scholarly journals Microbes Mediated Mitigation of Abiotic Stresses in Agriculture

Author(s):  
S.S. Bobade ◽  
S.P. Dhekane ◽  
P.A. Salunke ◽  
S.G. Mane ◽  
S.S. Dhawan ◽  
...  

Background: Crop yields are limited by major biotic and abiotic stresses. Various studies had been suggested that abiotic stresses like drought, flood and salinity play a major role in limiting crop yield. Heavy metal contamination is also a major problem in the agriculture sector.Methods: A pot experiment was conducted to elucidate the effect of inoculating bacterial strains on the wheat plant under various stress conditions. The bacteria were isolated and screened from drought, flood and heavy metal stressed soil samples. The selected strains were identified by morphological, biochemical and molecular methods. The ability of Acinetobacter junni S1, Acinetobacter junni S2, Leclercia adecarboxylata and Klebsiella variicola to stimulate the growth of plants were determined by pot experiment using a completely randomized design. The positive effect of isolates on seed germination percent, shoot and root length of the treated wheat plant were recorded. Analysis of soil samples from pots was carried out for evaluation of the presence of macro and micronutrients. Result: The pots inoculated with selected isolates showed a significant increase in pH 7.77, EC 2.11, carbon 0.78, nitrogen 30.83 kg/ha, phosphorus 2.95 kg/ha, potassium 535.32 kg/ha, zinc 0.15 ppm, manganese 0.376 ppm, iron 0.53 ppm and copper 0.15 ppm as compared to control. The chlorophyll content estimation was carried out by using Arnon’s method. The chlorophyll a, b and total chlorophyll was found to be 14.39, 39.74 and 38.75 respectively.

Author(s):  
Dr. Salem M. ELNakeib ◽  
Dr. Fathi K. Elyaagubi ◽  
Dr. Mohamed A. Alrabib ◽  
Eng. Afaf Abouzed ◽  
Eng. Hanan Saleh Wanis

Soil samples were collected from and around Almarqub cement factory, AL-Khums city, Libya. These samples were collected from four different sites M1 (inside the factory), M2 (150 m from the factory), M3 (350 m from the factory) and M4 (60 km away from the factory as the control samples. The study was conducted to determine the heavy metal concentration in the soil. Organic matter, pH and water content value were determined according to the method described by Chaturvedi and Sankar (2006). Metals were determined by Atomic Absorption Spectrophotometer. The results obtained for the examined physiochemical properties of soil in the area studied prove that cement dust from the Almarqub cement factory has had a significant impact on the soil. The affected soil properties are pH and total calcium content. These properties were found to be higher than those in similar soils from the same area unpolluted. The increase of soil pH in the same area may be a result of precipitation of cement dust over the years. Metal uptake from cement to soil and plants. Metals determined in contamination soil indicated high concentrations in M1 inside cement factory compared to soil samples as control. Results of the analysis have shown that there are signs of slight impact of soil properties arising from the cement dust on the soils, especially at location inside the factory. Recommendations were offered to monitor the dust falling on the soils through trapping and utilizing the dust emissions of cement.


Author(s):  
Muhammad Murtaza Qureshi ◽  
Mohammad Amin Qureshi ◽  
Muhammad Saeed Qureshi ◽  
Afzal Shah

This study was aimed to assess the severity of heavy metal contamination in eastern coastal area of Pakistan. Agriculture lands near district Badin coastal area found contaminated due to mega surface canal drain network, carrying untreated industrial and municipal effluents along with pumped saline water. Thirty-two random soil samples were collected from different coastal areas. Arc Geographic Information System was used for spatial mapping. Soil samples from coastal areas of Badin contain average concentrations of heavy metals (mg/kg) as Hg 0.247±0.207, Ni 2.622±1.107,Zn 3.121±0.929, Cu 0.059±0.066, Fe 70.447±1.163, Mn7.062±1.251, Co 0.0167±0.033,Cr0.799±0.718.


2021 ◽  
Vol 306 ◽  
pp. 04013
Author(s):  
Triyani Dewi ◽  
Edhi Martono ◽  
Eko Hanudin ◽  
Rika Harini

Monitoring and assessment of heavy metal concentrations in shallot fields are needed to evaluate the potential risk of contamination due to heavy metals. This study aims to define the status of heavy metal contamination in shallot fields using contamination indices. A total of 184 soil samples (0-20 cm) were taken from shallot fields in Brebes Regency, Central Java. The soil samples were analyzed for the concentration of five heavy metals (Cd, Pb, Ni, Cr, and Co) with HNO3 and HClO4 extracts and measured using AAS. Assessment of the status of heavy metals contamination in the soil using contaminant factor (CF), geo-accumulation index (I-geo), and pollution load index (PLI). The mean concentration in shallot fields showed the following order Cr > Ni > Pb > Co > Cd and the concentration were still below critical limit values. Four metals are Pb, Cr, Co, and Ni are low contamination (CF<1), while Cd is considerable until very high contamination factor. Based on I-geo values, shallot fields are practically uncontaminated of Pb, Co, Ni, and Cr (I-geo<1), meanwhile the status of Cd is uncontaminated to moderately contaminated (0<I-geo<1). Generally, the shallot fields in Brebes Regency, Central Java is unpolluted with five metals (PLI<1).


1995 ◽  
Vol 7 (1) ◽  
pp. 9-14 ◽  
Author(s):  
G.G.C. Claridge ◽  
I.B. Campbell ◽  
H.K.J. Powell ◽  
Z.H. Amin ◽  
M.R. Balks

Soil samples from eight sites at Marble Point and Pram Point, McMurdo Sound region, contaminated by human activities were examined for heavy metal content, using sequential extraction methods. The redistribution of lead, zinc and copper arising from point sources of these metals was demonstrated. The levels found are not considered to represent serious pollution but do indicate that human activities can change the chemistry of the Antarctic environment in localized areas.


2018 ◽  
Vol 7 (1) ◽  
pp. 110-115
Author(s):  
Galina Yurievna Samoilenko ◽  
Evgeniy Aleksandrovich Bondarevich ◽  
Natalia Nikolaevna Kotsyurzhinskaya ◽  
Igor Anatolyevich Boriskin

The paper presents data on the content of gross and mobile forms of zinc, cadmium, lead and copper in the soils of Chita and its surroundings. The paper contains a comparative analysis of the accumulation (Kn) and movement (KP) coefficients of these microelements in organs ( Potentilla tanacetifolia Willd. ex Schlecht.), relative to their gross content and mobile forms in soils. The authors have revealed that soil samples of the studied sites contain unequal gross amount of heavy metals. In some points (6 and 3) the content of cadmium and zinc exceeded the Mac, that is why such soils have been attributed to heavily polluted. The index of biological activity on mobile forms of heavy metals in all sites significantly exceeded the same index on gross forms. It was found that Potentilla tanacetifolia are accumulators of heavy metal ions. Aboveground bodies accumulate and absorb cadmium and copper especially intensively, thus the content of mobile forms of these metals in the soil is insignificant. Excessive adsorption of trace elements in the phytomass of plants can be connected with surface contamination. According to the content of zinc and lead, the accumulation values in the organs of P. tanacetifolia were characterized by small coefficient values, against the background of their high concentration in the soil.


2020 ◽  
Vol 3 (6) ◽  
pp. 37-44
Author(s):  
Tatiana Kravsun ◽  

The article presents the results of phytotesting of soil solutions with high concentrations of heavy metal ions. The sensitivity of Donbass species plant to soil pollution was established by specific transformations in the structures of the embryonic root Achillea nobilis L., Artemisia vulgaris L., Centaurea diffusa Lam., Galinsoga parviflora Cav., Senecio vulgaris L., Tripleurospermum inodorum (L.) Sch. Bip. Model experiments on plant germination were carried out in laboratory conditions with fixed concentrations of individual metals and with joint pollution, as well as when testing soil samples taken in the zones of influence of industrial facilities of Don-bass.


Author(s):  
Nausha Shetty ◽  
◽  
Jyothi K Shetty ◽  
Dr Mohandas Chadaga ◽  
Dr Udaya Shankara H N ◽  
...  

The study involves evaluation of quality of groundwater and soil near the Thermal power plant located in Udupi District, Karnataka, India based on seasonal variation. 24 samples of ground water and soil were collected during Pre-Monsoon, Post- Monsoon and Monsoon Seasons from the places which are surrounding the Thermal Power plant. Collected Ground water samples were tested for detection of various heavy metal concentrations such as Ni, Fe, Mn, Cr, and Pb and soil samples were detected for Ni, Fe, Mn, Cr, Pb, Cd and Co. Collected soil samples were sieved according to different Standard sieve size. After sieving, soil samples were digested using tri-acids (Nitric Acid, Hydrogen peroxide and Concentrated Hydrochloric acid). Both Ground water and Soil samples were analysed for heavy metal contamination by using Atomic Absorptive Spectrometry. From the results obtained for Pre-Monsoon, Post-Monsoon and Monsoon Season it showed that concentration of heavy metals in the samples were exceeding the permissible limit prescribed by WHO and BIS. Hence preliminary treatment should be done before discharging in to Ash ponds.


Author(s):  
Laxmi Kant Sharma

Pollution of natural environment due to release of heavy metals from various sources is a widespread problem throughout the world. This study explains the effect of heavy metal contaminants in Roadside soil of Morena district. Twelve air dried surface soil samples were collected from 50cm – 1m (point A) and twelve from 30m (point B) away from the roadside along a road with a distance of 50 km. Heavy metals were found in both points with highest concentration at 50cm – 1m (point A). Roadside soil is a definite indicator of vehicular pollution from where the high degree of contamination, is expected. The presence of heavy metals like Cu, Cr, Fe, Pb, Zn and Mn in the roadside soil was also considerable.


2018 ◽  
Vol 39 (5) ◽  
pp. 1921
Author(s):  
Laércio Santos Silva ◽  
Izabel Cristina de Luna Galindo ◽  
Vinícius Augusto Filla ◽  
Romário Pimenta Gomes ◽  
Milton César Costa Campos ◽  
...  

Sequential extraction or chemical fractionation of heavy metals allows inferences to be made about their origin, occurrence, bioavailability, toxic potential and environmental contamination. Thus, the present study aimed to assess the distribution of Cu, Mn, Ni, Pb and Zn among the different soil fractions and landscape compartments of a yellow latosol cultivated with vegetables. Soil samples were collected from five areas cultivated with tomato (Lycopersicon esculentum, Mill.), lettuce (Lactuca sativa), chili pepper (Capsicum annuum L.) and chard (Beta vulgaris L.) in different slope positions (upper, middle, lower), and four reference areas (native forest), at a depth of 0.00 - 0.20 m. Heavy metal levels were also assessed in water used to irrigate the crops and for human consumption by collecting 200 ml of water samples from reservoirs. The soil samples were sequentially fractionated to quantify the concentrations of adsorbed Cu, Mn, Ni, Pb and Zn in the exchangeable (EF), organic matter (OF), amorphous and crystalline iron oxide fractions (AFeOx and CFeOx). Landscape position only interfered significantly in heavy metal adsorption in the soil for Cu and Ni associated with CFeOx and Zn bound to the EF in the farming areas. The highest Cu, Ni, Pb and Zn levels were found in the fractions with less stable chemical bonds (bound to organic matter), in addition to a strong affinity between Cu, Zn and Mn and the oxide fractions (AFeOx + CFeOx). The low affinity of Pb and Ni for the AFeOx and CFeOx fractions indicates greater contamination potential for the water reservoirs. In the short term, organic matter is the main source of remediation for heavy metal contamination in soil, making it important to adopt conservation practices aimed at reducing OM losses.


2016 ◽  
Vol 18 (4) ◽  
pp. 742-760 ◽  

<div> <p>This paper present migration of some selected heavy metal (zinc, lead, copper, chromium and nickel) of roadside soil samples from along Ilesa-Akure highway with a view to assess the degree of contamination such soils contain and the likelihood that this contamination can be remobilized. Soil samples were collected from 5 locations (Ilesa, Ipetu-ijesa, JABU, Ilara-mokin and FUTA north gate) at depths of 0-5, 15-20, 35-40 and 55-60cm and analysed for the five selected heavy metals in the bulk sample and clay fraction. Their concentrations and distributions in four different road verge zones (5m, 30m, 60m and 110m) were determined. The 5m zone had the highest mean concentration of the five metals whereas the 110m zone exhibited the lowest mean concentration. Zinc and lead exhibited a significant decrease in the roadside soils with the increasing distance from the road while chromium and nickel showed significant increase, copper on the other hand showed no significant difference. Quantitative assessment of the heavy metal contamination using the I<sub>geo </sub>and <em>PI</em> indexes showed that the selected heavy metals were in the order of Cu &lt; Pb &lt; Zn &lt; Ni &lt;Cr for both Indexes. Soil characteristics (which include pH, Cation exchange capacity {CEC}, organic matter and other basic geotechnical tests) responsible for the mobility and vertical distributions of these heavy metals from the road side soil were also assessed.</p> </div> <p>&nbsp;</p>


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