Residual Mineral Research Articles

Use of in termediate winter, post-harvest and early spring green crops to improve the ecological and food security of the country

The article considers the prospects for the introduction of intermediate winter, post-harvest and early spring green manure plants as green fertilizers in the structure of sown areas of agricultural enterprises of the Kyrgyz Republic, conducting irrigated agriculture. The studies of intermediate winter, post-harvest and early spring green manure plants tested in Kyrgyzstan are relevant and are of theoretical and practical interest for the country's agro-industrial complex and serve to fully ensure food security of the country. Thus, fresh phytomasses of stubble green manure in the soil leave 165.07-343.61 kg/ha of nitrogen, 12.57-24.71 kg/ha of phosphorus and 105.43-237.28 kg/ha of potassium, which create a positive balance of nutrients - nitrogen, phosphorus, potassium and act as green fertilizers. The supply of fresh plant masses of winter, post-harvest and early spring intermediate crops of green manure plants does not occupy additional arable land and is an economically and environmentally beneficial innovative agricultural technology. Fresh green mass of the studied intermediate green manure crops has narrow carbon to nitrogen ratios and provides an increase in the biological activity of the soil and promotes faster mineralization of plant residues in the soil, since the consortium of soil microorganisms actively responds to the fresh supply of green fertilizers, improving the ecology of soils, which is accompanied by a positive restructuring of the microbial consortium and its functional activity. An increase in the microbiological activity of soils is accompanied by replenishment of soil organic matter and the release of easily digestible forms of nutrients, which serve to increase the yield of agricultural crops. It is advisable to place intermediate winter, post-harvest and early spring green manure crops in fields where row crops (potatoes, vegetables, beans, sugar beets, etc.) are repeatedly or monoculturally cultivated. They introduce plant diversity into the structure of crop areas, which improves the phytosanitary condition of irrigated arable land, and also enriches the soil with fresh phytomass and can stop the degradation of soil fertility of irrigated arable land, which is observed everywhere today. The introduction of winter, stubble and early spring intermediate green manure plants into the structure of crop areas of agricultural enterprises in the Kyrgyz Republic meets the requirements of organic farming for obtaining environmentally friendly products of agrocenoses and the sowing areas of intermediate green manure should be increased everywhere.

Hydrological dynamics following partial removal of an oil well pad undergoing restoration to a boreal peatland

Many peatlands on the North American Western Boreal Plain have been disturbed by industry, including through the construction of thousands of oil well pads. The introduction of fen mosses onto residual mineral well pads following their partial removal has been proposed as a novel technique to restore these sites. However, it has remained unclear whether this would support the requisite hydrological conditions for fen moss establishment. To assess this, a field study of hydrological function at a partially removed pad undergoing restoration near Slave Lake, Alberta, Canada was undertaken. Specifically, the hydrophysical properties of the residual fill and adjacent peatland (including hydraulic conductivity, bulk density, and porosity) were characterized, and related to subsurface flow and water table regulation within the partially removed pad and adjacent peatland. The results demonstrate that flow through the peatland was disrupted by the low saturated hydraulic conductivity of the residual fill (1.15 × 10−5 m s−1) and the compacted underlying peat (4.91 × 10−6 m s−1), resulting in preferential flow around the pad. On the residual pad, hydrological connectivity with the adjacent peatland resulted in a well-regulated, near-surface water table across nearly half of its surface area. However, limitations on subsurface flow through the pad footprint resulted in variable hydrological dynamics across much of its interior. These findings suggest that partially removed well pads have the potential to support requisite hydrological conditions for fen moss establishment, but further development of the technique should be undertaken to improve subsurface hydrological connectivity with adjacent peatlands.

Cysteine-Facilitated Cr(VI) reduction by Fe(II/III)-bearing phyllosilicates: Enhancement from In-Situ Fe(II) generation

Structural Fe in phyllosilicates represents a crucial and potentially renewable reservoir of electron equivalents for contaminants reduction in aquatic and soil systems. However, it remains unclear how in-situ modification of Fe redox states within Fe-bearing phyllosilicates, induced by electron shuttles such as naturally occurring organics, influences the fate of contaminants. Herein, this study investigated the processes and mechanism of Cr(VI) reduction on two typical Fe(II/III)-bearing phyllosilicates, biotite and chlorite, in the presence of cysteine (Cys) at circumneutral pH. The experimental results demonstrated that Cys markedly enhanced the rate and extent of Cr(VI) reduction by biotite/chlorite, likely because of the formation of Cr(V)-organic complexes and consequent electron transfer from Cys to Cr(V). The concomitant production of non-structural Fe(II) (including aqueous Fe(II), surface bound Fe(II), and Cys-Fe(II) complex) cascaded transferring electrons from Cys to surface Fe(III), which further contributed to Cr(VI) reduction. Notably, structural Fe(II) in phyllosilicates also facilitated Cr(VI) reduction by mediating electron transfer from Cys to structural Fe(III) and then to edge-sorbed Cr(VI). 57Fe Mössbauer analysis revealed that cis-coordinated Fe(II) in biotite and chlorite exhibits higher reductivity compared to trans-coordinated Fe(II). The Cr end-products were insoluble Cr(III)-organic complex and sub-nanometer Cr2O3/Cr(OH)3, associated with residual minerals as micro-aggregates. These findings highlight the significance of in-situ produced Fe(II) from Fe(II/III)-bearing phyllosilicates in the cycling of redox-sensitive contaminants in the environment.

Extraction and Characterization of Chitosan from Snail Shells (Achatina fulica)

Background: Chitosan due to biodegradable and non-toxic characteristics has versatile applications. Extraction and characterization of Chitosan from Snail Shells In January, 2023 Achatina fulica was performed. Methods: A chemical process involving demineralization and deproteinization was utilized to extract 2000g Chitin from Achatina fulica shells. To produce chitosan, the chitin was subjected to deacetylation. The chitosan was subsequently characterized using Fourier Transform Infrared spectroscopy, X-ray diffraction, and Scanning Electron Microscopy. The physicochemical charactristics and mineral compositionswere investigated and the data were analyzed using the Statistical Package for Social Sciences (SPSS) software version 20.0. Results: The chitosan obtained from the process was 75%. It exhibited a Degree Of Deacetylation of 82.31%, a molecular weight of 2.65×105 g/mol, an intrinsic viscosity of 1,007.2 mg/g, and a solubility of 70%. The pH value of chitosan in acetic acid solution was recorded at 6.38, with a solubility of 70%. The proximate analysis revealed moisture, ash, fat, protein, crude fiber, and carbohydrate contents of 0.32, 0.72, 2.01, 0.13, 0.15, and 96.67%, respectively.The mineral analysis revealed sodium, potassium, calcium, magnesium, phosphorus, iron, and zinc concentrations of 32.10, 21.80, 721, 288.60, 123.75, 41.77, and 8.48 mg/g, respectively. X-ray diffraction analysis identified the region characterized by the presence of calcite and calcium phosphate, indicating residual minerals in the extracted chitosan, which contribute to its crystalline structure. Fourier Transform Infrared spectroscopy demonstrated functional groups such as amino and hydroxyl groups, whereas Scanning Electron Microscopy reported an irregular particle size with rough surfaces and a microfibrillar crystalline structure. Conclusion: The current investigation has the potential to promote the sustainable use of a locally abundant yet underutilized resource, assisting in waste reduction and creation of innovative bioactive materials which could be applied in food preservation, pharmaceuticals, and medical devices.

Low N2O emissions induced by root-derived residues compared to aboveground residues of red clover or grass mixed into soil

The default The Intergovernmental Panel on Climate Change (IPCC) guidelines assume a constant N2O emission factor (EFN2O) for both belowground crop residues (BGR) and aboveground residues (AGR), and that ∼70 % of total N2O emissions following renewal of temporary grasslands come from BGR. However, empirical evidence is lacking, which motivated this study. BGR-free and BGR-rich clay loam collected in grass or red clover leys were incubated alone or mixed with AGR and different doses of nitrate over 107 days. The average EFN2O of BGR was around 18 % of that of AGR, and remained low even when soil nitrate concentration was very high, whereas EFN2O of AGR varied largely and rocketed even with a small increase in soil nitrate. The decomposition of the carbon present in crop residues was critical for N2O emissions. Lower EFN2O of BGR relative to AGR were related to slower C decomposition, which was not predicted by the biochemical characteristics. It is also likely that BGR were less conducive than AGR to develop into hotspots for N2O emission because of the roots’ finer distribution and closer contact with soil particles. Differences in EFN2O among AGR were mostly linked to the availability of N, either derived from residue mineralization or present in the soil. In conclusion, N2O accountings based on present IPCC default methodology likely overestimate the contribution by crops’ BGR.

Impact of winter coverage crops and nitrogen fertilization on soil respiration and nitrogen mineralization in no-tillage systems

Microbiological activity in soil is crucially important to maintaining soil quality. Soil is sensitive to management practices, and microbiological activity plays a crucial role in processes like transforming organic N into inorganic fractions. The objective of this study was to assess how winter coverage crop residues influence soil respiratory activity and N mineralization during successive corn crop developments under a no-tillage regime. We employed a randomized block experimental design with subdivided plots and three replications. The main plots comprised various coverage crops (Black Oats, Ryegrass, Rye, White Lupin, Common vetch, Turnip, consortia of Oats + Vetch and Oats + Vetch + Turnip, while subplots received doses of N-mineral (0 and 180 kg ha-1) during the corn growth stage. We evaluated the respiratory activity of microorganisms and levels of inorganic N in the soil throughout the corn crop cycle. The consortia of coverage crops exhibited distinct responses in respiratory rates, with Oats + Vetch having superior results compared to Oats + Vetch + Turnip. We observed positive responses in nitric N (N-NO3-) due to the mineralization of common vetch residues within the first fifteen Days After Sowing (DAS). However, N-mineral doses from nitrogen fertilization during the corn coverage age phase did not alter the respiratory of the microorganisms nor did it alter the concentrations of N-NH4+ in the soil. Mineral fertilization resulted in the immediate availability of N in the form of N-NO3-.

Physical and chemical characterization of chitin and chitosan extracted under different treatments from black soldier fly

The shell of Hermetia illucens L. contains considerable amounts of chitin, which has various biological activities. So far, few studies have focused on chitin of Hermetia illucens L. as a source of chitosan and oligosaccharides. There is great potential for utilizing Hermetia illucens L. chitin to produce chitosan films in biomaterials. We studied different extraction conditions for chitin and extracted it from black soldier fly (BSF) (Hermetia illucens L.). Three processing steps were adopted: (1) demineralization, (2) deproteinization, and (3) decolorization. The chemical components (moisture, ash, protein, fat, residual protein, and residual mineral contents) and physicochemical characteristics of the chitin and chitosan extracted under these three conditions were determined. In addition, Fourier transform infrared spectroscopy and X-ray diffraction were used to analyze the extracted chitin and commercial samples, and the results showed that demineralization–deproteinization–decolorization treatments could achieve the highest chitin yield (7.18 ± 0.11 %), chitosan yield (64.22 ± 0.79 %), and the best purity (residual protein 0.56 ± 0.01 % and residual ash 0.58 ± 0.04 %), making it the best treatment method. Using this method, the residues produced from farmed BSF can be recycled and used as a new source of chitin.

Enhanced mineralization of pharmaceutical residues at circumneutral pH by heterogeneous electro-Fenton-like process with Cu/C catalyst

Conventional electro-Fenton (EF) process at acidic pH ∼3 is recognized as a highly effective strategy to degrade organic pollutants; however, homogeneous metal catalysts cannot be employed in more alkaline media. To overcome this limitation, pyrolytic derivatives from metal-organic frameworks (MOFs) have emerged as promising heterogeneous catalysts. Cu-based MOFs were prepared using trimesic acid as the organic ligand and different pyrolysis conditions, yielding a set of nano-Cu/C catalysts that were analyzed by conventional methods. Among them, XPS revealed the surface of the Cu/C-A2-Ar/H2 catalyst was slightly oxidized to Cu(I) and, combined with XRD and HRTEM data, it can be concluded that the catalyst presents a core-shell structure where metallic copper is embedded in a carbon layer. The antihistamine diphenhydramine (DPH), spiked into either synthetic Na2SO4 solutions or actual urban wastewater, was treated in an undivided electrolytic cell equipped with a DSA-Cl2 anode and a commercial air-diffusion cathode able to electrogenerate H2O2. Using Cu/C as suspended catalyst, DPH was completely degraded in both media at pH 6–8, outperforming the EF process with Fe2+ catalyst at pH 3 in terms of degradation rate and mineralization degree thanks to the absence of refractory Fe(III)-carboxylate complexes that typically decelerate the TOC abatement. From the by-products detected by GC/MS, a reaction sequence for DPH mineralization is proposed.

Physical and numerical simulation of heat and mass transfer in the furnace of a thermogravimetric analyzer

A numerical study of the processes of heat and mass transfer in the furnace of a thermogravimetric analyzer was carried out, aimed at improving the accuracy of determining the kinetic characteristics of samples during their thermal transformations in different media. Validation of the model and prognostic estimates were carried out in relation to specially conducted thermogravimetric studies of the conversion of fossil and renewable carbon-containing raw materials in successive processes of decarbonization (combustion) and carbonation (mineralization of ash residue). The application of the study results allows to calculate the actual concentrations of the reagent over the sample uncontrolled by the device during pulsed switching of media and the actual temperatures of the sample during its thermochemical transformations.

Cyclicity of katatectic layers in anhydrite caprocks, U.S. Gulf Coastal Region

ABSTRACT An anhydrite caprock overlies 65% of the 329 onshore salt stocks of the U.S. Gulf Coastal Region, south-central U.S. The caprock consists of a succession of katatectic (downward-building) layers of anhydrite (typically 1–4 cm thick) each overlain by an upper, black pyrite lamina (∼ 0.1 mm thick). The older (upper) katatectic layers are usually highly deformed. During four stages, these fundamental layers formed at the crest of shallow (< 1,200 m) salt stocks. Repetition of sets of the stages resulted in the cyclicity. The closed stage A flush, nearly planar contact separated mature anhydrite caprock from an underlying salt-stock crest. As the diapir elevated by a few mm/yr, it arched the caprock; it also opened conduits at the stock’s uppermost anhydrite sheath, allowing NaCl-undersaturated water from outside the diapir to contact the salt stock. The open-dynamic stage: Along the perimeter of the uppermost salt stock, a narrow, annular halite cave advanced inward and upward directly below the slightly convex base of the anhydrite caprock. The most NaCl-aggressive water rose by free convection to the highest elevations and dissolved halite. The dense, solute-enhanced water then reversed direction and, again, by free convection, flowed past the stock’s margin into country rock; NaCl-undersaturated water replaced the departing brine. A water-filled, commonly ring-shaped, planar cave up to several meters high expanded over the stock’s crest. Sparse physical supports, buoyancy, arched caprock, and high artesian water pressure prevented the cave’s collapse. The cave’s halite floor dissolved vertically downward faster than it moved diapirically upward. As the crestal halite dissolved, a small amount of residual pyrite and, typically, a layer up to ∼ 10 cm thick of residual anhydrite (generally 3–8 wt % of the stocks) accumulated on the cave floor. The open-static stage: The persistent “attack” of halite highs by the NaCl-undersaturated water eventually caused the slope of the cave’s floor to approach horizontality. The density-driven flow slowed markedly, and a static cover of NaCl-saturated brine thwarted the dissolution of the halite floor. The downward movement of the cave’s floor reversed, and it moved slowly upward via diapirism. Concurrently, an anhydrite sheath evolved around the uppermost stock. The accretionary stage The cave closed in a few thousand years, and active diapirism underplated the admixed residual minerals onto the base of the caprock. The uppermost, now compact, residual anhydrite dissolved in the high-pressure environment, leaving the discrete, topmost, thin, black pyrite lamina. With the accretion of the residual minerals, a katatectic layer formed at the base of a succession of such layers. The closed stage recurred, and a new katatectic cycle began forming. Variations of the four genetic stages probably occurred during the formation of anhydrite caprocks in other worldwide salt-dome provinces, but because of insufficient data, they are usually unrecognizable.

Heavy magnesium isotopic signatures in arc lavas may be attributed to dehydration of subducting hydrated mantle

Fluids released from subducting slabs profoundly affect mantle composition, rock melting points, and arc magma generation. However, identifying fluid sources (sediments, crust, or mantle) and their ascent paths remains challenging. Magnesium isotopes are potential tracers for subduction-related fluids, though their behavior during hydrous peridotite dehydration remains unclear. Here we determined the equilibrium magnesium isotope fractionation factors between aqueous fluids and hydrous peridotitic minerals using first-principles calculations. Aqueous fluids prefer heavy magnesium isotopes relative to mantle silicate minerals, indicating that fluids released during hydrous peridotite dehydration are enriched in heavy magnesium isotopes relative to the residual minerals. Our simulations proposed that magnesium isotope variations in arc lavas from different subduction zones could be attributed to different dehydration reactions influenced by subduction zone thermal structures. This study highlights the potential of magnesium isotopes for tracing fluids originating from subducting hydrated mantle, providing insights into the thermal structure of various subduction zones.

Role of minerals in regulating the mineralization of cover crop residue and native organic matter and the community and necromass of microbes in flooded paddy soils

Role of minerals in regulating the mineralization of cover crop residue and native organic matter and the community and necromass of microbes in flooded paddy soils

Adsorption Efficiency of Cadmium (II) by Different Alkali-Activated Materials.

The objective of this study was to demonstrate the potential utilization of fly ash (FA), wood ash (WA), and metakaolin (MK) in developing new alkali-activated materials (AAMs) for the removal of cadmium ions from waste water. The synthesis of AAMs involved the dissolution of solid precursors, FA, WA, and MK, by a liquid activator (Na2SiO3 and NaOH). In concentrated solutions of the activator, the formation of an aluminosilicate gel structure occurred. DRIFT spectroscopy of the AAMs indicated main vibration bands between 1036 cm-1 and 996 cm-1, corresponding to Si-O-Si/Si-O-Al bands. Shifting vibration bands were seen at 1028 cm-1 to 1021 cm-1, indicating that the Si-O-Si/Si-O-Al bond is elongating, and the bond angle is decreasing. Based on the X-ray diffraction results, alkali-activated samples consist of an amorphous phase and residual mineral phases. The characteristic "hump" of an amorphous phase in the range from 20 to 40° 2θ was observed in FA and in all AWAFA samples. By the XRD patterns of the AAMs obtained by the activation of a solid three-component system, a new crystalline phase, gehlenite, was identified. The efficiency of AAMs in removing cadmium ions from aqueous solutions was tested under various conditions. The highest values of adsorption capacity, 64.76 mg/g (AWAFA6), 67.02 mg/g (AWAFAMK6), and 72.84 mg/g mg/g (AWAMK6), were obtained for materials activated with a 6 M NaOH solution in the alkali activator. The Langmuir adsorption isotherm and pseudo-second kinetic order provided the best fit for all investigated AAMs.

Unraveling Parent Rock and Mineral Influences in Tropical Weathering Profiles: REE, Nd and Sr Isotopic Geochemistry

This study aims to investigate the effects of parent rock and minerals on lateritic weathering. The study presents X-ray diffraction (XRD), whole-rock geochemistry, and Nd-Sr isotopic data for examining two profiles, 10 and 12 m thick, respectively, that illustrate the regional tropical weathering status in the Midwest of Brazil. The profiles, developed from metasedimentary and sedimentary rocks, are constituted by saprolite, mottled horizon, lateritic duricrust, and oxisol. Across the profiles, the minerals controlling the weathering geochemistry are muscovite, microcline, quartz, kaolinite, hematite, goethite, and gibbsite. Red and yellow zones in the saprolite and mottled horizon as well as the lateritic duricrust with breccia/fragmental, pisolitic, and oolitic textures make profile 1 more complex. In contrast, profile 2 has an oxisol that mantles the homogeneous vermiform lateritic duricrust. Fe2O3, accumulated during surface weathering, is a potent element in the geochemical profile control since it forms the harder goethite to hematite lateritic duricrust, bearing most of the trace elements (As, Cu, Cs, Pb, Sc, Sr, Th, U, V, and Zn) with similar ionic radii and electrovalence. The LREE have affinity for the elements of the Fe2O3 group of the lateritic duricrust. On the other hand, the K2O group together with Zr and TiO2 e in the phyllite, saprolite, and mottled horizon of profile 1, are associated with the HREE. Additionally, in profile 2, the HREE are mostly associated with the Al2O3 group and the residual minerals in the oxisol. The indication that REE is associated with phosphates, zircon, rutile/anatase, cereanite, and muscovite/illite, which have variable weathering behavior, caused the REE fractionation to occur across and between the profiles. Despite the REE fractionation, the ƐNd(0) values along the profiles consistently maintain the signature of the parent rock. Muscovite and microcline weathering, in profiles 1 and 2, respectively, control the decrease in 87Sr/86Sr signatures of both profiles and the distinct radiogenic ratios. The development of lateritic duricrust in both profiles indicates a similar weathering intensity, although the gibbsite–kaolinite predominance in the oxisol of profile 2 highlights a geochemical reorganization under humid conditions, as well as near-intense soluble silica leaching.

Formation of the nutrient regime of gray forest soil under different anthropogenic pressure in Forest-Steppe agrosystems

The purpose of the research is to establish the effectiveness of the use of alternative sources of organic fertilizers in short-rotation grain crop rotations, the influence of the volume of by-products and root residues in combination with the application of mineral fertilizers on the formation of the nutritional regime of gray forest soil. To analyze the impact of different crop rotations saturated with leguminous and grain ear crops on the amount of plant biomass input as an alternative organic fertilizer, to determine the effectiveness of the complex application of by-products and mineral fertilizers. Methods. Research methods are field, laboratory, measuring-weighing, comparative-calculating. The research was carried out in the conditions of the Forest Steppe of Ukraine in a long-term stationary experiment of the Department of Soil Tillage and Segetal Vegetation Control of the NSC «IZ NAAN» on gray forest soil in two short-rotational crop rotations. Results. Based on the results of the research, data were obtained on the influence of different tillage systems, the use of plant by-products in the organo-mineral fertilization system of short-rotation crops on the change in the nutrient regime of gray forest light loamy soil. The level of supply of nutrients in the crop rotation depended on the method of the main tillage, the yield level of the crops of the crop rotation, the amount of plant residues and the content of the main nutrients in them. It was noted that with the long-term use of tillage, the active and loosened 0–10 cm layer of the soil is the most saturated with nutrients, both due to the mineralization of crop residues and due to the localization of the main part of the applied mineral fertilizers, while the lower, 10–40 cm layer was characterized by low security level. Conclusions. Earning by-products of crops by carrying out shelf cultivation of the soil, both in 4 and in 5 field crop rotations, contributes to the differentiation of the 0-40 cm soil layer by the content of humus and biogenic nutrients. With the combined use of by-products with mineral fertilizers, the differentiation of the treated soil layer is more pronounced, which led to an increase in the productivity of crop rotations. The use of leaf-stem mass and root residues of corn as an organic fertilizer has a significant effect on improving soil fertility, due to which the largest reserves of humus are formed in 0-40 cm of soil and recirculation of nutrients occurs.

Restoration of soil fertility and improvement of phytosanitary condition of soil in short rotation of crops in Polissia of Ukraine

With the intensification of agricultural land use and changes in natural conditions, soil quality in Ukraine is deteriorating, with a decrease in humus content, the average annual loss of which is about 0.6 t/ha. Therefore, its reproduction is now becoming increasingly important through the use of organic raw materials and the introduction of legumes into the crop rotation, which leads to a partial replacement of nitrogen from mineral fertilisers with biological nitrogen. The purpose of this study was to find ways to provide the topsoil with organic residues, develop soil microflora, and improve the activity of nitrogen-fixing bacteria in a short grain legume crop rotation. The study was conducted in 2019-2023 using the following methods: visual – to determine the stages of organogenesis; field – to determine the interaction of abiotic factors; physiological – to determine the symbiotic fixation of atmospheric nitrogen. It was found that due to mineralisation of organic residues of legume crop rotation, the amount of macro- and microelements in the soil layers 0-10 cm, 10-20 cm, and 20-30 cm increased by 45.1-46.9-43.1 mg/kg, respectively. It was found that saturation of short crop rotation by 50% with legumes, straw residues, and green manure contributed to the reduction of pathogenic microorganisms and the growth of suppressive ones. It was found that in a short rotation of crops, 10.3 t/ha of organic matter in the form of stubble and root residues, straw and green manure enters the soil, which contributed to the cultivation of environmentally friendly agricultural products with the restoration of soil fertility. The biological activity of the soil during the growing season in the layer of 10-20 cm reached 47.4%, and the content of alkaline hydrolysed nitrogen in the rhizosphere of the root system increased by 43.9 mg/kg. The value of the study lies in the fact that the introduction of short organic crop rotations in farms of various forms of ownership is an innovative approach to providing light grey soils with organic raw materials, restoring and maintaining their fertility, improving their phytosanitary condition, promoting biodiversity, achieving environmental sustainability and high yields

Maize productivity and nutrient status in response to crop residue mineralization with beneficial microbes under various tillage practices

The sustainable intensification of agriculture has become a paramount concern in ensuring global food security on a sustainable basis. Crop residue (CR) management plays a pivotal role in this context, as it influences soil health, nutrients cycling, and overall crop productivity. However, information about the intricate relationship between beneficial microbes (BM), crop residue mineralization, and maize production under various tillage systems is limited. Therefore, we conducted field trials over two years (2018 and 2019) to assess the availability of nutrients and maize yield in response to CR placed at different soil depths with and without BM application. The study consisted of three tillage implements [field cultivator (FC), mouldboard plough (MBP) and chisel plough (CP)], four N augmented CR [no residue (Ro), wheat residue (Rw), chickpea residue (Rc), and Rw+Rc] and two levels of beneficial microbes [BMw -With 250 L BM ton−1 of CR and BMo-without BM]. An in-situ mini litterbag experiment using the CR with and without BM placed up to soil depth of 15, 30, and 45 cm, corresponding to three tillage systems in nylon bags was also performed for C and N decomposition. The field experiment was carried out in randomized complete block design (RCBD) with split plot arrangement having four replications. Tillage implements were allotted to main plots while CR and BM were allotted to sub plots. However, the litterbag study was performed using RCB design. A total of 160 kg N ha−1 was derived as 50% each from CR and urea. The Rc increased the soil mineral N (25.37 and 23.84%) and decreased the SOC (34.45 and 40.56%) over the Rw in soil sampled at maize sowing and harvesting stages, respectively. Similarly, the BM improved the soil mineral N after sowing and/or harvesting stages. The MBP had 13.9% higher grain yield than FC. The Rc had resulted in more ear m−2 (7.2), grains ear−1 (442), 1000 grain weight (319.28 g), and grain yield (8993 kg ha−1) of maize than other CR treatments. Structural equation modelling suggested that dry matter was directly affected by growth contributing components and negatively affected by crop phenological observations. In conclusion, the chickpea crop residues decomposed faster with the addition of BM (BMw) under MBP with improved maize grain yield.

Leaves, Infusion, and Grounds-A Three-Stage Assessment of Element Content in Yerba Mate (Ilex paraguariensis) Based on the Dynamic Extraction and Mineralization of Residues.

The more yerba mate infusions that are consumed, the larger the amount of grounds generated. What is more, both the infusion and the residues after brewing remain rich elements. Therefore, a strategy for the three-stage assessment of the element content was presented. A new brewing method was based on dynamic extraction, ensuring both the ease of preparing the infusion and recovering the grounds. In turn, microwave-assisted acid mineralization was used to decompose the leaves and twigs of yerba mate before and after brewing. In total, 30 products were analyzed by ICP OES in three fractions each, i.e., dry yerba mate, infusion, and grounds, to determine up to 25 elements. The elemental composition was considered in terms of the country of origin, type, or composition of yerba mate. The extraction percentages obtained with dynamic extraction were comparable to previously used ultrasound-assisted extraction, as well as data from the literature. The three-stage strategy is a novel approach in yerba mate studies, and it may be a model procedure for the laboratory preparation of yerba mate grounds (waste that can be re-used, e.g., a natural fertilizer).

Influence of hydro-cycloning, kiln and spray drying on the rheological properties of bentonite clays

Over the years, uncontrolled exploitation of bentonite clays in Boa Vista - PB has resulted in the exhaustion fat clay varieties. Bentonites with a high percentage of residual minerals - contaminants such as quartz - which negatively influence the rheological properties of the dispersions are the current norm. In order to obtain samples with rheological values that meet Petrobras standard EP-1EP-00011-A, this study recommends concentrating dispersions of the less fatty clays through a hydrocycloning, kiln and spray drying operation. Thus, prepared dispersions of two compositions of Bofe, Chocolate, Verde-Lodo and Chocobofe clays, with 4wt.% concentrations, were selected by experimental design to be concentrated through hydrocycloning. The concentrates were kiln and spray dried in two drying configurations. The results proved the efficacy of hydrocycloning and spray drying operations on these mixtures, with remarkable improvements in the rheological properties. Also, there was an increase in the quartz fraction in all wastes and a decrease in the clay mineral concentrates.

Characteristics of REE enrichments in the weathered granitic crust, Toboali, South Bangka: Possibility for ion adsorption‐type REE mineralization

AbstractThis study investigates the characteristics and fractionation of rare earth elements (REEs) in the weathered products of granite from South Bangka, Indonesia. Samples were collected from two drill holes (TBKP‐30 and TBKP‐38) at depths ranging from 0.5 to 18 m. Analytical methods, including X‐ray diffraction (XRD), X‐ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP‐MS), and scanning electron microscopy (SEM‐EDS), were used to examine mineral compositions and REE distribution. The parent granite is an S‐type biotite granite with total REE concentrations between 1081 and 1279 ppm. The dominant REE‐bearing minerals are REE‐fluorocarbonates (synchysite, parisite) and REE‐phosphates (apatite, monazite, xenotime), accompanied by REE‐silicates (allanite, thorite, zircon). Fluorocarbonates (synchysite, parisite) occur filling grain boundaries of the parental granite, suggesting later overprinting. Monazite, xenotime, and zircon were identified as part of the crystal lattice of residual minerals in both weathered profiles. TBKP‐30, has significantly depleted in REEs with high intensity degree of weathering and the occurrence of gibbsite minerals. TBKP‐38, has cerium enrichment in the lower profile, caused by the fixation into cerianite and/or it is incorporation with Fe‐Mn hydr(oxides) along with the occurrence of kaolinite minerals. This study highlights the patterns of REE enrichment as a potential indicator of weathering intensity, providing insights crucial for the exploration of REE deposits and the development of sustainable extraction methods.