Cristiano Casucci

Nickel, despite being an essential trace element in nature, is emerging as a pollutant, especially in agricultural environments, due to increasing concentrations detected in soil following human activities. In this scenario, vermiremediation represents a valid bioremediation technique that exploits the numerous ecological qualities of earthworms and their products. This work aimed to evaluate the effects of Eisenia fetida and vermicompost produced by this species, applied alone or in combination, on soil contaminated with three Ni doses (40, 140, and 240 mg kg⁻¹). The influence of the applied vermiremediation agents was assessed by measuring Ni concentrations in various fractions, microbial biomass content, and enzymatic activities over a 60-day trial. Earthworms did not bioaccumulate nickel within their tissues. However, they intermittently increased the water-soluble and bioavailable fractions of Ni, whereas the combination of earthworms and vermicompost treatment stabilised them. The combined treatment of E. fetida and vermicompost significantly increased microbial biomass carbon and the activities of alkaline phosphatase and β-glucosidase, while earthworms alone had a positive effect on N-acetyl-β-glucosaminidase activity. In conclusion, the vermiremediation agents improved overall soil health: vermicompost stabilised Ni, earthworms stimulated microbial activity, and their combination yielded synergistic benefits for soil functional recovery.

This study aims to evaluate the effects of two cover crop management practices on soil fertility. Key bioindicators, such as organic carbon content, were measured, along with the amount and activity of microbial biomass, which are mainly responsible for nutrient cycling. The conservative agricultural practices under study were either spontaneous meadows or annual overseeding with a barley (Hordeum vulgare) and faba bean (Vicia faba) mixture, both implemented for 4 consecutive years in the alleys of an organic vineyard. An untreated soil covered by a natural meadow for 30 years was used as the positive control. For each thesis, soil samples were collected at two depths (0–20 and 20–40 cm), and analyses were carried out on organic matter content and its fractions, as well as on relevant aspects of soil microbiota, such as microbial biomass carbon, microbial respiration, and soil enzyme activities. The effects of these practices on the quality and quantity of organic matter were evaluated by calculating the most commonly used humification indices and by assessing the metabolic and mineralisation quotients related to microbial biomass and activity. Over the relatively short treatment period, overseeding yielded better results than permanent grassland for organic matter content (plus 0.23%), overall hydrolytic activity (plus 17.62 µg g⁻¹ h⁻¹), and beta-glucosidase (plus 47.11 µg g⁻¹ h⁻¹) and beta-glucosaminidase (plus 11.56 µg p-NP g⁻¹ h⁻¹). However, several years of application are still needed to clearly assess the improvements and better compare different cover cropping techniques.

Understanding the spatial relationship between crop roots and soil biological functioning is essential for improving orchard management. This study investigated the spatial distribution of pear roots and selected soil biological indicators in five intensive ‘Abbé Fétel’ pear orchards in Emilia-Romagna, Italy, representing eight orchard–rootstock combinations. Soil cores were collected from along-row and inter-row positions at two depths (0–20 and 20–40 cm). Root length density (RLD), soil organic matter (SOM), microbial biomass carbon (MBC), soil basal respiration (SBR), and the activities of alkaline phosphatase (ALP), β-glucosidase (BGLU), and N-acetyl-β-D-glucosaminidase (NAG) were determined. Linear mixed-effects models showed that RLD was significantly higher along the tree row and in the upper soil layer. At 0–20 cm, mean RLD was approximately twofold higher along-row than in the inter-row (0.324 vs. 0.133 cm g⁻¹), indicating that pear roots were concentrated within the shallow along-row soil. Soil depth was the main factor influencing all biological indicators. SOM was higher along-row, whereas MBC varied mainly with depth. In contrast, BGLU and NAG activities were higher in the grass-covered inter-row despite lower pear-root density, while SBR showed the highest values in the shallow along-row soil. These findings demonstrate that soil biological indicators do not necessarily mirror crop-root distribution. Instead, belowground functioning in intensive pear orchards reflects the combined influence of crop roots and inter-row vegetation, highlighting the ecological importance of both orchard compartments when assessing soil functioning.

Understanding the spatial relationship between crop roots and soil biological functioning is essential for improving orchard management. This study investigated the spatial distribution of pear roots and selected soil biological indicators in five intensive ‘Abbé Fétel’ pear orchards in Emilia-Romagna, Italy, representing eight orchard–rootstock combinations. Soil cores were collected from along-row and inter-row positions at two depths (0–20 and 20–40 cm). Root length density (RLD), soil organic matter (SOM), microbial biomass carbon (MBC), soil basal respiration (SBR), and the activities of alkaline phosphatase (ALP), β-glucosidase (BGLU), and N-acetyl-β-D-glucosaminidase (NAG) were determined. Linear mixed-effects models showed that RLD was significantly higher along the tree row and in the upper soil layer, indicating that pear roots were concentrated within the shallow along-row soil. Soil depth was the main factor influencing all biological indicators. SOM was higher along-row, whereas MBC varied mainly with depth. In contrast, BGLU and NAG activities were higher in the grass-covered inter-row despite lower pear-root density, while SBR showed the highest values in the shallow along-row soil. These findings demonstrate that soil biological indicators do not necessarily mirror crop-root distribution. Instead, belowground functioning in intensive pear orchards reflects the combined influence of crop roots and inter-row vegetation, highlighting the ecological importance of both orchard compartments when assessing soil functioning.

Although the broad-spectrum pesticide chlorpyrifos (CP) was banned in many developed countries, it is still widely used in developing countries. Its residues persist in the environment for unpredictable times. CP is toxic to various non-target organisms and humans and inhibits soil enzyme activity and bacterial and fungal abundance. This paper aimed to evaluate the effect of vermiremediation on soil chlorpyrifos content and soil fertility. The application of Eisenia fetida or vermicompost was studied in terms of soil chlorpyrifos concentration, microbial biomass content, and enzymatic activities in a 120-day trial. Pesticide application rates were 0, 25, and 50 ppm. The CP did not affect the earthworm survival rate at the tested doses. The earthworms markedly increased microbial biomass carbon and the activity of β-glucosamminidase, while the vermicompost had a noticeably positive effect mainly on alkaline phosphatase activity. Finally, although the vermiremediation techniques studied did not perform a bioremediation activity, they proved effective in improving the biological fertility of the soil in the presence of high concentrations of chlorpyrifos.

The relationships between soil aggregates, aggregate-associated carbon (C), and soil compaction indices in pomegranate orchards of varying ages (0–30 years) in Assiut, Egypt, were investigated. Soil bulk density (Bd) and organic carbon (OC) content increased with orchard age in both the surface (0.00–0.20 m) and subsurface (0.20–0.40 m) layers 0.20–0.40 m). The percentage of macroaggregates (R_0.25) and their OC content in the aggregate fraction > 0.250 mm increased as the pomegranate orchard ages increased in the surface layer (0.00–0.20 m). Older pomegranate orchards show improved soil structure, indicated by higher mean weight diameter (MWD) and geometric mean diameter (GMD), alongside reduced fractal dimension (D) and erodibility (K). As orchard ages increased, maximum bulk density (B_Max) decreased due to an increase in OC, while the degree of compactness (DC) increased, reaching a maximum at both soil layers for the 30 Y orchards. Soil organic carbon and aggregate-associated C significantly influenced B_Max, which led to reducing the soil compaction risk. Multivariate analyses identified the >2 mm aggregate fraction as the most critical factor influencing the DC, soil compaction, and K indices in pomegranate orchards. The OC content in the >2 mm aggregates negatively correlated with B_Max, DC, and K but was positively associated with MWD and GMD. Moreover, DC and Bd decreased with higher proportions of >2 mm aggregates, whereas DC increased with a higher fraction of 2–0.250 mm aggregation. These findings highlight the role of aggregate size fractions and their associated C in enhancing soil structure stability, mitigating compaction, and reducing erosion risks in pomegranate orchards.

Biochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growth-promoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha⁻¹, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha⁻¹) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield production.

The oceans are one of the final destinations for the vast majority of plastic waste; in this sense, particles smaller than 5 mm, classified as microplastics (MPs), represent an environmental challenge with global impact on several ecosystems. The work evaluated the presence of MPs in marine waters off the northern coast of Santa Catarina (Brazil), addressing sampling procedures, opening, characterization, and polymer identification. A low-cost equipment developed with easily accessible materials was tested in the sampling, showing excellent results in terms of buoyancy, stability, and mechanical strength. The concentration of MPs obtained in the study was 0.01 MPs per m3. The particles found were analyzed by stereomicroscopy and classified according to morphological aspects in relation to shape into fragments 58,00%, films 25,00%, and lines 17,00%, and regarding the aspect related to color, blue was predominant. The characterization and polymeric identification was performed by Fourier transform infrared spectroscopy coupled to the total attenuated reflectance module (FTIR-ATR). The types of polymers identified were: polyethylene 33,33%; polypropylene 25,00%; butadiene-styrene copolymer 25,00%, and cellulose 16,66%. The work contributed to the evaluation of an area not yet studied in relation to the presence of MPs in marine waters, while at the same time described in detail the methodologies for analyzing microplastics proposed in the specialized literature.