Comparative plant uptake and microbial degradation of trichloroethylene in the rhizospheres of five plant species-- implications for bioremediation of contaminated surface soils

Degradation of chlorobenzoic acids (e.g., products of microbial degradation of PCB) by strains of microorganisms isolated from PCB contaminated soils was assessed. From seven bulk-soil isolates two strains unique in ability to degrade a wider range of chlorobenzoic acids than others were selected, individually and even in a complex mixture of 11 different chlorobenzoic acids. Such a feature is lacking in most tested degraders. To investigate the influence of vegetation on chlorobenzoic acids degraders, root exudates of two plant species known for supporting PCB degradation in soil were tested. While with individual chlorobenzoic acids the presence of plant exudates leads to a decrease of degradation yield, in case of a mixture of chlorobenzoic acids either a change in bacterial degradation specificity, associated with 3- and 4-chlorobenzoic acid, or an extension of the spectrum of degraded chlorobenzoic acids was observed.

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Recovery of Phosphorus in Soils Amended with Manure for 119 Years

Agronomy ◽

10.3390/agronomy10121947 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1947

Author(s):

Amber Pasket ◽

Hailin Zhang ◽

William Raun ◽

Shiping Deng

Keyword(s):

Soil Profile ◽

Plant Uptake ◽

Environmental Concern ◽

Fertilizer Application ◽

Chemical Fertilizer ◽

Surface Soils ◽

Manure Application ◽

P Accumulation ◽

Untreated Check ◽

Total P

Manure phosphorus (P) accumulation in soils is of environmental concern. The objectives were to determine P concentrations and fate in soils following 119 years of manure and 89 years of chemical fertilizer application. The recovery and distribution of P were evaluated for five years in soils from the untreated check, and soils amended with manure, fertilizer-P, or NPK. Total P concentrations were significantly higher in fertilizer-treated surface soils, compared to manure application. Treated plots had significantly higher P concentrations than the check. Virtually all of the added P was accounted for, either remaining in the soil or harvested in grains. Over 50% of fertilizer-P and about 38% of manure-P were found in the top 15 cm of the soil. A majority (81–99%) of the added fertilizer-P was found in the top 30 cm, while about 40% of manure-P leached down to the 30–90 cm level of the soil profile. Following 119 years of moderate application, manure-P did not reach deeper than 90 cm, suggesting that leaching to groundwater is not a concern at this site. Preserving P in the lower soil profile could enhance the potential for plant uptake.

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Microbial Degradation of Ametryn in Hawaiian Torrox and Hydrandept Surface Soils

Soil Science Society of America Journal ◽

10.2136/sssaj1975.03615995003900040027x ◽

1975 ◽

Vol 39 (4) ◽

pp. 669-673 ◽

Cited By ~ 2

Author(s):

Kishore P. Goswami ◽

Richard E. Green

Keyword(s):

Microbial Degradation ◽

Surface Soils

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Cadmium phytoavailability in some New Zealand soils

Soil Research ◽

10.1071/s98070 ◽

1999 ◽

Vol 37 (3) ◽

pp. 461 ◽

Cited By ~ 50

Author(s):

C. W. Gray ◽

R. G. McLaren ◽

A. H. C. Roberts ◽

L. M. Condron

Keyword(s):

New Zealand ◽

Plant Species ◽

Plant Uptake ◽

Ammonium Acetate ◽

Human Consumption ◽

Maximum Residue Limit ◽

Fresh Weight ◽

Cd Uptake ◽

Significant Relationships ◽

Level Of Significance

The suitability of 8 common soil extractants to predict plant uptake of cadmium (Cd) from 10 New Zealand soils at low Cd concentrations was investigated in a glasshouse experiment. In addition, a study of Cd uptake by several vegetable, cereal, and pasture species in relation to different soil types was undertaken. The concentrations of Cd extracted from soils varied with each extractant: 0·05 acid ammonium acetate-EDTA (pH 4·65) extracted the greatest concentration of Cd, whereas 0·01 CaCl2 extracted the least. Results indicate that for all extractants tested, there were significant relationships between the concentration of Cd extracted and the concentration of Cd in plant material; however, the level of significance depended on the plant species and individual soil extractant. When all plants were considered together, it was found that 0·05 Ca(NO3)2 was the best predictor of plant Cd concentrations. Total Cd concentration was found to be the most important soil parameter influencing plant Cd concentrations. Plant Cd concentrations varied greatly among different plant species. The greatest uptake was found in lettuce and to a lesser extent carrot tops, and least in ryegrass, clover, and barley. All plants examined were within the maximum residue limit (MRL) in New Zealand for the Cd content of all foodstuffs intended for human consumption (i.e. 1 mg Cd/kg fresh weight).

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