Dataset on the soil properties of Early Iron Age and Medieval archaeological sites in the forest-steppe zone of the East European Plain.

Paleosols are frequently used to recreate past climates. In the forest-steppe zone of the Russian Plain (Lipetsk region, Russia), Early Iron and Middle Ages defensive ramparts' buried soils were discovered. The parent material and similar topographic situations served as the foundation for the comparison of buried and surface soils. Following the dynamics of the landscape from 2500 years ago to the present is possible according to detailed chrono-sequences of soils positioned in similar relief positions and in the same parent material. In this article, an analysis of 8 soils buried at various times is described. The data add to the original research and include detailed morphological descriptions that conform to international standards. Physico-chemical analysis includes determination of pH, organic and carbonate carbon, exchange cations, macro- and microelements. Numerous analytical techniques can be used to investigate issues including the genesis and deterioration of the mollic horizon, the influence of human activity on the production and preservation of Chernozems, and the degree and rate of changes in soil features driven on by climatic changes.

Pedological data for the study of soils developed over a limestone bed in a humid tropical environment.

Lithological characteristics interact with other factors of soil formation to define soil genesis. This becomes more interesting as data on the mineral and elemental oxide components of soils developed from limestone are rarely available in the humid tropical environment. The present study investigated the elemental oxide content, forms of sesquioxides, and clay mineral species in some limestone soils. Soil samples were obtained from three (3) crestal soil profile pits and analyzed for elemental content by the use of an X-ray fluorescence spectrometer, and sesquioxide forms by inductively coupled plasma-mass spectrometer. Analyses were done in triplicates. The mineralogy of the clay fraction was determined on the A, B, and C horizon samples using an X-ray diffraction technique. The occurrence of SiO2 (203-277 g/kg), Al2O3 (65-105 g/kg), and Fe2O3 (14-95 g/kg) in substantial amounts over MnO2, ZrO2, and TiO2 with negligible quantities of CaO suggested comparatively more developed soils in the Agoi Ibami and Mfamosing tropical rainforests. Crystalline form of Fe was dominant over amorphous form, with indications of the co-migration of dithionite Fe with clay to the B horizons of the soils. Quartz, kaolinite, montmorillonite, and chlorite-vermiculite-montmorillonite interlayered minerals dominated the clay mineralogy of the studied soils. Mineral transformation places the soils at the transitory stage from the intermediate to the complete stage of soil development. The expanding clay minerals are most likely to increase plant nutrient adsorption and soil fertility status to accommodate the cultivation of a wider range of crops.

Digital Mapping of Soil Organic Carbon Based on Machine Learning and Regression Kriging.

In the last two decades, machine learning (ML) methods have been widely used in digital soil mapping (DSM), but the regression kriging (RK) model which combines the advantages of the ML and kriging methods has rarely been used in DSM. In addition, due to the limitation of a single-model structure, many ML methods have poor prediction accuracy in undulating terrain areas. In this study, we collected the SOC content of 115 soil samples in a hilly farming area with continuous undulating terrain. According to the theory of soil-forming factors in pedogenesis, we selected 10 topographic indices, 7 vegetation indices, and 2 soil indices as environmental covariates, and according to the law of geographical similarity, we used ML and RK methods to mine the relationship between SOC and environmental covariates to predict the SOC content. Four ensemble models-random forest (RF), Cubist, stochastic gradient boosting (SGB), and Bayesian regularized neural networks (BRNNs)-were used to fit the trend of SOC content, and the simple kriging (SK) method was used to interpolate the residuals of the ensemble models, and then the SOC and residual were superimposed to obtain the RK prediction result. Moreover, the 115 samples were divided into calibration and validation sets at a ratio of 80%, and the tenfold cross-validation method was used to fit the optimal parameters of the model. From the results of four ensemble models: RF performed best in the calibration set (R2c = 0.834) but poorly in the validation set (R2v = 0.362); Cubist had good accuracy and stability in both the calibration and validation sets (R2c = 0.693 and R2v = 0.445); SGB performed poorly (R2c = 0.430 and R2v = 0.336); and BRNN had the lowest accuracy (R2c = 0.323 and R2v = 0.282). The results showed that the R2 of the four RK models in the validation set were 0.718, 0.674, 0.724, and 0.625, respectively. Compared with the ensemble models without superimposed residuals, the prediction accuracy was improved by 0.356, 0.229, 0.388, and 0.343, respectively. In conclusion, Cubist has high prediction accuracy and generalization ability in areas with complex topography, and the RK model can make full use of trends and spatial structural factors that are not easy to mine by ML models, which can effectively improve the prediction accuracy. This provides a reference for soil survey and digital mapping in complex terrain areas.

[Natural soil genesis in red mud and underlying microbial mechanism.] / èµ¤æ³¥è‡ªç„¶æˆåœŸè¿‡ç¨‹åŠå ¶å¾®ç”Ÿç‰©é©±åŠ¨æœºåˆ¶.

Soil genesis is important for ecological restoration of red mud disposal area. Soil genesis of red mud and the microbial mechanism were studied by analyzing the change of physicochemical and biochemical characteristics of red mud. We analyzed the microbial community structure in a red mud disposal area without any human-induced restoration through a space for time substitution approach. The results showed that, with the increases of storage time, the physical parameters of porosity, water-stable aggregates content, and mean weight diameter increased, but the bulk density decreased. The chemical parameters, including pH, electrical conductivity, acid neutralizing capacity, and exchangeable sodium percentage, decreased with increasing storage time. The bio-chemical parameters of total organic carbon, total nitrogen, available phosphorus, microbial biomass carbon and basal respiration increased, but the metabolic quotient decreased. The Shannon diversity index increased, and the dominant microflora in red mud changed from the oxygenic photosynthetic bacteria Cyanobacteria and thanaerobic anoxygenic phototrophic bacteria Chlorobi and Chloroflexi to Proteobacteria, Actinobacteria and Firmicutes. The ratio between eutrophic and oligotrophic bacteria substantially increased. The micromorphology results showed that the microorga-nism-red mud aggregates were formed through adsorption, linkage, intertwinement and package between red mud particles, microbial cells and their metabolites. The red mud biotope changed spontaneously from extreme and oligotrophic into soil-like under natural stockpiling. The soil genesis process was mediated by microbes through increasing nutrient level, decreasing alkalinity and sali-nity, and improving soil structure.

Soils characterization and classification in clean field, dirty field and forest areas in amazonian environments / Caracterização e classificação de solos em área de campo limpo, campo sujo e floresta em ambientes amazônicos

The soil and vegetation characteristics of the southern Amazonas region include highly weathered soils, high aluminum content and some hydromorphic conditions, its vegetation is composed from grasslands to small isolated trees and forest galleries along the rivers streams. In this way, this work aims to characterize and classify the soil in areas of clean field, dirty field, and forest in Humaitá region AM. Soil trenches were opened in the clean field, dirty field, and forest environments, soil profiles were morphologically characterized, and samples were collected from their horizons. Physical analysis of texture, dispersed clay in water, flocculation, bulk density, particle density and porosity were performed. The chemical analyzes included pH and KCl in water; Ca, Mg, K, Al, and; available P; H+Al and organic C; SiO2, Al2O3 and Fe2O3 sulfuric attack. The soils were classified according to criteria established by the Brazilian System of Soil Classification and Soil Taxonomy. The forest, dirty field (high) and clean field (low) showed different soil types, Typic Dystrudept for the first two environments and Typic Fluvaquents for last. Multivariate techniques expressed the similarity relations presenting between the different environments studied, characterizing, which are of great importance in the relation landscape-soil studies.

As características do solo e da vegetação da região sul do Amazonas incluem solos altamente intemperizados, alto teor de alumínio e algumas condições hidromórficas, sendo sua vegetaçãocomposta por pastos, pequenas árvores isoladas e galerias florestais ao longo dos cursos d'água. Desta forma, este trabalho tem como objetivo caracterizar e classificar o solo em áreas de campo limpo, campo sujo e floresta na região de Humaitá AM. As valas foram abertas no campo limpo, no campo sujo e nos ambientesflorestais, os perfis dos solos foram caracterizados morfologicamente e as amostras foram coletadas de seus horizontes. Análises físicas de textura, argila dispersa em água, floculação, densidade do solo, densidade de partículas e porosidade foram realizadas. As análises químicas incluíram pH e KCl em água; Ca, Mg, K, Al e; P disponível; H + Al e C orgânico; Ataque sulfúrico de SiO2, Al2O3 e Fe2O3. Os solos foram classificados de acordo com critérios estabelecidos pelo Sistema Brasileiro de Classificação de Solos e Taxonomia de Solos. A mata, o campo sujo (alto) e o campo limpo (baixo) apresentaram diferentes tipos de solo, distritos típicos para os dois primeiros ambientes e fluídicos típicos para o último. Técnicas multivariadas expressaram as relações de similaridade que se apresentam entre os diferentes ambientes estudados, caracterizando, que são de grande importância na relação paisagem-solo.

Implementación del mapa de geopedología como base para la delimitación de unidades de ecosistemas a nivel nacional en colombia

Geopedología corresponde a la integración entre geomorfología y pedología; es el concepto que se aplica en Colombia, para interpretar la información de los suelos y, a través de ella, generar cartografía temática, que pueda ser representada en diferentes escalas. Una aplicación reciente de la geopedología es la definición del medio pedológico como sustrato, que soporta ecosistemas terrestres y que hace parte del ambiente, debido a que cumple la función de permitir los flujos de energía entre coberturas vegetales y seres vivos. En este artículo, se realiza una reflexión sobre el papel que, históricamente, ha tenido la información de los suelos en el contexto colombiano y su aporte a las ciencias del ambiente; se muestra un desarrollo histórico, que permite analizar cómo se ha integrado la información de suelos realizada en el Instituto Geográfico Agustín Codazzi (IGAC), por más de setenta años y cómo el mejoramiento continuo ha permitido el acercamiento teórico a la delimitación de ecosistemas para dos escalas: la nacional y la general. La ciencia del suelo ha tenido poco reconocimiento en la elaboración de informes recientes relacionados con el ambiente, por ello, es importante que se muestren conceptos y trabajos realizados por expertos en suelos y se divulgue la labor de quienes la desarrollan, así como los resultados obtenidos en la investigación realizada por Progasp, relacionado con el tema de escalas y de representación de variables, que permiten mostrar la realidad ambiental y avance en los procesos que, actualmente, se llevan a cabo en Colombia.

Geopedology corresponds to the integration between geomorphology and soil science and this concept is applied in Colombia to interpret the information of soil for generating thematic maps that can be displayed on different scales; a recent application of the geopedology is the definition of pedological zone as the substrate that supports terrestrial ecosystems and is part of the environment because it serves to allow the energy flows between mulches and living things. This article presents a reflection on the role that historically has had the soils information in the Colombian context and its contribution to environmental science; a historical development is done about soil information to analyze its integration in the Instituto Geográfico Agustín Codazzi (IGAC) for over seventy years and how the continuous improvement has allowed the theoretical approach and the delimitation of ecosystems are close to each other to two scales: national and overall. Soil science has had little recognition in the development of recent reports related to the environment, so it is important that concepts and work done by experts in soils are shown; it is equally important that result obtained in the investigation performed by the research group Progasp, related to the topic of scales and representation of variables which allow display environmental reality and the processes that are advancing in Colombia.

Novel predictors of soil genesis following natural weathering processes of bauxite residues.

Bauxite residue often has chemical and physical limitations to support plant growth, and improving its matrix properties is crucial to support sustainable vegetation in the long term. Spontaneous vegetation colonization on deposits in Central China, over a period of 20 years, has revealed that natural weathering processes may convert bauxite residue to a soil-like medium. Residue samples from different stacking ages were collected to determine the effect of natural processes on matrix properties over time. It was demonstrated that natural processes decreased pH (10.98 to 9.45), electrical conductivity (EC) (3.73 to 0.36 mS/cm), and exchangeable sodium percentage (ESP) (72.51 to 28.99 %), while increasing bulk density (1.91 to 1.39 g/cm(3)), improving the mean weight diameter (MWD) of water-stable aggregates (0.24 to 0.52 mm), and the proportion of >0.25-mm water-stable aggregates (19.91 to 50.73 %). The accumulation of organic carbon and the reduction of ESP and exchangeable Na had positive effects on soil aggregate formation, while exchangeable Ca and Mg were significantly beneficial to aggregation of water-stable aggregates. Climate, stacking time, and biological factors appear to improve the structure of bauxite residue. Our findings demonstrate soil genesis occurring following natural weathering processes of bauxite residues over time.