Aluminum Saturation Research Articles

Evolution of magma compositions and phosphorus availability in early Earth’s crust: New constraints from zircon-melt partitioning experiments

Abstract Zircons are the oldest remaining witnesses of Earth’s near-surface processes, and conditions in the Hadean and Archaean crust are derived predominantly from their trace element and isotopic compositions. However, quantitative assessment of element and isotope partitioning between zircon and melt remains incomplete. We experimentally determined the effect of phosphorus (P) abundance on zircon-melt partition coefficients of Al (DAl), Li (DLi), and P (DP). Results indicate that P content has opposite effects on DAl and DLi, whereas the partitioning of P itself and other trace elements is independent of P abundance. Parametrization of our results yields new assessments of the aluminum saturation index (ASI) and P and Li contents of Hadean magmas. Magma ASI values are ~0.5 lower than previously thought and consistently remain below 1 during the first ~1 Ga of Earth evolution, suggesting involvement of only igneous protoliths. First peraluminous (ASI > 1) melts do not appear until ca. 3.6 Ga, supporting the hypothesis that a transition from a tectonic style dominated by vertical motion to horizontal tectonics accompanied by partial melting of sediments did not occur before that time. New calculated magma Li concentrations for young zircons are in much better agreement with the continental crust Li abundance. Average calculated Archaean and Hadean magma Li concentrations are unrealistically large (>1000 ppm), suggesting that Li in zircons formed before 2 Ga is not primary. Calculated magma P abundances are uniform (~1900 ± 400 ppm) throughout Earth history, suggesting sufficient crustal P was available throughout the Hadean to support the origin of life.

The formation of the granite complex in the Wuhe Mari area of Bayankala Mountain on the northeastern margin of the Tibetan Plateau: constraints from lithogeochemistry and U–Pb zircon dating

The granite complex in the Wuhe Mari area lies in the tectonic magma belt of the North Bayankala Mountains on the northeastern edge of the Qinghai-Tibet Plateau. It is located in the middle of the first member of the Changmahe Formation of the Early and Middle Triassic Bayankala Mountains Group. This article presents a systematic study of the petrological and geochemical characteristics and chronology of porphyrite granilite, monzogranite, porphyritic monzogranite and diorite in the granite complex in Wuhe Mari area. The genetic relationship between these four rock types as well as the type of source area and tectonic environment are clarified. Zircon LA-ICP-MS-U–Pb dating shows that the porphyritic granodiorite, monzogranite, porphyritic monzogranite and diorite have ages of 221.0 ± 2.7 Ma, 219.8 ± 3.0 Ma, 216.6 ± 4.3 Ma and 213.4 ± 1.6 Ma, respectively. The petrogeochemical characteristics show that the porphyritic granodiorite, monzogranite and porphyritic monzogranite in the granite complex have the characteristics of high Si, Al2O3, K, low Na, Ca, Mg, Fe, K, Rb and Th—Content in the strongly incompatible elements of the granite complex have three, the relative loss of Ba, Ta, Nb, Ce, slight enrichment or no anomaly, the loss of Sm, Hf and Zr, the strong loss of Y and Yb and the aluminum saturation index < 1.1. Combined with the geological data all three samples belong to Type I granite formed in the same collision environment. Based on the lithogeochemical characteristics and the results of U–Pb chronology, these three rock formations are believed to have been formed by a series of magmatic melting events and are the result of homologous magma crystallization and differentiation. The diorite forms in an intraplate tectonic setting as a result of the evolution of co-collision granite to intraplate granite.

Characterization of Soils in Coffee Productive Areas in the Provinces of Cocle and Veraguas-Republic of Panama

The objective of the work was to characterize the properties of the soils of coffee-producing farms in the provinces of Cocle and Veraguas that allow the preparation of regionalized fertilization cards according to the edaphoclimatic characteristics of each area. Planting robusta coffee is gaining greater interest among Panamanian farmers as an alternative for soil conservation. On 16 farms in the province of Coclé and 18 in Veraguas, samples were taken (0-20 cm) to understand their properties and initiate a sustainable fertilization program that contributes to improving productivity. Digital maps were created using the Q-Gis v.3.32.1 program and regionalized fertilization cards for each zone. The soils of the province of Coclé presented a high percentage of aluminum saturation, 88% with low porosity problems, average pH of 4.9, low levels of organic matter and phosphorus (100%), and 75% low in potassium. 56% low in calcium. Imbalances were found in the Ca/Mg and Ca + Mg/K ratios, which causes nutritional problems. In Veraguas soils, 22% presented a high percentage of aluminum saturation, 67% average acid pH, 94% low organic matter and phosphorus content, 89% low in potassium, medium and high levels of magnesium and calcium. A positive and statistically significant correlation was found between % clay, organic matter, pH, and calcium. It is expected that this soil characterization and regionalized fertilization cards will contribute to improving soil properties and achieving sustainable production. Fertilization recommendation cards have been prepared for these two provinces and they take into account this entire situation and physical problems found in the soils. Much emphasis is also placed on organic fertilization of plantations as a complement to traditional fertilization, seeking more balanced nutrition.

Soil aluminum saturation threshold for subtropical crops in no-tillage system

Soil aluminum saturation threshold for subtropical crops in no-tillage system

A Comparative Study of Soil Fertility in Organic, Semi-Organic, and Conventional Rice Field Farming Systems (Case Study: Nguntoronadi District, Wonogiri, Indonesia)

The soil fertility of rice fields is closely related to rice crop production. The research aims to identify soil fertility under different rice field farming systems, find the key factor of soil fertility, and recommend strategies to improve soil fertility based on the key factor. The research was conducted in Nguntoronadi District, Indonesia, on conventional, semi-organic, and organic rice fields. The research was an exploratory descriptive survey through a field survey approach and soil chemistry and physics analysis. Soil sampling was conducted in 12 Land Map Units (LMUs) with three replicates using purposive sampling methods. Observation indicators include soil pH, organic C, total N, C/N ratio, available P, available K, exchangeable Ca, exchangeable Mg, Cation Exchangeable Capacity (CEC), Base Saturation (BS), Aluminum saturation, soil texture, and worm population density representing soil chemical, physical, and biological properties. Soil fertility is determined using Principal Component Analysis (PCA) and scoring based on the category. The research results show that the level of soil fertility under various rice field farming systems was included in the moderate with ranges of 0.53-0.70, and organic farming has the highest soil fertility. The key factors of soil fertility include pH, organic C, available P, available K, Ca-dd, CEC, and Aluminum saturation. The appropriate management direction is the addition of organic fertilizer in the planting period.

Indium partitioning between silicate melts and magmatic fluids: implications for indium ore genesis and the tracing of magma degassing

Most of the global indium resources are from deposits associated with felsic rocks. Considering that the indium concentration in the average upper crust is extremely low, magmatic-hydrothermal processes play a critical role in the enrichment and mineralization of indium. However, the extraction efficiency of indium by magmatic fluids remains unclear. We performed experiments at 800 °C, 150 MPa and oxygen fugacity of Ni-NiO buffer to determine the partition coefficient of indium between aqueous fluids and granitic melts (DInf/m). To counteract the rapid loss of indium into the noble metal container wall, the DInf/m were obtained by the method of local equilibrium between microscopic-sized fluid bubbles and surrounding silicate melt. The results show that indium has the highest fluid-melt partition coefficients of all metals investigated so far. At a constant aluminum saturation index (ASI = 1.07–1.12), DInf/m correlates linearly with the total Cl concentration in the coexisting fluid (mCltotal), increasing from 61 ± 11 (1σ) at mCltotal = 1.0 mol/kg H2O to 895 ± 105 (1σ) at mCltotal = 16 mol/kg H2O. When the HCl concentration in the solution increases from 0.13 to 0.49 mol/kg H2O at a fixed mCltotal = 2 mol/kg H2O, DInf/m increases parabolically from 129 ± 21 to 320 ± 24. The observed partitioning data suggest that indium was dominantly present as In(OH)2Cl in the low-HCl and In(OH)Cl2 in high-HCl aqueous fluid at the experimental conditions. Numerical modeling indicates that the extraction efficiency of indium from S-type felsic magmas is very high (>85 %) and magmatic fluids may be the major source of indium for most indium deposits. Due to the high DInf/m values, fluid saturation and exsolution result in a sharp drop of indium concentration in both the residual melt and crystallized minerals, which makes the indium concentration in whole rock and minerals an indicator of fluid exsolution.

The Availability of Soil N, P, K, and Mustard Yield after the Application of Liquid Organic Fertilizer from Household Waste in Ultisols

Ultisols are one of the dominant soil orders in Indonesia, accounting for approximately 25% of the total land area. The main problem of this soil is high aluminum (Al) saturation with low pH and plant nutrients. The study was intended to determine the effect of liquid organic fertilizer (LOF) from household waste on the availability of N, P, K, and mustard yield in Ultisols. The research used a complete randomized design (CRD) with six concentrations of liquid organic fertilizer of household waste. The treatments were repeated four times. The treatment included control, 10, 20, 30,40, and 50 ml LOF in a liter of water. The study revealed that the liquid organic fertilizer from household waste increased 1.06 folds of total soil N and 1.04 folds of exchangeable-K compared to the control but did not affect available P. Also, soil pH was comparable among treatments. The greatest concentration of LOF (50 ml per liter of water) exhibited the highest yield of mustard, indicated by the highest fresh and dry shoot weight. In general, the study contributes to the development of eco-frindly agriculture.

Origin and Geological Implications of Monzogranites and Rhyolitic Porphyries in the Wunugetu Porphyry Copper–Molybdenum Deposit, Northeast China: Evidence from Zircon U-Pb-Hf Isotopes and Whole-Rock Geochemistry

The Wunugetu deposit, a large-scale porphyry copper–molybdenum deposit, is located in the southern Erguna block. Its ore bodies are primarily found within monzogranites, granite porphyries, and biotite monzogranites. Additionally, the deposit contains late-stage intrusive dykes of rhyolitic porphyries. This study examined the deposit’s monzogranites and rhyolitic porphyries using lithogeochemistry, zircon U-Pb dating, and Hf isotopic analysis. The main findings include: (1) Zircon U-Pb dating showed that the monzogranites formed around 209.0 ± 1.0 Ma, whereas the rhyolitic porphyries in the northern portion formed around 170.49 ± 0.81 Ma, suggesting magmatic activity in the deposit spanned from the Late Triassic to the Middle Jurassic. (2) The monzogranites exhibited high silicon content (73.16–80.47 wt.%) and relatively low aluminum content (10.98–14.37 wt.%). They are enriched in alkalis (content: 3.42–10.10 wt.%) and deficient in magnesium and sodium, with aluminum saturation indices (A/CNK) ranging from 1.1 to 2.9. In addition, the monzogranites are enriched in large-ion lithophile elements (LILEs) such as Rb, K, and Ba and deficient in high-field-strength elements (HFSEs) like Nb, P, and Ti. (3) The monzogranites have low Zr + Nb + Ce + Y contents of (151.3–298.6 ppm) × 10−6 and 10,000 × Ga/Al ratios varying between 1.20 and 2.33, suggesting that they are characteristic of I-type granites. (4) Positive zircon εHf(t) values ranging from +0.3 to +7.6 in both rhyolitic porphyry and monzogranite samples, increasing with younger emplacement ages, imply that the deposit’s rocks originated from magmatic mixing between mantle-derived mafic magmas and remelts of the juvenile crust. Considering these results and the regional geological evolution, this study proposes that the Wunugetu deposit was formed in an active continental margin setting and was influenced by the Late Triassic–Middle Jurassic southeastward subduction of the Mongol-Okhotsk Ocean.

Summarizing soil chemical variables into homogeneous management zones – case study in a specialty coffee crop

Homogeneous management zones (HMZs) delineation is important for the application of precision agriculture because farm management decisions are based on it. Diverse soil chemical characteristics are important for the HMZs delineation. However, summarizing several variables into homogeneous zoning while taking into account the spatial distribution pattern of soil chemical characteristics is a challenge. Addressing this challenge is important to produce HMZs oriented for practical use for the farmers. In this work, 17 soil chemical variables were jointly analyzed for HMZ delineation by using indicator kriging (IK) to interpolate a soil fertility index (SFI). Soil samples were taken from a 4.5 ha area in a quasi-regular grid at 0 - 0.20 m depths in November 2019 (66 samples) and May 2021 (40 samples). Soil P, K, Ca, Mg, S, Na, H, Mn, Fe, Zn, B, cation exchange capacity, aluminum saturation, total organic carbon, base saturation, and organic matter were analyzed. In May 2021 the coffee yield was sampled together with the soil. Applying the SFI and then interpolating it using IK were effective for summarizing soil chemical variables into binary HMZs, showing a zone with higher priority for fertilization (therefore, lower general soil fertility) and another zone with low priority for fertilization. The summarizing process of several variables into binary HMZ was validated by evaluating the boxplots of each variable in each HMZ. Also, higher soil fertility areas presented a higher average coffee yield. Results indicated that joint use of SFI and IK was adequate to delineate HMZs in terms of summarizing soil fertility and separating coffee yield average variability. Delineating management zones by using the SFI approach is flexible for relatively limited sampled studies (less than one hundred samples) where machine learning and geostatistical methods may fail for lack of data.

The Role of Peritectic Biotite for the Chemical and Mechanical Differentiation of Felsic Plutonic Rocks (Western Adamello, Italy)

Abstract The volcanic–plutonic connection plays a fundamental role for magmatic systems, linking crystallising plutons, volcanic activity, volatile exsolution and ore deposits. Nonetheless, our understanding of the nature of these links is limited by the scarcity of continuous outcrops exhibiting clear relationships between the plutonic roots that feed its volcanic counterpart. One way to better characterise the volcanic–plutonic connection is to quantify the amount of melt segregation within crystallising tonalitic to granodioritic plutonic rocks, and to compare those with recent silicic eruptions. Here we investigate the processes of interstitial melt segregation in the calc-alkaline Western Adamello pluton (Italy). The Western Adamello tonalite exhibits a coarse-grained, equigranular texture and is mainly composed of hornblende partially replaced by biotite, plagioclase, quartz and alkali feldspar. Within the tonalites, several types of schlieren textures, crystal accumulation zones and dikes are found, comprising: (i) hornblende-biotite-gabbros, spatially related to (ii) plagioclase- and quartz-rich leucotonalites; and (iii) quartz-, albite- and alkali-feldspar-rich domains forming aplitic to pegmatitic dikes indicative of melt segregation and extraction. Hornblende, biotite and plagioclase phenocrysts have essentially the same compositional range in the tonalites, gabbros and leucotonalites. Together with field observations, this indicates that deformation-driven crystal–melt segregation controls the modal variation within the host tonalite. The calculated melt in equilibrium with the primitive amphiboles has the same trace element composition as the host tonalite to within 5% to 10%, indicating that the tonalite did not experience substantial melt loss. Quantitative modal compositions and crystallisation–differentiation calculations suggest that the evolution of the tonalite is controlled by plagioclase and hornblende crystallisation followed by a biotite-forming peritectic reaction. This peritectic reaction can be written as melt1 + amphibole = melt2 + biotite + quartz + plagioclase and decreases the remaining interstitial melt fraction from 40% to 15% in a small temperature interval (~50°C), therefore, reducing the temperature window for large-scale melt segregation. The biotite-forming reaction initiates in weakly corundum-normative compositions in low to intermediate K calc-alkaline differentiation (e.g. Western Adamello and Peninsular Ranges Batholith, California), whereas it seems absent in intermediate to high K, clinopyroxene-normative melts (e.g. Tuolumne Intrusive Suite, California). This difference is likely controlled by the initial aluminium saturation index and the differentiation path of the parental melt within the middle to lower crust. Textural observations and mass balance models indicate that 75% to 88% plagioclase and quartz and 30% to 70% interstitial melt was mechanically removed from the Western Adamello tonalite to form hornblende-biotite-gabbros, whereas the leucotonalites result from the accumulation of 40% to 80% plagioclase and quartz. Of the emplaced 300 to 400 km3 of Western Adamello tonalite, only about 0.8 to 2.4 km3 represent rock types related to physical segregation processes, indicating limited melt extraction. Such crystal–melt segregation processes in tonalitic to granodioritic plutons are observed worldwide and facilitate the extraction of granitic liquids. This mechanism as observed in the Western Adamello tonalite potentially contributes to the accumulation of crystal-poor rhyolites and the segregation of metal-rich brines.

Characterization of Some Selected Soils Based on Fertility Capability Classification. In Madagali Local Government Area of Adamawa State, Nigeria

Characterization of soils using a scientific procedure is essential to assess the potential and constraints of a given land for agricultural purposes. The knowledge of soil limitations arising from land evaluation reports aims to provide practical approaches to ameliorating such limitations before or during the cropping period. This study was conducted to characterize selected soils in Madagali Local Government Area based on fertility capability classification. A reconnaissance soil survey was conducted in the study area. Ten auger point soil samples from each ward were randomly collected at depths of 0-20cm and 20-50cm using a digger, hoe, spade, and polyethylene bag. For each surface and sub-surface, ten samples were collected, making twenty samples representative of each ward. The twenty auger points collected from each ward were taken to the laboratory for analysis. Based on the laboratory results of selected soil properties, the fertility capability classification system classified the soils of Madagali Local Government into one FCC class (LLaedmk) for Hymbula, Gulak, Duhu, Kirchinga, and Palam. The fertility capability classification (FCC) revealed that all the soils in the study area were facing major constraints such as soil moisture stress (d), low organic matter (m), aluminium saturation (a), and low nutrient reserve (k). However, in the studied area, it is necessary to add potassium fertilizers or organic amendments with a significant K content, irrigate for dry-season farming, and add lime to overcome aluminium toxicity.

Petrogenesis and geodynamic implications of the Late Devonian dioritic and granitic intrusive rocks in the Dananhu Belt, Eastern Tianshan Orogenic Belt

The Late Devonian magmatism of the Dananhu arc belt in the Central Asian Orogenic Belt provides a critical geological record. This study provides new comprehensive geochronological, geochemical, and Sr–Nd isotopic data of granodioritic and dioritic intrusions in the Dananhu belt. These findings contribute to unraveling the regional tectonic history and constraining the geodynamic processes involved. Zircon U–Pb dating indicates that the granodiorites and diorites were formed at 382.7 ± 3.8Ma and 363.1 ± 4.3Ma, respectively. The granodiorites show characteristics similar to I-type granites with high SiO2, low MgO and Mg# and aluminium saturation index (<1.1), negligible Eu anomalies, low (K2O + Na2O)/CaO ratios and zircon saturation temperatures (average = 696 °C). Granodiorites also show depleted isotope signatures (εNd(t) = +5.85 to +6.27 and low (87Sr/86Sr)i = 0.704082–0.704583) and juvenile TDM ages (741–793Ma), indicating their origin from a juvenile crust. The diorites are characterized by enrichments in large ion lithophile elements, U and Pb, but depleted in Nb and Ta displaying typical geochemical features of a subduction-related origin, together with high εNd(t) (+6.10 to +6.84) and low initial Sr isotopes (0.703745–0.704601), suggesting that they originated from a subduction fluid modified depleted mantle. The petrogenesis of both granodiorites and diorites in the Dananhu arc provides evidence that they formed through magmatic processes in a subduction tectonic setting. Considering the adakites associated with slab melting from previous studies in the Dananhu arc, it is plausible that the north-dipping subduction of the North Tianshan oceanic lithosphere have contributed to the Dananhu arc magmatism during the Late Devonian.

Influence of Vinasse and Mechanized Harvesting on the Physical and Chemical Aspects of Soil in Paudalho Municipality - PE

Sugarcane cultivation methods and processes usually have negative impacts on the environment. However, this industry has been seeking more sustainable technologies, ranging from the adequate disposal of the organic residues produced to the elimination of pre-harvest burning and introduction of mechanized harvest. The objective of this work was to verify the influence of vinasse application and mechanized harvesting on the physical and chemical aspects of a dystrophic Red Yellow Argisol of medium texture, cultivated with sugarcane. For this, a field experiment in a Completely Randomized Design, with a factorial scheme was conducted. Four management treatments, with three replications, were evaluated: T1 - Without application of vinasse, burned cane followed by manual harvest, without irrigation; T2 - With application of vinasse, mechanized harvest, without irrigation; T3 - With application of vinasse, mechanized harvest, with irrigation; T4 - With application of vinasse, burned cane followed by manual harvest, without irrigation. Soil samples were collected in three depths (0 – 20 cm, 20 – 40 cm and 40 – 60 cm) and soil physical and chemical characteristics were determined. The data obtained were submitted to ANOVA and compared by the Tukey test (p≤0.05) of probability, using the statistical program ASSISTAT 7.7 beta. The results showed that fertigation with vinasse did not influence soil density, particle density, and total porosity. However, mechanized harvesting increased soil density and total porosity. The soil in the experimental unit without vinasse application presented a more acidic pH and high levels of aluminum saturation, causing a decrease in the availability of nutrients, and the soils treated with vinasse had an increase in nutrient availability. Therefore, the addition of vinasse can be an important strategy in maintaining and increasing long-term soil fertility in sugarcane cropping systems.

Investigating patterns in aluminum distribution and stability in mordenite zeolite structure: Analysis and theoretical conclusions from existing experimental data

Building upon our prior theoretical study, this work focuses on determining the position of the seventh, eighth, and ninth aluminum atoms, along with their respective exchange ▪ cations, within the unit cell of mordenite zeolite. The main objective was to identify the positions of these atoms and cations that correspond to the minimum energy state. As a result, the ground state sequence that describes the order in which aluminum atoms enter in the framework as their number increases was completed. Through our investigation, we were able to derive an analytical expression, based on the Madelung energy, which describes the stability of mordenite zeolite as a function of its Si/Al ratio. This expression provides valuable insights, revealing that as the aluminum content within the framework increases, the stability of the zeolite exhibits an asymptotic decrease. It was found that for the mordenite zeolite, Löwenstein's rule is valid for the full range of Si/Al ratios. Interestingly, the restriction that only one aluminum atom can be accommodated per ζ-cage justifies the nature of the aluminum saturation limit (Si/Al=5) in the mordenite zeolite framework. Furthermore, we conducted an evaluation of the aluminum distribution across various configurations and compared it to different experimental observations. This analysis allowed us to make a comprehensive comparison and draw meaningful insights regarding the distribution patterns of aluminum in the mordenite zeolite.

Soil Quality Indicators in Peasant Agroecosystems in Paraíba State, Brazil

Background and Research Aims: Soil quality (SQ) is the basis for the Sustainability of Peasant Farming Systems (PFS). We hypothesized that different land uses modify soil quality through changes that can be analyzed by determining the Soil Quality Index (SQI). Methods: Soil samples were collected from the 0-20 cm layer in five subsystems of peasant agroecosystems located in the municipalities of Solânea (A), Casserengue (B), and Serraria (C). SQI was calculated using non-linear scoring, while a principal component analysis was performed using all data (bulk and particle density, total porosity, particle size, pH, macronutrients, and soil organic carbon) to determine a Minimum Data Set (MDS). Results: The MDS composed of P available, Ca+2, Al+3, sand, silt, H+Al, base saturation (BS%), and the aluminum saturation (AS%) indicate that these parameters can serve as indicators for soil quality assessment in peasant agroecosystems. Sand and silt are related to pedogenic processes and parent material, while the remaining indicators reflect management practices. Land conversion from forest to cropland decreased nutrient availability and soil organic matter in agroecosystems A (Arenosol) and B (Luvisol) and increased the cation exchange capacity in agroecosystem C (Lixisol). Conclusions: All agroecosystems showed low SQI values, highlighting the need to expand conservation practices in the studied agricultural subsystems, especially regarding the increase of soil organic matter. Our results contribute to improving the use and management of soils and the vulnerability assessment in peasant farming, an essential requirement for the sustainability of agroecosystems. Implications for Conservation: Our results also demonstrated that agroforestry practices can significantly increase soil quality and soil carbon sequestration, a viable alternative for maintaining organic matter in areas susceptible to degradation.

Níveis de acidez do solo para recomendação de calagem e aumento de produção da amora-preta

Abstract The objective of this work was to determine the acidity levels to obtain adequate soil chemical attributes for the maximum fruit yield of blackberry trees grown in acidic soils subjected to increasing limestone rates. The BRS Tupy, Brazos, Guarani, and BRS Xavante blackberry cultivars were evaluated on the Typic Hapludox (LVdf) and Rhodic Hapludox (LVd) soils, to which four rates of dolomitic limestone were applied (0, 1.5, 3.0, and 6.0 Mg ha-1). The effect of liming on soil chemical attributes, in a 2×4 factorial arrangement (soils and limestone rates), as well as leaf nutrient content and fruit yield, in a 2×4×4 factorial arrangement (soils, limestone rates, and cultivars), were evaluated. The maximum fruit yield was obtained with 3.3 Mg ha-1 dolomitic limestone. The blackberry cultivars showed a high demand for Ca, Mg, and base saturation and a low tolerance to aluminum in the soils. From 3.3 Mg ha-1 dolomitic limestone, the maximum fruit yield of blackberry trees grown in acidic soils is obtained with pH 5.6, maximum tolerated aluminum saturation of 6%, Ca and Mg concentration of 45.3 mmolc kg-1, and base saturation of 48.3%.

Aplicações de gesso e calcário melhoram a fertilidade do solo sob cultivo de coco na Amazônia Oriental, Brasil

ABSTRACT Gypsum and lime application causes chemical modifications in the soil that influence nutrient content, root growth and development of plants. An experiment was carried out in the municipality of Santa Isabel, Pará state, Brazil, to evaluate the chemical changes in the soil and the responses of green dwarf coconut to gypsum and lime at 6 and 12 months after application. The experimental design was completely randomized blocks, with 4 blocks and 7 treatments: T1 = control; T2 = 2000 kg ha-1 lime; T3 = 500 kg ha-1 gypsum; T4 = 2000 kg ha-1 lime + 300 kg ha-1 gypsum; T5 = 2000 kg ha-1 lime + 500 kg ha-1 gypsum; T6 = 2000 kg ha-1 lime + 700 kg ha-1 gypsum; T7 = 2000 kg ha-1 lime and 1000 kg ha-1 gypsum. After 12 months of applying the treatments, the combination of gypsum and limestone was used to reduce aluminum saturation, with values of 0% at a depth of 0.0-10 cm of the soil, as well as increments in sulfur contents and base saturation of the soil, with values of 70% at a depth of 0.0-10 cm of the soil; with positive effects on macronutrients concentrations in leaf tissue and on root growth. Application of agricultural gypsum, associated with lime, is efficient to improve the chemical attributes of the soil and the development of green dwarf coconut plants.

Petrogenesis and metallogenic significance of late Mesozoic granites in the Akjilga mining area, Tajikistan: constraints from geochronology and geochemistry

The Akjilga (Акджилга) mining area in Tajikistan sits in the central part of the Pamir syntaxis in the western part of the Indo–Eurasia collisional orogenic belt. Recently, the mineralization phenomena of skarn-type tin polymetallic ore bodies and dolomite-type rare-earth metals in the copper polymetallic mining area have been reported. However, the limited knowledge on the genesis of granite and its relationship with mineralization in this area hinders further research. Here, the Late Mesozoic granite rocks in the mining area were studied by petrology, geochemistry, and zircon U–Pb dating. The results showed that the rocks comprise majorly porphyric biotite syenogranite and minorly porphyric biotite monzogranite. The zircon U–Pb age of the porphyric biotite syenogranite was 108.3 ± 2.0 Ma, highlighting the Early Cretaceous period. The porphyric biotite syenogranite features high silicon and potassium contents and low iron, magnesium, calcium, sodium, titanium, and phosphorus contents. Furthermore, their aluminum saturation indexes were 1.11–1.21. Therefore, they were classified as high-potassium calc-alkaline strong peraluminous rocks. Trace-element analysis showed the enrichment of large ionic lithophile elements and light rare-earth elements (REEs); the deficiency of high-field-strength elements and heavy REEs; and the negative anomalies of Nb, P, and Ti. Compared with ordinary granites, the porphyric biotite syenogranite exhibits a higher differentiation index (91.20–93.96) and strong negative Eu anomaly (0.05–0.26), as well as a low Zr content and abnormally low Nb/Ta, Zr/Hf, Y/Ho, ∑LREE/∑HREE ratios. Therefore, the rocks are considered highly differentiated I-type granites with good Sn polymetallic and rare-metal prospecting potentials, and it resulted in the subduction-collision of the Rushan-Pshart ocean between the Middle Pamir block and the South Pamir block during the northward subduction process of the Late Mesozoic New Tethys ocean (Shyok ocean).

Lime microdosing: A new liming strategy for increased productivity in acid soils

AbstractDespite the effectiveness of the fertilizer microdosing technique, lime microdosing (LMD) to alleviate the negative impacts of soil acidity has not been comprehensively assessed. In a 3‐year study at four sites across three countries (one in the United States, two in Ghana, and one in Burkina Faso), we evaluated the effectiveness of the microdosing technique for lime application to alleviate the adverse effects of soil acidity in cropping systems, using corn (Zea mays L.) as the study crop. LMD was evaluated at four lime application rates, including 5%, 10%, 25%, and 50% of the calculated lime‐requirement rate (LR), which was compared to the traditional lime broadcasting strategy using 75% and 100% LR. Averaged across all experimental sites for the duration of the study, LMD with 25% LR resulted in similar grain yield, and nitrogen, phosphorus, and potassium recovery efficiency as those of the traditional lime broadcast techniques with 100% LR, but significantly greater than those of the lime broadcast techniques with 75% LR. Postharvest rhizosphere aluminum saturation percentage of the LMD with 25% LR was similar to that of the traditional lime broadcast techniques with 100% LR. However, LMD with lime application rates lower than 25% LR was not agronomically effective. The combined results suggest that LMD could be an efficient liming technique, and that with this technique, as little lime material as 25% LR could be used to mitigate the negative impacts of Al toxicity associated with soil acidity. Nevertheless, economic analyses are required to determine the profitability of utilizing the LMD technique to mitigate the negative impacts of soil acidity on crop production relative to the traditional lime‐broadcast approach.

Feasibility evaluation of the use of mud residue from marble shop as soil remineralizer

Brazil is a major producer of dimension/ornamental stones, with a great diversity of raw materials. The sawing process transforms 20 to 30% of the extracted block into powder, with the generation of fine waste around 800,000 t/year. An alternative to reusing this waste is its application as a source of nutrients for the soil. This study evaluated the potential use of mud residue from a marble shop located in João Monlevade, Minas Gerais, as a remineralizer, based on fertility, mineralogical and chemical analysis performed by X-ray diffraction and X-ray fluorescence. For fertility, pH in CaCl2 0.01 mol L-1, organic matter, aluminum saturation, potential acidity, sum of bases, cation-exchange capacity, base saturation, macro and micronutrients were determined. The studied residue has free silica, the sum of basis, and K2O content in the range established by MAPA to be certified as a remineralizer. The sample contains 6.7% phyllosilicates, a source of faster K availability, and 19.4% K-feldspar, a slow-release source. Results described in this study indicate that residue can be a promising, efficient, and low-cost alternative to improve soil fertility.