Luis Fernández-Pozo

Understanding how management and seasonality are associated with the soil microbiome is relevant for the sustainability of Mediterranean viticulture. This observational study compared the rhizosphere microbiome of rainfed and irrigated ‘Pardina’ vineyards on Calcaric Cambisols (Tierra de Barros, Extremadura, Spain) in five sampling campaigns (spring 2024–spring 2026) using 16S rRNA gene and ITS1 amplicon metabarcoding. The 30 soil samples were aggregated into ten community profiles per marker (five campaigns × two management), so inference is exploratory and limited by the absence of plot-level replication. Fungal communities in irrigated vineyards showed lower observed genus richness (median 180 vs. 297), Shannon diversity (3.05 vs. 3.84) and evenness than rainfed ones, with the same direction in all five campaigns, and a tendency toward higher dominance of a few genera (Berger–Parker 19.3% vs. 11.9%; not significant after correction), whereas prokaryotic richness and Shannon diversity did not differ consistently. Bray–Curtis PERMANOVA indicated a modest association between management and prokaryotic composition (R² = 0.237, p = 0.048), which was not robust to permutations restricted within campaigns, and no detectable association for fungi (R² = 0.151, p = 0.269); both results were sensitive to the inclusion of the spring 2026 campaign. The season and its interaction with management were not significant. Soil pH, available phosphorus and organic carbon differed between managements and planting density differed by design, so the patterns cannot be attributed to irrigation itself. The bacteria-to-fungi ratio, a sequencing-derived index, is reported descriptively only. These results identify candidate taxa and hypotheses to be tested in replicated experiments that include soil moisture and functional measurements.

Understanding the interactions between agricultural management and seasonal climate variability is essential for maintaining soil biological sustainability and resilience. This study evaluated the effects of irrigation regime (irrigated vs. rainfed) and seasonality (autumn vs. spring) on rhizosphere microbiome diversity and composition using 16S and ITS amplicon metabarcoding during 2024–2026. Rainfed vineyards showed substantially higher bacterial richness (median Chao1: ≈1,220 vs. 710) and greater fungal diversity and richness than irrigated vineyards (Shannon H′: 4.71 vs. 3.86; Chao1: ≈595 vs. 335, re-spectively). PERMANOVA based on Bray–Curtis dissimilarity confirmed irrigation re-gime as the main structuring factor for bacterial (R² = 0.264, p = 0.042) and fungal communities (R² = 0.272, p = 0.005), whereas seasonality had no significant effect (p > 0.30). Taxonomic analysis revealed a marked dominance of Ascomycota under irrigation (80–98% relative abundance), accompanied by reduced fungal evenness. The bacte-ria-to-fungi ratio indicated a higher bacterial proportion under rainfed conditions and in autumn. These results suggest a plant-mediated buffering effect in the rhizosphere and indicate that continuous irrigation may promote microbial homogenization, potentially reducing soil biodiversity. Controlled deficit irrigation strategies may therefore help preserve microbial diversity and support soil functionality and resilience in Mediterra-nean vineyards.

This study deals with a circular economy model to manage biomass of Lavandula stoechas L. derived from the phytoremediation of soils with Pb, Zn and Tl metal(oid)s. The species showed high efficacy in phytostabilization, retaining 65% of the metals in the roots. Bioconcentration factors (BAF < 0.5) and translocation (TF < 1) confirmed its behavior as an excluder, minimizing the risk of trophic transfer. This research validated the transformation of this biomass under a zero-residue approach. Via hydrodistillation, essential oils and hydrosols (yield > 0.4%; 0.93 g/mL) were obtained, whose chemical safety was guaranteed by the absence of heavy metals (ICP-MS). Subsequently, the residual biomass was recovered by pyrolysis at 600 °C, obtaining a biochar with a specific surface area (SSA) of 393.7 m²/g and an electrical conductivity of 35 S/cm. This performance can be attributed to the synergistic effect of the carbonaceous matrix and encapsulated metals, which act as natural dopants for supercapacitor electrodes. In conclusion, the work demonstrated the transition from hazardous waste to advanced industrial byproducts, integrating environmental remediation with the production of materials for energy storage under safety and sustainability criteria.

This study proposes a circular economy model to manage plant residues derived from the phytoremediation of soils contaminated with heavy metals (Pb, Zn and Tl) by means of Lavandula stoechas L. Under greenhouse conditions, its effectiveness for phytostabilization was confirmed, as it retains most of the metals in its roots (65%) with bioconcentration factors less than one, confirming the suitability of the species for phytostabilization. The research focuses on the transformation of this waste into high value-added resources for various industries. In pharmaceutical and cosmetic applications, as essential oil and hydrosol were obtained through distillation with a yield of more than 0.4%. These products, rich in therapeutic terpenoids, are safe for public health as they are free of metal contaminants. Or in the energy sector, since the post-distillation residual biomass, which contains the metals retained in its tissues, was processed by pyrolysis to obtain biochar. This material achieved an electrical conductivity of 35 S/cm, demonstrating great potential for fabricating supercapacitor electrodes. In conclusion, this work validates the transition from hazardous waste to valuable industrial by-products, laying the foundations for its future implementation on an industrial scale under environmental safety criteria.

A small fragment of the Olivenza meteorite (fell in 1924 near Olivenza, Spain) was recently rediscovered in the teaching mineral collection of the University of Extremadura. The fragment (22.07 g) matches two known pieces of the same meteorite based on visual inspection. A preliminary Laser-Induced Breakdown Spectroscopy chemical analysis detected the expected lithophile and siderophile elements, including nickel, confirming its meteoritic origin. Since the Olivenza meteorite is a rare LL5 ordinary chondrite, this newly identified fragment adds valuable material for future scientific study.

The transformation of natural ecosystems into agroecosystems due to changes in land use/land cover (LULC) has been shown to significantly affect soil characterization and classification. The impact of LULC on soil taxonomy was assessed in a primary forest located in central–eastern Honduras, which had been deforested approximately forty years prior to the study. Morphological, physical, and physicochemical analyses were performed by describing 10 representative profiles, applying the Soil Taxonomy (ST) and World Reference Base for Soil Resources (WRB) nomenclatures. LULC resulted in physical degradation in agricultural areas, as evidenced by lighter-colored horizons (P02), reduced granular structure (P01, P02, P05), higher bulk densities (≤1.73 Mg m⁻³), and surface crusting (P02, P05); this phenomenon was also observed in pastures (P06–P09). SOC loss was 62% in croplands, 47–53% in agroforestry systems (P03) and fruit tree plantations (P04), and 25% in pastures. All profiles exhibited pH values between 6.5 and 8.4 and complete base saturation (BS), except for P08 and P09, which had pH values below 5.5, high levels of Al³⁺, and reduced BS (50–60%). Mollic epipedons and variability in the endopedons were also observed. According to the ST of the System of Soil Classification (SSC), the soils were classified as Mollisols, Entisols, Vertisols, and Alfisols; and as Phaeozems, Fluvisols, Gleysols, Anthrosols, Gypsisols, and Plinthosols by the WRB. We advocate for the inclusion of Anthropogenic Soils as a distinct Order within Soil Taxonomy (ST). The implementation of sustainable agricultural practices, in conjunction with the formulation of regulatory frameworks governing land use based on capacity and suitability, is imperative, particularly within the context of fragile tropical systems.

Anthropogenic land cover change is directly responsible for the deforestation and degradation of tropical forests. In this context, assessing soil organic carbon (SOC) stocks is key to understanding the impact of anthropogenic activities on SOC so that we can implement management practices that effectively reduce emissions or promote carbon sequestration. Our objective was to assess the effect of land-use change on the dynamics and distribution of SOC in three systems (agriculture, pasture and agroforestry) after 40 years of deforestation in a tropical dry forest in the central–eastern region of Honduras. For this purpose, the bulk density, percentage of coarse fragments (>2 mm) and soil organic carbon content were determined at three depths (0.00–0.10 m, 0.10–0.20 m and 0.20–0.30 m). The results showed an increase in bulk density for all new uses, although soil compaction had not yet occurred. In terms of total soil organic carbon (TOC) stocks, deforestation caused a decrease from 17% to 48% in agricultural and agroforestry soils, respectively; on the other hand, grasslands did not show significant differences compared to tropical dry forest, suggesting that they have a high potential as carbon sinks in deforested tropical areas. However, this did not imply a better state of the system, as the greatest increases in bulk density were found in pastures.

With increasing urbanization and industrialization, soil and forest resources are facing considerable pressure, as well as the demand for water for domestic, agricultural, and industrial activities. Therefore, it is essential to conduct regular assessments of water quality and ensure that water is consistently maintained in the context of ecosystem services (ESs). Our objective was to apply the driving forces–pressures–state–impacts–responses (DPSIR) model to understand the cause–effect relationships and interactions with anthropogenic pressures on deforestation and water quality in the Talgua River watershed and associated valley and plain areas in central-eastern Honduras. Physicochemical and microbiological analyses were conducted to determine the water quality index (NSF–WQI) and other contamination indexes. The results identified high contamination by coliforms, up to 920.00 NPM/100 mL, and high levels of contamination by organic matter (ICOMO, 0.65), solids (ICOSUS, 0.79), mineralization (ICOMI, 0.99), and the presence of bacteria (BPI, 8.50), as well as the development of eutrophication processes (ICOTRO), resulting in generally low water quality. These problems were caused by the socio-demographic and economic growth of the area, as well as the high demand for water, vulnerability to climate change, and intense agro-livestock and industrial activity, which led to deforestation processes, changes in land use, and contamination of natural water bodies that impacted the overexploitation of aquifers. After applying the DPSIR model, strategies are proposed for the management and administration of the watershed aimed at preserving the water, soils, and forest resources, while promoting stakeholder, business, education sector, and public administration participation.

An abandoned sphalerite mining area in the southwest (SW) of the Iberian Peninsula was studied to evaluate the impact that the presence of metal(loid)s has on soil and ecosystem health. Five zones were delimited: sludge, dump, scrubland, riparian zone, and dehesa. Critical total levels of lead (Pb), zinc (Zn), thallium (Tl), and chromium (Cr), well above the limit indicative of toxicity problems, were found in the areas close to the sources of contamination. Pb-Zn concentrations were very high in the riparian zone, reaching values of 5875 mg/kg Pb and 4570 mg/kg Zn. The whole area is classifiable as extremely contaminated with Tl, with concentrations above 370 mg/kg in the scrubland. Cr accumulation mainly occurred in areas away from the dump, with levels up to 240 mg/kg in the dehesa. In the study area, several plants were found growing luxuriantly despite the contamination. The measured metal(loid)s content is the cause of a significant decrease in ecosystem services, resulting in unsafe soils for food and water production, so the implementation of a decontamination program is advisable. The plant species Retama sphaerocarpa, present in the sludge, scrubland, riparian zone, and dehesa, is postulated as suitable for use in phytoremediation.