ALBERT

Description: This paper provides new insights into the geochemical cycling of rare earth elements (REEs) in acid sulfate soils developed on salt marsh sediments of the Huelva estuary (Spain) as a result of sulfide mineral oxidation in abandoned ore stockpiles. The study was aimed at determining the REE abundance, fractionation pattern and mineralogical control of the dispersal and retention of REEs in the soil system. Forty-one samples were collected at 13 core sampling sites along two transects extending across the degraded marshland, and they were subjected to XRD, ESEM-EDS and ICP-MS analyses. Measurements revealed that the soil receiving acid discharges has relatively high concentrations of ΣREEs (174.77 ± 19.77 mg kg−1) compared to local baseline concentrations. Shale-normalized REE patterns are generally flat, but a slight middle REE (MREE) enrichment is consistently apparent in all soil samples, involving relatively low LaN/GdN ratios (0.83 ± 0.08) and GdN/LuN ratios up to 1.42. The convex-upward REE pattern supports the possibility that iron oxy-hydroxide minerals play an important role in MREE retention through adsorption and co-precipitation mechanisms. Efflorescent sulfate salts left on the topsoil by the evaporation of acid waters show a strong depletion of light REEs (LaN/GdN = 0.16 ± 0.10) and act as a temporary reservoir of labile MREEs and heavy REEs during dry periods.

Description: The anthropogenic loading of phosphorus (P) to water bodies continues to increase worldwide, in many cases leading to increased eutrophication and harmful algal blooms [...]

Description: The present paper presents the interactions between water retention/evaporation and cracking during the desiccation of intact and disturbed Belgian Luvisol. The disturbed (DS) and undisturbed (NDS) samples (reduced-tillage-residue-in (RTRI) and conventional-tillage-residue-out (CTRO)) were collected from an agricultural field in Gembloux, Wallonia, Belgium. The drying experiment took place in controlled laboratory conditions at 25 °C. Moisture content, soil suction and surface cracks were monitored with a precision balance, a tensiometer and a digital camera, respectively. The image processing and analysis were performed using PCAS® and ImageJ® software. The results showed that crack formation was initiated at a stronger negative suction and a lower water content (Wc) in DS 〉 CTRO 〉 RTRI. The suction and the crack propagation were positively correlated until 300 kPa for the DS and far beyond the wilting point for the NDS. For the NDS, the cracking accelerated after reaching the critical water content (~20% Wc) which arrived at the end of the plateau of evaporation (40 h after crack initiation). The Krischer curve revealed that the soil pore size 〉 50 µm, and that it is likely that cracks are important parameters for soil permeability. The soil structure and soil fibre content could influence the crack formation dynamic during drying. The agricultural tillage management also influences the crack propagation. As retention and conductivity functions are affected by cracks, it is likely that the movement of fluids in the soil will also be affected by the cracks following a desiccation period (i.e., when the cracked soil is rewetted).

Description: The present study pertains to assessing the heavy metal (Cd, Cr, Co, Cu, Pb, and Zn) contents of untreated and treated effluents of two textile industries and agricultural soil samples in the vicinity of these industries located in Ludhiana, Punjab (India). The genotoxicity of the effluents samples was estimated using Allium cepa root chromosomal aberration assay. The exposure of Allium cepa roots to untreated effluents from both industries resulted in the reduction of mitotic index (MI) and increase in chromosomal aberrations in the root tip meristematic cells when compared to those that were exposed to the treated effluents indicating the significant genotoxic potential of untreated effluents. Risk characterization of soil sample was carried out by calculating the potential ecological and human health risks of heavy metals. The hazard index was observed to be less than 1, indicating there was no potential health risk of heavy metals in soil samples. Furthermore, bioaccumulation potential studies on plant species grown in the vicinity of these industries have shown that bioaccumulation factor (BAF) varied as Ricinus communis L. 〉 Chenopodium album L. 〉 Cannabis sativa L. with Co and Pb having maximum and minimum values, respectively.

Description: Sub-Saharan Africa is one of the most severely affected regions regarding soil degradation, a global issue with the loss of nutrients caused by inappropriate management, leading to low agricultural productivity. Here we asked the question of how soil prokaryotic communities are affected by shifts in land use management and subsequent losses in soil organic carbon. We sampled soils from three sites in Zambia which have neighboring natural and managed sites. After the measurement of soil properties, soil DNA was sequenced, targeting the 16S rRNA gene. As expected, total carbon in soil was decreased in the managed sites, with significant reductions of bacterial biomass. However, the diversity indices in the managed soils were higher than in natural soils. Particularly, the relative abundance of nitrifiers was increased in the managed soils, most likely as a result of fertilization. However also other bacteria, e.g., those which formed tight interactions with the cultivated crops including the genera Balneimonas, and Bacillus, were increased in the managed soils. In contrast bacteria belonging to the family Chloroflexi, which were high in abundance in the natural soil were outcompeted by other prokaryotes in the managed soils most likely as a result of changes in the amount of soil organic carbon. Overall, our results suggest that we need to discuss the trends of prokaryotic diversity separately from those for prokaryotic abundance. Even when bacterial abundances were decreased in the managed soils, nitrifiers’ relative abundance and diversity increased in our experiment, suggesting the possible alteration of the nitrogen cycle in managed soils in sub-Saharan Africa.

Description: In the past decade soil health has been intensively studied as a science and practiced as a means to help improve the global social, environmental, and economic sustainability. This paper reviews the recent advances of the scientific soil health system. The current understanding and interpretation of soil health from the perspectives of soil functions, processes, and properties is summarized. Multi-tier soil health indicators were selected from relevant soil physical, chemical, and biological parameters. A suite of soil health assessment methods have been developed, such as soil health card, Solvita soil health tests, Haney soil health test, and comprehensive assessment of soil health. An array of soil health management practices have been recommended, including proper land use, crop rotation, cover crops, conservation tillage, soil organic amendment, crop-range-livestock integration, and rotational grazing. Overall, the recommended soil health indicators and assessment methods need further validation and improvement in relevance, scientific validity, practicality, and local adaptation. Continuous research, education, and outreach efforts are warranted to promote localized development, adoption, and implementation of soil health assessment and management.

Description: The effect of a municipal solid waste compost (MSWC), added at 1 and 2% rates, on the mobility, phytotoxicity, and bioavailability of antimony (Sb) was investigated in two soils (SA: acidic soil; SB: alkaline soil), spiked with two Sb concentrations (100 and 1000 mg kg−1). The impact of MSWC on microbial activity and biochemical functioning within the Sb-polluted soils was also considered. MSWC addition reduced water-soluble Sb and favored an increase in residual Sb (e.g., by 1.45- and 1.14-fold in SA-100 and SA-1000 treated with 2% MSWC, respectively). Significant increases in dehydrogenase activity were recorded in both the amended soils, as well as a clear positive effect of MSWC on the metabolic activity and catabolic diversity of respective microbial communities. MSWC alleviated Sb phytotoxicity in triticale plants and decreased Sb uptake by roots. However, increased Sb translocation from roots to shoots was recorded in the amended soils, according to the compost rate. Overall, the results obtained indicated that MSWC, particularly at a 2% rate, can be used for the recovery of Sb-polluted soils. It also emerged that using MSWC in combination with triticale plants can be an option for the remediation of Sb-polluted soils, by means of assisted phytoextraction.

Description: Lead (Pb) is one of the most common metal pollutants in soil, and phytoextraction is a sustainable and cost-effective way to remove it. The purpose of this work was to develop a phytoextraction strategy able to efficiently remove Pb from the soil of a decommissioned fuel depot located in Italy by the combined use of EDTA and endophytic bacteria isolated from indigenous plants. A total of 12 endophytic strains from three native species (Lotus cornicolatus, Sonchus tenerrimus, Bromus sterilis) were isolated and selected to prepare a microbial consortium used to inoculate microcosms of Brassica juncea and Helianthus annuus. As for B. juncea, experimental data showed that treatment with microbial inoculum alone was the most effective in improving Pb phytoextraction in shoots (up to 25 times more than the control). In H. annuus, on the other hand, the most effective treatment was the combined treatment (EDTA and inoculum) with up to three times more Pb uptake values. These results, also validated by the metagenomic analysis, confirm that plant-microbe interaction is a crucial key point in phytoremediation.

Description: The general concept of sustainable development has been specified in terms of goals, targets, and indicators by the UN Sustainable Development Goals, adopted in 2015, followed by the Green Deal of the European Union in 2019. The focus on targets and indicators does, however, not address the issue as to how these goals can be achieved for land-related SDGs in the real world, and attention in this paper is therefore focused on how land management can contribute to providing ecosystem services in line with the aims of the SDGs and the Green Deal. Agricultural production systems should at least produce healthy food (SDG2 and 3), protect ground- and surface water quality (SDG6), mitigate climate change (SDG13), avoid soil degradation, and support biodiversity (SDG15). The corresponding ecosystem services are discussed with particular emphasis on the role of soils, which are characterized in terms of soil health, defined as: contributing to ecosystem services in line with the SDGs and the Green Deal. Appropriate management, as developed and proposed by researchers working jointly with farmers in living labs, can only be realized when it is part of sound long-term business plans, supported by independent advice that is focused on farmers’ concerns based on the requirements for adaptive management. The research effort in living labs, addressing “wicked” problems, needs to be judged differently from classical linear research. As the development of successful ecosystem services requires an interdisciplinary research effort based on a systems analysis, SDG-oriented soil research in the future should be focused on: (i) presenting suitable data to the interdisciplinary effort beyond standard data to be found in existing databases; (ii) using soil types as “carriers of information” to allow extrapolation of results; (iii) providing data with a comparable degree of detail when analyzing the various ecosystem services, and (iv) revisit past experiences in soil survey and soil fertility research when contact with farmers was intense, as is again needed in future to realize ecosystem services in line with the SDGs and the Green Deal.

Description: In this study, we analyse soil system responses—in particular, the colours of soils resulting from different types of land use (arable land and residential areas) caused by the construction of an ancient boundary rampart near a multilayer monument dating from between prehistory and the Middle Ages within the boundaries of the Bosporus Kingdom (Eastern Crimea)—in an area of modern and ancient (4th–2nd centuries BC) land use (Northwestern Crimea). These differences are of interest because they offer the chance to decipher different types of ancient land use and systems of land surveying, incorporating data from colour aerial photographs obtained with the help of unmanned aerial vehicles. Soil samples displaying different types of anthropogenic transformation were taken from the ancient boundary ramparts and adjacent land. The soil colour coordinates in the CIE L*a*b system were measured with the help of an AvaSpec-2048 spectrometer. Differences in colour coordinates were analysed using analysis of variance (NPMANOVA) based on the permutation test, the Kruskal–Wallis test, and the Mann–Whitney test, corrected according to multiple comparisons carried out as per the Bonferroni method. The results of this statistical analysis show that there are statistically significant differences in soil colour coordinates between samples collected on the ramparts and under various other types of land use. These differences are more pronounced in the samples characterised by the agrogenic transformation of soil. This makes it possible to use remote sensing data to detect traces of ancient boundary ramparts, even if the ramparts are partially destroyed by ploughing.