Soil Chemical Analysis Research Articles

Growth, forest floor, and soil chemical analysis comparison between two management practices in chestnut forests of Greece

ABSTRACT The effects of management mode and intensity both on growth parameters (diameter and height of sprouts) and soil fertility were studied in experimental plots in coppice chestnut forests of Athos and Pelion mountains – Greece. The empirical management practice applied in Athos is intensive with a rotation period every 20–22 years, including removal of timber products during selective loggings and final clear-cut loggings. The management type applied in Pelion by the Forest Service is more flexible (much longer rotation period) with remaining in situ of plant residues. The soils of both areas were originated by the same parent material (gneiss), they have loamy texture, similar bulk density values, and they are acidic. Higher values of diameter and height of sprouts were observed in Athos compared to Pelion (statistically significant differences). Pelion soils presented higher levels of soil fertility, i.e., in forest floor higher organic matter and nutrients content (significant differences for P, Ca, Na, Cu, and Mn), and in soil higher levels of N, Ca, Na, Fe, Cu, Zn, Mn and organic matter (significant differences for N, Cu, Mn, and organic matter). The findings of this work could be an important tool to the perspective of chestnut forests management practices.

Ecological-hygienic evaluation of the environment of territories being adjacent to decultivated uranium mines

On the territory of Kazakhstan there are uranium deposits, many ofwhich are in mothballed since times of perestroika. Often, the mines are flooded and represent a “time-delay bomb”. Inside of mines various there are accumulated gases of both organic and inorganic nature, periodically thrown out and adversely affecting on the health of local populations. The aim of the study was the investigation of the state of the environment of Esilsky district of the Akmola region by common pollutants and chemicals. As the basic variable for the investigation of ambient air there was accepted the maximum one-time concentration of suspended substances, phenol, nitrogen dioxide, sulfur dioxide. The results were evaluated in relation to the MPC for the analyzed substance in the air according to maximal single MPC (MPCms) and daily average MPC (MPCda). The content of metals in the water was determined with the use of spectrophotometer PD-303S. Evaluation of the results was executed in relation of the MPC of substances in water, by means of the comparison with the requirements of Federal standards for drinking water, samples from drinking water sources. There were executed calculations of the overall index of water pollution (IWVgen), the index of water pollution by heavy metals (IWVhm). Chemical analysis of soil was carried out with the use of spectrophotometer PD- 303S (Japan), the photometer expert-003 “Ekoniks”. Evaluation of the results was carried out with the respect to the MPC in the soil, the toxicity of all components. Summarizing soil pollution index was evaluated for metals contained in the soil at the level of more than or equal to 1 MAC. The settlement Krasnogorskiy and the village of Kalachi were found to be characterized by a low level of air pollution, increased rigidity of drinking water exceeded the maximum permissible concentrations of copper by 3.45 times and chloride by 1.17 times in the soil cover.

Technical Note: Regression Analysis of Proximal Hyperspectral Data to Predict Soil pH and Olsen P

This work examines two large data sets to demonstrate that hyperspectral proximal devices may be able to measure soil nutrient. One data set has 3189 soil samples from four hill country pastoral farms and the second data set has 883 soil samples taken from a stratified nested grid survey. These were regressed with spectra from a proximal hyperspectral device measured on the same samples. This aim was to obtain wavelengths, which may be proxy indicators for measurements of soil nutrients. Olsen P and pH were regressed with 2150 wave bands between 350 nm and 2500 nm to find wavebands, which were significant indicators. The 100 most significant wavebands for each proxy were used to regress both data sets. The regression equations from the smaller data set were used to predict the values of pH and Olsen P to validate the larger data set. The predictions from the equations from the smaller data set were as good as the regression analyses from the large data set when applied to it. This may mean that, in the future, hyperspectral analysis may be a proxy to soil chemical analysis; or increase the intensity of soil testing by finding markers of fertility cheaply in the field.

Vibrational spectroscopy and Aquaphotomics holistic approach to determine chemical compounds related to sustainability in soil profiles

Advances in laboratory instrumentation and chemometrics provide alternatives to traditional methods of conducting soil chemical analysis. One of these is infrared diffuse reflectance spectroscopy in the near-infrared spectral range. The usefulness of Near Infra-Red Spectroscopy (NIRS), as a nondestructive, quick, and low-cost method to provide scientific expertise on a large scale, has been proved in several fields of applications. Soil samples were collected from alluvial and loess-sampling sites in the North Sardinia, where precipitation, climate, and land use conditions can be very similar. A total of 95 soil samples were collected from three study areas (Berchidda, Arborea, and Ottava). The C and N contents in the soil samples were determined using an elemental analyzer and spectra of soil samples were collected using microNIR 1700 spectrometer. Data processing was carried out using the NIR region of the first water overtone. PLSR applied for calibration of C and N content, allowed the quantitative determination of both elements with good performances. Areas with low Soil Organic Carbon (SOC) can be identified and mapped, thus facilitating the development of both remediation strategies in terms of application of fertilization, environmental protection, and methods for modeling soil properties with great potential for diagnosing the nutrient deficiency and assessing the risk of soil parameters on the environment. The Aquaphotomics approach was able to associate one specific water absorption spectral pattern (WASP) to each studied area, detecting great differences in particular between the Berchidda zone and the other two sampling areas (Arborea, Ottava).

Stabilization of Expansive Soil Using Tire Rubber Powder and Cement Kiln Dust

There are different techniques to stabilize and improve the properties of soils with low shear strength, bearing capacity and other swelling parameters. This study includes the chemical analysis of expansive soils using X-ray diffraction (XRD) and scanning electron microscopy (SEM) before and after the stabilization using tire rubber powder (TRP) and cement kiln dust (CKD) in order to evaluate the geotechnical properties. Test results indicate that the inclusion of CKD-TRP mixture, not only reduces the plasticity of soil but also increases its unconfined compression strength, maximum dry density, and other strength characteristics. Finally, 5% TRP and 10% CKD addition is recommended as an optimum amount from the viewpoint of plasticity and strength characteristics.

Improvement of Egyptian Clover Yield and Quality by Using Bio and Organic Fertilizers in Newly Cultivated Saline Soil

This work was performed at Sahl El-Hossinia Agric. Res. Station, El-Sharkia, Governorate, throughout winter seasons of the year 2016/2017 and 2017/2018 to investigate the foliar application of compost tea humic acid, and bio-fertilizer on forage production, seeds, chemical analysis of plant and soil. Using bio-fertilizer; humic and compost tea on plant increases significantly the clover yield. Humic acid recorded that increased of values for yield, yield components and quality as compared by other treatments. Results pointed that forage yield was affected by whole treatments under saline soil conditions. In general, berseem clover treated with humic acid increased the plant height, fresh, dry yield, seeds yield, weight of 1000 seeds, crude protein, fiber fraction, Total carbohydrate, digestible crude protein of forage yield as compared with control. Values of EC and pH of soil were decline due to various traits using foliar application, while the highest rate of EC in soil run to (5.72 dsm-1) at bio-fertilizer. Values of soil properties treated by whole traits were slightly low comparing control (7.72 dsm-1). It is clear that the minimum total costs were those of application of Bio-fertilizer, being 4570 L.E and the maximum total costs were those of the plants received Compost-t rate which was 5180 L.E. Average over all treatments of total costs were 4847.5 L.E for the two season. The highest value of net return per one invested L.E was achieved when using humic acid (5.40 L.E) and Compost-t (4.15 L.E) compared with N fertilization (control 2.63 L.E).

Benefit of Bed Raising to Manage Acid Sulphate Soil Under Industrial Forest Plantations Area

Industrial Forest Plantations (IFP) are intended to increase the productivity non-productive natural forest production. In South Sumatra Province IFP is widely developed in wetlands; one of them is in acid sulphate soils which have major problems with flooding and waterlogging. To solve this problem, the technology other than making drainage canals is Bed Raising. Bed Raising is to make beds to facilitate the implementation of planting, maintenance and harvesting, in addition to maintaining good soil aeration conditions. However, Bed Raising on acid sulphate soil raises a new problem is pirite oxidation, which affects the chemical properties of acidic sulphate soil. The purpose of this study was to see the benefits of bed raising in the management of acid sulphate land in IFP areas. This study uses survey methods and data are presented in tabulations. The results of this study indicate that the benefits of bed raising in the management of acid sulphate land are no longer flooded or waterlogging. While the results of chemical analysis of soil in bed raising plots are very acidic soil pH (pH 70%), and high pyrite concentration (> 2.4%). This value is not suitable for plant growth.

Physical chemical properties and BCR speciation analysis of cr-contaminated soil in plateau

To explore physical and chemical properties and abundant form of Cr pollution red soil in plateau, study the transition and transform rule of Cr in red soil. In this paper, Cr pollution red soil in plateau as the research object, use the leaching toxicity experiment and BCR(Bureau Community of Reference) three steps extraction method, to study the change of valence state and occurrence form of heavy metal. The result shows that the acid red soil pH value is 6.13, organic matter content is 18.8 g/kg, silt and clay proportion is nearly 50%, 60%, high cation exchange capacity. The carbonate bound state accounted for 30.24% of total species, The Fe-Mn oxidation state accounted for 19.31, the organic matter and sulfide bound state accounted for 29.51%, and the residue state accounted for 20.94%. The result shows that the physical and chemical properties of the red soil in plateau have certain effects on the accumulation migration and transformation of heavy metals.

Physico-Chemical Properties of Volcanic Soils under Different Perennial Plants from Upland Area of Mt. Merapi, Indonesia

Vegetation recovery is essential in land restoration after the eruption of Mount Merapi in 2010. Vegetation i s a source of organic material that produces root exudate containing organic acids. These acids accelerate the dissolution process of volcanic material so that it affects the soil characteristics. This study was conducted to analyze the effect of four types of perennial plants on soil chemical and physical characteristics. The soil samples were taken on the area planted with cinnamon, albizia, bamboo, and acacia, at depths of 0 – 10 cm, 10 – 20 cm, 20 – 30 cm, 30 – 40 cm, and 40 – 50cm. The soil chemical analysis carried out included pH H 2 O, pH KCl, pH NaF, C-organic, Humic acid and Fulvic acid, c ation e xchange c apacity, Ca, Mg, K, Na, available P, base saturation, and particle size distribution. The results show that pH H 2 O, pH KCl, C-organic, humic acid and fulvic acid, CEC, K, Na, Ca, Mg, available P, base saturation, and particle size distribution were significantly affected by vegetation type. Meanwhile, the pH of NaF was not significantly influenced by vegetation type. Cinnamon is a plant that gives the strongest influence in the improvement of soil chemical-physical properties compared to the other three types of vegetation. Therefore cinnamon is quite prospective plant to be developed for post-eruption land reclamation.

Soil Chemical Analysis of Kazi and Kazi Organic Tea Garden and Compared to Ordinary Tea Gardens of Bangladesh

Tea is grown in Bangladesh under marginal climatic and soil conditions. Its production is greatly influenced by many physical, chemical, biological and natural factors. The increasing land use intensity without adequate and balanced use of chemical fertilizers and with little or no use of organic manure has caused severe fertility deterioration of our soils resulting in stagnating or even declining of crop productivity. The need of the hour is to achieve substantially higher crop yield than the present yield levels from our limited land resources on a sustainable basis. A feasibility study was carried out of one and only organic tea garden namely Kazi & Kazi Tea Estate at Panchaghar and compared to ordinary tea gardens located at Sylhet namely Zareen Tea Estate, Nurjahan Tea Estate and Malnichara Tea Estate as secondary data to investigate the fertility status of soil. Results of the present study showed that soil solutions were acidic in nature in all seasons. Medium to high soil organic matter, medium to high available iron and phosphorous, and low availability of potash showed that soils were not sufficiently fertile for crop production. Student t-test values of all the parameters with control sample showed statistically significant results for SOM and available P. The critical values have been fixed at 0.1% for N and 1% for OM, 10 μg/g for P, 80 μg/g for K, 25 μg/g for Mg, 90 μg/g for Ca, 2 μg/g for Zn and 20 μg/g for S. The nutrient status is much higher in Kazi & Kazi organic tea estate in compared to other ordinary tea estates in Bangladesh.

Increasing concentration of deicing salt in soils in the Bavarian Forest National Park

The negative effects of applying deicing salts to ecosystems are well documented for many countries. Most chemical transport from roads occurs in stormwater runoff through or over soil. Runoff pollutants alter soil chemistry, may be absorbed by plants and affect stream ecosystems, where they are dispersed and diluted over considerable distances. There was little detailed knowledge of the effects of deicing salts on ecosystems in the Bavarian Forest NP until 2011, when nine permanent sites were established along the main road in the eastern part of the NP. Soil samples were collected from four of these permanent sites in 2012, 2015 and 2018 and analysed by a certified laboratory. The results of soil chemical analysis were used to compare sites and samples from years 2012, 2015 and 2018. Our research confirmed the increasing concentrations of Na+ and Cl− ions in ecosystems in the Bavarian Forest NP. The highest concentrations of Na+ and Cl− ions were recorded in samples from sites # 4 and 5, which are located only several meters from the bank of the Grosse Ohe River. These concentrations were more than ten times higher than in samples from sites where deicing salt was not used. Amphibians, water insects and other extremely sensitive species and habitats occur in this part of the Bavarian Forest NP and are probably suffering from increasing salinity of their habitats. More research focusing on a better understanding of the spread of deicing salt in the ecosystem together with improving road maintenance technologies are need in order to improve the situation.

Cover crops in arable lands increase functional complementarity and redundancy of bacterial communities

Abstract Reducing the deleterious effects of intensive tillage and fertilization on ecosystem integrity and human health is challenging for sustainable agriculture. The use of cover crops has been advocated as a suitable technique for this purpose, but scientific evidence to support this has been scarce. After four years and a complete rotation, including wheat, maize, and green pea as main crops in a ploughing system, we investigated the respective and combined effects of cover crops and nitrogen fertilization on soil chemical and biological properties using a controlled experiment combining soil chemical analyses, high‐throughput sequencing and community level physiological profiles. Cover crops impeded the soil carbon and nitrogen depletion induced by intensive tillage, not only in the topsoil but also within deeper soil horizons, where more specialized bacterial communities established. Cover crops induced a significant shift in soil bacterial community diversity and composition, which was associated with changes in soil chemical features and bacterial metabolic activities along the entire soil profile. Cover crops enhanced soil resilience to nitrogen fertilization by increasing functional redundancy and complementarity within soil bacterial communities and across soil horizons. Synthesis and applications. In the ploughing systems commonly used for intensive agriculture in Western Europe, the use of cover crops fosters a high functional diversity among soil bacteria and thus can help to achieve a more sustainable agriculture by reducing nitrogen fertilization while maintaining yields.

Modeling in the Adjustment of Fertilization Recommendation through Leaf Analysis in Fertigated ‘Prata’ Banana

ABSTRACT: In banana cultivation, fertilization recommendations are almost exclusively based on soil chemical analysis, without considering leaf analysis and expected yield, which can help in the adjustment of fertilization programs. The aim of this study was to develop a method to recommend macronutrient fertilization rates which integrates data on leaf analysis, soil chemical analysis, and yield. Yield, soil chemical analysis, and leaf analysis data of fertigated plantations of ‘Prata’ banana were obtained for the first and second halves of the years from 2010 to 2015. Yield was correlated with soil organic matter (SOM) and soil contents of macronutrients (P, K, Ca, and Mg) to obtain the critical level (CLNui). Then, leaf nutrient contents were plotted on a dispersion graph as a function of soil contents using the method of Quadrant Diagram of the Plant-Soil Relationship (QDpsR). Based on leaf analysis, recommended rates were simulated for four plots and compared with rates recommended by other methods. The values of CLNui obtained were 13.2 g dm−3for SOM; 97.5 and 91.5 mg dm−3for P and K; and 2.71 and 0.61 cmolc dm−3for Ca2+and Mg2+. The rates recommended based on leaf analysis diverged from the recommendations of Ferticalc®-Bananeira and the Recommendation Table for Banana Fertilization; in plots for which recommendations were made, there were higher rates of P2O5 and Ca and lower rates of K2O. However, in most cases, applications were not recommended, either because contents in leaves and soil were adequate or because yield was being limited by non-nutritional factors or, if nutritional, related to other nutrient(s). Leaf analysis satisfactorily adjusts the recommended rates of nutrients and has advantages if incorporated in nutritional balance models.

Evaluation of Water Erosion in Sugarcane Crops Using Erosion Plots and Photo Comparison Technics

The objective of this study was to evaluate processes of water erosion in sugarcane crops using experimental plots and photo comparison technics. Soil losses were quantified in four erosion monitoring plots located in two watersheds in the center-east region of the state of São Paulo, Brazil. Soil physical and chemical analysis were performed, and precipitation and slope data were collected. These data were analyzed together with soil vegetation cover indexes obtained from the classification of digital photographs. Photo comparison and classification methods were used to follow the sugarcane crop development, and quantify and qualify the soil cover. The physical and chemical characteristics of the soils caused lower vegetation development and greater soil susceptibility to erosive processes. The management of the sugarcane crops evaluated were inadequate; physical and slope limitations of the soils that compose the landscapes were not considered. Sugarcane areas are expanding in the state of São Paulo, and the months with higher rainfall rates coincide with the periods in which this crop is not covering the soil, thus, adopting adequate soil management practices, and land use planning is necessary.

Impact of crop-livestock-forest integration on soil quality

Integrated agricultural production systems with trees, grain crops and forage species are important for land use optimization. However, they can result in non-uniform changes in physical and chemical soil properties. The objective of this work was to evaluate chemical and physical soil properties in a eucalyptus-based agroforestry system. The experiment was conducted in a Red–Yellow Argisol in Southeast Brazil. Eucalyptus (Eucalyptus grandis × E. camoldulensis) seedlings were planted in rows 12.0 m apart, and 2.0 m between plants. For 4 years the inter-row space was cropped to soybeans (Glycine max L. Merrill), Sunn hemp (Crotalaria juncea) and maize (Zea mays L.) in association with palisade grass (Urochloa brizantha). After that, the forage was grazed by beef cattle. Five years after the implementation of the experiment, chemical and physical soil analyses were performed along the profile. Non-uniform changes were observed in fertility and soil physics in the transect between the eucalyptus planting lines, both at the soil surface layers and in depth. Integrated crop/livestock production systems, where eucalyptus is intercropped with annual crops and forage grasses for grazing, results in lower soil fertility near tree lines and up to 100 cm deep over time. Next to the tree line there is an increase in soil compaction and reduced aggregate stability in the uppermost soil layer, while microporosity and soil structuring are increased in the soil deeper layers. These effects are probably due to animal trampling under the trees.

SALT AND CARBONATE REGIMES OF SOUTHERN C HERNOZEM IN THE DRIP IRRIGATION CONDITIONS

Problem Statement and Purpose. Drip irrigation is used more widely for cultivation of agricultural crops in the Steppe of Ukraine. Influence of this method of moisture supply on the southern chernozems and patterns of their salt and carbonate regimes in condition of drip irrigation by first class water stays insufficiently studied. Accordingly to this the purpose of the study is the estimate of influence of long-term drip irrigation on salt and carbonate regimes of southern chernozems, their essence and direction of change and fertility in irrigational conditions.Data&Methods. Physical and chemical analyses of soils and irrigational water were made in order to certified standard methods and mobile calcium was defined using Drueeno-Gale method. Research was conducted on the territory of agricultural firm “Dobra Gorodyna ”, Bilyayivka district of Odesa region.Results.Vue results of research of drip irrigation influence on the chemical composition and chernozems properties show that the applying of the drip irrigation method to vegetables led to certain degradation agio-meliorative condition in chernozems and high variability of their fertility indicators. The salt regime of southern chernozems in drip irrigation conditions is characterized with a tendency of increasing of salts in arable and sub-plow horizons. The greatest differences in chernozems salt content, which are irrigated in drip method, are noted till 70 cm depth and then they are leveled. The tendency to decrease of the relation of absorbed Ca2+: Na+ and increasing of relation Na++ K+ with the sum of absorbed cations are visible throughout the soil profile. The top part of chernozem profile is lixiviated because of calcium carbonates and their active forms during vegetative and irrigational period. The condition of chernozem does not restore under spring barley during two vegetative season without irrigation. The differences in salt composition of soil profile maintain without irrigation during two years under barley. In arable horizon of this chernozems the differences of salinity persists and the content of sulfates and sodium stays little more heightened. The level of possible irrigational salt content of arable layer stays on the verge of weak ones. Under the barley the profile allocation of active calcium restores to initial values whereas general carbonate content stays a little bit lower.

Fertility Assessment of a Farm Soil (Ferrosol) Located in Toowoomba, Queensland

A series of analyses and bio-essays were conducted on a Ferrosol collected in Toowoomba (Queensland) to assess its nutrient status and suitability for cereal cropping. The aim was to reveal its nutrient deficiencies or sufficiency and make sound fertilizer recommendations for cereal cropping. An omission trial was first run followed by Phosphorus rate and adsorption trials. Omission and rate trials were conducted on pots with maize as a test plant. Besides, soil chemical analyses were carried out. Results of these analyses revealed that the soil was deficient in key micro- and macro-nutrients and that it exhibited a high P-fixing capacity. This latter property is manageable with addition of organic amendments. The following report presents and discusses these results.

Эколого-геохимическое обоснование возможности переработки породных отвалов угольных шахт луганщины

Objective: To justify ecologically and geochemically rock dump processability of the Luhansk region coal mine for obtaining metals. Methods: The common methods of chemical and physicochemical analysis of debris, soil and vegetation samples as well as the valuation methods of ecological situation were applied. Results: The research data on migration of heavy metals to soils contiguous to dump and in the “soilplant” system were presented. The type of ecological situation when heavy metals pollute vegetation was established. The main cause of heavy metals migration is in the processes of chemical and biochemical oxidation of sulfide minerals being a part of stock debris as well as the processes of sulfuric acid formation. It was shown that debris contained a large number of metals with ferrous oxide, aluminum and silicon prevailing. While the debris of coal mines could be regarded as lean aluminum raw material. Practical importance: It was suggested to use natural processes for the formation of sulfuric acid in debris for the purpose of biochemical oxidation of aluminum as the main method of reducing the environmental impact and rational use of natural resources.

Determination of predominant soluble salts in soils of the irrigation district Alto Chicamocha of Boyacá

El distrito de riego y drenaje del Alto Chicamocha (DRACH por sus siglas en español), es la principal unidad de producción agropecuaria del departamento de Boyacá, Colombia, abarca un área de 8016,78 hectáreas y debido a las condiciones naturales y al manejo que se le ha venido dando a la cuenca alta del Río Chicamocha, la salinización ha sido reconocida como limitante. Por lo anterior se buscó determinar las sales solubles predominantes en los suelos que comprenden el DRACH. Con base en la información de análisis químicos de suelos de 301 muestras, obtenidas de estudios realizados por el GISSAT-UPTC y Corpoica, se determinó C.E, pH, aniones y cationes presentes en el suelo. Para el análisis espacial de las variables estudiadas se usó el sofware ArcGis 10.3. Se colectaron 31 muestras de agua en pozos de la red freatimétrica para realizar la caracterización química del agua. Se encontró que el 48,01% de los suelos del distrito eran no salinos, el 22,93% ligeramente salino, el 14,74% moderadamente salino y salinos el 14,33%. Las principales sales solubles en el suelo fueron el Na2SO4, Ca2SO4, NaCl2 y CaCl2, las cuales están relacionadas con el origen lacustre y la presencia de termales en la región. Las zonas con mayor riesgo de salinización se presentan en los municipios de Tibasosa, veredas Patrocinio, Ucaca, las Vueltas; en Santa Rosa de Viterbo en la vereda Salitre; en Duitama en las veredas Cebadero e Higueras con C.E. mayores a 2,00 dS m-1.

Mineralogy, magnetic susceptibility and geochemistry of Fe-rich Oxisols developed from several parent materials

Fe-rich Oxisols on mafic rocks in Brazil generally have high magnetic susceptibility with high contents of some trace elements. These are taxonomically similar soils; however, differences in magnetic and geochemical properties may affect agricultural or environmental usability and subsequent management. This study investigated the pedogenesis of Fe-rich Oxisols from various parent materials and evaluated the lithogenetic influence on magnetic susceptibility and trace elements contents. Soil samples were collected from Bw horizons in 13 Rhodic Oxisols and a Typic Oxisol developed from several parent materials in Minas Gerais State, Brazil. Soils were analyzed by X-ray diffractometry (XRD) and magnetometry. Soil chemical analyses consisted of sulfuric and total (tri-acid) digestions and selective Fe oxides dissolutions and statistical correlations were determined. Fe-rich Oxisols presented a typical mineralogical composition of highly weathered soils with structural stability. The results confirm the difficulty to identify accurately magnetic minerals in different grain sizes using XRD. However, coarse fractions still exert dominant influence on the magnetic properties of the Fe-rich Rhodic Oxisols. In addition, coarse fractions probably contribute to the enrichment of superparamagnetic particles for the clay fraction. Although highly weathered, Fe-rich Oxisols may have their geochemical attributes still controlled by the parent material, where trace elements seem to be correlated with the magnetic minerals in the coarse fractions. Thus, the natural replacement of some trace elements from soil-solution equilibrium reactions during plant development could be more effective in soils with higher magnetic particles concentrations in the coarse fractions.