scholarly journals Effect of Bacterial Application on Metal Availability and Plant Growth in Farmland-Contaminated Soils

2016 ◽  
Vol 07 (02) ◽  
Author(s):  
Du RY Wen D
Keyword(s):  
Plant Growth ◽  
Contaminated Soils ◽  
Metal Availability

Biochar vs magnesite amendments for metals immobilization: lab-scale and field experiments

2021 ◽  
Author(s):  
Diego Baragaño ◽  
Daniel Arenas Lago ◽  
José Luis R. Gallego ◽  
Rubén Forján Castro
Keyword(s):  
Plant Growth ◽  
Soil Properties ◽  
Brassica Juncea ◽  
Contaminated Soils ◽  
Urban Areas ◽  
Field Experiments ◽  
Greenhouse Experiment ◽  
Metal Availability ◽  
Industrial Change ◽  
The Impact

<p>The process of industrial change has resulted in the creation of so-called ‘brownfields’ across Europe, particularly in urban areas, in the industrial sections of cities. The need to recover these brownfields can be linked to the new European Commission program "Zero Wastes", that is, to restore or recondition these areas by applying amendments made with by-products or green elements. In this sense, the capacities of magnesite and biochar, inorganic and organic soil amendments respectively, were tested to reduce metal availability and improve the properties of a soil severely contaminated by Cu, Cd, Pb and Zn. To this end, two implementation steps were performed.</p><p>First, 1 kg pots containing the polluted soil were amended with either magnesite or biochar and then determined metal availability and soil properties at days 15 and 75 in a greenhouse experiment. In addition, to evaluate the impact of the two treatments on plant growth, the experimental trials were carried out using Brassica juncea L. and compost addition. Both amendments, but particularly magnesite, markedly decreased metal availability. Soil properties were also improved, as revealed by increases in the cation exchangeable capacity. However, plant growth was inhibited by magnesite amendment. This effect was probably due to an increase in soil pH, cation exchange capacity and a high Mg concentration. In contrast, biochar increased biomass production whereas decreased the content of metals harvested. Then, a field scale experiment was performed in situ by means of treating 1 ton of the soil with the magnesite and also with the biochar. Brassica juncea L. was used for testing the impact on plants, and the experiment was monitored at 3, 30 and 60 days from the beginning of the experiment. Similar results to the greenhouse experiment were obtained.</p><p>In conclusion, the results indicate that magnesite amendment may be suitable for stabilizing contaminated soils (or even spoil heaps) where revegetation is not a priority. In contrast, although biochar has a lower, but still significant, capacity to immobilize metals, its use emerges as a promising tool for restoring soil properties and thus favoring plant growth.</p><p><strong>Acknowledgment</strong></p><p>This work was supported by the research projects NANOBIOWASH CTM2016-75894-P (AEI/FEDER, UE) and NANOCAREM MCI-20-PID2019-106939GB-I00 (AEI/FEDER, UE).</p><p>Diego Baragaño obtained a grant from the “Formación del Profesorado Universitario” program, financed by the “Ministerio de Educación, Cultura y Deporte de España”.</p><p>Arenas-Lago D. thanks to his postdoc contract ED481D 2019/007 (Xunta de Galicia and Universidade de Vigo).</p>

scholarly journals Role of Two Plant Growth-Promoting Bacteria in Remediating Cadmium-Contaminated Soil Combined with Miscanthus floridulus (Lab.)

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 912
Author(s):  
Shuming Liu ◽  
Hongmei Liu ◽  
Rui Chen ◽  
Yong Ma ◽  
Bo Yang ◽  
...  
Keyword(s):  
Plant Growth ◽  
Contaminated Soils ◽  
Translocation Factor ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Strains ◽  
Pgp Traits ◽  
Cd Tolerance ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Cd Translocation

Miscanthus spp. are energy plants and excellent candidates for phytoremediation approaches of metal(loid)s-contaminated soils, especially when combined with plant growth-promoting bacteria. Forty-one bacterial strains were isolated from the rhizosphere soils and roots tissue of five dominant plants (Artemisia argyi Levl., Gladiolus gandavensis Vaniot Houtt, Boehmeria nivea L., Veronica didyma Tenore, and Miscanthus floridulus Lab.) colonizing a cadmium (Cd)-contaminated mining area (Huayuan, Hunan, China). We subsequently tested their plant growth-promoting (PGP) traits (e.g., production of indole-3-acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase) and Cd tolerance. Among bacteria, two strains, Klebsiella michiganensis TS8 and Lelliottia jeotgali MR2, presented higher Cd tolerance and showed the best results regarding in vitro growth-promoting traits. In the subsequent pot experiments using soil spiked with 10 mg Cd·kg−1, we investigated the effects of TS8 and MR2 strains on soil Cd phytoremediation when combined with M. floridulus (Lab.). After sixty days of planting M. floridulus (Lab.), we found that TS8 increased plant height by 39.9%, dry weight of leaves by 99.1%, and the total Cd in the rhizosphere soil was reduced by 49.2%. Although MR2 had no significant effects on the efficiency of phytoremediation, it significantly enhanced the Cd translocation from the root to the aboveground tissues (translocation factor > 1). The combination of K. michiganensis TS8 and M. floridulus (Lab.) may be an effective method to remediate Cd-contaminated soils, while the inoculation of L. jeotgali MR2 may be used to enhance the phytoextraction potential of M. floridulus.

scholarly journals Perchlorate and Agriculture on Mars

Soil Systems ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 37
Author(s):  
Christopher Oze ◽  
Joshua Beisel ◽  
Edward Dabsys ◽  
Jacqueline Dall ◽  
Gretchen North ◽  
...  
Keyword(s):  
Plant Growth ◽  
Soil Column ◽  
Metal Availability ◽  
Metal Release ◽  
High Solubility ◽  
Plant Life ◽  
Growing Medium ◽  
Successful Removal ◽  
Flow Through ◽  
Martian Regolith

Perchlorate (ClO4−) is globally enriched in Martian regolith at levels commonly toxic to plants. Consequently, perchlorate in Martian regolith presents an obstacle to developing agriculture on Mars. Here, we assess the effect of perchlorate at different concentrations on plant growth and germination, as well as metal release in a simulated Gusev Crater regolith and generic potting soil. The presence of perchlorate was uniformly detrimental to plant growth regardless of growing medium. Plants in potting soil were able to germinate in 1 wt.% perchlorate; however, these plants showed restricted growth and decreased leaf area and biomass. Some plants were able to germinate in regolith simulant without perchlorate; however, they showed reduced growth. In Martian regolith simulant, the presence of perchlorate prevented germination across all plant treatments. Soil column flow-through experiments of perchlorate-containing Martian regolith simulant and potting soil were unable to completely remove perchlorate despite its high solubility. Additionally, perchlorate present in the simulant increased metal/phosphorous release, which may also affect plant growth and biochemistry. Our results support that perchlorate may modify metal availability to such an extent that, even with the successful removal of perchlorate, Martian regolith may continue to be toxic to plant life. Overall, our study demonstrates that the presence of perchlorate in Martian regolith provides a significant challenge in its use as an agricultural substrate and that further steps, such as restricted metal availability and nutrient enrichment, are necessary to make it a viable growing substrate.

scholarly journals Efficacy of Indole Acetic Acid and Exopolysaccharides-Producing Bacillus safensis Strain FN13 for Inducing Cd-Stress Tolerance and Plant Growth Promotion in Brassica juncea (L.)

2021 ◽  
Vol 11 (9) ◽  
pp. 4160
Author(s):  
Farheen Nazli ◽  
Xiukang Wang ◽  
Maqshoof Ahmad ◽  
Azhar Hussain ◽  
Bushra ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Plant Growth ◽  
Stress Tolerance ◽  
Brassica Juncea ◽  
Contaminated Soils ◽  
Effective Strain ◽  
Antioxidant Enzyme Activities ◽  
Cd Stress ◽  
Cd Accumulation ◽  
Bacillus Safensis

Untreated wastewater used for irrigating crops is the major source of toxic heavy metals and other pollutants in soils. These heavy metals affect plant growth and deteriorate the quality of edible parts of growing plants. Phytohormone (IAA) and exopolysaccharides (EPS) producing plant growth-promoting rhizobacteria can reduce the toxicity of metals by stabilizing them in soil. The present experiment was conducted to evaluate the IAA and EPS-producing rhizobacterial strains for improving growth, physiology, and antioxidant activity of Brassica juncea (L.) under Cd-stress. Results showed that Cd-stress significantly decreased the growth and physiological parameters of mustard plants. Inoculation with Cd-tolerant, IAA and EPS-producing rhizobacterial strains, however, significantly retrieved the inhibitory effects of Cd-stress on mustard growth, and physiology by up regulating antioxidant enzyme activities. Higher Cd accumulation and proline content was observed in the roots and shoot tissues upon Cd-stress in mustard plants while reduced proline and Cd accumulation was recorded upon rhizobacterial strains inoculation. Maximum decrease in proline contents (12.4%) and Cd concentration in root (26.9%) and shoot (29%) in comparison to control plants was observed due to inoculation with Bacillus safensis strain FN13. The activity of antioxidant enzymes was increased due to Cd-stress; however, the inoculation with Cd-tolerant, IAA-producing rhizobacterial strains showed a non-significant impact in the case of the activity of superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) in Brassica juncea (L.) plants under Cd-stress. Overall, Bacillus safensis strain FN13 was the most effective strain in improving the Brassica juncea (L.) growth and physiology under Cd-stress. It can be concluded, as the strain FN13 is a potential phytostabilizing biofertilizer for heavy metal contaminated soils, that it can be recommended to induce Cd-stress tolerance in crop plants.

Integrated phytoremediation system for uranium-contaminated soils by adding a plant growth promoting bacterial mixture and mowing grass

2018 ◽  
Vol 19 (4) ◽  
pp. 1799-1808 ◽  
Author(s):  
Xin Qi ◽  
Xichao Hao ◽  
Xiaoming Chen ◽  
Shiqi Xiao ◽  
Shilin Chen ◽  
...  
Keyword(s):  
Plant Growth ◽  
Contaminated Soils ◽  
Plant Growth Promoting ◽  
Growth Promoting

scholarly journals The availability of Cd, Pb and Zn and their relationships with soil pH and microbial biomass in soils amended by natural clinoptilolite

2011 ◽  
Vol 51 (No. 1) ◽  
pp. 26-33 ◽  
Author(s):  
G. Mühlbachová ◽  
T. Šimon ◽  
M. Pechová
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Maximum Increase ◽  
Glucose Addition ◽  
Soil Microbial ◽  
Significant Relationships ◽  
Metal Contents ◽  
Natural Clinoptilolite

The relationships among soil microbial biomass, pH and available of heavy metal fractions were evaluated in longterm contaminated soils during an incubation experiment with the amendment of zeolite (natural clinoptilolite) and the subsequent addition of glucose. The values of pH after the addition of glucose decreased during the first day of incubation approximately at about one unit and corresponded with the maximum increase of microbial biomass. The available heavy metal contents extracted by H<sub>2</sub>O, 1 mol/l NH<sub>4</sub>NO<sub>3</sub> and 0.005 mol/l DTPA increased during the first two days of incubation. Only a few significant relationships were found between the available metal contents and pH or microbial biomass. This fact could be ascribed to the different dynamics of the microbial biomass, pH and metal availability after glucose addition, when the highest metal contents during the incubation were usually reached one day later in respect to the greatest changes of pH and microbial activity. In comparison to soils without zeolite addition, the variants with natural clinoptilolite showed lower heavy metal contents in all used extractants with the exception of Cd which in H<sub>2</sub>O extracts tended to increase.

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