Soil Zinc Research Articles

Heavy metal toxicological analysis of vegetables cultivated in sewage-irrigated soil in the Indian metropolis of Ahmedabad City, Gujarat

Using wastewater for irrigation poses a significant health risk. We measured the concentration of (cobalt, chromium, copper, manganese, nickel, lead, and zinc) in wastewater, soil, and vegetation at 8 sites along a 60 km stretch of the Sabarmati River in Ahmedabad city. An evaluation of the potential danger from consuming contaminated vegetables was conducted using Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), and Target Cancer danger (TCR). The average concentration of the metals Co, Cr, Cu, Mn, Ni, Pb, and Zn exceeds the maximum permitted limits for irrigation purposes as established by regulatory bodies. The heavy metals in the collected soil sample are ranked in descending order of concentration as follows: Zn > Mn > Cu > Cr > Ni > Pb > Co. The average metal concentrations in vegetables range from 0.10-11.3 µg g-1 for Co, 5.2-11.8 µg g-1 for Cr, 0.04-9.9 µg g-1 for Cu, 12.3-110 µg g-1 for Mn, 0.7-4.2 µg g-1 for Ni, 0.4-8.4 µg g-1 for Pb, and 4.4-44 µg g-1 for Zn. The mean content of heavy metals (µg g-1) in the collected vegetable samples is highest in spinach, followed by brinjal, cabbage, tomato, and cauliflower. The Hazardous Quotient (THQ) shows a high health risk for Pb (6.1) and Mn (1.02), and a medium health risk for Cr (0.9). The Target Cancer Risk (TCR) emphasized the cancer risk posed by Chromium (Cr) and Nickel (Ni), following with Lead (Pb). The study indicates a link between health risks and consuming vegetables grown in the study area. It recommends improving wastewater treatment facilities and monitoring heavy metal levels in vegetables grown in soil irrigated with wastewater at regular intervals.

Investigation of Zinc Corrosion in Tropical Soil Solution

The paper presents a large experimental study on the corrosion of zinc in tropical soil and in the ground water at the various depths. Through this study, the corrosion rate prediction was done based on two methods the electrochemical method and the gravimetric. The electrochemical results showed that the corrosion rate is more important at the depth levels 0 m to 0.5 m and 0.5 m to 1 m and beyond these depth levels, the corrosion rate is less important. The electrochemical results indicated also that a passive layer is formed on the zinc surface. The found SEM and EDX micrographs displayed that the surface is extremely attacked and confirmed that a zinc oxide layer is present on the surface whose thickness and relief increase as the contact with soil increases.

Response of Wheat to Farmyard Manure and Zinc Application in a Vertisol of Central India

Zinc (Zn) deficiency is one of the major global nutrition concerns, particularly in regions where diets are cereal dominant. About 50% of soils poor in zinc have resulted in zinc deficiency in cereal grains. Farmyard manure (FYM) with Zn application is the way to meet the Zn needs of crops and to raise the Zn content of grain that is ultimately consumed by people. Therefore, a pot experiment was conducted at the Department of Soil Science and Agricultural Chemistry of JNKVV, Jabalpur, in the Rabi season of 2020-2021 with three levels of FYM (0, 5.0, and 10 t ha-1) and three levels of zinc (0, 5 and 10 kg Zn ha-1) through ZnSO4.7H2O in a completely randomized design (CRD). Results revealed that the addition of 5 t FYM ha-1 + 10 kg Zn ha-1 produced significantly better results for the plant height compared to the control. The combined application of 10 t FYM ha-1 + 10 kg Zn ha-1 showed the highest SPAD (Soil Plant Analysis Development) meter reading at 21 DAS (Days after sowing), but it was the highest at the sole application of 10 t FYM ha-1 at 45 DAS. Significant enhancements in spike length (7.65 cm), weight and number of grains per spike (23.90), and DMP of 7.12 g pot-1 were recorded with the 5 kg Zn ha-1 sole application. However, the highest grain weight (2.50 g pot-1) was recorded with 5 t FYM ha-1 + 5 kg Zn ha-1, which was on par with 5 t FYM ha-1, 5 kg Zn ha-1, and 10 t FYM ha-1+10 kg Zn ha-1. The highest Zn content (48.95 mg kg-1) in wheat grain was recorded with 10 kg Zn ha-1, followed by 5 t FYM ha-1 + 10 kg Zn ha-1 (44.45 mg kg-1). The highest Zn uptake of 99.53 µg pot-1 by grain of wheat was recorded with 5 t FYM ha-1 + 5 kg Zn ha-1, which was significantly superior to all the treatments but on par with 5 kg Zn ha-1 (98.82 µg pot-1). Combined application of 5 t FYM ha-1 +10 kg Zn ha-1 maintain extractable zinc in soil as compared to control.

Comparative Study of Traditional and Environmentally Friendly Zinc Sources Applied in Alkaline Fluvisol Soil: Lettuce Biofortification and Soil Zinc Status

The use of highly effective sources of zinc (Zn) in alkaline agricultural soils is essential to achieve crop biofortification, maintain crop quality, and avoid potential environmental risks. This research examines the efficacy of environmentally friendly Zn complexes (citric acid, CIT and glycine, GLY) compared to a traditional source (ZnSO4) for the lettuce cultivation in alkaline soil. The effectiveness of Zn sources was assessed based on the concentration of total and soluble Zn, plant biomass, and contents of photosynthetic pigments. The soil Zn status was also evaluated. While all Zn sources (Zn-GLY, Zn-CIT, and ZnSO4) showed positive effects on lettuce growth, Zn-GLY exhibited the highest efficacy. This source exhibited increases of 230%, 502%, 296%, and 409% over the control in Zn concentration in young and mature leaves, soluble Zn, and Zn uptake, respectively. Zn-GLY also resulted in a 371% increase in soil exchangeable Zn concentration, compared to the control treatment. Our findings indicate that Zn-GLY could replace the traditional ZnSO4 treatment, as it achieved high Zn biofortification of lettuce and a high concentration of Zn available in the medium-long term in the soil. The beneficial effect of the chelating agent GLY on plant chlorophyll and carotenoid contents is also remarkable.

Necrophagous flies as bioindicators in Cd and Zn co-contaminated areas of Tak Province, Thailand

Necrophagous flies may be effective bioindicators of chemical substances within polluted locations, as they are sensitive to environmental changes, have large populations, and thrive in a single location over their lifespan. Diversity and abundance of necrophagous flies were determined at livestock farms contaminated with potentially toxic elements (PTEs) in Tak Province and Nakhon Sawan Province, Thailand. Substantial soil zinc (Zn) concentrations (> 1100 mg kg−1) were detected at a cattle farm at Khaothong, Nakhon Sawan Province, and soil cadmium (Cd) values were significantly elevated (> 3 mg kg−1) at a cattle farm in Pha De, Tak Province. Anthropogenic inputs including Zn mining, domestic wastewater, and certain materials used in local agriculture were point sources of PTEs at the livestock farms in the Pha De and Khaothong subdistricts. Lower temperatures and humidity during the rainy season may have resulted in increased numbers of necrophagous flies, which was 1.5 times greater compared to the dry season. However, the dry season exhibited a higher PTE buildup in fly tissue. The order of important value index (IVI) values of the necrophagous flies were: Chrysomya megacephala (56.80), Musca domestica (27.21), C. rufifacies (25.40) and Sarcophaga spp. (17.54), respectively. These necrophagous flies may play a significant role in PTE-contaminated ecosystems based on their high IVI values, suggesting that they could be used as bioindicators of PTEs. Principal component analysis (PCA) results for necrophagous flies associated with each sampling site during the dry season were consistent with flies having substantial IVI values. Musca domestica and C. megacephala of both sexes displayed substantial correlations with Cr, Al, and Mn, while females of Sarcophaga spp. displayed strong associations with Cd. At the cattle farm in Khaothong, males of M. domestica showed a significant relationship with Zn, Cu, Pb, and Ni. When considering PTE accumulation capacity in flies commonly found at field sites, C. megacephala and M. domestica are the most suitable bioindicators of PTEs. This study confirms that necrophagous flies serve as reliable bioindicators of PTE pollution.

Phytoremediation of Zinc and Lead from Polluted Soils Using Sunflower

Phytoremediation is a new, cost-effective remediation technique. Sunflower, a plant grown in Pb- and Zn-contaminated soils, underwent pot trials to examine its biomass and determine how well may remove the metals. According to the findings, the fresh and dry weights of the developing plants gradually reduced, as the amount of heavy metals in the soil increased. The fresh weights of the shoot and root were decreased by the application of 835 mg/kg soil of Pb and 598 mg/kg Zn. The maximum concentration of lead and zinc in the shoot (146.27and 277.83 mg/kg) and roots (589.77 and 287.97 mg/kg, respectively) was recorded in the plant cultivated in contaminated soil. The root growing on soil treated with 835 mg/kg had the maximum bioaccumulation of lead. The control soil had the longest plant shoot and root lengths, averaging 75.67 cm and 9.5 cm, respectively. Under a soil Pb concentration of 835 mg/kg, the shortest plants had shoots that measured 58.5 cm and roots that measured 6 cm. Similarly, when the soil was treated with 598 mg/kg soil zinc, the plant?s shoot and root decreased dramatically by 55.67 cm and 7 cm, respectively. As a result, the study shows that sunflower plants were better at absorbing lead and zinc, and we recommend using them to clean up soil that has been contaminated with these metals. . KEYWORDS :Sunflower, Heavy Metals, Lead, Phytoremediation, Zinc

Integrated Application of Inorganic, Organic Sources and Biofertilizers on Nutrient Status of Soil and Aonla Leaves under Sub-Tropics of Madhya Pradesh, India

The field experiment was conducted at the Horticulture Research CRC Farm – 1 of the Department of Horticulture, School of Agriculture, ITM University Gwalior (M.P.) during the year 2019 and 2020 to study the Influence of Integrated Nutrient Management on nutrient status of soil and aonla leaves under sub-tropics of Madhya Pradesh. The experiment was laid out in the randomized block design with three replications and eleven treatments viz. (control) - RDF (1000: 500:1000 g/ tree), 3/4thof RDF + FYM, 3/4th of RDF + FYM + Azotobacter (100 g), 3/4th of RDF + FYM+ Azospirillum (100 g), 3/4th of RDF + FYM+ PSB (100 g), 3/4thof RDF + FYM+ Azotobacter + Azospirillum + PSB(100 g/tree each), ½ of RDF + FYM, 1/2 of RDF + FYM+ Azotobacter (100 g), 1/2 of RDF + FYM + Azospirillum(100 g), ½ of RDF + FYM + PSB(100 g), ½ of RDF + FYM + Azotobacter + Azospirillum + PSB (100 g/tree, each. The results revealed that among different treatments, application of ½ of RDF + FYM + Azotobacter + Azospirillum + PSB recorded higher microbial population, available nitroge, phosphorus, potassium and available soil zinc, copper and boron which was followed by application of 1/2 of RDF + FYM+ Azotobacter (100 g). Thus, application of ½ of RDF + FYM + Azotobacter + Azospirillum + PSB was found to best for improving the soil nutrient status which will in turn help in improving the yield of Aonla.

Spatial distribution and migration of lead and zinc and the influence of parent materials in typical paddy soils of Hunan Province, China.

This study aimed to investigate the distribution and migration characteristics of lead (Pb) and zinc (Zn) in paddy soils in Hunan Province, China. A total of 343 soil samples from 63 profiles were collected from typical regions. The concentration, spatial distribution, and migration behaviors of Pb and Zn in the paddy soils were examined. The results showed that (1) the concentration ranges of Pb and Zn in the surface layer were 17.62-114.07 mg/kg and 44.98-146.84 mg/kg, respectively. (2) The content was higher in the middle and lower reaches of the Xiangjiang River basin horizontally and exhibited shallow enrichment characteristics vertically. (3) Pb migration was weaker than Zn migration, and the parent material had the most significant influence on Pb and Zn content in the bottom soil layer. The research results will clarify the characteristics of Pb and Zn contents in paddy soils in Hunan Province, further understand the horizontal distribution and vertical migration and transformation characteristics of Pb and Zn contents in paddy soils, and provide basic data for scientific rice cultivation and safe food production.

Differences in microbial communities and potato growth in two soil types under organic cultivation.

Organic agriculture plays a positive role in promoting genetic diversity, including living organisms, plants, and cultivated crops in the soil. However, few comparative studies reported whether different soil types were suitable for organic cultivation. In this study, loam and clay-loam soils under continuous organic cultivation were analyzed. The results showed that there were no significant differences between two soil types in soil pH, bulk density, total porosity, moisture content and three soil phases. The capillary porosity and organic matter content of loam were significantly higher than those of clay-loam. Compared with clay-loam soil, the contents of total nitrogen, phosphorus, potassium, calcium, zinc and silicon in loam soil were also significantly higher. The microbial diversity was higher in loam and the dominant microbes differed between the two soils. Glycosyl transferases and carbohydrate esterases were enriched in loam, whereas glycoside hydrolases and carbohydrate-binding modules were enriched in clay loam. The potato yield in loam was significantly higher than that in clay loam. Among the tuber quality indicators, the protein content of potatoes in loam was higher than that in clay-loam, but the reducing sugar content was lower for loam than for clay-loam. In conclusion, compared with clay loam, loam was more suitable for organic cultivation of potatoes on account of the high contents of nitrogen, phosphorus, and potassium and the rich microbial community, thus promoting a high yield of tubers. This study provided a theoretical reference for the selection of soil type suitable for organic cultivation.

Alkaline humic acid fertilizer alters the distribution, availability, and translocation of cadmium and zinc in the acidic soil–Sauropus androgynus system

Humic acids (HA) are a popular soil additive to reduce metal availability, but they have the drawbacks of reduced effectiveness over time and a significant reduction in soil pH. An alkaline humic acid fertilizer (AHAF) combining alkaline additives with HA was developed to overcome such drawbacks. A field experiment was conducted to investigate the effects of different AHAF application rates on the physicochemical properties, bioavailability, accumulation, and translocation of Cd and Zn heavy metals in Sauropus androgynus grown in acidic soil. Based on our results, the 100AF (100% AHAF) treatment significantly increased soil pH, cation exchange capacity (CEC), and organic matter content (OM) after one year of application. Compared with the control treatment (CK), the application of different rates of AHAF resulted in a 37.1–40.3% decrease in soil exchangeable Cd fractions (Exc-Cd) and an increase in the humic acid-bound Cd fractions (HA-Cd) Fe- and Mn-oxide-bound Cd fractions (OX-Cd), and organic matter-bound Cd fractions (OM-Cd) by 9.5–64.6%, 24.8–45.1%, and 158.8–191.2%, respectively (P < 0.05). The different AHAF treatments decreased the Res-Zn, Exc-Zn, and OM-Zn fractions by 69.6–73.0%, 7.4–23.9%, and 18.1–23.2%, respectively (P < 0.05), and increased the HA-Zn fraction by 8.4–28.1%. In the control treatment, the bioconcentration factors (BCFs) for Cd and Zn in different S. androgynus plant organs were in the following order: (Cd) Leaves > Stems > Branches > Roots > Edible branches; (Zn) Roots > Stems > Leaves > Branches > Edible branches. The transfer factors (TFs) of Cd and Zn in S. androgynus were classified as follows: TF2 > TF1 > TF3 > TF4. Thus, S. androgynus stems, and roots had a strong ability to transport Cd and Zn to the leaves. Compared with CK, the 100AF treatment significantly increased the BCFs for Zn in all plant parts (except BCFedible branches). In contrast, it significantly decreased all BCFs and TFs for Cd and the TF4 for Zn, effectively reducing Cd and Zn accumulation in the edible branches of S. androgynus. Soil pH, CEC, OM, and HA-M fraction were highly and significantly negatively correlated with Cd and Zn content in edible branches (P < 0.001). Stepwise multiple linear regression analysis revealed that the soil HA-M fraction was the key contributing factor for Zn accumulation and translocation in S. androgynus. Moreover, based on our findings, the absorption, uptake, and translocation of Cd and Zn were mainly determined by metal speciation and the pH in the soil. Moreover, the competitive antagonistic mechanisms between Zn and Cd absorption also affected their accumulation in S. androgynus. Thus, AHAF can be used as a soil amendment to sustainably improve acidic soils and effectively reduce Cd and Zn accumulation in edible branches of S. androgynus.

Agricultural soil contamination and degradation near a mining area in an arid region

Industrial and mining activities release toxic substances and heavy metals into the soil of the surrounding environment and result in soil degradation and desertification. The contaminated residential areas near mines can endanger the health of residents, and the agricultural lands at the fringes of mines contaminate agricultural products with heavy metals. In this study, in order to determine the rate of soil degradation and its contamination at the margins of Koushk Pb-Zn mine, the surface of the agricultural soil adjacent to the mine was sampled. Surface soil samples were also prepared from around two villages in the vicinity of the mine and along the roadside. The samples were digested using four acid methods and analyzed by ICP-OES, and the concentrations of Pb, Zn, Cr, Co, Sb, and Ba were measured in the samples. The difference between the concentrations of heavy metals in the agricultural and rangeland soil samples was assessed with a t-test, and the corresponding contamination maps were plotted. The results showed that the agricultural soil in both villages was more polluted than the rangeland soil around the villages. Indeed, the lead and zinc concentrations in the agricultural soil of Koushk were several times higher than environmental standards. Also, despite the equal distance of the villages from the mine, the average amounts of barium, lead, and zinc in Koushk soil were 1.5, 26, and 11 times higher than those in Seyyedabad, respectively. As a result, the parent materials geochemistry is a major source of variation in soil pollution in two villages. In addition the agriculture management style can play a role in elemental content of the samples.

Growth Performance, Zinc Uptake and Response of Clonal Eucalyptus to Application of Zinc in Soils of Variable Texture

ABSTRACT Eucalyptus (Eucalyptus spp.) leads to depletion of nutrients from the soil due to its fast growing nature. Therefore, a pot experiment was conducted to study the effect of zinc (Zn) application on clonal eucalyptus growth, biomass output and its uptake, as well as response of eucalyptus to Zn in soils of three textures. The treatments consisted of eight levels of Zn (0, 5, 10, 15, 20, 25, 30, and 35 mg kg−1 applied through ZnSO4.H2O) in a completely randomized design triplicated in soils of three distinct textures (loamy sand, sandy loam and sandy clay). The plant height, collar diameter, dry weight of shoot and roots, soil plant analysis development (SPAD) readings, Zn concentration and uptake by leaves, stem+branches and roots increased significantly with Zn application. Average dry weight of shoot and roots (31.93 and 15.12 g plant−1, respectively) was significantly highest at 15 mg Zn kg−1 whereas Zn concentration and uptake (18.35 mg kg−1 and 286.2 µg plant−1, respectively) by roots were highest at 20 mg Zn kg−1. The above parameters differed significantly among soils as sandy clay>sandy loam>loamy sand except Zn content and uptake by roots and SPAD values which were highest in sandy loam soil. Loamy sand and sandy loam soil exhibited higher Zn use efficiency, shoot biomass response and uptake response to applied Zn than sandy clay soil. It is concluded to apply 20 mg Zn kg−1 in light soil and 15 mg Zn kg−1 in heavy textured soil for better growth and productivity of eucalyptus.

Environmental assessment of heavy metal contamination at Chekfa aggregate quarry (Jijel, North‐East Algeria)

AbstractIt is fascinating to observe the potential hazards associated with mining and quarrying activities, despite the limited number of comprehensive studies conducted in Algeria to evaluate their environmental impact. This particular investigation focuses on El M'cif quarry in Chekfa, located within the Nil watershed in Jijel, a region situated in the North‐East of Algeria. The primary objective is to assess the concentrations of lead (Pb), zinc (Zn), copper (Cu), and cadmium (Cd) in surface water, groundwater, stream sediments, and soil. Consequently, a suite of petrographic and geochemical analyses is undertaken to discern the origins of these heavy metals. Employing statistical methodologies, notably the Geo‐accumulation Index (Igeo), Pollution Index (PI+PI), and Ecological Risk Assessment (ER), this study is further fortified to quantify the levels of hazardous contaminants. The findings reveal that the concentrations of Cd and Pb in surface water are recorded at 22 and 654.3 μg/L, respectively, surpassing both Algerian and WHO standards. Meanwhile, the heavy metal concentrations in stream sediments are ranked in the order of Zn &gt; Cu &gt; Cd, with respectively mean concentrations of 1085.30, 14.60, and 1.49 (mg/kg). The mean concentrations of Zn, Pb, Cd, and Cu in soil are measured respectively at 219.78, 128.86, 20.76, and 2.42 (mg/kg). Based on the statistical methods such as I‐geo, PI, IPI, and RI, the research reveals that the sediments of the Aftis River are uncontaminated by Cu, moderately to heavily contaminated with Zn and heavily contaminated by Cd. Besides the soil samples which are found to be extremely contaminated with Cd, moderately contaminated with Pb, and uncontaminated with Cu and Zn. Additionally, the X‐ray fluorescence analysis reveals that the limestone extracted from the quarry contains 0.7% cadmium, suggesting that the quarry could potentially contribute to cadmium contamination. The surrounding rocks exhibit significant concentrations of iron, lead, and zinc. Therefore, the elevated levels of these heavy metals can primarily be attributed to geological factors rather than human activities, highlighting the combined influence of the extractive industry and the geological environment.

Effects of Different Zinc and Copper Concentrations in Soil on Morphological and Biochemical Properties of Ipomea aquatica

Zinc and copper pollution in agricultural lands due to anthropogenic activities has become a major environmental problem. While these metals are essential for plant growth, their excessive presence can lead to plant toxicity. This experiment aimed to investigate the effects of different concentrations of zinc and copper (0, 100, 200, and 300 ppm) in soil on the morphological and biochemical properties of I. aquatica, commonly known as water spinach. The morphological properties, including plant height, number of leaves, and stem diameter, were assessed, along with soil pH and electrical conductivity (EC). Biochemical properties, specifically the Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) in plant tissues, were measured using colorimetric assays. The results revealed significant morphological changes in plant height, stem diameter, and number of leaves at 200 ppm zinc treatment compared to the control. Additionally, the number of leaves significantly increased at the 100 ppm copper treatment, while the stem diameter decreased significantly at 300 ppm. Both zinc and copper treatments slightly reduced soil pH and increased soil EC. At the 300 ppm treatment, substantial changes in phenolic and flavonoid contents were observed in the stems and leaves of I. aquatica. Copper treatment at 200 ppm increased the TPC of leaves, while 100 ppm copper treatment increased the TFC of stems. Furthermore, the 300 ppm zinc treatment significantly increased the TPC and TFC in stems and leaves. These findings indicate that zinc and copper concentrations have notable effects on the morphological and biochemical properties of I. aquatica. Therefore, it is crucial to maintain an appropriate balance of these metal elements to cultivate plants that are morphologically and physiologically resilient.

Hyperspectral Inversion and Analysis of Zinc Concentration in Urban Soil in the Urumqi City of China

Excessive accumulation of zinc (Zn) in urban soil can lead to environmental pollution and pose a potential threat to human health and the ecosystem. How to quickly and accurately monitor the urban soil zinc content on a large scale in real time and dynamically is crucial. Hyperspectral remote sensing technology provides a new method for rapid and nondestructive soil property detection. The main goal of this study is to find an optimal combination of spectral transformation and a hyperspectral estimation model to predict the Zn content in urban soil. A total of 88 soil samples were collected to obtain the Zn contents and related hyperspectral data, and perform 18 transformations on the original spectral data. Then, select important wavelengths by Pearson's correlation coefficient analysis (PCC) and CARS. Finally, establish a partial least squares regression model (PLSR) and random forest regression model (RFR) with soil Zn content and important wavelengths. The results indicated that the average Zn content of the collected soil samples is 60.88 mg/kg. Pearson's correlation coefficient analysis (PCC) and CARS for the original and transformed wavelengths can effectively improve the correlations between the spectral data and soil Zn content. The number of important wavelengths selected by CARS is less than the important wavelengths selected by PCC. Partial least squares regression model based on first-order differentiation of the reciprocal by CARS (CARS-RTFD-PLSR) is more stable and has the highest prediction ability (R2 = 0.937, RMSE = 8.914, MAE = 2.735, RPD = 3.985). The CARS-RTFD-PLSR method can be used as a means of prediction of Zn content in soil in oasis cities. The results of the study can provide technical support for the hyperspectral estimation of the soil Zn content.

Metabolomics reveals the impact of nitrogen combined with the zinc supply on zinc availability in calcareous soil via root exudates of winter wheat (Triticum aestivum)

A possible mechanism for the improved availability of zinc (Zn) in soil by combining nitrogen (N) with Zn supply was investigated based on the root exudates of winter wheat. N, Zn supply as well as their combination significantly regulated nine root exudates in winter wheat; in which, the secretion of cis-aconitic acid involving in the TCA cycle, C5-branched dibasic acid metabolism, glyoxylate and dicarboxylate metabolism and 2-oxocarboxylic acid metabolism was upregulated by N, Zn supply as well as their combination. N–Zn combination induced the activities of citrate synthase and cis-aconitase in roots and shoots of winter wheat thus to increase the concentrations of citric and aconitic acid; the decrease of isocitric acid concentrations in shoots indicated the inhibited conversion of aconitic acid to isocitric acid by N–Zn combination. It revealed a possible reason for the enhanced secretion of cis-aconitic acid by N–Zn combination. Exogenous addition of 10 μ plant−1 cis-aconitate significantly increased available Zn concentrations in soil and Zn concentrations in winter wheat under N–Zn combination. Thus, the N–Zn combination regulated the metabolism of cis-aconitic acid in winter wheat, thus enhancing the secretion of cis-aconitic acid to increase the bioavailability of Zn in soil.

Presenting of Model in Distribution of Nutrients (Iron, Zinc, and Manganese) in Soil and Leaves of Orange Orchard Trees in the Southwest of Iran

ABSTRACT Among the soil nutrients, iron, zinc, and manganese are particularly important in producing plant product quality. The aim of this study was Presenting of Model in Distribution of Nutrients (Iron, Zinc, and Manganese) in Soil and Leaves of Orange Orchard Trees were in the Southwest of Iran, which was done using the Geographic Information System (GIS) in 2020. One hundred and thirty points were determined using Global Positioning System (GPS), and sampling of soil and leaves of orange trees was performed. Elements were measured using an atomic absorption spectrophotometer. The location of sampling points was simulated using R software. Interpolation was performed using simple kriging and kernel methods. The accuracy of the interpolation was also assessed using the baseline variance method. Finally, the simulated values in the model were implemented in the GIS software environment. The results showed that the interpolation accuracy was optimal for modeling iron and zinc elements in the soil samples. Correlation analysis showed a significant correlation between the amounts of elements in the soil and the leaves of the orange trees (p < .05). The strongest positive correlation is found for the iron values. The research results show the optimal efficiency of geostatistical methods in managing agricultural lands and orchards.

Effect of Sulfur Fertilization on Productivity and Grain Zinc Yield of Rice Grown under Low and Adequate Soil Zinc Applications

Effect of Sulfur Fertilization on Productivity and Grain Zinc Yield of Rice Grown under Low and Adequate Soil Zinc Applications

Bioavailability of Cd in Agricultural Soils Evaluated by DGT Measurements and the DIFS Model in Relation to Uptake by Rice and Tea Plants

The elevated accumulation of cadmium (Cd) in rice (Oryza sativa L.) and tea (Camellia sinensis L.) grown in agricultural soils may lead to a variety of adverse health effects. This study collected and analyzed crop samples along with paired rhizosphere soil samples from 61 sites in Cd-contaminated regions in Anhui Province, China. The findings revealed that both the diffusive gradients in thin-films (DGT) and soil solution were capable of effectively predicting Cd contents in crops. Conventional chemical extraction methods were inappropriate to evaluate the bioavailability of Cd. However, the effective concentrations (CE) corrected by the DGT-induced fluxes in soils (DIFS) model exhibited the strongest correlation with crop Cd contents. Except for CE, various measurement methods yielded better results for predicting Cd bioavailability in tea compared to rice. Pearson’s correlation analysis and the random forest (RF) model identified the key influencing factors controlling Cd uptake by rice and tea, including pH, soil texture, and contents of zinc (Zn) and selenium (Se) in soils, which antagonize Cd. To reduce the potential health risk from rice and tea, the application of soil liming and/or Se-oxidizing bacteria was expected to be an effective management strategy.

Magnetic signature and X-ray fluorescence for mapping trace elements in soils originating from basalt and sandstone

The knowledge of the lithological context is necessary to interpret trace elements concentrations in the soil. Soil magnetic signature (χ) and soil X-ray fluorescence (XRF) are promising approaches in the study of the spatial variability of trace elements and the environmental monitoring of soil quality. This research aimed to assess the efficiency of measurements of χ and XRF sensors for spatial characterization of zinc (Zn), manganese (Mn), and copper (Cu) contents in soils of a sandstone-basalt transitional environment, using machine learning modeling. The studied area consisted of the Western Plateau of São Paulo (WPSP), with soils originating from sandstone and basalt. A total of 253 soil samples were collected at a depth of 0.0–0.2 m. The soils were characterized by particle size and chemical analysis: organic matter (OM), cation exchange capacity (CEC), ammonium oxalate-extracted iron (Feo), sodium dithionite-citrate-bicarbonate-extracted iron (Fed), and sulfuric acid-extracted iron (Fet). Hematite (Hm), goethite (Gt), kaolinite (Kt), and gibbsite (Gb) contents were obtained by X-ray diffraction (XRD). Magnetite (Mt) and maghemite (Mh) contents were obtained by soil χ, while trace elements contents were obtained by XRF and predicted by χ. Descriptive analysis, the test of means, and correlation were performed between attributes. Zn, Mn, and Cu contents were predicted using the machine learning algorithm random forest, and the spatial variability was obtained using the ordinary kriging interpolation technique. Landscape dissections influenced iron oxides, which had the highest contents in slightly dissected environments. Trace elements contents were not influenced by landscape dissections, demonstrating that lithological knowledge is necessary to characterize trace elements in soils. The prediction models developed through the machine learning algorithm random forest showed that χ can be used to characterize trace elements. The similar spatial pattern of trace elements obtained by XRF and χ measurements confirm the applicability of these sensors for mapping it under lithological and landscape transition, aiming for sustainable strategic planning of land use and occupation.