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Weathering indices are quantitative models that relate the soil's geochemical characteristics to its weathering state. Wetland soils derived from basement complexes and sedimentary rocks were studied to determine their elemental composition and degree of weathering for soil fertility management. Three profile pits were dug in each formation and described using the FAO guidelines. Soil samples were collected from genetic horizons and analyzed for major elements (Si, Fe, Al, Ti, Ca, Mg, Na, K, Mn, and P) using appropriate methods. The weathering degree was characterized using eleven indices (SCR, SSR, V, WIP, CIA, CIW, CPA, MIA, PWI, PIA, and IOL). Results showed that the wetlands had a loamy sand texture at the surface, while the subsurface horizons had sandy loam and sandy clay texture. Soil pH ranged from strongly acidic to neutral (4.1–7.6). Ca and Mg dominated the exchange sites. Geochemically, Na2O, K2O, CaO, MgO, MnO, and P2O5 contents decreased while SiO2, Al2O3, Fe2O3, and TiO2 tend to accumulate in both formations. The indices values were in the ranges: SCR 0.21–0.67; SSR 2.21–15.69; V 0.85–1.75; WIP 602.10–1388.11; CIA 51.31–69.32; CIW 54.00–71.28; CPA 88.26–95.97; MIA 2.16–38.64; PWI 68.85–86.60; PIA 51.45–70.45, and IOL 12.90–30.35. Pearson coefficients and principal component analysis (PCA) of the oxides and the indices showed a highly significant (p <.05) correlation. Based on weathering indices, the soils in both formations showed a moderate degree of weathering. With the levels of OC and CEC, the soils were moderately fertile and could sustain crops grown on them with or without inputs. [ABSTRACT FROM AUTHOR]

Background: The development of superior summer maize hybrids with high-yield potential and essential agronomic traits, such as resistance to lodging, is crucial for ensuring the sustainability of maize cultivation. However, the task of identifying and breeding genotypes that exhibit exceptional performance and stability across multiple environment conditions, while considering a wide range of traits, is challenging. Given the backdrop of global climate change, understanding which climate variables and soil properties most significantly impact environmental similarity is essential for selecting hybrids with improved adaptability to regions with diverse climatic and soil conditions. This study aimed to integrate envirotyping techniques (ETs) with a multi-trait selection approach to carry out a comprehensive evaluation of maize genotypes for performance and stability. Results: The grain yields of 13 maize hybrids, along with their four critical agronomic parameters, were assessed in the Huang-Huai-Hai Plain of China across 40 locations in eight provinces. By considering 20 years of climatic factors and soil covariates, these 40 locations were divided into six mega-environments (MEs) based on similar long-term weather patterns and soil characteristics. Additive main effects and multiplicative interaction (AMMI) analyses revealed that genotype (G), environment (E), and the GxE interaction had significant effects on all agronomic parameters (P < 0.001). The mean performance and stability of the genotypes in each mega-environment were assessed, allowing for the identification of superior hybrids using the multi-trait stability index (MTSI). In two of the MEs (ME2 and ME3), only two hybrids, HY321 and HY9112, were selected concurrently. Conclusion: Overall, this study provides valuable insights into the effects of ETs on maize hybrids and enhances our understanding of GxE interactions in multi-environment trials. This understanding is essential for improving maize cultivation practices and breeding program in diverse environments. [ABSTRACT FROM AUTHOR]

The abundance and oxidation states (II, III and IV) of manganese (Mn) in a weathering profile encompassing both the soil layers (A and B horizons) and the underlaid saprolite (C horizons) determine the availability of Mn as a plant nutrient and regulate its role in cycles of other elements in Earth's critical zone. However, it remains unclear how the abundance and oxidation states vary with depth under different climates, and how the soil forming processes and soil properties control the variations. We examined four forest granite weathering profiles developed under climates ranging from temperate to tropical climate. Regardless of climate types, all four profiles showed similar vertical variation patterns of Mn concentration and oxidation states. The major features of the patterns can be understood from the perspective of soil forming processes and soil properties. Climate affected the Mn oxidation states in the fine fraction (< 2 mm; i.e., the soil fraction) of the poorly weathered saprolite by controlling the weathering degree of Mn-bearing primary minerals. The weathering released Mn(II) and Mn(III) in the primary minerals to the circumneutral environment where it was subsequently oxidized by O 2. In contrast, climate affected the Mn oxidation states in the soil layers poor in parent materials largely by controlling soil redox conditions and pH because most of the Mn in soils was reactive. As the climate became warmer/wetter, the weathering intensified and soils became more reducing and acidic, resulting in more reduced Mn in the soil layers but more oxidized Mn in the fine fraction of saprolite. Moreover, relative to Mn(II) and Mn(IV), Mn(III) preferentially accumulated in the subsoil (B horizons), likely as Mn(III) oxyhydroxides in the colder and drier climates, and as a substitute ion in well-crystallized Fe(III) oxides in the warmer and wetter climates. These findings improve our understanding of Mn availability and cycling and its role in biogeochemical cycles of other elements in Earth's critical zone. [ABSTRACT FROM AUTHOR]

Magnetic studies of loess–paleosol sequences have shown that the magnetic properties of loess and its parent material are sensitive to weathering degree. However, the relationship between magnetic properties and weathering processes in red soils of southern China remains unclear due to the diversity of parent rocks and the influence of climate. This study focused on red soils developed on weakly magnetic sandstone, in tropical and subtropical regions of Yunnan, China. The principal element content, magnetic susceptibility, temperature-dependent susceptibility curve (χ–T curve, where χ represents the magnetic susceptibility at the corresponding temperature during the heating and cooling process of the sample, and T represents the temperature during the heating and cooling process.), hysteresis loop and Isothermal Remanent Magnetization (IRM) of the samples were determined, the weathering characteristics and magnetic properties of profile samples were analyzed, and their relationship was examined, as well as the impact of climate change on fine-grained ferrimagnetic minerals and magnetic properties. The results revealed that red soils developed on weakly magnetic sandstone exhibited significant correlations between three magnetic indices, low-frequency magnetic susceptibility (χlf), frequency-dependent susceptibility (χfd), (χpost-pre + χd)/χpara, and the silica-sesquioxide ratio (SAF), indicating that these indices can be used to assess soil weathering. Additionally, this study proposed a new index based on the 1 < Log10Bh < 1.5 mT component obtained from decomposition of the IRM curve, which can also be used to assess soil weathering. The enhancement of magnetic properties in red soils along a single profile was found to be related to the increase in the content of fine-grained ferrimagnetic com-ponents controlled by weathering. Comparing the two climatic regions, it was found that in Yunnan, China, as the climate changes from subtropical humid to tropical humid, the weathering of the red soil profiles becomes stronger, and the fine-grained ferrimagnetic components increase, indirectly enhancing the magnetic properties of red soils. [ABSTRACT FROM AUTHOR]

India, renowned for its rich agricultural heritage, is ranked among the three world crop suppliers. Farmers face numerous challenges, including difficulty in selecting profitable crops suited to their soil and unpredictable weather conditions that affect yield predictions. To address these issues, various analytical methods have been employed in agricultural yield-prediction studies. Plant diseases are prevalent in agriculture, prompting the need for effective detection methods. Therefore, in this study, the proposed agro insights' model aimed at assisting farmers in predicting or deciding the type of soil and crop to sow, which is implemented through ML and DL methods to predict the optimal crop to be cultivated by deciding diverse input variables such as the region, soil, and crop type. The accuracy of soil classification and crop recommendation is 93.3% using random forest technique and crop disease detection is 96% using CNN technique. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum) production at subtropical latitude is highly influenced by varying weather and soil microclimate. There is a need to quantify the requirement of key weather and soil climatic variables during the critical growth stages of potato. The present investigation was carried out to study the effect of varying weather and soil microclimatic factors during critical growth stages on potato yield in the subtropical climate. Field experiments were conducted in 2018–2019 and 2019–2020 at Kharagpur, India, to determine the relationship between key weather as well as soil microclimate factors and potato tuber yield. The experimental data were used for validation of the crop model DSSAT-SUBSTOR-Potato and simulation of potato tuber yield for varying weather. The effects of three weather variables, i.e. maximum temperature (Tmax), minimum temperature (Tmin), and solar radiation (Srad), and two soil variables, i.e. soil moisture (SM) content and soil temperature (ST), on potato yield were assessed through regression analysis. During the 'Emergence to tuber initiation' stage, the factors Tmax, Srad, and SM and during 'Tuber initiation to maturity' stage, the factors Srad and SM had significant effects (p ≤ 0.05) on potato production. The optimum values of Tmax were 17.58 (± 1.97) and 27.39 (± 0.9) °C; Srad values were 14.28 (± 2.03) and 19.32 (± 1.96) MJ m−2 day−1; and SM values were 21.79 (± 2.35) and 21.77 (± 1.74) % during 'emergence to tuber initiation' and 'tuber initiation to maturity' stages, respectively, for increased potato production. The results stated the need for an optimum planting window for providing favourable weather and soil microclimate for potato production in subtropical climate. [ABSTRACT FROM AUTHOR]

With the development and utilization of large‐scale urban underground space, the interaction between groundwater and underground structures has become a research hotspot. To analyze the pore pressure transfer mechanism of granite weathered soil under high water head conditions, this article uses the consolidation differential equation of saturated soil to solve the pore pressure transfer model for specific boundary conditions. To verify the effectiveness of the theoretical model, a large‐scale head loss test system was constructed to carry out seepage tests of groundwater in granite weathered soil under high water head conditions. Using the experimental results, an expression for the relationship between the permeability coefficient and hydraulic gradient of granite weathered soil was established. Finally, the influence factors in the process of pore water pressure transfer in soil were studied using the pore pressure transfer theory model. The research conclusions can be used for antifloating design and seepage field analysis of underground structures, providing a basic theoretical basis and analytical method for studying the seepage law of soil, which is of great significance for ensuring the safety of underground structures. [ABSTRACT FROM AUTHOR]

The Himalayas significantly impact local and regional hydro-sedimentary processes and weathering rates. Utilizing geomorphometric anomalies offers insights into the connections between topographic factors and rates of cation weathering and sedimentary flux. An empirical model RS-GIS tool was used to compute the runoff and weathering rates of the basin. The 6th-order Lolab River with 451 different lower-order streams is dominated by dendritic to semi-dendritic draining patterns with the presence of steep slopes. The linear aspects of the basin showed the drainage pattern is influenced by geological and lithological factors. Additionally, other parameters such as rotundity factor, circulation factor, compactness coefficient, and elongation ratio indicate an elongated shape, reduced peak flow, and a complex structure. The significant reduction in Runoff (Q) and Sediment Production Rate (SPR) within the Lolab basin, measuring 4.61 sq km-cm/sq km and 0.17 ha-m/100-sq km/year respectively, suggests minimal runoff and reduced soil erosion. These findings can provide valuable information about weathering, erosion, and sediment delivery processes. This data helps understand how environmental changes and natural hazards affect the fragile Himalayan landscape and aids in regional land management decisions for sustainable land use policies. [ABSTRACT FROM AUTHOR]

The importance of biota to soil formation and landscape development is widely recognized. As biotic complexity increases during early succession via colonization by soil microbes followed by vascular plants, effects of biota on mineral weathering and soil formation become more complex. Knowledge of the interactions among groups of organisms and environmental conditions will enable us to better understand landscape evolution. Here, we used experimental columns of unweathered granular basalt to investigate how early successional soil microbes, vascular plants (alfalfa; Medicago sativa), and soil moisture interact to affect both plant performance and mineral weathering. We found that the presence of soil microbes reduced plant growth rates, total biomass, and survival, which suggests that plants and microbes were competing for nutrients in this environment. However, we also found considerable genotype‐specific variation in plant–microbial interactions, which underscores the importance of within‐species genetic variation on biotic interactions. We also found that the presence of vascular plants reduced variability in pH and electrical conductivity, suggesting that plants may homogenize weathering reactions across the soil column. We also show that there is heterogeneity in the abiotic conditions in which microbes, plants, or their combination have the strongest effect on weathering, and that many of these relationships are sensitive to soil moisture. Our findings highlight the importance of interdependent effects of environmental and biotic factors on weathering during initial landscape formation. [ABSTRACT FROM AUTHOR]

Carbon sink processes related to the weathering of silicate minerals are often accompanied by physical, chemical, and biological effects. In particular, plant-microbe synergistic effects are important for soil mineral weathering, but relevant correlation analyses and quantitative studies remain sparse. In this research, a standard serpentine test specimens (STSs) with specific specifications were used to study serpentine weathering under different environmental conditions (abiotic or biotic) and correlated it with the microbial community structure under the growth of Setaria viridis. The results showed that the environment with growing S. viridis had the strongest weathering capacity for STSs, which was 35 times higher than that of the abiotic environment group, and a significant increase in soil inorganic and organic carbon contents compared with the abiotic environment and the environment without plant growth. The bacteria with strong weathering ability were enriched in the soil of around STSs, such as Pseudomonas spp. and Sphingomonas spp. In addition, the fungal community of Ascomycetes is also heavily enriched, accelerating STSs weathering. The addition of bacterial agent (Bacillus subtilis) further promoted the STSs weathering under the growth conditions of S. viridis. The soil surrounding the buried STSs was also enriched with heavy metal tolerant Massilia spp. and disease suppressing Lysobacter spp., while the abundance of fungi functionally associated with pathotypes was reduced, thereby benefiting plant growth. This study provides basic information for the serpentine bio-weathering coupled with carbon sequestration by using plant-microbe synergistic effects. [ABSTRACT FROM AUTHOR]

Among 50 environments in the United States, we screened 35 hairy vetch (Vicia villosa Roth.) lines for traits of interest to cover cropping. We analyzed the influence of genotype, environment, and the genotype‐by‐environment interaction (G × E) on biomass, vigor, winter survival, emergence, flowering time, and nitrogen fixation. To explore how environments and G × E impacted each trait, we associated environment predictions and G × E loadings with weather and soil parameters. Environment had the largest influence on all traits, representing more than half of the variance. Environment predictions were significantly associated with weather and/or soil parameters for each trait. Biomass was associated with growing degree days, winter survival with freezing degree days without snow cover, growth stage with shortwave radiation, and emergence with soil texture. The G × E interaction was larger than genotypic variance for all traits except for winter survival and flowering time. The G × E interaction loadings were associated with soil sand content for biomass, air temperature for fall vigor and emergence, and snow cover for winter survival. Although it represented the smallest proportion of total variance, genetic effects were significant for all traits except for emergence, Ndfa, %N, and C:N. New hairy vetch breeding lines were superior to all commercially available lines for biomass and winter survival. Biomass harvest timing did not significantly change line rank, indicating that top‐performing lines can be used in diverse management systems. To select for high nitrogen contribution to subsequent crops, breeding programs can indirectly select for biomass rather than expensively evaluating symbiotic nitrogen fixation. Core Ideas: New hairy vetch varieties have higher biomass and winter survival than check cultivars.Genotype‐by‐environment interactions were larger than genetic effects for biomass, vigor, and emergence.Weather and soil parameters that were associated with G × E could be used to optimize selection.There are few tradeoffs in selecting multiple cover crop traits in hairy vetch.Across our sites, aboveground biomass accurately predicted total fixed nitrogen (N). [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are crucial strategic resources, and weathering-crust rare earth deposits are one of the primary sources. To systematically understand the geochemical behaviour (e.g. enrichment and leaching) of REEs in soils (or weathering crusts) formed from diverse parent rocks under varying climatic conditions, 171 soil profiles (weathering crusts) developed from three main types of parent rocks (granite, basalt and carbonate rock) worldwide were studied. Granite shows the highest concentration of REEs at 264 [interquartile range (IQR): 278] ppm with 171 (IQR: 151) ppm and 11.9 (IQR: 36.4) ppm in basalt and carbonate rock, respectively (median test: p < 0.05). The median REE values within the soil profiles were significantly different (median test: p < 0.05), with the concentration of 318 (IQR: 441) ppm, 267 (IQR: 217) ppm and 207 (IQR: 417) ppm in soils derived from granite, carbonate rock and basalt, respectively. Principal component analysis and linear mixed-effects models revealed that soils developed from granite and basalt inherit the mineral characteristics of their parent rocks, with REE concentrations primarily influenced by the REE content of the parent rock and climate. In contrast, the REE concentrations in soils developed from carbonate rocks are predominantly controlled by climate. Linear mixed-effects models and correlation analysis indicate that the enrichment of REEs (QREE) shows a trend of initially increasing and then decreasing with rising temperature and precipitation, due to variations in the host clay minerals. The greatest enrichment occurs in the subtropical region (mean annual temperature = 15–23°C; mean annual precipitation = 1000–2000 mm); weathering-crust type REE deposits are primarily found in the subtropics. [ABSTRACT FROM AUTHOR]

Humalite is a humic acid‐rich biostimulant known for its ability to improve plant agronomic parameters and increase crop nitrogen use. Limited field research exists on Humalite effect, its application rate, and its interaction with urea, especially at reduced rates on grain agronomic parameters. Therefore, a field study was conducted from 2021 to 2023 at three Alberta sites—Battle River Research Group (BRRG), Gateway Research Organization (GRO), and St. Albert Research Station (St. Albert), in a split‐plot design with four replications, three urea levels (i.e., recommended, half‐recommend, and zero urea) combined with five Humalite rates (0, 56 (or 112), 224, 448, and 896 kg ha−1). In 2021, the highest wheat yields were observed at half urea rates plus 224 kg ha−1 at BRRG (35% yield increase), GRO (8.4% yield increase), and St. Albert (33.5% yield increase). In 2022, canola yields were unaffected by Humalite application rates. In 2023, wheat yields from half‐recommended and recommended urea rates plots outperformed zero urea plots across all sites, regardless of Humalite rates. The highest wheat grain protein content values were observed at 224–448 kg ha−1 of Humalite plus half‐recommended or recommended urea rate. Depending on the site, the highest net revenue resulted from half urea rates plus Humalite at application rates between 112 and 448 kg ha−1 in wheat, that is, optimal Humalite rate for increased profitability. Therefore, the incorporation of biostimulants such as Humalite can reduce urea use and contribute to the sustainability of wheat cropping systems. Core Ideas: The effect of Humalite and urea on wheat and canola yields varies depending on soil type and weather conditions.Irrespective of urea rates, lower Humalite rates (112−448 kg ha−1) consistently improved wheat yields.Urea and Humalite application affected grain protein but not total kernel weight.Higher net revenue gains were mostly achieved with lower urea rates, regardless of Humalite application rates. [ABSTRACT FROM AUTHOR]

A linear relationship between rates of physical erosion and chemical weathering is apparent in slowly eroding landscapes. Whether the relationship remains linear in rapidly eroding landscapes is less clear. Field‐based research into this relationship between erosion and weathering rates has largely been conducted in temperate climates with granitic bedrock. In tropical settings, the contribution of chemical mass loss to total denudation may approach, or even exceed, that of erosion. We report 10Be‐in‐quartz cosmogenic radionuclide and soil chemistry data from the Suckling‐Dayman Metamorphic Core Complex (SDMCC) in Papua New Guinea. Despite being exhumed at cm‐per‐year rates, its lower‐plate domed and striated morphology suggests minimal denudation, which is confirmed by our 10Be‐in‐quartz data (0.02–0.18 mm/yr). We suggest that rolling hinge‐style back‐rotation of the SDMCC's lower plate and the combination of a tropical climate and highly weatherable metabasalt bedrock have played a fundamental role in preserving the tectonic topography of this remarkable metamorphic core complex. Plain Language Summary: Where mountains are raised (uplifted) slowly by plate tectonics, erosion (the removal of rocks/soils) tends to be slow. Where erosion is slow, chemical weathering (the local breaking down or dissolving of rocks/minerals) is usually slow as well. This observation has been made in mountainous regions around the world with temperate climates, and where mountains consist predominantly of granitic rocks. However, much less is known about how rates of erosion and weathering relate in tropical climates where mountains rise rapidly. We studied a unique geological structure in tropical Papua New Guinea (the Suckling‐Dayman Metamorphic Core Complex, SDMCC) to provide new data for addressing this knowledge gap. We measured denudation rates (the sum of physical and chemical mass loss) using a method that is based on the accumulation of atomic particles that form in the crystal lattice of minerals in rocks and soils by cosmic rays. Our denudation rates are much slower than the rate at which the SDMCC is being raised by tectonic processes, requiring some erosion‐limiting mechanism(s). The chemical compositions of basaltic soils from the SDMCC, however, imply intense weathering. We argue that the style of tectonic uplift and the tropical weathering regime are responsible for the slow denudation rates. Key Points: 10Be‐in‐quartz denudation rates of the rapidly uplifting Suckling‐Dayman Metamorphic Core Complex are in the range of 0.02–0.18 mm/yrRapid, intense weathering of its metabasaltic footwall bedrock is implied by mobile and immobile weathering indices in soil samplesThe pristine topography of Mount Dayman is strongly influenced by rolling hinge‐style tectonics and the tropical weathering regime [ABSTRACT FROM AUTHOR]

Studying the effects of weathering on the mechanical properties and microscopic evolution of weathered granite soil (WGS) is essential for connecting microstructure with macroscopic behavior. This study conducts systematic monotonic and cyclic triaxial tests, along with a series of microscopic tests on WGS samples, to explore the influence of weathering on WGS mechanical properties and the mechanism of granite weathering. Results indicate that both effective internal friction angle and effective cohesion decrease progressively with increased weathering. Completely weathered granite (CWG) exhibits greater dynamic strength compared to granite residual soil (GRS). Additionally, as weathering progresses, quartz fragments are lost, while feldspar and biotite weather to form secondary minerals such as kaolinite and illite, leading to an overall enrichment in aluminum and iron in the granite. Weathering causes structural deterioration of WGS. Finally, the mechanical parameters of WGS and their chemical weathering indices show a coefficient of determination ranging from 60 to 99%. This study helps elucidate the fundamental causes of performance changes in WGS, thereby optimizing engineering design and enhancing disaster prediction accuracy, while providing new research perspectives and experimental evidence for WGS. [ABSTRACT FROM AUTHOR]

High-yielding traits can potentially improve yield performance under climate change. However, data for these traits are limited to specific field sites. Despite this limitation, field-scale calibrated crop models for high-yielding traits are being applied over large scales using gridded weather and soil datasets. This study investigates the implications of this practice. The SIMPLACE modeling platform was applied using field, 1 km, 25 km, and 50 km input data resolution and sources, with 1881 combinations of three traits [radiation use efficiency (RUE), light extinction coefficient (K), and fruiting efficiency (FE)] for the period 2001–2010 across Germany. Simulations at the grid level were aggregated to the administrative units, enabling the quantification of the aggregation effect. The simulated yield increased by between 1.4 and 3.1 t ha− 1 with a maximum RUE trait value, compared to a control cultivar. No significant yield improvement (< 0.4 t ha− 1) was observed with increases in K and FE alone. Utilizing field-scale input data showed the greatest yield improvement per unit increment in RUE. Resolution of water related inputs (soil characteristics and precipitation) had a notably higher impact on simulated yield than of temperature. However, it did not alter the effects of high-yielding traits on yield. Simulated yields were only slightly affected by data aggregation for the different trait combinations. Warm-dry conditions diminished the benefits of high-yielding traits, suggesting that benefits from high-yielding traits depend on environments. The current findings emphasize the critical role of input data resolution and source in quantifying a large-scale impact of high-yielding traits. [ABSTRACT FROM AUTHOR]

Survival and reproduction tests were conducted using two native springtail (subclass: Collembola) species to determine the toxicity of a fine-grained (< 0.005 – 0.425 mm) soil from an industrial site located in the Canadian boreal ecozone. Accidental petroleum hydrocarbon (PHC) release continuously occurred at this site until 1998, resulting in a total hydrocarbon concentration of 12,800 mg/kg (soil dry weight). Subfractions of the PHC-contaminated soil were characterized using Canadian Council of Ministers of the Environment Fractions, which are based on effective carbon numbers (nC). Fraction 2 (> nC10 to nC16) was measured at 8400 mg/kg and Fraction 3 (> nC16 to nC34) at 4250 mg/kg in the contaminated soil. Age-synchronized colonies of Folsomia candida and Proisotoma minuta were subject to 0%, 25%, 50%, 75%, and 100% relative contamination mixtures of the PHC-contaminated and background site soil (< 100 mg/kg total PHCs) for 28 and 21 days, respectively. Survival and reproduction decreased significantly (Kruskal–Wallis Tests: p < 0.05, df = 4.0) in treatments of the contaminated site soil compared to the background soil. In both species, the most significant decline in survival and reproduction occurred between the 0% and 25% contaminated soil. Toxicity responses in the two springtails were ascribed to the standardized test design, short lifespans, and high fecundity in both species. This study showed that 25 + years of soil weathering has not eliminated the toxicity of fine-grained PHC-contaminated soil on two native terrestrial springtail species. Adverse effects to springtail health were attributed to exposure to soils dominated by genotoxic PHC Fraction 2 compounds and slow weathering processes due to the cold climate at the site. [ABSTRACT FROM AUTHOR]

The geotechnical behavior of residual soil differs essentially from that of sedimentary soil because of the weathering pedogenesis of the former, thereby posing significant difficulties in predicting soil response. In this study, the shear strength and stiffness of natural granite residual soil are evaluated through systematic monotonic and cyclic simple shear tests performed using a hollow-cylinder apparatus. Simple shear testing provides critical information about soil behavior under plane-strain conditions and involves principal stress rotation, which is beyond the scope of triaxial shear tests. The mechanical properties of granite residual soil measured in monotonic simple shear are found to be different from those obtained through other routine laboratory tests such as triaxial shear and resonant column tests. Whereas the conventional triaxial compression test gives unconservatively high soil strength parameters, those from simple shear testing appear more reasonable than the triaxial results. The cyclic behavior of residual soil in simple shear is dominated by the cyclic stress ratio, a higher value of which results in more significant deformation and pore water pressure build-up as well as more rapid stiffness degradation. This is particularly the case when the cyclic stress ratio exceeds a critical value in the range of 0.125–0.1875. No consistent pattern can be established for how the loading frequency influences soil responses within the range of 0.01–1.0 Hz. This study enriches the techniques for characterizing residual soil and provides new data sets about its mechanical behavior. [ABSTRACT FROM AUTHOR]

Solar energy plays a major role in the transition to renewable energy. To ensure that large-scale photovoltaic (PV) power plants operate at their full potential, their monitoring is essential. It is common practice to utilize drones equipped with infrared thermography (IRT) cameras to detect defects in modules, as the latter can lead to deviating thermal behavior. However, IRT images can also show temperature hot-spots caused by inhomogeneous soiling on the module's surface. Hence, the method does not differentiate between defective and soiled modules, which may cause false identification and economic and resource loss when replacing soiled but intact modules. To avoid this, we propose to detect spatially inhomogeneous soiling losses and model temperature variations explained by soiling. The spatially resolved soiling information can be obtained, for example, using aerial images captured with ordinary RGB cameras during drone flights. This paper presents an electrothermal model that translates the spatially resolved soiling losses of PV modules into temperature maps. By comparing such temperature maps with IRT images, it can be determined whether the module is soiled or defective. The proposed solution consists of an electrical model and a thermal model which influence each other. The electrical model of Bishop is used which is based on the single-diode model and replicates the power output or consumption of each cell, whereas the thermal model calculates the individual cell temperatures. Both models consider the given soiling and weather conditions. The developed model is capable of calculating the module temperature for a variety of different weather conditions. Furthermore, the model is capable of predicting which soiling pattern can cause critical hot-spots. [ABSTRACT FROM AUTHOR]

[Objective］ The specific mechanism of influence of low molecular weight organic acids in root exudates on metal cation release in purple soil in Yuanmou dry and hot river valley of Yunnan Province was explored to fill the current research gap and provide scientific basis for understanding soil weathering and pl ant-soil interaction. _ Methods］ The organic acid leaching test was employed to investigate the structural disintegration characteristics of purple soil under various low molecular weight organic acids and the release kinetics of ions during weathering. The quantitative analysis of the relationship between release rate and time was conducted, and the influence of different organic acids on CT A (chemical index of alteration) was discussed. Results］ Application of organic acids leads to a substantial increase in C'TA value for purple soil weathering products ranging from 7.25% to 15.42%. Citric acid, at equivalent concentrations, demonstrates greater efficacy in accelerating weathering compared to oxalic acid. Scanning electron microscopy (SEM) results reveal that organic acids induce structural damage in purple soil, while MATLAB software analysis indicates that leaching by organic acids promotes the development of surface pores in soil minerals and reduces particle uniformity. The release rates of metal cations from soil vary with concentrations of low molecular weight organic acids (LMWOAs), decreasing gradually over leaching time. The metal ion release rates increase with increasing organic acid concentrations, and the total ion release pattern follows Fe>+ > Mg'+MnJ+ '> K+ >• Ca'+二> Na+. A quantitative analysis model for the metal cation release rate under changing acidity conditions is established using multivariate nonlinear regression. There exists a significant exponential function relationship between the release rate of metal cations and time. _Conclusion] The leaching of low molecular weight organic acids promoted metal cation release and weathering of purple soil, and citric acid was more significant than oxalic acid. [ABSTRACT FROM AUTHOR]

Ectomycorrhizal (ECM) fungi play a major role in forest ecosystems and managed tree plantations. Particularly, they facilitate mineral weathering and nutrient transfer towards colonized roots. Among nutrients provided by these fungi, potassium (K) has been understudied compared to phosphorus (P) or nitrogen (N). The ECM fungus Paxillus ammoniavirescens is a generalist species that interacts with the root of many trees and can directly transfer K to them, including loblolly pine. However, the forms of K that ECM fungi can store is still unknown. Here, we used synchrotron potassium X-ray fluorescence (XRF) and K-edge X-ray Absorption Near Edge Structure (XANES) spectroscopy on P. ammoniavirescens growing in axenic conditions to investigate the K chemistries accumulating in the center and the edge of the mycelium. We observed that various K forms accumulated in different part of the mycelium, including K-nitrate (KNO 3), K-C-O compounds (such as K-tartrate K 2 (C 4 H 4 O 6) and K-oxalate (K 2 C 2 O 4)), K-S and K-P compounds. Saprotrophic fungi have been shown to excrete carboxylic acids, which in turn play a role in soil mineral weathering. Our finding of several K counter-ions to carboxylic acids may suggest that, besides their direct transfer to colonized roots, K ions can also be involved in the production of compounds necessary for sourcing nutrients from their surrounding environment by ECM fungi. Additionally, this work reveals that XANES spectroscopy can be used to identify the various forms of K accumulating in biological systems. • We use XANES to identify the K chemistries in the ECM fungus Paxillus ammoniavirescens. • Hotspots of various K forms accumulate in the hyphae P. ammoniavirescens. • K-nitrate, K-C-O, K-S, and K-P compounds were found in P. ammoniavirescens hyphae. • K ions can be involved in compounds needed for mineral weathering by ECM fungi. [ABSTRACT FROM AUTHOR]

Species interaction effects on populations can vary in both magnitude (i.e. strong vs. weak) and sign (positive, negative, or no effect). Context‐dependent effects of species interactions occur when the sign or strength of the interaction's effect on population growth rate changes across abiotic gradients.We know that species can vary substantially in the degree of context dependence they exhibit, even across similar abiotic gradients. However, few studies have characterised context dependence of co‐occurring species, limiting our ability to understand the implications of context dependence for species interaction effects on community composition.Using over three decades of data collected for 13 tallgrass prairie forbs at the Konza Prairie Biological Station, we parameterise density structured population models that predict population dynamics as functions of abiotic conditions and bison herbivory. We use these models to estimate the degree of context dependence in responses to bison herbivory for 13 species across three abiotic gradients: weather, fire frequency and soil type.All species showed significant context dependence for fire frequency in the same direction, though with variable magnitude, such that herbivory increased cover with more frequent fires. Context dependence with weather and soil type varied dramatically across species in both direction and magnitude. For example, herbivory effects on 3/13 species were stronger in wet conditions, but herbivory effects on 5/13 species were stronger in dry conditions. Thus, context dependence exhibited by individual species, as opposed to effects of abiotic conditions on the relative abundances of species, could generate much of the weather‐dependent effects of herbivory on community composition.Synthesis: Our work suggests that species can vary dramatically in the presence, direction and magnitude of context dependence, even when occurring in the same community and when considering the same species interaction (i.e. response to a herbivore). In addition, we find that context dependence could drive substantial variation in the effect of species interactions on community characteristics (e.g. composition) across multiple abiotic gradients. [ABSTRACT FROM AUTHOR]

The establishment of SPAC (soil–plant‐atmosphere continuum) stations is essential for comprehensive monitoring of land‐atmosphere interactions and ecological and hydrological processes. This paper addresses the critical limitations of existing observation networks, which often rely on single‐aspect observations, resulting in insufficient data for a holistic understanding of SPAC dynamics. Specifically, SPAC stations provide critical multi‐variable observations that enhance process‐based model calibration and physical constraints and improve the empirical basis of data‐driven models. Advanced technologies such as machine learning and remote sensing are proposed to transform current weather and soil moisture stations into quasi‐SPAC sites capable of estimating carbon and water flux data. Additionally, the strategic placement of new SPAC sites in regions projected to be sensitive to future climate change and climate risks, as indicated by models such as CMIP6, is recommended. Furthermore, promoting comprehensive observational systems like Europe's Integrated Carbon Observation System (ICOS) in other regions, establishing a unified management framework and coordinating the upgrading of existing global observation networks are essential steps. Ultimately, the proposed enhancements will advance global ecological and hydrological studies, providing a more integrated and accurate understanding of the SPAC system and its responses to climate variability. [ABSTRACT FROM AUTHOR]

Remote sensing offers a low-cost method for estimating yields at large spatio-temporal scales. Here, we examined the ability of Sentinel-2 satellite imagery to map field-level maize yields across smallholder farms in two regions in Oromia district, Ethiopia. We evaluated how effectively different indices, the MTCI, GCVI, and NDVI, and different models, linear regression and random forest regression, can be used to map field-level yields. We also examined if models improved by adding weather and soil data and how generalizable our models were if trained in one region and applied to another region, where no data were used for model calibration. We found that random forest regression models that used monthly MTCI composites led to the highest yield prediction accuracies (R2 up to 0.63), particularly when using only localized data for training the model. These models were not very generalizable, especially when applied to regions that had significant haze remaining in the imagery. We also found that adding soil and weather data did little to improve model fit. Our results highlight the ability of Sentinel-2 imagery to map field-level yields in smallholder systems, though accuracies are limited in regions with high cloud cover and haze. [ABSTRACT FROM AUTHOR]

Accurate yield prediction is essential for global food security and effective agricultural management. Traditional empirical statistical models and crop models face significant limitations, including high computational demands and dependency on high-resolution soil and daily weather data, that restrict their scalability across different temporal and spatial scales. Moreover, the lack of sufficient observational data further hinders the broad application of these methods. In this study, building on the SCYM method, we propose an integrated framework that combines crop models and machine learning techniques to optimize crop yield modeling methods and the selection of vegetation indices. We evaluated three commonly used vegetation indices and three widely applied ML techniques. Additionally, we assessed the impact of combining meteorological and phenological variables on yield estimation accuracy. The results indicated that the green chlorophyll vegetation index (GCVI) outperformed the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) in linear models, achieving an R2 of 0.31 and an RMSE of 396 kg/ha. Non-linear ML methods, particularly LightGBM, demonstrated superior performance, with an R2 of 0.42 and RMSE of 365 kg/ha for GCVI. The combination of GCVI with meteorological and phenological data provided the best results, with an R2 of 0.60 and an RMSE of 295 kg/ha. Our proposed framework significantly enhances the accuracy and efficiency of winter wheat yield estimation, supporting more effective agricultural management and policymaking. [ABSTRACT FROM AUTHOR]

Water drives the decay of road subgrades such as frost heave in cold areas and collapse in saline soil areas, which influences the safety and comfort of vehicle transportation. This paper proposes a novel geotechnical material, namely hydrophobized soil, as a subgrade fill material to mitigate water-induced degradation of subgrade. Hydrophobized soil has a low affinity to water and therefore can prevent the subgrade from water infiltration, enhancing the volume stability of subgrades. To demonstrate its feasibility, the hydrophobicity and its durability were investigated in this study. A one-year outdoor weathering test on hydrophobized soil columns was conducted, with the hydrophobicity measured. The results show that hydrophobized sand has different durabilities and exhibits different degradations depending on the chosen hydrophobizing agent and its concentration. Based on the testing results and capillary rise model, the design of hydrophobic hydraulic barrier in subgrade was discussed at the end. [ABSTRACT FROM AUTHOR]

Climate change is one of the most urgent environmental challenges that humanity faces. In addition to the reduction of greenhouse gas emissions, safe and robust carbon dioxide removal (CDR) technologies that capture atmospheric CO2 and ensure long‐term sequestration are required. Among CDR technologies, enhanced silicate weathering (ESW) has been suggested as a promising option. While ESW has been demonstrated to depend strongly on pH, water, and temperature, recent studies suggest that biota may accelerate mineral weathering rates. Bacillus subtilis is a plant growth‐promoting rhizobacterium that can facilitate weathering to obtain mineral nutrients. It is a promising agricultural biofertilizer, as it helps plants acquire nutrients and protects them from environmental stresses. Given that croplands are optimal implementation fields for ESW, any synergy between ESW and B. subtilis can hold great potential for further practice. B. subtilis was reported to enhance weathering under laboratory conditions, but there is a lack of data for soil applications. In a soil‐mesocosm experiment, we examined the effect of B. subtilis on basalt weathering. B. subtilis–basalt interaction stimulated basalt weathering and increased soil extractable Fe. The combined application displayed higher CDR potential compared to basalt‐only application (3.7 vs. 2.3 tons CO2 ha−1) taking solid and liquid cation pools into account. However, the cumulative CO2 efflux decreased by approximately 2 tons CO2 ha−1 with basalt‐only treatment, while the combined application did not affect the CO2 efflux. We found limited mobilization of cations to the liquid phase as most were retained in the soil. Additionally, we found substantial mobilization of basalt‐originated Mg, Fe, and Al to oxide‐ and organic‐bound soil fractions. We, therefore, conclude that basalt addition showed relatively low inorganic CDR potential but a high capacity for SOM stabilization. The outcomes indicated the importance of weathering rate–GHG emission integration and the high potential of SOM stabilization in ESW studies. [ABSTRACT FROM AUTHOR]

Volcanic soils are among the most productive soils in the world as they can accumulate large amounts of organic carbon and nitrogen and have good water storage capacity. They are extensively used worldwide for agriculture, which makes it difficult to study the soil‐landscape dynamics under natural conditions. By working in the Galápagos Islands, a UNESCO World Heritage Site, we aimed to constrain soil development over millennial timescales using empirical data. Our monitoring sites on Santa Cruz Island cover a 10 km long NW‐SE transect with an 8‐fold increase in precipitation and associated vegetation changes. By controlling for age and chemical composition of the basaltic parent material, we investigated the influence of precipitation rates on soil weathering. At the landscape scale, soil weathering degree increased with increasing precipitation, as shown by the spatial patterns in soil depth, pH, mass loss coefficients, chemical index of alteration, chemical depletion fraction, and total reserve in bases. In addition to the climatic effect, rock porosity strongly enhanced basalt weathering. Porosity‐enhanced weathering is particularly important in the humid and perhumid precipitation regimes: soils developed on porous scoriae developed weathering mantles that are ∼10‐fold thicker and have 10‐fold higher mass losses due to weathering compared to soils developed on basalt lava flows. Our results demonstrated that variations in rock pore dimensions and distribution can lead to large variations in basalt weathering rates, particularly in humid and perhumid climates where deep leaching can be facilitated by rock porosity. Plain Language Summary: Tropical volcanic islands are global weathering hotspots. Soil weathering is controlled by climate and lithology, as temperature and precipitation facilitate weathering reactions, solute and nutrient fluxes, and CO2 drawdown. By studying soil‐landscape dynamics along a climosequence in Santa Cruz Island (Galápagos Archipelago), we first explored how precipitation facilitates basalt weathering. Then, we investigated whether rock porosity can further enhance weathering rates. Our data showed that soils are largely composed of atmospheric dust in arid regimes. With increasing precipitation, soil development is increasingly being controlled by in situ soil weathering. Soil weathering rates increased with precipitation, in particular in regions receiving more than 1,000 mm of annual precipitation. We also noted marked differences in soil thickness and degree of weathering between soils developed on basalt lava flows and porous scoriae, with soils developed on scoriae being significantly deeper and more weathered. Key Points: Basalt weathering increases with precipitation while temperature plays a secondary roleSoil weathering depth and rate are higher on porous scoria deposits than on basalt lava flowsPorosity‐enhanced weathering is particularly important in humid and perhumid precipitation regimes [ABSTRACT FROM AUTHOR]

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Soil degradation has led to a continuous decline in the quality of phaeozem, which is seriously threatening the foundation of national food security. Therefore, precisely evaluating the health status of phaeozem resources and their spatial and temporal variations are crucial for ensuring the effective implementation of soil degradation prevention and control strategies. In this study, soil data from 140 sites were collected, and eight physical and chemical indices (sand content, silt content, pedon thickness, organic matter, total potassium, total nitrogen, total phosphorus, and pH) were utilized to assess the soil health status of phaeozem in Liaoning Province. The results showed the following: (1) The minimum data set is aligned with previous research findings and effectively mirrors the soil's health condition. (2) The substantial coefficients of variation observed for pedon thickness, sand content, and silt content across regions suggest notable differences, likely influenced by climatic variations, parent material differences, and anthropogenic activities. (3) The study area's average soil pH of 6.39 indicates an overall acidic nature, potentially attributed to intense soil weathering and suboptimal fertilization practices. (4) The soil health index (SHI) ranged from 0.33 to 0.91, with an average of 0.62, which indicates that the majority of the phaeozem in Liaoning Province are in a sub-healthy state (SHI < 0.6 = unhealthy, SHI 0.6–0.8 = sub-healthy, SHI ≥ 0.8 = healthy). These sub-healthy areas are primarily located in hills, mountains, and the Liaohe Plain, and are significantly impacted by rainfall and wind erosion. Meanwhile, unhealthy areas are concentrated in the south and center of the province, characterized by fragile ecological environments and challenging agricultural conditions. [ABSTRACT FROM AUTHOR]

Enhanced rock weathering (ERW), the application of crushed silicate rock to soil, can remove atmospheric carbon dioxide by converting it to (bi) carbonate ions or solid carbonate minerals. However, few studies have empirically evaluated ERW in field settings. A critical question remains as to whether additions of crushed rock might positively or negatively affect soil organic matter (SOM)—Earth's largest terrestrial organic carbon (C) pool and a massive reservoir of organic nitrogen (N). Here, in three irrigated cropland field trials in California, USA, we investigated the effect of crushed meta-basalt rock additions on different pools of soil organic carbon and nitrogen (i.e., mineral-associated organic matter, MAOM, and particulate organic matter, POM), active microbial biomass, and microbial community composition. After 2 years of crushed rock additions, MAOM stocks were lower in the upper surface soil (0–10 cm) of plots with crushed rock compared to unamended control plots. At the 2 sites where baseline pre-treatment data were available, neither total SOC nor SON decreased over the 2 years of study in plots with crushed rock or unamended control plots. However, the accrual rate of MAOM-C and MAOM-N at 0–10 cm was lower in plots with crushed rock vs. unamended controls. Before ERW is deployed at large scales, our results suggest that field trials should assess the effects of crushed rock on SOM pools, especially over multi-year time scales and in different environmental contexts, to accurately assess changes in net C and understand the mechanisms driving interactions between ERW and SOM cycling. [ABSTRACT FROM AUTHOR]

Many scientific studies have been conducted to constrain present and past source‐to‐sink processes and their controlling factors. The role of typhoon and monsoon rainfall on chemical weathering and soils erosion in east Asia is still not well established. Clay minerals and major elements, combined with Nd and Sr isotopic compositions were analyzed on sediments from Core MD18‐3569 located on the Taiwan margin in the northeastern South China Sea. The aim was to reconstruct the weathering history of small river basins of southwest Taiwan and to establish the impact of East Asian summer monsoon and typhoon rainfall on source to sink processes since the last glacial period. 87Sr/86Sr and ɛNd values and predominant illite‐chlorite indicate that the rivers of southwest Taiwan is the sole source of sediments to Core MD18‐3569 since last deglaciation. Variations in clay mineral assemblages and major elements allowed us to evaluate the intensity of past weathering in the rivers of southwest Taiwan. We demonstrated that long‐term changes of chemical weathering intensity record from Taiwan are driven by changes in the summer monsoon rainfall. The deglaciation is characterized by a progressive increase in the intensity of chemical weathering, which peaked at the beginning of the Holocene. The chemical weathering degree of sediments from Taiwan decreases during the Holocene concurrently with a weakening of the summer monsoon, increase in typhoon activity, and changes in the vegetation cover. All these processes induce soil erosion, regressive pedogenesis, due to shorter residence time of minerals in the soils of southwest Taiwan. Plain Language Summary: East Asian summer monsoon and typhoon rainfall are important controls on the sediment transfer from land‐sea. It is important to understand their impacts on chemical weathering and soil erosion. We analyzed the clay mineralogy and geochemistry of sediments from Core MD18‐3569, from the Taiwan margin in the South China Sea, to trace the provenance of the sediments and reconstruct the chemical weathering history of soils of southwestern Taiwan since last glacial period. Clay minerals and Nd and Sr isotopic compositions determine that the rivers of southwest Taiwan are the sources of sediments to Core MD18‐3569. Changes in chemical weathering intensity from Taiwan, recorded by clay mineral assemblages and major elements, are controlled by the East Asian summer monsoon precipitation and temperature changes from the last glacial period to the early Holocene. Chemical weathering intensity in southwestern Taiwan reaches its maximum in the early Holocene, which is associated with the increase in monsoon precipitation and temperature. During the Holocene, the weakening of the summer monsoon rainfall is accompanied by changes in vegetation cover and an increase extreme typhoon rainfall, resulting in significant soil erosion, shortening of sediment residence time, and reducing chemical weathering intensity in the southwestern of Taiwan. Key Points: Penghu Canyon levee sediments have been derived from southwest Taiwan rivers since last deglaciationEast Asian summer monsoon and typhoons control the chemical weathering intensity and soil erosion of southwest Taiwan river basinsSediment to Taiwan margin is less chemically weathered during the middle and late Holocene due to short residence time induced by typhoons [ABSTRACT FROM AUTHOR]

This study presents an analysis of the influence of weather conditions on the performance of a multicrystalline silicon photovoltaic module, which operates under constant resistive load and is situated near a limestone quarry. The quarry is a significant source of dust, and hence the focus of the study is on the weather factors influencing the presence of soiling on the module's surface. The analysis encompasses a three-week period, during which the global horizontal irradiance and wind speed were recorded at 10-min intervals by an on-site weather station. The current, voltage, and back temperature of the module were also measured. Supplementary weather data were obtained from the Copernicus Atmosphere Monitoring Service and the NASA POWER databases. The primary objective is to assess whether any influence of the observed weather conditions on the presence of soiling can be inferred from the recorded data. The contribution is in part intended to test how different techniques can be used to extract useful information on the weather-related effects from somewhat limited data, assembled from various sources, while dealing with the underlying uncertainties. The analysis indicates a persistent deterioration of the module's performance because of soiling and its subsequent improvement due to a favourable weather event. [ABSTRACT FROM AUTHOR]

Chemical and physical denudation rates have been assessed in areas with different lithologies. Surprisingly, there are no studies that attempt to document these rates in the Poços de Caldas Alkaline Massif (PC), the largest alkaline magmatism in South America and an important Al supergene deposit in Brazil. Therefore, the chemical and physical denudation rates were assessed and explained in the PC. Surface water and rainwater samples were collected at the Amoras Stream basin, covering one complete hydrological cycle (2016). All samples were analyzed for dissolved cations, silica, anions, total dissolved solids (TDS), and total suspended solids (TSS). The results reflected the seasonal variation on discharge, water temperature, and electrical conductivity in the Amoras Stream, with most of the cations, anions, silica TDS, and TSS being carried in the wet season. Partial hydrolysis and silicate incongruent dissolution are the main water/rock interactions in the PC, with an atmospheric/soil CO2 consumption rate of 1.6 × 105 mol/km2/a. The annual fluxes of Cl−, PO43−, NO3−, and Al3+ were significantly influenced from rainwater. Chemical and physical weathering rates were 4 ± 0.8 and 3.0 ± 0.6 m/Ma in the PC, respectively, indicating that under the current climatic condition, the weathering profile is in dynamic equilibrium. [ABSTRACT FROM AUTHOR]

The aim of this study is to examine the effect of wood ash in association with planted maize in the remediation of total petroleum hydrocarbon in weathered crude oil polluted. In the study, soils were artificially polluted with weathered crude oil (50g Kg-1). Soil pollution, treatment, incubation and analysis were done using standard laboratory protocol. The wood ash used for soil treatment is alkaline with pH of 10.2, the ash also contained remarkable quantity of essential nutrients. There was a reduction in the level of pH and nutrients at the end of the incubation period. The sample treated with ash in association with planted maize recorded the highest reduction. There is also a decline in total petroleum hydrocarbon soil after the remediation period in the entire samples, ash and maize plant combination gave the highest reduction at the end of the remediation period. Therefore; this research has shown that wood ash assisted maize plants in synergistic relationship enhanced the reduction of total petroleum hydrocarbon in soil than singly ash and maize plants strategies. [ABSTRACT FROM AUTHOR]

The influence of parent material mineralogy on nutrient release rates in wood production forests remains poorly understood, despite its importance for sustainable forest management. This study investigated how parent material mineralogy impacts soil nutrient abundance and release rates. We studied three forests in Vermont and New Hampshire across a Ca and Mg richness gradient within the soil parent material. We found that both exchangeable and total nutrient concentrations followed the nutrient richness gradient with exchangeable Ca concentrations highest at the rich (758 mg/kg) and lowest at the poor (51.3 mg/kg) sites. Exchangeable Mg concentrations were higher at the rich (41.5 mg/kg) and moderate (42.9 mg/kg) sites relative to the poor (7.04 mg/kg) sites. Total concentrations of Ca were highest at the rich sites (13 mg/g) compared to the moderate (5.73 mg/g) and poor (5.89 mg/g). Total Mg concentrations were higher at the rich (27.3 mg/g) than the moderate (9.47 mg/g) and poor (3.07 mg/g) sites. Using τ values throughout the soil profile compared to the parent material, we found that all three forests were moderate to weakly depleted in Ca, Mg, and K in the upper 30 cm, but P was slightly enriched due to biological uplift. Additionally, we found that calculated field nutrient release rates did not significantly differ among forest nutrient status (p > 0.05), indicating the limited effects from across parent materials. We also conducted a follow up batch reactor experiment at varying pH conditions (4, 5, 6) with organic acids (NaCl, catechol, and citric acid). As expected, pH 4 had the highest Mg release rate (2.19 mg/m2/day) compared to pH 5 (1.27 mg/m2/day), and pH 6 (0.888 mg/m2/day), but surprisingly no effect on Ca release rates, suggesting the more acidic soils of the base cation poor soils results in higher release rates. Our results highlight the dominant contributions of parent material mineralogy has on Ca and Mg release rates, but also that weathering of primary minerals can sustain forest ecosystem productivity.

This study presents the development and evaluation of machine learning models to predict winter wheat crop yield using heterogeneous soil and weather data sets. A concept of an error stabilisation stopping mechanism is introduced in an LSTM model specifically designed for heterogeneous datasets. The comparative analysis of this model against an LSTM model highlighted its superior predictive performance. Furthermore, weighted regression models were developed to capture environmental factors using agroclimatic indices. Finally, a neural meta model was built by combining the predictions of several individual models. The experimental results indicated that a neural meta model with an MAE of 0.82 and RMSE of 0.983 tons/hectare demonstrated a notable performance, highlighting the importance of incorporating weighted regression models based on agroclimatic indices. This study shows the potential for improved yield prediction through the proposed model and the subsequent development of a meta model. [ABSTRACT FROM AUTHOR]

The amendment of agricultural soils by crushed silicate minerals has been proposed to enhance weathering rates and facilitate carbon dioxide (CO2) removal from the atmosphere. Laboratory dissolution experiments typically provide weathering rates that are significantly higher than those observed under natural conditions, while field studies are limited in the nature of data they can collect. This study uses an experimental setup that aims to emulate natural field conditions in a controlled setting using soil cores retrieved from UK cropland amended with crushed olivine at 32°C. Results are compared to enhanced weathering experiments run at 4°C and 19°C under otherwise identical conditions. The data reveal temperature-dependent variations in the behaviour of different elements, most importantly Mg and Si, with silicon being retained at moderate temperatures and magnesium being retained at higher temperatures. These patterns are most likely due to different retention mechanisms, notably Si reprecipitation (e.g. as cation-depleted Si-enriched mineral surface coatings) and cation exchange (affecting Mg, but to a lesser degree Si), such that the influence of cation exchange should be accounted for when interpreting enhanced weathering field data. We therefore recommend that estimates of carbon sequestration should not be based on the behaviour of individual elements. A temperature effect on the weathering rate of olivine added to soil columns is observed with the weathering rate being higher at 32°C than at 19°C and 4°C, and significantly lower than laboratory experiment-derived weathering rates. This further emphasises the need for enhanced weathering field trials, as simple laboratory-derived rates cannot be used to assess the feasibility of enhanced weathering measures. The carbon dioxide capture potential at 32°C is conservatively estimated at ~115 t CO2 km-2 yr-1 assuming an olivine amendment rate of 12.7 kg m-2. Our data suggests that soil accumulation of heavy metals like Cu and Cr at high temperatures (hence high weathering rates) is nondangerous, however, Ni concentrations in the effluent solution are close to EU guidelines while Cr and Cu are considerably lower than guidelines. All of these conclusions have implications for the application of enhanced weathering for carbon dioxide removal from the atmosphere. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are essential raw materials for modern industries but mining them has caused severe environmental issues, particularly the recovery of heavy REEs (HREEs) from ion-adsorption deposits (IADs). Very recently, an emerging technology, electrokinetic mining (EKM), has been proposed for the green and efficient recovery of REEs from IADs. However, the conduction mechanism of the weathering crust soil, which is also a prerequisite for EKM, remains unclear, making the EKM process unpredictable. Here, we systematically investigated the conductivity of weathering crust soil in the presence of light REEs (LREEs, i.e., La3+ and Sm3+) and HREEs (Er3+ and Y3+), respectively. Results suggested that the voltage was dynamically and spatially redistributed by the movement of REEs and water during EKM, and the conventional assumption of the linear distribution of voltage leads to an inaccurate description of soil voltage. We proposed an improved Archie's equation by coupling the mechanisms of liquid phase and solid-liquid interface conduction, which can predict soil conductivity more precisely. Moreover, the extended Archie's equation is able to recalculate the voltage distribution at distinct times and spaces well during EKM. More importantly, the water content in field-scale weathered-crust soils can be retrieved by the newly proposed Archie's equation, which helps optimize the leaching wells and improve the recovery rate of REE. This study focuses on the conduction mechanism of weathering crust soil, which provides a theoretical basis for better use of the EKM technology and promotes mining efficiency fundamentally. [ABSTRACT FROM AUTHOR]

Climate change and inter-annual variability cause variation in rainfall commencement and cessation which has consequences for the maize growing season length and thus impact yields. This study therefore sought to determine the spatially explicit optimum maize sowing dates to enable site specific recommendations in Nigeria. Gridded weather and soil data, crop management and cultivar were used to simulate maize yield from 1981–2019 at a scale of 0.5°. A total of 37 potential sowing dates between 1 March and 7 November at an interval of 7 days for each year were evaluated. The optimum sowing date was the date which maximizes yield at harvest, keeping all other management factors constant. The results show that optimum sowing dates significantly vary across the country with northern Nigeria having notably delayed sowing dates compared to southern Nigeria which has earlier planting dates. The long-term optimal sowing dates significantly (p<0.05), shifted between the 1980s (1981–1990), and current (2011–2019), for most of the country. The most optimum planting dates of southern Nigeria shifted to later sowing dates while most optimum sowing dates of central and northern Nigeria shifted to earlier sowing dates. There was more variation in optimum sowing dates in the wetter than the drier agro-ecologies. Changes in climate explain changes in sowing dates in wetter agro-ecologies compared to drier agro-ecologies. The study concludes that the optimum sowing dates derived from this study and the corresponding methodology used to generate them can be used to improve cropping calendars in maize farming in Nigeria. [ABSTRACT FROM AUTHOR]

Enhanced rock weathering (ERW) has been proposed as a measure to enhance the carbon (C)‐sequestration potential and fertility of soils. The effects of this practice on the soil phosphorus (P) pools and the general mechanisms affecting microbial P cycling, as well as plant P uptake are not well understood. Here, the impact of ERW on soil P availability and microbial P cycling functional groups and root P‐acquisition traits were explored through a 2‐year wollastonite field addition experiment in a tropical rubber plantation. The results show that ERW significantly increased soil microbial carbon‐use efficiency and total P concentrations and indirectly increased soil P availability by enhancing organic P mobilization and mineralization of rhizosheath carboxylates and phosphatase, respectively. Also, ERW stimulated the activities of P‐solubilizing (gcd, ppa and ppx) and mineralizing enzymes (phoADN and phnAPHLFXIM), thus contributing to the inorganic P solubilization and organic P mineralization. Accompanying the increase in soil P availability, the P‐acquisition strategy of the rubber fine roots changed from do‐it‐yourself acquisition by roots to dependence on mycorrhizal collaboration and the release of root exudates. In addition, the direct effects of ERW on root P‐acquisition traits (such as root diameter, specific root length, and mycorrhizal colonization rate) may also be related to changes in the pattern of belowground carbon investments in plants. Our study provides a new insight that ERW increases carbon‐sequestration potential and P availability in tropical forests and profoundly affects belowground plant resource‐use strategies. [ABSTRACT FROM AUTHOR]

How do agricultural productivity gains affect the distribution of agricultural land? Exploiting three waves of census data from the Philippines covering 21 years and 17 million plots, this article finds that municipalities endowed with favorable soil and weather conditions for genetically modified (GM) corn cultivation experience a relative increase in landholding inequality. Agricultural land is decreasing during this period and this decrease is driven by a decline in the size of large farms. The introduction of GM corn slows down this process by keeping more land under cultivation, which contributes to the documented relative increase in inequality. [ABSTRACT FROM AUTHOR]

Extreme weather (high rainfall and temperatures) and challenging soils are sources of uncertainties in the use of current crop models that have been developed for more favorable environments. This may limit their applicability to guide and support decision making for the development of new agricultural regions in tropical environments. We evaluated the accuracy of the Agricultural Production Systems Simulator (APSIM) framework in representing yield and development of a range of crops across multiple locations in the Northern Territory of Australia, a tropical region with large potential for agricultural development. Observations of yield, biomass, and phenology for a range of crops from 28 experiments undertaken at three locations were compiled and used to develop simulations undertaken using APSIM version 7.10. Model performance varied with coefficients of determination and concordance correlation coefficients ranging from 0.36 to 0.98 and 0.37 to 0.93, respectively. Instances where model performance was less than ideal were associated with conditions presenting a limited number of observed values. Deviations by the model from yield observations were larger for situations with high‐yielding crops and low daily maximum temperatures during vegetative growth stages. Deviations in phenology were larger for conditions associated with water and N stress. APSIM was capable of representing the yield, biomass, and development of cereal and pulse crops and can be used with confidence to assist the expansion of agriculture in tropical environments such as the Northern Territory of Australia. Core Ideas: The accuracy of crop models for environments frequented by challenging weather and soils is rarely reported.We showed that the Agricultural Production Systems Simulator (APSIM) performs well in one such environment, the Northern Territory of Australia.APSIM can be used with confidence in environments with challenging weather and soil conditions. [ABSTRACT FROM AUTHOR]

We study a hypoplastic model for soil and granular materials stemming from geomechanical engineering which further incorporates effects of degradation of the granular hardness, therefore allowing for the description of environmental weathering. The governing system is described by a nonlinear system of transcendental-differential equations for stress and strain rate, which is investigated with respect to its long-time dynamic. Under deviatoric stress control, two different solutions of the underlying, implicit differential equations are constructed analytically. The spherical components of stress and strain rate converge asymptotically to an attractor and lead to the sparsification of material states. Whereas under cyclic loading-unloading carried out in a numerical simulation, finite ratcheting of the deviatoric strain rate is observed in the form of a square spiral. [ABSTRACT FROM AUTHOR]

A comprehensive analysis of outdoor weathering and soil burial of cork during 1-year experiments was carried out with measurements of CIELAB color parameters, cellular observations by scanning electron microscopy, and surface chemical features analysed by ATR-FTIR and wet chemical analysis. Cork applied in outdoor conditions above and below ground retained its physical structure and integrity without signs of deterioration or fracturing. The cellular structure was maintained with some small changes at the one-cell layer at the surface, featuring cellular expansion and minute cell wall fractures. Surface color and chemistry showed distinct results for outdoor exposure and soil burial. The weathered cork surfaces acquired a lighter color while the soil buried cork surfaces became darker. With outdoor weathering, the cork polar solubles increased (13.0% vs. 7.6% o.d. mass) while a substantial decrease of lignin occurred (about 28% of the original lignin was removed) leading to a suberin-enriched cork surface. The chemical impact on lignin is therefore responsible for the surface change towards lighter colors. Soil-burial induced hydrolysis of ester bonds of suberin and xylan, and the lignin-enriched cork surface displayed a dark brown color. FTIR and wet chemical results were consistent. Overall cork showed a considerable structural and physical stability that allows its application in outdoor conditions, namely for building façades or other surfacing applications. Architects and designers should take into account the color dynamics of the cork surfaces. [ABSTRACT FROM AUTHOR]

As the urgency to address climate change intensifies, the exploration of sustainable negative emission technologies becomes imperative. Enhanced weathering (EW) represents an approach by leveraging the natural process of rock weathering to sequester atmospheric carbon dioxide (CO2) in agricultural lands. This review synthesizes current research on EW, focusing on its mechanisms, influencing factors, and pathways for successful integration into agricultural practices. It evaluates key factors such as material suitability, particle size, application rates, soil properties, and climate, which are crucial for optimizing EW's efficacy. The study highlights the multifaceted benefits of EW, including soil fertility improvement, pH regulation, and enhanced water retention, which collectively contribute to increased agricultural productivity and climate change mitigation. Furthermore, the review introduces Monitoring, Reporting, and Verification (MRV) and Carbon Dioxide Removal (CDR) verification frameworks as essential components for assessing and enhancing EW's effectiveness and credibility. By examining the current state of research and proposing avenues for future investigation, this review aims to deepen the understanding of EW's role in sustainable agriculture and climate change mitigation strategies. [ABSTRACT FROM AUTHOR]

We present the first national-scale lead (Pb) isotope maps of Australia based on surface regolith for five isotope ratios, 206Pb/204Pb , 207Pb/204Pb , 208Pb/204Pb , 207Pb/206Pb , and 208Pb/206Pb , determined by single-collector sector field inductively coupled plasma mass spectrometry after an ammonium acetate leach followed by aqua regia digestion. The dataset is underpinned principally by the National Geochemical Survey of Australia (NGSA) archived floodplain sediment samples. We analysed 1219 samples (0–10 cm depth, <2 mm grain size), collected near the outlet of 1119 large catchments covering 5.647×106 km 2 (∼75% of Australia). The samples consist of mixtures of the dominant soils and rocks weathering in their respective catchments (and possibly those upstream) and are therefore assumed to form a reasonable representation of the average isotopic signature of those catchments. This assumption was tested in one of the NGSA catchments, within which 12 similar samples were also taken; results show that the Pb isotope ratios of the NGSA catchment outlet sediment sample are close to the average of the 12 upstream sub-catchment samples. National minimum, median, and maximum values were 15.56, 18.84, and 30.64 for 206Pb/204Pb ; 14.36, 15.69, and 18.01 for 207Pb/204Pb ; 33.56, 38.99, and 48.87 for 208Pb/204Pb ; 0.5880, 0.8318, and 0.9847 for 207Pb/206Pb ; and 1.4149, 2.0665, and 2.3002 for 208Pb/206Pb , respectively. The new dataset was compared with published bedrock and ore Pb isotope data, and it was found to dependably represent crustal elements of various ages from Archaean to Phanerozoic. This suggests that floodplain sediment samples are a suitable proxy for basement and basin geology at this scale, despite various degrees of transport, mixing, and weathering experienced in the regolith environment, locally over protracted periods of time. An example of atmospheric Pb contamination around Port Pirie, South Australia, where a Pb smelter has operated since the 1890s, is shown to illustrate potential environmental applications of this new dataset. Other applications may include elucidating details of Australian crustal evolution and mineralisation-related investigations. The new regolith Pb isotope dataset for Australia is publicly available (Desem et al., 2023; 10.26186/5ea8f6fd3de64). [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the mineral-associated organic carbon (MOC) and its relationship to clay minerals under different temperatures and precipitation. We selected three typical grassland transects in China: Titanium Plate (TP), Mongolian Plate (MP), and Loess Plate (LP) with natural temperature gradients. Along the transect, there is a gradient in the precipitation between the various types of grasslands. The surface soil (0–10 cm) was sampled to determine the MOC. Clay minerals were charactered by X-ray diffraction (XRD). According to the findings, the MOC content increased with decreasing temperature (5.41–14.89 g/kg). MOC had a positive correlation (r = 0.67) with the amount of clay mineral content. In the large-scale study of transects, precipitation masks the effect of temperature change on the MOC to a certain extent. It indirectly affected the MOC content by affecting the mixed-layer illite/smectite (I/Sme) content, and this effect was strongest at the lowest temperature TP (r = −0.73). Except for precipitation, CaO in the soil can affect soil organic carbon (SOC) stability by influencing the pH and I/Sme. The amount of bacteria increased as a result of I/Sme, and the influence of bacteria on the MOC was surpassed only by the soil pH. Climate and clay mineral composition characteristics affected the MOC to a certain extent. Among them, the effect of precipitation change on the MOC is higher than temperature, but it has little effect on soil with a higher weathering degree and CaO content. [ABSTRACT FROM AUTHOR]

Granites, widely distributed in the Earth's crust, undergo pedogenic processes, shaping diverse soil-mantled landscapes influenced by climatic factors in different regions. Investigating the geochemical signatures in granite weathering profiles across varying climatic conditions provides valuable insights into the intricate interplay between weathering and landscape evolution. In this study, the geochemical features, particularly major and rare earth elements, and the weathering degree of granites across temperate to subtropical regions in China were examined. The results indicated significant variations in the geochemical characteristics of granite weathering profiles, both at a pedon and regional scale (p < 0.01). With increasing hydrothermal conditions from north to south, soil pH shifted from neutral to acidic, accompanied by the leaching of major elements (K2O, Na2O, CaO, and MgO) and the enrichment of Al and Fe. The total rare earth elements (∑REEs) ranged from 75 to 352 ppm, and light rare earth elements (LREEs) from 71 to 317 ppm, exhibiting less significant variations across the study area, while heavy rare earth elements (HREEs) showed higher concentrations in the subtropical region (3 to 35 ppm). Plagioclases dominated the weathering process in temperate regions, with K-feldspar progressively increasing and, eventually, dominating from temperate to subtropic regions, resulting in a shift in clay minerals from 2:1-type in the temperate to 1:1-type in the subtropic. The chemical index of alteration (CIA) and comprehensive weathering index (W) increased from fresh rock to residual soils along the weathering profiles and from north to south across the study area, ranging from 50.72 to 97.44 and 35.11 to 70.62, respectively. The intensified granite weathering degree was significantly influenced by climatic conditions (p < 0.05), especially the multi-year average precipitation (22.4%) and relative humidity (9.1%) (p < 0.01). Gully erosion on the granite weathering mantle was concentrated in granites with a comprehensive weathering index exceeding 52.51, and the spatial variation of the granite weathering degree aligned with the spatial distribution of gully density across the study area. [ABSTRACT FROM AUTHOR]