Soil Cadmium Concentration Research Articles

Planning of ecologically suitable areas for Ligusticum chuanxiong under background of soil cadmium pollution

Chuanxiong Rhizoma is a traditional Chinese medicinal material mainly produced in Sichuan and Chongqing of China. In recent years, the cadmium content in Chuanxiong Rhizoma produced in most of the genuine producing areas has exceeded the standard, which makes Chuanxiong Rhizoma difficult to be exported. To solve the problem of excessive cadmium content in soil, this study employed the MaxEnt model to simulate the potential geographic distribution of Ligusticum chuanxiong and evaluate important environmental factors, and re-plan its ecologically suitable areas based on the mineral distribution characteristics and soil cadmium pollution status. The results showed that the places suitable for L. chuanxiong growing covered an area of 335 523.69 km~2, mainly in central and eastern Sichuan, southern Shaanxi and most parts of Chongqing. Among them, the highly suitable areas of L. chuanxiong were mainly concentrated in Chengdu, Ya'an, Deyang, and Mianyang. Solar radiation, annual precipitation, and annual range of temperature were evaluated as important variables affecting the distribution of L. chuanxiong, with the contribution rates of 62.3%, 13.3%, and 6.8%, respectively. In addition, Qionglai county, Chongqing county, Mianyang city(Youxian district and Fucheng district), Qingchuan county, and Xinjin county were classified into the first-class ecologically suitable zone, covering a total area of 2 768.87 km~2. The se-cond-class ecologically suitable zone was even wider, involving such counties as Tongjiang county, Renshou county, Jianyang county, and Nanjiang county, and the total area reached 43 616.92 km~2. The re-planning of the ecologically suitable areas for L. chuanxiong has provided strong data support for the cultivation and resource development of L. chuanxiong and also new ideas for solving the problem of excessive cadmium content in L. chuanxiong.

Cadmium concentrations in Idaho wheat grain and soil

AbstractCurrent efforts to reduce the maximum allowable cadmium (Cd) concentrations in wheat (Triticum aestivum L.) for at‐risk populations such as infants require sourcing wheat with low concentrations of Cd. Since Idaho (USA) is a major wheat supplier, there is a need to understand which varieties and locations in Idaho produce wheat containing low Cd. Therefore, the main objective of this paper is to report on a survey of total Cd concentrations in 469 wheat grain samples and 216 soil samples from several varieties and locations throughout Idaho. Total Cd concentrations in wheat grain ranged from <0.01 to 0.28 mg kg−1, varying by both wheat variety and location grown. Total soil Cd ranged from 0.450 to 1.85 mg kg−1. Bioaccumulation factor (BAF) was calculated by dividing the grain total Cd concentration by the soil total Cd concentration and ranged from 0.05 to 0.5. The variety ‘UI Sparrow’ had the lowest mean BAF (0.06), and several other varieties were also relatively low. Overall, almost all wheat varieties meet European Food Safety Authority (EFSA) requirements for Cd concentration for adult consumption. However, meeting the EFSA maximum allowable limit of Cd in infant food requires planting varieties noted for low Cd uptake, like UI Sparrow, and careful selection of growing regions with the lowest total soil Cd, such as northern, central, or western Idaho.

Effects of Full Inversion Tillage During Pasture Renewal on Soil and Plant Cadmium Concentrations: A Case Study in New Zealand

Effects of Full Inversion Tillage During Pasture Renewal on Soil and Plant Cadmium Concentrations: A Case Study in New Zealand

Fungal Population and Physicochemical Characteristics of Abattoir-Impacted Soil in Iwofe, Rivers State

Aim: To determine the fungal population and physicochemistry of abattoir impacted soil in Iwofe, Rivers State.
 Study Design: This study focused on Abattoir impacted soil. Statistical analysis of data and interpretation was carried out.
 Place and Duration of Study: Abattoir impacted soil was collected from three points in an abattoir located in Iwofe, Rivers State while the unpolluted soil which served as control was collected from the Rivers State University, Port Harcourt in January, 2021.
 Methodology: Standard microbiological techniques were used: the fungal population was determined by inoculating aliquots of an appropriate dilution resulting from a ten-fold serial dilution on prepared Sabouraud dextrose agar plates in duplicates. Plates were later incubated for 3-5 days after which colonies were enumerated and used in obtaining the fungal population in the soil samples while distinct colonies were subcultured for macroscopic and microscopic identification of fungi. The physicochemical parameters and heavy metals were analyzed using standard methods.
 Results: Fungal load in the control and abattoir impacted soil were 1.09×105 and 3.9×104 CFU/g, respectively. The fungal load of the control soil was significantly higher (P˂0.05) than the abattoir impacted soil. The fungal isolates identified in the abattoir impacted soil were Microsporium sp, Aspergillus niger and Candida sp while Aspergillus niger, Aspergillus flavus, Fusarium sp, Penicillium sp, Mucor sp and Rhizopus sp were identified from the control soil. The pH, temperature, nitrate and phosphate of the abattoir soil were 6.7, 28.33℃, 27.83(mgKg-1) and 1055(mgKg-1), respectively. The concentrations of Cadmium, Iron and Lead in the abattoir Impacted soil and control soil were 0.81, 563.35 and 7.12 mgKg-1, 0.51, 582.0 and 3.18 mgKg-1, respectively. The physico chemistry and heavy metals in the abattoir soil were within acceptable limits.
 Discussion and Conclusion: The findings from this study showed that heavy metals in abattoir impacted soil had an impact in the fungal population which led to the isolation of only three fungal isolates belonging to Microsporium sp, Candida sp and Aspergillus niger. More so, despite the presence of heavy metals in the abattoir impacted soil, the metals were all within permissible limits. Thus, the abattoir impacted soil was not heavily polluted.

Impact of Industrial Pollution of Cadmium on Traditional Crop Planting Areas and Land Management: A Case Study in Northwest China

Cadmium in soils not only reduces crop yield and quality but also threatens the safety of human health and wildlife due to bioaccumulation. Baiyin City, a typical industrial region located in northwest China, was evaluated to examine the spatial distribution of cadmium. We simulated soil cadmium concentrations in the laboratory, based on levels found at local sampling sites, to examine how both Medicago sativa and Zea mays plants accumulate cadmium. The experimental results revealed that cadmium in all soil samples exceeded China’s national standard levels for general farmland; in addition, cadmium accumulation in all tissues of M. sativa and Z. mays exceeded the national fodder standards. Therefore, M. sativa and Z. mays from the study area should not be used for fodder. However, about 36% of the planting area of M. sativa and Z. mays can be used for phytoextraction because of cadmium accumulation. For soil pollution management, we suggest dividing the study area into three different regions, including a non-planting region, a phytoremediation region, and a planting region. Our soil management model can effectively help local people to avoid food safety risks and to realize sustainable development of soil utilization in contaminated areas.

Fertilization and soil pH affect seed and biomass yield, plant morphology, and cadmium uptake in hemp (Cannabis sativa L.)

The phytoremediation potential of industrial hemp (Cannabis sativa L.) becomes a new target of hemp cultivation. The ability to accumulate cadmium depends on genetic, anatomical and physiological characteristics of the varieties. The published data show that the level of fertilization affects many metabolic pathways, the development of plants and cannabinoid concentration. In addition, there are inconsistent data on the cadmium accumulation capacity depending on the mineral nutrition and pH. A study was carried out to assess the potential of two hemp varieties (‘Henola’ and ‘Białobrzeskie’) as a decontaminator of cadmium, depending on soil pH and phosphorous fertilizer level. The influence of pH, fertilization and cadmium concentration in the soil on plant morphology and on the yield of seeds and biomass were also assessed. The soil with two different pH was used in the experiment: acidic (pH 4) and alkaline (pH 7.5). Two concentrations of aqueous solution of cadmium nitrate (Cd(NO3)2) were added to the soil to obtain final concentration of Cd: 4 mg/kg and 8 mg/kg of soil, respectively. The phosphorous fertilizer was supplied in the amounts of: 50 kg/ha, 100 kg/ha, 150 kg/ha. The cadmium content in soil and in hemp plants was determined with a flame atomic absorption spectrophotometry and a plasma optical emission spectrometry (ICP-OES), respectively. Based on two years of experiments, the highest cadmium concentration in seeds and biomass, were revealed for Henola variety, when fertilizer was applied in the amount of 150 kg/ha. The results revealed that the fertilization ant pH level are important factors in the cultivation of hemp. They affect the intensity of cadmium uptake from the soil. Higher soil pH was correlated with the highest concentration of Cd in seeds and straw of Białobrzeskie variety. Such a relationship has not been demonstrated in the case of the Henola variety. The highest BCF (bioconcentration factor) value was calculated for Cd uptake in ‘Henola’ biomass. Increased cadmium concentration in the soil did not adversely affect development and growth of two hemp varieties studied. The phytoremediation potential of individual hemp varieties is different. Higher pH increases the cadmium uptake by some hemp varieties, but in the case of other varieties this relationship is reversed. It is necessary to assess the phytoremediation potential of each hemp cultivar in different agrotechnical conditions.

Spatial Distribution Characteristics and Risk Assessment of Cadmium Pollution in Soil-crops system of an E-waste Dismantling Area

With the rapid development of electronic technology, soil heavy metal contamination caused by electronic waste dismantling activities has attracted the attention of many researchers. To investigate the contamination status and spatial distribution of Cd in soil-crop systems around an e-waste dismantling area, 171 pairs of soil and crop samples were collected for analysis. The concentrations of cadmium in root vegetable soil, leaf vegetable soil, solanaceous vegetable soil, and orchard soil were (1.292±0.647), (1.010±0.201), (0.921±0.125), and (0.861±0.135) mg·kg-1, respectively. The average values of cadmium in these four soil types were 10.0, 7.8, 7.1, and 6.3 times the background values of soil Cd in Zhejiang Province, respectively, and 4.31, 3.4, 3.07, and 2.72 times the risk screening values for soil contamination of agricultural land, clearly indicating cadmium accumulation in the soil. However, only a small percentage of crops contained cadmium levels that exceeded food safety limits. Moreover, different types of crops showed different capacities for cadmium enrichment and can be ranked accordingly: leaf vegetables > root vegetables > solanaceous vegetables > fruits. The single factor pollution index and the potential ecological risk assessment revealed severe Cd contamination in the study area, with a high potential ecological risk. Cadmium exposure posed a higher health risk for children than for adults. However, the single heavy metal cadmium pollution index does not indicate a threat to local residents at this time. Moran's I index and kriging interpolation results revealed that Cd has significant spatial autocorrelation, with high values mainly concentrating around the e-waste dismantling area, indicating a significant correlation with e-waste dismantling activities.

Do soil cadmium concentrations decline after phosphate fertiliser application is stopped: A comparison of long-term pasture trials in New Zealand?

Decreasing soil cadmium (Cd) is one method of removing Cd from the food chain. Phosphorus (P) fertilisers are a major source of Cd inputs into soil. Stopping P fertiliser should theoretically decrease Cd inputs and soil Cd accumulation, but there are few field data to show if this occurs. We examined three long-term grazed pasture trials in New Zealand (Ballantrae, Winchmore and Whatawhata) where P fertiliser had been applied (from 10 to 100 kg P ha−1 yr−1) for up to six years and then stopped for 10 to 26 years. Stopping P fertiliser applications reduced soil Cd concentrations at Winchmore and Whatawhata where P had been applied at ≥34 kg P ha−1 yr−1. No reductions occurred below this rate nor at Ballantrae where only 10 years post P-application data were available. Decreases were ascribed to moderate rainfall (1630 mm at Whatawhata and 740 mm rainfall plus 770 mm irrigation at Winchmore) that enhanced Cd leaching and may have been aided at Winchmore by a decrease in soil pH over time (0.4 units). However, because stopping P fertiliser inputs may quickly impair pasture production, additional strategies may be required to decrease soil Cd quickly.

Supplemental Effects of Biochar and Foliar Application of Ascorbic Acid on Physio-Biochemical Attributes of Barley (Hordeum vulgare L.) under Cadmium-Contaminated Soil

Biochar, prepared from organic waste materials, can improve the quality of contaminated soil areas. Biochar can be used as an economic centerpiece over other available resources and can properly utilize large amounts of waste. Soil contaminated with cadmium (Cd) is a worldwide problem that poses potential agricultural and human health hazards. Moreover, Cd toxicity causes serious problems for sustainable food production, especially in food crops like barley. High cadmium concentration in soil is phytotoxic and decreases plant growth and ultimately yields. Biochar and ascorbic acid in ameliorating Cd stress are economically compatible and consistent approaches in agriculture. The present study aimed to evaluate biochar’s and foliar-applied ascorbic acid’s influence on some growth and biochemical characteristics of barley (Hordeum vulgare L.) to Cd stress. The soil was supplemented with biochar 2% w/w and 20 mg Cd kg−1. The foliar application of 30 mM ascorbic acid was done on plants. The results revealed that Cd stress decreased chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids. It also increased oxidative stress indicators, i.e., APX, COD, POD, flavonoids, anthocyanin, phenolics, and electrolyte leakage, in barley with Cd-contamination. A significant enhancement in root and shoot length, gas exchange attributes, and chlorophyll contents validated the effectiveness of Bio + Asa treatments over all other treatments under Cd contamination. In conclusion, the sole applications of biochar and Asa in Cd contamination are also effective, but Bio + Asa is a better amendment for Cd stress alleviation in barley plants.

SOIL CONTAMINATION IN THE IMPACT ZONES OF ELECTRONIC AND ELECTRICAL EQUIPMENT PRODUCTION AND WASTE RECYCLING

Soil pollution in the impact zones of enterprises for the collection and processing of electronic and electrical equipment (EEE) wastes is caused by the chemicals they contain. The article presents the results of studying the content of heavy metals in soils and technogenic substrates selected in the impact zones of enterprises for the production of EEE and waste processing, located in the city of Minsk, Belarus. A total of 15 soil samples and 13 samples of technogenic deposits were taken and analyzed. Atomic absorption spectroscopy (AAS) was used in chemical analytical tests. Statistical parameters of the content of heavy metals are presented, their comparison with published data is done. It is shown that the obtained average concentrations of cadmium and lead in the soils of the investigated enterprises are
 1.2–1.5 times, and copper and zinc are 2.7–4.6 times higher than those for the industrial zones of Minsk. The maximum
 concentrations of heavy metals were detected in samples of technogenic deposits containing waste impurities, including
 plastic particles. On the example of other countries, the importance of EEE plastic waste as a source of soil contamination
 is shown.

Land Suitability Mapping Using Geochemical and Spatial Analysis Methods

Assessing the suitability of urban and agricultural land is essential for planning sustainable urban and agricultural systems. The main objective of this study is to evaluate the suitability of land in Ioannina plain (western Greece) concerning the soil contents of two potentially toxic elements, cadmium (Cd) and cobalt (Co). Geochemical and spatial analysis methods were applied to assess the distribution of Cd and Co in the soil of the Ioannina plain and identify their origin. The primary anthropogenic sources of Cd and Co in the topsoil of the study area can be attributed to traffic emissions, aircraft operations, vehicle crushing and dismantling activities. Element content is compared to international guidelines and screening values. Cadmium and Co concentration in the soil of the study area is well above the European topsoil mean. Thus, the urban and agricultural lands cover the vast majority (92%) of the total area. Cadmium concentration in soil of the study area with a mean (mg kg−1) 1.7 and 2.0 was observed in agricultural and urban land use, respectively. Cobalt content in soil of the area studied with a mean (mg kg−1) 30.8 and 37.1 was recorded in agricultural and urban land use, respectively. Land evaluation suitability by adopting criteria provided from the international literature is discussed.

Different sources of phosphorus fertilizers and soil amendments affected the phosphorus and cadmium content in soil, roots and seeds of maize (Zea mays L.)

Phosphorus (P) fertilizers contain cadmium (Cd) as a contaminant at levels varying from trace amounts to high levels and therefore, can be a major source of Cd to agricultural systems. This study was designed to assess the impact on application of Eppawala rock phosphate (ERP) and triple super phosphate (TSP) as P fertilizers and different soil amendments on P and Cd uptake in maize (Zea mays L.). The field trial was carried out at Field Crop Research and Development Institute at Mahailluppallama, Sri Lanka. A randomized complete block design was employed with three replicates as ERP and TSP separately applied with arbuscular mycorrhizal fungi (AMF) and three types of amendments (biochar, compost and dolomite) and the control without adding P fertilizers. Phosphorus content and Cd content of soil, maize roots and seeds were quantified. Results revealed that available soil Cd and total accumulated root and seed Cd amounts were significantly higher in TSP added treatments with and without amendments compared with ERP added soil. Considering soil available P, root and seed P, there was no significant difference observed in different treatments of TSP and ERP added treatments. A similar phenomenon was also observed in growth and yield parameters with both fertilizers added and with the added amendments. There was no colonization of AMF in maize roots in TSP applied soil while 25-60% of colonization was recorded with ERP. Synthetic fertilizer (TSP) must have inhibited the AMF colonization and thereby increasing the Cd content in maize seeds. AMF colonization increased with comparatively low soil available P in ERP added treatments. The results revealed that TSP could be effectively substituted by ERP as a source of P for maize soils. The addition of AMF, compost and biochar further increased the effect.

Residual Effects of Long-term Biosolids Application on Concentrations of Carbon, Cadmium, Copper, Lead and Zinc in Soils from Two Regions of the United States

ABSTRACT Biosolids are used to improve soil physical and chemical properties. Analysis of biosolids-amended soils from multiple regions of United States using consistent analytical methods is lacking. This Study determined long-term biosolids application on soil pH, electrical conductivity (EC), carbon, cadmium, copper, lead, and zinc concentrations in soils from two regions in United States. At one region, little difference was observed in pH and EC between biosolids-amended surface soils and control, the second region ranged from 5.46 to 7.87 and 50.2 to 402 µS cm−1 respectively. Trace metal levels at this region ranged from 0.76 to 3.79, 8.7 to 54.1, 15.2 to 53.9, and 26 to 207 mg kg−1 for Cadmium, Copper, lead and Zinc respectively; with its carbon levels ranging from 14.5 to 90.0 g kg−1. Metal levels were within the standards for residential occupation with the 40 Code of Federal Regulations (CFR) Part 503 and should not affect soil and groundwater quality.

Root morphological, Cd accumulation and tolerance characteristics of 2 Dianthus caryophyllus cultivars under Cd stress

For studying the physiological response of two different Dianthus caryophyllus cultivars on Cd stress, pot experiment was carried out to measure proline and glutathione in leaves, five types of organic acids in root exudates (oxalic acid, malic acid, acetic acid, tartaric acid, citric acid), soluble sugars and free amino acids, root length, root surface area, root volume, root projected area and Cadmium content in soil, plant roots and aboveground. According to the effects of cadmium stress on the physiological and biochemical characteristics of two Dianthus caryophyllus, the results showed that: the growth of two cultivars are affected, “Master” and “Xiao Yan” are manifested as plant height, leaf, flower buds and biomass decreased, but the “Master” by the stronger inhibitory effect. The root length, total root surface area, total root projected area, and average root diameter of the “Master” increased under cadmium stress, but the root volume decreased. However, the root length, total root surface area, root volume, and root projected area of the “Xiao Yan” under cadmium stress decreased, while the average root diameter increased. The glutathione in the leaves of the two cultivars decreased, the proline content of the leaves of the “Xiao Yan” increased, while that of the “Master” decreased. In the root exudates, the free amino acid content of the two cultivars are reduced, and the secretion of organic acids is also inhibited (except for the citric acid secreted in the “Master”), while the soluble sugar content in the root exudates is expressed as “Xiao Yan” increased, and the “Master” decreased. According to the physiological response to the two cultivars under cadmium stress, the “Xiao Yan” is more suitable for soil restoration in the mining area of Lanping area.

Effects of cadmium on mitochondrial structure and function in different organs: studies on the soil centipede Lithobius forficatus (Myriapoda, Chilopoda)

Mitochondria are organelles that play a crucial role in cell physiology, cell death, and aging. They are among the first responders to different stressors that originate from the environment. Cadmium as a heavy metal affects different levels of body organization: from organs through tissues and cells to organelles. Based on our previous research results, we decided to check how the exposure to cadmium affects the functioning of mitochondria in different organs of soil living centipede Lithobius forficatus. The activity of mitochondria in somatic and germ cells has been analyzed using transmission electron microscopy (TEM), confocal microscopy, and flow cytometry. Changes in the mitochondrial membrane potential and mitochondrial dismutase (MnSOD) activity in relation to the accumulation of reactive oxygen species (ROS) caused by cadmium exposure have been studied. Individuals were divided into 3 experimental groups depending on cadmium concentration in soil. Changes in mitochondrial ultrastructure caused by cadmium are tissue-dependent and associated with an increase of ROS levels. The system of ROS and MnSOD activation works more efficiently in the case of gonads than in the digestive system. While the short-term cadmium exposure alters the fine structure of both the somatic and germ-line cells in gonads, the long-term cadmium exposure causes mitochondrial ultrastructure regeneration.

Health risk assessment of heavy metals exposure via consumption of crops grown in phosphogypsum-contaminated soils.

The management of phosphogypsum (PG) heap, located south of the Sfax city in Tunisia, has been going on for decades. But dumping this solid waste still poses environmental problems. Even though valorized as amendment to agriculture soils, the sanitary impact of this practice is not seriously considered. To assess the risk of the transference of contaminants from PG to agricultural soil-plants food chain, a wild plant species Salicornia arabica grown in PG-contaminated field and tomato (Lycopersicon esculentum) and oat (Avena sativa) grown in laboratory using different rates (10, 20 and 30%) of PG amendment, were tested. The cadmium, lead, chromium, nickel, copper and zinc concentrations in soils and plants were determined by atomic absorption spectrometry and by inductively coupled plasma-mass spectrometry, respectively. Measurements showed that Ni, Cu and Pb levels in the amended soils were below international standards except for Cd and Cr which exceeded Chinese, FAO/WHO and European allowable standard limits. Gathered results showed that the more the PG rate increases, the more the bioconcentration factors of heavy metals increased in plants, particularly in the roots. This is a prospective study assuming direct or indirect exposure scenario of different human cohorts by consuming varied common food stuffs. The Human Exposure to Soil Pollutants evaluation and United State Environment Protection Agency models were adopted for the hazard quotient calculation to assess the acceptability of sanitary risk related to each metal. The direct and indirect health risk assessments varied in the decreasing order: children, adolescents and then adults. Therefore, the PG amendment must not exceed the rate of 10%.

Dihydroquercetin increases the adaptive potential of wild soybean against copper sulfate and cadmium sulfate toxicity

In this study, the mechanism of the biochemical adaptation of wild soybean to the experimentally modeled effects of cadmium sulfate and copper sulfate in approximately double permissible concentration was investigated. The extracted concentrations of cadmium and copper in the experimental soil were determined by inversion voltammetry - 1.46 and 48.25 mg/kg, respectively. Growing soybeans in soil with the addition of copper and cadmium sulfates led to an increase in the concentration of malonic dialdehyde in soybean seeds relative to control by 62% and 38%, respectively, which confirmed the strengthening of oxidative processes. There was also an increase in the specific activity of peroxidase by 198% under the action of copper sulfate and 122% under the action of cadmium sulfate. Copper in the studied concentration was more toxic than cadmium. Acid phosphatase showed stable specific activity under the action of the studied metals. PAGE revealed multiple forms that were absent from the control: under the action of copper sulfate-AP7, AP12; cadmium sulfate-AP12. Dihydroquercetin treatment of soybean seeds before sowing in soil contaminated with copper and cadmium sulfates led to a decrease in the level of malonic dialdehyde by 20% and 11%, respectively, and a decrease in the specific activity of peroxidase by an average of 12%. There was a decrease in specific activity and the appearance of new multiple forms of acid phosphatase: under the action of copper sulfate by 18%, AP13; cadmium sulfate - 25%, AP2 and AP13. Thus, we suggest that flavonoids may take part in the adaptation of plants to the effects of copper and cadmium.

Heavy metal accumulation efficiency, growth and centelloside production in the medicinal herb Centella asiatica (L.) urban under different soil concentrations of cadmium and lead

The present study explores the effect of varying concentrations of soil cadmium (50−200 mg/kg soil) and lead (200−800 mg/kg soil) on glasshouse grown plantlets of Centella asiatica. The plantlets were fairly tolerant to soil cadmium and lower concentrations of lead in terms of biomass accumulation. Application of 200 mg/kg soil cadmium concentration, led to enhanced biomass/two-fold increase in shoot length and a significant accumulation of cadmium in shoots and roots. Specific activities of anti-oxidant enzyme systems such as superoxide dismutase, ascorbate peroxidase, and guaicol peroxidase were also found to be elevated under treated conditions. Interestingly, the ratio of cadmium concentration in roots: soil (bioaccumulation coefficient factor) was more than 1, Centella asiatica could be a potential bioaccumulator of cadmium. Also since translocation of cadmium from roots to shoots was less than 40 %, the leaves, accumulating more than twenty five fold more centellosides (in 200 mg/kg soil cadmium v/s control conditions) could also be potentially exploited for phytochemicals with minimum post-harvest processing. Real time PCR analysis also revealed higher population of centelloside biosynthetic gene transcripts such as squalene synthase, farnesyl pyrophosphate synthase, β amyrin synthase, as compared to control conditions. Plant growth, although tolerant to lower concentrations of soil lead could not effectively accumulate lead in roots, and centelloside contents was also found to be only marginally higher than control. This study reports the possibility of exploiting C. asiatica as potential plant systems that may be cultivated on cadmium contaminated soils to reap phyto-pharmaceutical benefits.

Soil Cadmium content on Chaponne of Carixien soil series in France comparing with the result on Domerien soil series

Objectives: The present research was carried out in order to know soil cadmium (Cd) availability. Method: The researchers present results of analyzing soil Cd contents on a Carixien soil series of a part of Burgundy (in French Bourgongne) in France. And the researchers compared this data on the Carixien soil series with the data on Dubloc (Domerien soil series), the result on Domerien soil has been already published. Findings: The pH value on Dubloc and that on Chaponne were very different. On Chaponne the pH changed in big range, while on Dubloc the value ranged little. The Chaponne soil extracted large amount of Cd up to 1440 minutes (24 hours), while the Dubloc soil did in smaller amounts. Novelty: The researchers take a hypothesis for this result.On Chaponne soil the ‘hole’ occurred with the rapid change of pH value, and then from the hole the Cd in the soil continued to be extracted, while there was not ‘hole’ in the Dubloc soil. But the real reason of ‘hole’ of the Chaponne soil is not explained until now. Keywords: Absorbance; Cadmium; Chaponne; Carixien soil; Cd extraction; pH change

Effects of the Immobilization of Cadmium in Soil Alone or Combined with Foliar Application of Selenium on Cadmium Accumulation in the Plants of Different Genotypes of Tsai-tai

To explore the safe utilization of technology in mildly and moderately cadmium (Cd)-contaminated farmland and realize the safe production of agricultural products, two different cadmium-accumulating genotypes of Tsai-tai were used as test crops, using the pot experiment method. The same six treatments were set on the soil where the two test crops were planted:control (CK), addition of 3% (mass fraction) biochar (BC), addition of 0.17% calcium magnesium phosphate fertilizers (CMP), foliar application of 3 mg·L-1 Na2SeO3 aqueous solution (Se), BC+Se, and CMP+Se, to study the changes in available cadmium in soil under different treatments and the characteristics of cadmium accumulation in different parts of the plant. The results showed that:① Under the same treatment, the content of available cadmium in soil near the root of the low-cadmium-accumulating genotype of Tsai-tai of Jinqiuhong Ⅲ was significantly lower than that of the high-cadmium-accumulating genotype of Shiyuehong. BC and CMP had a significant passivating effect on cadmium in the soil near the root of Jinqiuhong Ⅲ, and the passivating effect of BC was better than that of CMP; the effect of passivating treatment was significantly better than that of foliar application of selenium. ② The root system of Tsai-tai of Jinqiuhong Ⅲ had a stronger ability to accumulate cadmium than that of Shiyuehong, and the accumulated cadmium tended to be stored in the root. There were no synergistic effects between the foliar application of selenium and the two kinds of passivants on inhibiting the transfer and enrichment of cadmium to the edible parts of Tsai-tai. ③ Under the treatments of BC and CMP, the content of cadmium in the edible part of Tsai-tai of Jinqiuhong Ⅲ was lower than the limit value of cadmium in GB 2762-2017 (0.10 mg·kg-1). This study shows that for mildly and moderately cadmium-contaminated farmland, applying green passivants such as biochar, calcium magnesium phosphate fertilizers, and planting crops with weak absorption and low accumulation can achieve the safe use of the cadmium-contaminated farmland and safe production of agricultural products.