evaluated with a survey in intensive agricultural land of the Campania region (Italy), aiming to evaluate Cu accumulation in food crops. The health risk due to dietary exposure was estimated by using the Hazard Quotient (HQ), calculated as the ratio between the average daily dose and the reference dose of copper, suggesting that when HQ > 1 there is a potential risk for consumers. According to a survey of soils with a Cu content up to 217 mg kg−1, no foodstuffs showed dietary risks. Nevertheless, the contribution of Cu contained in these foodstuffs to the overall intake of Cu by consumers could increase health risks since such risks must be evaluated on the basis of the whole standard diet by quantifying the Cu content not only in vegetables and fruits but also in other sources, such as cereals, not cultivated in the study area and thus not considered in this paper.
The environmental risks due to copper accumulation in agricultural soils were then evaluated with a field experiment in a soil characterized by a very high Cu concentration (up to 1700 mg kg−1), aiming to study the impacts of Cu on native soil microorganisms. The study of the microbiota highlighted that the presence of Cu in soil did not reduce the total richness and diversity of microorganisms, which were not related to increasing concentrations of Cu in the soil. Nevertheless, Cu contamination was found to exert significant selection pressure on the soil microbiota, as shown by beta diversity and correlation analysis between taxa and Cu content.
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•Human health problems due to the consumption of foodstuffs produced in the Cu-contaminated studied soils can be excluded.•An increasing Cu concentration is not related to microbial richness and diversity indices.•Cu can exert selection pressure on the soil microbiota.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
Broad bean fits sustainable agriculture model due to symbiosis with
Rhizobium
, the seeds being a good source of energy, proteins, polyphenols, and fiber. The large amount of broad bean ...biomass residues can be employed for biofuel production, thus valorizing the overall production process. This research was aimed to investigate on the effects of farming management, such as greenhouse cultivation and appropriate planting time on the qualities of broad bean seeds and residual biomass for conversion into biofuel. The related balances of energy gain associated to both ethanol yield and nitrogen fertilizer saving due to
Rhizobium
nitrogen fixation were assessed.
Methods
Research was carried out on broad bean in Portici, province of Naples, southern Italy, based on the factorial combination of two farming systems (open field, greenhouse) and five planting times: 27 September and 11 October, to obtain early production; 25 October, which fell in the usual period for broad bean planting in the province area; and 8 November and 22 November, for late production. For each of these cultivation conditions, the quality of seeds, in terms of protein, fiber and antioxidant concentrations, and of crop residual biomass were determined. In addition, the energy yield as ethanol production from residual biomass and nitrogen fertilizer saving due to
Rhizobium
atmospheric fixation were assessed.
Results and discussion
The highest plant nitrogen uptake was recorded under the fourth planting time in open field and the third in greenhouse, the average accumulation attaining 87% in residual biomass, 7.4% in pods, and 5.6% in seeds. Seed protein content was 12.6% higher in greenhouse than in open field and 16.2% higher under the latest planting time compared to the earliest one. Seed polyphenol concentration was higher in open field than in greenhouse and with the two earliest planting times. Greenhouse grown biomass showed higher values of lignin, hemicellulose and pectin, compared to open field, whereas the opposite trend was for cellulose. Lignin showed a decrease from the first to the last crop cycle, opposite to cellulose, and glucose was the most represented monosaccharide. Both the highest theoretical ethanol and overall energy production were highest with the fourth planting time.
Conclusions
Greenhouse management enabled broad bean plants to accumulate higher proteins in seeds, but open field conditions resulted in better residual biomass quality for ethanol and
Rhizobium
-depending energy production.
A number of stilbene polyphenols, dimers, trimers and tetramers of resveratrol (viniferins), which are typical Vitaceae metabolites, were extracted from asymptomatic wood (AW) and symptomatic ...brown-red discoloured wood (BRW) of Vitis vinifera cv. Sangiovese affected by "esca proper", the trunk disease caused by the fungal complex Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and Fomitiporia mediterranea. Resveratrol and the same types of viniferins were found in both AW and BRW, with the exception of α-viniferin, which was only detected in AW, and ampelopsin B, only in BRW. The total concentration of stilbene polyphenols was higher in symptomatic wood (3.7% in BRW vs 1.2% in AW). The absolute variations in molar concentrations of each stilbene polyphenol (i) between BRW and AW (Δi = Ci
BRW - Ci
AW), were higher for ε-viniferin and resveratrol than the other compounds, while the relative variations (Δi/Ci
AW), were lower for ampelopsin H and isohopeaphenol, and higher for ampelopsin B, hopeaphenol, ampelopsin A, leachianol F and G, pallidol and ε-viniferin (in descending order), than the relative variation for resveratrol. Aspects relating to the biosynthesis of stilbene polyphenols and their role in the host-esca pathogen interaction are discussed.
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BFBNIB, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Soil pollution in agricultural lands poses a serious threat to food safety, and suggests the need for consolidated methods providing advisory indications for soil management and crop production. In ...this work, the three-step extraction procedure developed by the EU Measurement and Testing Programme and two soil-to-plant transfer factors (relative to total and bioavailable concentration of elements in soil) were applied on polluted agricultural soils from southern Italy to obtain information on the retention mechanisms of metals in soils and on their level of translocation to edible vegetables. The study was carried out in the Sarno river plain of Campania, an area affected by severe environmental degradation potentially impacting the health of those consuming locally produced vegetables. Soil samples were collected in 36 locations along the two main rivers flowing into the plain. In 11 sites, lettuce plants were collected at the normal stage of consumption. According to Italian environmental law governing residential soils, and on the basis of soil background reference values for the study area, we found diffuse pollution by Be, Sn and Tl, of geogenic origin, Cr and Cu from anthropogenic sources such as tanneries and intensive agriculture, and more limited pollution by Pb, Zn and V. It was found that metals polluting soils as a result of human activities were mainly associated to residual, oxidizable and reducible phases, relatively immobile and only potentially bioavailable to plants. By contrast, the essential elements Zn and Cu showed a tendency to become more readily mobile and bioavailable as their total content in soil increased and were more easily transported to the edible parts of lettuce than other pollutants. According to our results, current soil pollution in the studied area does not affect the proportion of metals taken up by lettuce plants and there is a limited health risk incurred.
•Soil pollution in an intensively farmed area of southern Italy was investigated•Soil background reference values discriminated geogenic from anthropogenic pollution•Metal bioavailability in soil was assessed by sequential extractions•Transfer factors for available metal content accurately described bioaccumulation•Essential elements Cu and Zn were more easily transported to lettuce edible parts than other pollutants
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Potentially toxic elements are widespread soil contaminants, whose occurrence could entail a concern for human health upon ingestion of fruit and vegetables harvested in a polluted area. This work ...set out to evaluate the concentrations of lead and cadmium as well as the levels of thirteen heavy metals for which a limit value is yet to be established by the food safety authorities, in order to perform a risk characterization related to the dietary intake of these metals and to provide a scientific opinion with wider relevance in the light of current worldwide regulatory issues. The sampling consisted of fruit and vegetables grown in a potentially contaminated area of southern Italy due to the illegal dump of hazardous wastes. An evaluation of the dietary exposure through the calculation of the Hazard Index (HI), the Maximum Cumulative Ratio (MCR) and the Target Cancer Risk (TCR) was adopted to this end. The results revealed that about the 30% of samples showed quantifiable levels of chemicals and no significant difference emerged between the potentially polluted area and the nearby cities that were selected as a control landfill site. The overall risk characterization for non-carcinogenic endpoints showed that the HI did not reach unsafe values, except for a small number of samples mainly because of aberrant occurrences and, in any case, the cumulative toxicity was mainly driven by thallium and vanadium. As far as the carcinogenic effects of arsenic are concerned, the distribution of TCR values broadly lay below the safety threshold; a certain percentage of data, however, exceeded this limit and should be taken into account for the enforcement of future regulatory thresholds.
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•This study was based on the remarkable issue of the “Land of Fires”.•No significant difference emerged between the two areas in terms of concentrations of metals in food.•A low percentage of samples was related to not negligible non-carcinogenic endpoints.•The cumulative toxic effect was mainly driven by 2 out of 13 metals.•The findings may have a bearing on the enforcement of future regulatory thresholds.
An approach based on the analysis of Maximum Cumulative Effect and of the Total Hazard Quotients was proposed to tackle an important environmental pollution issue.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Mediterranean grasslands are semi-natural, fire-prone, species-rich ecosystems that have been maintained for centuries through a combination of fire, grazing, and mowing. Over the past half century, ...however, grasslands have faced numerous threats, including the abandonment of traditional agro-pastoral practices. Our hypothesis was that mowing and prescribed burning are management practices potentially effective in counteracting the reduction of plant diversity triggered by land abandonment. However, the long-term effects of such management practices on plant communities and soil microbiota in Mediterranean grassland remain poorly studied. Here, we conducted a 5-year field experiment comparing prescribed fire, vegetation mowing, and abandonment in a fire-prone Mediterranean grassland in southern Italy in order to evaluate the capability of such management strategies to counteract the detrimental impacts of land abandonment on plant diversity and the associated increase of wildfire. We combined vegetation analysis and soil chemical characterization and several microbiota analyses, including microbial biomass and respiration, arthropod community, and high-throughput sequencing of bacterial and eukaryotic rRNA gene markers. Burning and mowing significantly increased plant species richness and diversity compared to abandonment plots, reducing the abundance of perennial tall grasses in favour of short-lived species. Standing litter followed the same trend, being 3.8-fold greater and largely composed of grass remains in the abandoned compared to burnt and mowed plots. In the soil, prescribed burning caused significant increase in pH, a reduction in organic carbon, total N, and cation exchange capacity. Diversity and taxonomic composition of bacterial and fungal microbiota was affected by burning and mowing treatments. Abandonment caused shifts of microbiota towards a fungal-dominated system, composed of late successional fungi of the Basidiomycota. Fast-growing and putative fungal pathogens were more abundant under burnt and mowed treatments. Soil arthropods were influenced by vegetation and microbiota changes, being strongly reduced in mowed plots. Our study demonstrated that grassland abandonment promotes the spread of tall grasses, reducing plant diversity and increasing the risk of wildfire, while prescribed burning and mowing are effective in counteracting such negative effects.
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•5-Year experiment testing prescribed burning, mowing and abandonment on grassland.•We used vegetation analysis, soil chemistry and next-generation sequencing of the soil microbiota.•Burning significantly increased pH, reduced soil organic carbon and nitrogen.•Burning and mowing significantly increased plant species richness.•Soil microbiota was shaped by burning and mowing, but was unaffected by land abandonment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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