Search Results (187)

Petrological knowledge on weathering processes controlling the mobility of chemical elements is still limited in the dry tropical zone of Cameroon. This study aims to investigate the mobility of major and trace elements during rhyolite weathering and soil formation in Mobono by understanding the mineralogical and elemental vertical variation. The studied soil was classified as Cambisols containing mainly quartz, K-feldspar, plagioclase, smectite, kaolinite, illite, calcite, lepidocrocite, goethite, sepiolite, and interstratified clay minerals. pH values ranging between 6.11 and 8.77 indicated that hydrolysis, superimposed on oxidation and carbonation, is the main process responsible for the formation of secondary minerals, leading to the formation of iron oxides and calcite. The bedrock was mainly constituted of SiO₂, Al₂O₃, Na₂O, Fe₂O₃, Ba, Zr, Sr, Y, Ga, and Rb. Ce and Eu anomalies, and chondrite-normalized La/Yb ratios were 0.98, 0.67, and 2.86, respectively. SiO₂, Al₂O₃, Fe₂O₃, Na₂O, and K₂O were major elements in soil horizons. Trace elements revealed high levels of Ba (385 to 1320 mg kg⁻¹), Zr (158 to 429 mg kg⁻¹), Zn (61 to 151 mg kg⁻¹), Sr (62 to 243 mg kg⁻¹), Y (55 to 81 mg kg⁻¹), Rb (1102 to 58 mg kg⁻¹), and Ga (17.70 to 35 mg kg⁻¹). LREEs were more abundant than HREEs, with LREE/HREE ratio ranging between 2.60 and 6.24. Ce and Eu anomalies ranged from 1.08 to 1.21 and 0.58 to 1.24 respectively. The rhyolite-normalized La/Yb ratios varied between 0.56 and 0.96. Mass balance revealed the depletion of Si, Ca, Na, Mn, Sr, Ta, W, U, La, Ce, Pr, Nd, Sm, Gd and Lu, and the accumulation of Al, Fe, K, Mg, P, Sc, V, Co, Ni, Cu, Zn, Ga, Ge, Rb, Y, Zr, Nb, Cs, Ba, Hf, Pb, Th, Eu, Tb, Dy, Ho, Er, Tm and Yb during weathering along the soil profile. Full article

Acid soils are often a limiting factor in the production of most cultivated plants. In practice, the application of inadequate, physiologically acidic fertilizers, urea and NPK, is often encountered, which further worsens the already poor physicochemical properties of such soils. In this study, the influence of different amounts of NPK and urea fertilizers and methods of their application on the chemical properties of a very acidic soil and the accumulation of essential biogenic elements (N, P, K, Ca, Mg, and Al) in raspberry plants (leaves and fruits) was evaluated. The field trial with the raspberry plants was set up on a very acidic soil (pH in KCl 3.6), type Dystric Cambisol, and was monitored for 2 years. The application of NPK and urea mainly increased soil acidity in the second year in all treatments (for 0.10–0.18 pH unit) (except for urea applied in rows). The application of higher amounts of NPK increased the content of available forms of P (for 9.3–30.8 mg/kg) and K (for 57–95 mg/kg) in soil in both years, as well as exchangeable Ca (for 200–510 mg/kg) and Mg in the first year (15–165 mg/kg). The introduction of fertilizers in rows, compared to fertilization of the entire surface, influenced the reduction in mobile Al (especially when applying NPK, from 5.89 to 7.13 mg/100 g), the increase in mineral N and K content in the soil, and the increase in Ca and Mg only when applying urea, i.e., P when applying NPK in rows. In the leaves, the application of fertilizers in rows increased the content of Ca and Mg in the first year and P and K in the second year. In the fruits, the content of all estimated elements was not in correlation with their content in leaves and the fertilizer application, which indicates the influence of other ecological and biological factors on plant nutrition. Full article

Foliar fertilization is an effective practice that improves both the yield and quality of maize, a crop with high and specific micronutrient demands. This study hypothesized that foliar application of Fe, Cu, Mn, Mo, Zn and B would improve grain size and quality in GS210 maize compared to the control. The single-factor field experiment was conducted in 2023–2024 on Haplic Cambisol (Eutric) soil, under a variety of meteorological conditions. The application of Zn and B fertilizers significantly increased the soil plant analysis development (SPAD) index. Yield components (number of grains per ear, thousand-grain weight) and grain yield increased significantly following Zn foliar application compared to the control. Zn application increased grain yield by 0.59 t ha⁻¹ and 0.49 t ha⁻¹ in 2023 and 2024, respectively. Smaller but beneficial effects were observed with Cu and B applications. In contrast, the effects of fertilization with other micronutrients (Fe, Mn, Mo) were less pronounced than anticipated. Biochemical analyses revealed that foliar fertilization with Fe, Cu and Mo increased total phenolic content and antioxidant capacity, while Fe and Mo enhanced carotenoid accumulation, and Cu and B significantly influenced grain color parameters. The study highlights the potential of foliar fertilization to improve maize performance and grain quality, despite possible antagonisms between micronutrients. Full article

Soil structure has an important role in storing and transporting substances, providing natural habitats for soil microorganisms, and allowing chemical reactions in the soil. A complex investigation on factors affecting soil structure characteristics under herbaceous (H), deciduous (D), mixed (M), and coniferous (SP—Scots Pine and NS—Norway Spruce) vegetation was conducted at three experimental stations—Gabra, Govedartsi, and Igralishte, located correspondingly in the Lozenska, Rila, and Maleshevska Mountains in South-West Bulgaria. The data set obtained includes soil structure indicators and physical, physicochemical, chemical, mineralogical, and microbiological parameters of the A and AC horizons of 11 soil profiles. Under different vegetation conditions, soil structure indicators respond differently depending on climatic conditions and basic soil properties. Regarding the plant available water capacity (PAWC), air capacity (AC), and water-stable aggregates (WSAs), the surface soil layers have an optimal structure in Gabra (H, D), Govedartsi (H, SP, NS), and Igralishte (H). The values for the relative field capacity (RFC < 0.6) showed that the studied soils were water-limited. The WSAs correlated with SOC in Gabra, while in Govedartsi and Igralishte, the WSAs correlated with the β-glucosidase known to hydrolyze organic carbon compounds in soil. The information obtained is important for soil quality monitoring under climatic and anthropogenic changes. Full article

Modern wheat breeding has largely emphasized aboveground traits, often at the expense of belowground characteristics such as root biomass, architecture, and beneficial microbial associations. This has narrowed genetic diversity, impacting traits essential for stress resilience and efficient nutrient and water acquisition—factors expected to become increasingly critical under climate change. In this study, we evaluated 36 primary synthetic (PS) hexaploid wheat lines developed by crossing Aegilops tauschii with the durum wheat cultivar Langdon (LNG) and compared them with LNG and the hexaploid variety Norin 61 (N61). We observed significant variation in root length, biomass, and associations with fungal endophytes, including beneficial Arbuscular Mycorrhizal Fungi (AMF) and Serendipita indica, and pathogenic Alternaria sp. Clustering analysis based on these traits identified three distinct PS groups: (1) lines with greater root length and biomass, high AMF and S. indica colonization, and low Alternaria infection; (2) lines with intermediate traits; and (3) lines with reduced root traits and high Alternaria susceptibility. Notably, these phenotypic patterns corresponded closely with the soil classification of the Ae. tauschii progenitors’ origin, such as Cambisols (supportive of root growth), and Gleysols and Calcisols (restrictive of root growth). This highlights the soil microenvironment as a key determinant of belowground trait expression. By comparing PS lines with domesticated tetraploid and hexaploid wheat, we identified and selected PS lines derived from diverse Ae. tauschii with enhanced root traits. Our study emphasizes the potential of wild D-genome diversity to restore critical root traits for breeding resilient wheat. Full article

Despite their effectiveness in eliminating weeds, herbicides can indirectly and directly affect organisms, leading to a decline in species abundance as well as disruptions to the structure and functioning of ecosystems. Boxer 800 EC, whose active ingredient is prosulfocarb, is an active herbicide commonly used for weed control, but its potential ecological risks are not well understood. With this in mind, a study was conducted to evaluate the effectiveness of sodium alginate and sodium polyacrylate in restoring homeostasis to soil exposed to Boxer 800 EC herbicide. This involved a two-factor pot experiment: factor I—herbicide dose (0.0, 0.8, 4.8, and 48.0 mg kg⁻¹ d.m.); factor II—polymer type (soil with the polymer additives sodium alginate, and sodium polyacrylate). The experiment was carried out on Eutric Cambisols with four replicates and lasted for 50 days. The test plant was Triticum aestivum L., cultivar “KWS Dorium C1”. The contaminant herbicide doses inhibited the proliferation of organotrophic bacteria and actinobacteria and reduced the colony development index (CD) and ecophysiological diversity index (EP) values for these microorganisms. The addition of sodium alginate to the soil increased the proliferation of these microorganisms, whereas sodium polyacrylate inhibited their development. Sodium alginate also increased the colony development index value of organotrophic bacteria and actinobacteria. Across all the analyzed factors, bacteria from the phylum Proteobacteriota dominated. However, the presence of herbicides and polymers changed the abundance of these bacteria. Bacteria of the genus Sphingomonas were the most prevalent genus in the samples. The herbicide Boxer 800 EC exerted a toxic effect on the growth and development of spring wheat, which was reflected in the plant biomass yield (shoot and ear) and the SPAD index. The recommended herbicide dose (0.80 mg kg⁻¹) did not cause significant changes in the growth and development of spring wheat. The hydrogel control additives deepened the negative effect of the herbicide on plant development. While the herbicide significantly reduced the levels of available carbon and total nitrogen in the soil, the polymers increased these parameters. Full article

Estrone (E1) is a female hormone present in large quantities in animal farming, which has, in recent decades, resulted in increasing water and soil pollution. Research into its behaviour in the environment has been more focused on water pollution than on soil or soil groups. Three agricultural soils from the Czech Republic—cambisol, fluvisol, and chernozem—were analyzed in a pot experiment to determine their influence on estrone transformation, with laccase, and Mn-oxidoreductases enzymes being measured for this purpose. From the initial concentration of 50 μg·kg⁻¹ soil E1 solution, 1.36 μg·kg⁻¹ were measured on average in the soils after 28 days. There was a clear transition in estrone concentration between 24 h and day 3, reflected in all three soils by increased enzymatic activity. Aside from this, the three soils behaved differently. Results showed that fluvisol was the most different to both cambisol and chernozem. It had the highest enzymatic activity, but also the highest estrone levels in soil at 28 days (5.09 μg·kg⁻¹) vs. cambisol (1.36 μg·kg⁻¹) and chernozem (0.94 μg·kg⁻¹). The removal mechanisms were considered a combination of estrone soil sorption and enzymatic activity, with each soil exhibiting an individual combination of the two. In fluvisol, sorption was considered predominant, thoughenzymatic activity was also relevant; cambisol presented an alternation of sorption and biodegradation, with neither deemed the main mechanism; and chernozem exhibited predominantly high enzymatic activity at the end of the experiment, which resulted in the lowest estrone in soil at the end of the experiment. Overall, all three soils presented good estrone degradation potential through their various soil properties. Full article

This study assesses the current status of selected soil properties of an expanding equatorial agricultural region (Arauca, Colombia) across six landscapes, with the final focus being on evaluating overall soil quality. Field surveys, morphological descriptions, and laboratory analyses of 133 soil profiles were investigated. The landscapes include mountains (25 profiles), foothills (17), hills (11), alluvial plains (43), alluvial plains with dunes (21), and alluvial valleys (16). Soils are classified into six Reference Soil Groups (WRB FAO): Gleysols, Acrisols, Arenosols, Ferralsols, Leptosols, and Cambisols. The findings indicate high acidity, low fertility, and deficient exchangeable bases. Indeed, pH ranges from extremely acid to slightly acid (3.5–6.4), and exchangeable acidity saturation percentage (%SAI) values reach 100% in some areas. Soil textures vary from clay loam to sandy loam and clay. Nutrient contents are ranked in the order Cambisols > Gleysols > Arenosols > Ferralsols > Acrisols > Leptosols. Correlation analysis reveals that clay content positively influences the exchangeable basis percentage, while organic matter (OM) negatively correlates with the nutrients phosphorus, calcium, and magnesium. This study highlights that landscape position influences soil quality, with lower landscape positions having better quality than upper ones. These results provide insights into soil fertility and nutrient availability, which helps to predict suitable plant cultivation areas when increasing areas for agricultural use versus forestry in Arauca. The inclusion or maintenance of diverse tree species is a key element in maintaining the production of organic matter and, consequently, generating better soil quality. Full article

The effects of climate change are particularly pronounced in cities, where urban green infrastructure—such as trees, parks, and green spaces—plays a vital role in both climate adaptation and mitigation. This study assesses the carbon sequestration potential of urban forests in Budapest, the capital city of Hungary, which lies at the intersection of the Great Hungarian Plain and the Buda Hills, and is traversed by the Danube River. The city is characterized by a temperate climate with hot summers and cold winters, and a diverse range of soil types, including shallow Leptosols and Cambisols in the limestone and dolomite hills of Buda, well-developed Luvisols and Regosols in the valleys, Fluvisols and Arenosols in the flood-affected areas of Pest, and Technosols found on both sides of the city. The assessment utilizes data from the National Forestry Database and the Copernicus Land Monitoring Service High Resolution Layer Tree Cover Density. The results show that Budapest’s urban forests and trees contribute an estimated annual carbon offset of −41,338 tCO₂, approximately 1% of the city’s total emissions. The urban forests on the Buda and Pest sides of the city exhibit notable differences in carbon sequestration and storage, age class structure, tree species composition, and naturalness. On the Buda side, older semi-natural forests dominated by native species primarily act as in situ carbon reservoirs, with limited additional sequestration capacity due to their older age, slower growth, and longer rotation periods. In contrast, the Pest-side forests, which are primarily extensively managed introduced forests and tree plantations, contain a higher proportion of non-native species such as black locust (Robinia pseudoacacia) and hybrid poplars (Populus × euramericana). Despite harsher climatic conditions, Pest-side forests perform better in carbon sink capacity compared to those on the Buda side, as they are younger, with lower carbon stocks but higher sequestration rates. Our findings provide valuable insights for the development of climate-resilient urban forestry and planning strategies, emphasizing the importance of enhancing the long-term carbon sequestration potential of urban forests. Full article

Biochar has gained significant attention for its potential in carbon sequestration, soil health improvement, and crop production sustainability. However, the existing studies predominantly focus on short-term experiments conducted in acidic or neutral soils. This study investigates the long-term effects of biochar application in a calcaric cambisol in a field experiment with four treatments: CK (no fertilizer or biochar), B (only biochar), NPK (chemical fertilizer), and NPKB (combination of chemical fertilizer and biochar). This study assessed soil organic carbon (SOC), sorghum yield, soil bacteria, plant nutrient accumulation in 2020 and 2022, and soil chemical properties after 12 years of consecutive application in 2022. The results revealed a significant increase in SOC due to biochar application in both 2020 and 2022 compared to the treatments without biochar. The 12-year biochar application also significantly enhanced soil total nitrogen (N), available phosphorus (P), and available potassium (K), irrespective of chemical fertilizer application. Notably, sorghum plant N and P accumulation remained unaffected by biochar, and plant N accumulation induced by NPKB was even lower than that of the NPK treatment in 2022. Furthermore, soil bacterial diversity and composition, as well as sorghum yield, showed no significant alterations due to biochar application in both years, despite increased soil nutrient content. These findings affirmed the benefits of carbon accumulation through long-term biochar application in calcaric cambisols, but the positive effects on crop production were found to be negligible. Full article

Microplastics (MP) are widespread pollutants that pose a risk to soil ecosystems globally, especially in agricultural soils. This study introduces a method to extract and identify MP in Brazilian tropical soils, targeting debris of low-density polyethylene (LDPE) and polyvinyl chloride (PVC) polymers, commonly present in agricultural settings. The method involves removing organic matter and extracting MP using density separation with three flotation solutions: distilled water, NaCl, and ZnCl₂. Extracted MP are then analyzed through optical microscopy and Fourier transform infrared spectroscopy. The organic matter removal efficiency ranged from 46% to 89%, depending on the initial organic matter content in the soil. Recovery rates for LDPE ranged from 81.0% to 98.8%, while PVC samples showed a range of 59.7% to 75.2%. Finally, this methodology was tested in four agricultural raw soil samples (i.e., without any polymer enrichment) The values found in the soil samples were 2517.5, 2245.0, 3867.5, and 1725.0 items kg⁻¹, for ferralsol, nitisol, gleysol, and cambisol samples, respectively, with MP having diverse shapes including fragments, granules, films, and fibers. This approach lays the groundwork for future studies on MP behavior in Brazilian tropical agricultural soils. Full article

Water quality affects soils by promoting their degradation by the accumulation of salts that will lead to salinization and sodification. However, the magnitude of these processes varies with soil attributes. Saturated hydraulic conductivity (K_sat) is the rate at which water passes through saturated soil, which is fundamental to determining water movement through the soil profile. The K_sat may differ from soil to soil according to the sodium adsorption ratio (SAR), water electrical conductivity (EC_w), soil texture, and clay mineralogical assemblage. In this study, an experiment with vertical columns and constant-load permeameters was conducted to evaluate changes in soil K_sat with waters comprising five EC_w values (128, 718, 1709, 2865, and 4671 µS cm⁻¹) and five SAR values [0, 5, 12, 20, and 30 (mmol_c L⁻¹)^0.5] in combination. Horizons from nine northeastern Brazilian soils (ranging from tropical to semiarid) were selected according to their texture and clay mineralogical composition. The data obtained were fit with multiple regression equations for K_sat as a function of EC_w and SAR. This study also determined the null SAR at each EC_w level, using K_sat = 0 on each equation, to predict the SAR needed to achieve zero drainage on each soil for each EC_w level and the threshold electrolyte concentration (C_TH) that would lead to a 20% reduction of maximum K_sat. Neither the EC_w nor SAR of the applied waters affected the K_sat of soils with a mineralogical assemblage of oxides and kaolinite such as Ferralsol, Nitisol, and Lixisol, with an average K_sat of 2.75, 6.06, and 3.33 cm h⁻¹, respectively. In smectite- and illite-rich soils, the K_sat increased with higher EC_w levels and decreased with higher SAR levels, especially comparing the soil’s estimated K_sat for water with low EC_w and high SAR in combination (EC_w of 128 µS cm⁻¹ and SAR 30) and water with high EC_w and low SAR in combination (EC_w of 4671 µS cm⁻¹ and SAR 0) such as Regosol (4.95 to 10.94 cm h⁻¹); Vertisol (0.28 to 2.04 cm h⁻¹); Planosol (0 to 0.29 cm h⁻¹); Luvisol (0.46 to 2.12 cm h⁻¹); Cambisol (0 to 0.23 cm h⁻¹); and Fluvisol (1.87 to 3.34 cm h⁻¹). The C_TH was easily reached in soils with high concentrations of highly active clays such as smectites. In sandy soils, the target C_TH was only reached under extremely high SAR values, indicating a greater resistance of these soils to salinization/sodification. Due to their mineralogical assemblage, soils from tropical sub-humid/hot and semiarid climates were more affected by treatments than soils from tropical humid/hot climates, indicating serious risks of physical and chemical degradation. The results showed the importance of monitoring water quality for irrigation, mainly in less weathered, more clayey soils, with high clay activity to minimize the rate of salt accumulation in soils of the Brazilian semiarid region. Our study also proved that clay mineralogy had more influence on the K_sat than clay concentration, mainly in soils irrigated with saline and sodic waters, and that soils with highly active smectite are more prone to degradation than soils with high concentrations of kaolinite. Full article

The influence of different mineral and organic fertiliser applications on the soil organic matter (SOM) content and quality was monitored in long-term field trials. We used long-term field experiments (27 years) with a crop rotation of potatoes, winter wheat, and spring barley on cambisol soil. The treatments were as follows: an unfertilised control (Cont), sewage sludge in normal and triple doses (SS1 and SS3, respectively), farmyard manure (F1) in a conventional dose, a half dose of farmyard manure with a half dose of mineral nitrogen (F1/2 + N1/2), straw with mineral nitrogen fertiliser (N + St), and mineral nitrogen without any organic fertiliser (N). This study focused on the ability of the total and easily extractable glomalin-related soil protein (T-GRSP and EE-GRSP, respectively) and the water stability of aggregates (WSA) as indicators of long-term SOM quality changes. The results were compared with the content of humic substance fractions and the carbon in humic substances (C_HS), humic acids (C_HA), and fulvic acids (C_FA). The lowest SOM content and quality were observed in the control treatment. The highest overall SOM quality, including the degree of polymerisation (HA) and the GRSP content, was found in the F1 treatment. The organic matter in sewage sludge contributed less to the formation of stable SOM than straw. A significant correlation was found between both the EE-GRSP and the T-GRSP and the content of the C_SOM, C_HS, C_HA, and HA, but not with the C_FA. The influence of fertiliser on the GRSP content was demonstrated. However, no relationship was observed between the WSA and SOM quality, the EE-GRSP, or the T-GRSP content. Full article

Finding ways to enhance the resilience of soil ecosystems in the context of heavy metal contamination remains an important and urgent challenge. This work is devoted to assessing the impact of the soil composition in Primorsky Krai on the efficiency of using hydroxyapatite to decrease lead intake into plants. The physicochemical characteristics of Luvic Anthrosol and Gleyic Cambisol and their absorption properties with respect to lead have been studied. Adsorption, distribution of forms, and biotesting were carried out under lead saturation of soils conditions. It has been found that soil composition determines sorption properties and the proportion of mobile lead. The high organic carbon content in Gleyic Cambisol explains its high adsorption capacity and low content of water-soluble lead fraction. The addition of hydroxyapatite reduces the water solubility of lead in Luvic Anthrosol by three orders of magnitude and in the ion mobile form by one order. The capacity of hydroxyapatite decreases by more than thirty times when added to Luvic Anthrosol. With a ratio of hydroxyapatite/soil 0.2, oat germination increases by 18.7%, average seedling length increases by 7 cm, and lead uptake into tissues decreases by 83%. Full article

This five-year study examined the impact of simplified tillage practices and shortened crop rotations on soil physical attributes and earthworm populations as an important indicator of soil health in Central Lithuanian Cambisols. The experiment was set up following a split-plot design to compare conventional tillage and no-tillage systems across three rotation schemes (three-field, two-field, and monoculture). The experiment was carried out over a period of 5 years, from 2010 to 2014. Preliminary soil conditions revealed notable disparities in moisture content across tillage methods (20.0 ± 0.3% against 17.9 ± 0.3% at a depth of 5–10 cm; p < 0.001), although variations in bulk density were more evident in the deeper soil layer (1.42 ± 0.02 versus 1.47 ± 0.01 mg m⁻³ at 15–20 cm). Earthworm abundance exhibited a strong negative association with bulk density (r = −0.612, p = 0.041) and a positive correlation with total porosity (r = 0.583, p = 0.044) in the upper soil layer. Notably, this study revealed the unexpected resilience of earthworm populations to tillage practices, with no significant differences between conventional and no-till systems (F_1,108 = 1.414, p = 0.237). Rotation effects showed more significance than tillage intensity, as both two-field and three-field rotations sustained comparable earthworm populations (127.5–131.2 ind. m⁻², 32.8–35.4 g m⁻²), but monoculture exhibited markedly lower figures (105.0 ± 13.2 ind. m⁻², 25.6 ± 2.7 g m⁻²; p < 0.048). Three-way ANOVA indicated substantial temporal effects (F_4,108 = 17.227, p < 0.001), demonstrating that environmental influences gained prominence as systems evolved. These findings challenge traditional assumptions about tillage impacts on soil fauna and indicate that crop diversification within the rotation cycle, rather than tillage intensity or rotation duration, is the essential determinant for sustaining earthworm populations in agricultural systems. Soil structural factors proved to be a significant factor but played a less substantial role. Full article