Search Results (24)

Nitrogen (N) is the most widely used nutrient in agriculture in the form of urea, yet it is one of the least efficient in terms of application due to losses through volatilization and leaching. The combination of urea with micronutrient sources, especially in the form of nanoparticles, is a promising technology for reducing these losses. Two greenhouse experiments were conducted with the objective of evaluating the influence of coating urea with zinc oxide nanoparticles (NPZnO) and iron oxide nanoparticles (NPFe₂O₃), associated with elemental sulfur (S°), on the leaching of mineral nitrogen and the production of dry mass and accumulation of N in young corn plants. The coating (0.26% w/w) of urea with elemental sulfur (S°) and NPZnO and NPFe₂O₃ reduced N losses through leaching (−21.3%) and delayed the nitrification process of N in the soil (−71.8%). This coating increased the efficiency of nitrogen fertilization in young corn plants, boosting the production of dry mass in leaves (+39.4%), stems (+68.8%), and roots (+61.6%), as well as the absorption of N in the above-ground biomass (+64.1%), compared to conventional urea. The use of urea coated with NPZnO and NPFe₂O₃ associated with S° is an environmentally sound solution for supplying N and micronutrients such as Fe and Zn in a more efficient and sustainable manner, especially in sandy soils with low organic matter content, which are common in the semi-arid region of Brazil. Full article

Efficient nutrient management is vital to sustaining rice production in the sandy soils of Northeast Thailand, where zinc (Zn) deficiency and low organic matter often constrain yield. This study evaluated the effects of Zn fertilization on the growth, yield, and Zn use efficiency (ZUE) of rice (Oryza sativa L. cv. Chai Nat 1) grown under greenhouse conditions in contrasting soil textures (loamy sand and clay). Four Zn rates were applied: 0, 5, 10, and 15 kg ZnSO₄·7H₂O ha⁻¹ (0, 0.013, 0.026, and 0.039 g ZnSO₄·7H₂O pot⁻¹). Clay soil, with higher organic matter, nitrogen, and available Zn, supported greater vegetative growth, biomass, and yield than loamy sand. Zinc fertilization significantly increased plant height, tiller number, chlorophyll content, biomass, panicle number, grain number, and filled grain weight. Yield improvement in loamy sand was associated mainly with reproductive efficiency, whereas in clay it was driven by vegetative vigor, biomass accumulation, and Zn uptake. Thousand-grain weight was not affected by Zn. ZUE peaked at 5 kg ha⁻¹ in loamy sand and 10 kg ha⁻¹ in clay, with clay showing a greater overall increase in ZUE across Zn rates and loamy sand exhibiting diminishing returns at higher application rates, reflecting differences in Zn availability and retention capacity. Correlation, PCA, and SEM analyses confirmed soil-specific yield mechanisms. Overall, Zn fertilization improved rice productivity and tissue Zn concentration, with optimal rates differing by soil texture. These findings highlight the importance of site-specific Zn management in enhancing yield, nutrient efficiency, and biofortification in rice-based systems of Northeast Thailand. Full article

Fungal endophytes can be identified in a wide range of plant species which help to protect from both abiotic and biotic stressors. This research focused on using high-throughput sequencing (HTS) analysis to gain insight into the foliar endophytic fungal diversity between Morinda tinctoria and Pithecellobium dulce. The study obtained a total of 118,547 sequencing reads, which were grouped into 266 Operational Taxonomic Units (OTUs) with a 97% similarity threshold. M. tinctoria had more OTUs than P. dulce. Alpha diversity results show that both plant species support varied microbial communities with similar but distinct biodiversity profiles. The Shannon index revealed that M. tinctoria had considerably more fungal diversity than P. dulce. The correlation matrix and PCoA depicts the pairwise correlations between several soil metrics such as the total nitrogen level, entire phosphorus, overall potassium, and the electrical conductivity, total carbon from organic matter, pH levels, manganese, iron, zinc, copper, and boron. The OTUs were classified into 5 phyla, 18 classes, 40 orders, 70 families, and 36 genera, where the phylum Ascomycota has a relative abundance of (50–55%), followed by Basidiomycota at (55–60%). The most abundant genera were Wallemia (30–35%), Saitozyma (30–40%), and Talaromyces (20–25%), with average relative abundances. Unassigned genera show a significant proportion of fungal taxa that are still taxonomically unclear. A comparative analysis has been performed between the two plants, M. tinctoria has a higher fungal diversity, which is frequently associated with increased ecological stability, disease resistance, and better functional relationships with the host plant. Full article

Water quality management is crucial for sustainable whiteleg shrimp (Litopenaeus vannamei) aquaculture, though little research has comprehensively investigated the spatiotemporal fluctuation of trace elements in tropical semi-intensive ponds. This study investigated the water quality variations and trace element concentrations in an earthen pond across a 56-day culture cycle during the dry season. Physicochemical parameters (temperature, pH, salinity, dissolved oxygen, ammonia, nitrite, and nitrate) and trace elements (Cu, Zn, Mn, Fe, and Mg) were measured concurrently with shrimp growth and survival. The DO and pH readings were observed to fluctuate significantly during the mid-to-late stages of culture, with DO nearing critical thresholds (<5.0 mg L⁻¹). A sudden increase in ammonia and nitrite levels suggested the accumulation of organic matter and a microbial imbalance. Zinc concentrations (0.28–1.00 mg L⁻¹) approached stress-inducing levels, while magnesium remained low (10.44–10.72 mg L⁻¹). Pearson’s correlation revealed strong positive associations between ammonia and nitrate (r = 0.95) and between DO and pH (r = 0.94), while Mg was negatively correlated with Fe (r = −0.99) and nitrite (r = −0.88). Shrimp achieved 13.43 ± 0.73 g mean weight, with 77.8% survival and an FCR of 1.08. These results provide baseline evidence that combined water quality and trace element monitoring can become an early warning framework for pond management. Future studies integrating shrimp physiology and immune responses are needed to establish direct causal relationships. Full article

Microelement deficiencies, often termed “hidden hunger”, represent a significant global health challenge. Optimal human health relies on adequate dietary intake of essential microelements, including selenium (Se), zinc (Zn), copper (Cu), boron (B), manganese (Mn), molybdenum (Mo), iron (Fe), nickel (Ni), and chlorine (Cl). In recent years, there has been a growing focus on vitality and longevity, which are closely associated with the sufficient intake of essential microelements. This review focuses on these nine elements, whose bioavailability in the food chain is critically determined by their geochemical behavior in soils. There is a necessity for an understanding of the sources, soil–plant transfer, and plant uptake mechanisms of these microelements, with particular emphasis on the influence of key soil properties, including pH, redox potential, organic matter content, and mineral composition. There is a dual challenge of microelement deficiencies in agricultural soils, leading to inadequate crop accumulation, and the potential for localized toxicities arising from anthropogenic inputs or geogenic enrichment. A promising solution to microelement deficiencies in crops is biofortification, which enhances nutrient content in food by improving soil and plant uptake. This strategy includes agronomic methods (e.g., fertilization, soil amendments) and genetic approaches (e.g., marker-assisted selection, genetic engineering) to boost microelement density in edible tissues. Moreover, emphasizing the need for advanced predictive modeling techniques, such as ensemble learning-based digital soil mapping, enhances regional soil microelement management. Integrating machine learning with digital covariates improves spatial prediction accuracy, optimizes soil fertility management, and supports sustainable agriculture. Given the rising global population and the consequent pressures on agricultural production, a comprehensive understanding of microelement dynamics in the soil–plant system is essential for developing sustainable strategies to mitigate deficiencies and ensure food and nutritional security. This review specifically focuses on the bioavailability of these nine essential microelements (Se, Zn, Cu, B, Mn, Mo, Fe, Ni, and Cl), examining the soil–plant transfer mechanisms and their ultimate implications for human health within the soil–plant–human system. The selection of these nine microelements for this review is based on their recognized dual importance: they are not only essential for various plant metabolic functions, but also play a critical role in human nutrition, with widespread deficiencies reported globally in diverse populations and agricultural systems. While other elements, such as cobalt (Co) and iodine (I), are vital for health, Co is primarily required by nitrogen-fixing microorganisms rather than directly by all plants, and the main pathway for iodine intake is often marine-based rather than soil-to-crop. Full article

The high concentration of arsenic in coal does great harm to the environment. It is important to research the occurrence mode of As in coal to promote the removal of As in coal and understand the migration and transformation of As in coal. In this work, eleven samples from the Hanshuiquan coal mine, in the Santanghu Coalfield, were tested by X-ray diffraction (XRD) and Scanning Electron Microscopy with an Energy Dispersive Spectrometer (SEM-EDS). The results show that maximum arsenic content in the coal seam was 108.37 μg/g, which was 13 times more than that of the world coal, and 28 times more than that of the Chinese coal. Through X-ray diffraction (XRD) experiments, ojuelaite and scorodite were found in the samples. Scanning Electron Microscopy (SEM) and an Energy Dispersive Spectrometer (EDS) were used to determine the occurrence location of the arsenic elements. In combination with geochemistry and mineralogy theory, the occurrence modes of the arsenic were studied in detail. The occurrence modes of arsenic in coal from the study area are dominated by sulfide-bound arsenic. At the same time, it was found that arsenic in the study area might occur in the form of arsenate containing zinc and organic bound arsenic. Previous studies and this work have shown that (1) arsenic in coal is predominantly in the form of pyrite, and (2) arsenic in coal is associated with organic matter in low-rank coal and to a lesser extent in high-rank coal. Understanding the occurrence modes of arsenic in coal is of great significance because it has significant impacts on coal mining, preparation, combustion, and utilization, and has adverse effects on the environment and human health. Full article

Background: Stachys alpina is a medicinal plant from the Lamiaceae family whose biological potential remains poorly explored. Methods: The aim of this study was to comprehensively assess the pol-yphenol profile, macro- and microelement composition, and the antioxidant, an-ti-diabetic, and anti-obesity activities of various plant organs (leaves, flowers, stems, and roots). Results: The leaves and flowers exhibited the highest concentration of phenolic compounds, while anthocyanins were detected exclusively in the flowers (215.05 mg/100 g dry matter (dm)) and constituted 3% of the total polyphenols. Verbas-coside and chlorogenic acid were the most abundant polyphenols, reaching 4618.88 and 3277.83 mg/ 100 g dm in the leaves. The highest ABTS and FRAP scavenging activity was observed in leaves (19.30 and 7.62 mmol TE/g dm, respectively). Principal component analysis demonstrated a strong correlation between polyphenol content and antioxidant activity (ABTS-r= 0.87 and FRAP-r = 0.90), which was further confirmed by Pearson’s correlation coefficients. The study also highlighted the significant impact of mineral composition on biological activity—calcium and magnesium dominated in stems (10,100 and 3900 mg/kg) and in roots (9200 and 3100 mg/kg), supporting the functioning of an-tioxidant enzymes, while zinc and manganese in leaves (89.43 and 155.33 mg/kg) con-tributed to intense metabolic processes. Conclusions: S. aplina could serve as a valuable source of natural antioxidants and enzyme inhibitors associated with glucose and lipid metabolism, suggesting its promising application in the prevention and management of metabolic disorders.. Full article

From the point of view of farming utilization, investigations on the recognition of the mineral composition of sedges appears important, appropriate and useful. Sedges are often found in many meadow and pasture communities. It is therefore worth paying attention to the mineral content of their tissues and their possible impact on the organisms of farm animals such as pigs. The basic objective of this study was to determine the concentration of selected macro and microelements: phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), silicon (Si), copper (Cu), zinc (Zn), chrome (Cr) and nickel (Ni) in the biomass of seven sedge species, potentially used as fodder, commonly occurring in natural sites in Central Europe. The material was collected twice during one growing season in the Krześniczka (N 52°37′14′ E 14°46′06′)—lubuskie voivodeship. The first harvest was carried out at the beginning of May, during the shooting and earring phase. The collected plant material included stems and leaves. The second harvest—the end of June—was collected at a time when the seedlings were developing flowers and young fruits, and their vegetative organs were developing dynamically. In June, the collected material represented organs in all possible development phases. The collected material was dried at a temperature of 65 °C, ground, and analyzed. The obtained results showed a difference in the content of microelements between the May and June harvest dates in the dry matter of all analyzed sedge species, which differed statistically significantly only in relation to copper. The harvest date had a statistically significant impact on the change in the content of macroelements in the dry matter of all analyzed sedge species and was associated with a decrease in the content of phosphorus, magnesium and calcium, while in the case of silicon, the delay in mowing resulted in an increase in the content of this element. Full article

The Nevşehir coals are located in the Central Anatolian Crystalline Complex (CACC), Türkiye, and no reports exist on trace element, nitrogen, and carbon isotope composition data of the Nevşehir coals. The present study aims to geochemically characterise the Nevşehir coals to determine their trace elemental enrichment patterns and possible sources. Nevşehir coals are found within Late Miocene Kızılöz Formation (Arafa Member) rocks. These coals are part of the huminite maceral group; the dominant maceral group is ulminites. The minerals in coals are inorganic, such as oxidised framboidal pyrite, iron oxide minerals, quartz, clay, and carbonate minerals. Coals have great potential regarding trace elements. Benefits might arise from mining and using some of the critical elements derived from coal. Compared with the world coal average, the coal samples in this study are enriched in As (149.25 μg/g), V (245 μg/g), Cr (159 μg/g), Ga (18 μg/g), Ni (216 μg/g), Th (17 μg/g), Zn (143 μg/g), and U (54 μg/g). The arsenic content in this study is associated with inorganic components such as oxidised framboidal pyrite. Vanadium in coal is mainly associated with aluminosilicates and organic matter. Chromium originates from the clay minerals within coals. Uranium in coal is mainly associated with organic matter. Nickel and zinc in coal are predominantly associated with sulphides. The δ¹⁵N contents of the samples are comparable to those of several references, including plants, terrestrial creatures, and organic nitrogen. The δ¹³C–δ¹⁵N isotopic range and average values for four coal samples ranged from −25.66‰ to −25.91‰ (−25.80‰) and 3.6‰ to 4.3‰ (3.9‰), respectively, demonstrating that C3 type modern terrestrial vegetation was common in the palaeomires of the studied coal seams. Full article

Cadmium (Cd) is a naturally occurring element often associated with lead (Pb) in the Earth’s crust, particularly in karst regions, posing significant safety hazards for locally grown rice. Identifying the key factors controlling Cd and Pb content in local rice is essential under the natural soil condition, as this will provide a crucial theoretical foundation for implementing security intervention measures within the local rice-growing industry. This study collected three types of paddy field soils with varying Cd concentrations from karst areas for pot experiments. The rice varieties tested included a low-Cd-accumulating variety, a high-Cd-accumulating variety, and a locally cultivated variety. Soil physicochemical properties and plant physiological indices were monitored throughout the rice growth stages. These data were used to construct a segmented regression model of Cd and Pb levels in rice grains based on the plant’s metabolic pathways and the structure of polynomial regression equations. Stepwise regression identified the key factors controlling Cd and Pb accumulation in rice grains. In conclusion, the key factors controlling Cd and Pb levels in rice grains should be classified into two categories: (i) factors influencing accumulation in roots and (ii) factors regulating transport from roots to grains. The aboveground translocation abilities for Cd, Pb, zinc (Zn), iron (Fe), manganese (Mn), calcium (Ca), and magnesium (Mg) in soil among the three rice varieties showed no significant interspecific differences under identical soil conditions. Soil Mg uptake by rice roots may represent a key mechanism for inhibiting soil Cd uptake by rice roots. In karst areas with high background soil Cd, increased soil organic matter (SOM) levels enhance Pb bioavailability. Additionally, the rice YXY may possess a potential for low Cd accumulation. Full article

Zinc is an essential element for plant nutrition, but it may cause toxicity depending on its bioavailability and potential transformation in soil. In vineyard soils, high concentrations of Zn are usually found, mainly due to agricultural practices. However, a great abandonment of vineyards has recently occurred, leading to changes in the total and bioavailable Zn concentrations, as well as Zn fractionation. We analyzed Zn concentrations (total, Zn_T, and bioavailable, Zn_ED) and fractionation in the soil of three paired sites (PM, PT, and AR) up to depths of 50 cm in active and adjacent abandoned vineyards that were already transformed into forests. The Zn_T averaged at 210 mg kg⁻¹ among all studied vineyards. The results showed changes in the vertical pattern Zn_T concentrations after vineyard abandonment at the PM and PT sites, while at the AR site, no great variation occurred. The Zn_ED (mean values = 7 mg kg⁻¹) decreased after abandonment at PM and AR in the uppermost surface layers, while it increased in the top 10 cm at the PT site, reaching up to 60 mg kg⁻¹. Regarding Zn fractionation in active vineyards, the residual fraction (Zn_R) was the most abundant, followed by Zn bound to crystalline Fe and Al oxy-hydroxides (Zn_C) and Zn bound to soil organic matter (Zn_OM). After abandonment, the Zn_R slightly increased and the Zn_C slightly decreased at the PM and AR sites at all depths, while the Zn_OM showed a noticeable variation in the uppermost 10 cm of the PT site. These results suggest that the soil organic matter that is provided during afforestation may play an important role in Zn fractionation and mobilization, depending on its humification degree and chemical stability. Zn mobilization could result in a positive nutrient supply for plants, but caution must be taken, since an excess of Zn could cause toxicity in long-term abandoned vineyards. Full article

Fusarium wilt of banana caused by the soil-borne fungi Fusarium oxysporum f. sp. cubense, Tropical Race 4 (Foc TR4) (Syn. Fusarium odoratissimum), is a major threat to the global banana industry. Aiming to identify predisposing soil factors for Fusarium wilt of banana (FWB) TR4, the 23 physical and chemical soil properties were studied in three commercial banana farms in La Guajira, Colombia. Disturbed and undisturbed soil samples were collected from areas affected by the disease (affected plots) and disease-free areas (healthy plots). Five repetitions per farm were considered, with a total sample of n = 30. The data were analyzed using one-way analysis of variance (ANOVA). Subsequently, the debiased sparse partial correlation (DSPC) algorithm was applied. Organic matter (OM), pH, calcium (Ca), magnesium (Mg), zinc (Zn), and cation-exchange capacity on the exchange complex (ECEC), showed significant differences between the affected and healthy plots. In addition, the bulk density and saturated hydraulic conductivity (HC) were associated suggesting that physical attributes, such as soil compaction and poor drainage, create favorable conditions for FWB. According to the DSPC algorithm, the HC variable presented a grade of 5 and an intermediation of 14.67, which indicates that it has significant associations with BD, sand, porosity, ECEC, and OM and plays a critical role in the connection of other variables in the network and the differentiation of healthy and affected plots. These findings establish a baseline of information under field conditions in Colombia, which can be used to design soil management strategies to mitigate the detrimental effects of Foc TR4 by creating less favorable conditions for the pathogen. Full article

Due to the growing population of Earth, the problem of providing food comes to the fore. Therefore, the search for new, economically available sources of trace elements for crop production is relevant. One of these potential sources is blast-furnace sludge: highly dispersed metallurgical waste, the industrial processing of which is difficult due to its high zinc content. We studied the effect of blast-furnace sludge on rapeseed plants in laboratory, greenhouse, and field experiments and also assessed the accumulation of sludge components in plant organs. The studied sludge sample consisted of micron and submicron particles containing compounds of iron, silicon, aluminum, zinc, calcium, and sulfur. Used concentrations: laboratory—0.01, 0.1, 1%, 10, and 100 g L⁻¹; greenhouse—0.01, 0.1, 1, 10, and 100 g kg⁻¹; field—0.5, 2, and 4 t ha⁻¹. During a laboratory experiment, a decrease in the germination of rapeseed seeds exposed to 0.01, 0.1, 10, and 100 g L⁻¹ waste was observed, but 1 g L⁻¹ promoted the increase of this indicator by 7% regarding control (0 g L⁻¹). While inhibiting seed germination, the sludge had a beneficial effect on the vegetative performance of plants. Reverse effects were noted in the greenhouse experiment as an increase in seed germination (introduction of 1 g kg⁻¹ of sludge to the substrate caused maximum stimulation) and a decrease in rapeseed morphometric parameters were observed. However, at a concentration of 10 g kg⁻¹, the root mass increased by 43% and the stem mass by 63%. In the same group, the highest content of chlorophylls was noted. The number of pods in all experimental groups of plants was less than in control (0 g kg⁻¹) plants, but at the same time, in the variants of 0.01 and 1 g kg⁻¹, the weight of seeds was noticeably increased, by 15.6 and 50%, respectively. Under the conditions of the field experiment, the sludge had a positive effect on the indicators of biological and economic productivity. Thus, exposure to 0.5 and 2 t ha⁻¹ of sludge significantly increased the dry matter and leaf area. The highest values of photosynthetic capacity were recorded at a dose of 2 t ha⁻¹. The maximum increase in yield was ensured by the introduction of sludge at a concentration of 0.5 and 2 t ha⁻¹. The sludge dose of 4 t ha⁻¹, which was also used, either had no effect or suppressed the development of the analyzed traits. The study of the accumulation of zinc and iron in the organs of plants showed the absence of a pronounced dose-dependent accumulation of zinc in the organs of rapeseed, while for iron, an increase in the content of the element in the organs of plants associated with an increase in the concentration of sludge in the soil was recorded. Our results demonstrate the promise of further research and development of methods for the agricultural use of highly dispersed sludge from wet gas cleaning of blast furnace production. Full article

The coexistence of numerous Mississippi Valley-type (MVT) Pb–Zn deposits and oil/gas reservoirs in the world suggests a close genetic relationship between mineralization and hydrocarbon accumulation. The Wusihe MVT Pb–Zn deposits are located along the southwestern margin of the Sichuan Basin. Based on the spatiotemporal relation between Pb–Zn deposits and paleo-oil/gas reservoirs, ore material sources, and processes of mineralization and hydrocarbon accumulation, a new genetic relationship between mineralization and hydrocarbon accumulation is suggested for these deposits. The Wusihe Pb–Zn deposits are hosted in the Ediacaran Dengying Formation dolostone, accompanied by a large amount of thermally cracked bitumen in the ore bodies. The Pb–Zn deposits and paleo-oil/gas reservoirs are distributed along the paleokarst interface; they overlap spatially, and the ore body occupies the upper part of the paleo-oil/gas reservoirs. Both the Pb–Zn ore and sphalerite are rich in thermally cracked bitumen, in which µm sized galena and sphalerite may be observed, and the contents of lead and zinc in the bitumen are higher than those required for Pb–Zn mineralization. The paleo-oil/gas reservoirs experienced paleo-oil reservoir formation, paleo-gas reservoir generation, and paleo-gas reservoir destruction. The generation time of the paleo-gas reservoirs is similar to the metallogenic time. The source rocks from the Cambrian Qiongzhusi Formation not only provided oil sources for paleo-oil reservoirs but also provided ore-forming metal elements for mineralization. Liquid oil with abundant ore-forming metals accumulated to form paleo-oil reservoirs with mature organic matter in source rocks. As paleo-oil reservoirs were buried, the oil underwent in situ thermal cracking to form overpressure paleo-gas reservoirs and a large amount of bitumen. Along with the thermal cracking of the oil, the metal elements decoupled from organic matter and H₂S formed by thermochemical sulfate reduction (TSR) and minor decomposition of the organic matter dissolved in oilfield brine to form the ore fluid. The large-scale Pb–Zn mineralization is mainly related to the destruction of the overpressured paleo-gas reservoir; the sudden pressure relief caused the ore fluid around the gas–water interface to migrate upward into the paleo-gas reservoirs and induced extensive metal sulfide precipitation in the ore fluid, resulting in special spatiotemporal associated or paragenetic relations of galena, sphalerite, and bitumen. Full article

The agar extraction process of the red algae Gelidium sesquipedale generates a solid residue as the main by-product. However, this residue remains non-valorized, despite its potential as a fertilizer. This study aims to determine the value of G. sesquipedale residue as organic fertilizer and for soil amendments. An incubation test of G. sesquipedale residue in soils was performed to measure the nitrogen (N), phosphorus (P), and calcium (Ca) release. The potential fertilization effect of the residue was evaluated in a greenhouse on two crops: strawberry and corn. The amount of available P was high at the beginning of the incubation experiment. The amounts of nitrate–nitrogen (NO_₃⁻-N) and available Ca increased over the incubation time. A high efficiency of fertilization using the residue at different concentrations was observed in both crops. Application of the residue enhanced crop growth. The fertilization effect was associated with increased macro- and micro-elements in the strawberry fruit’s N, Ca, iron (Fe), manganese (Mn), and zinc (Zn) and in the corn leaves’ N, P, magnesium (Mg), and Fe. Moreover, the residue was a good soil organic amendment as it enhanced the amount of organic matter (OM) and some macro- and micro-elements in the soil after plant harvest. Full article