Responses of Soil Microorganisms and Enzymes to Repeated Applications of Chlorothalonil

Tannins (produced by plants) can reduce the solubility of soil-N. However, comparisons of tannins to related non-tannins on different land uses are limited. We extracted soluble-N from forest and pasture soils (0–5 cm) with repeated applications of water (Control) or solutions containing procyanidin from sorghum, catechin, tannic acid, β-1,2,3,4,6-penta-O-galloyl-D-glucose (PGG), gallic acid, or methyl gallate (10 mg g−1soil). After eight treatments, samples were rinsed with cool water (23°C) and incubated in hot water (16 hrs, 80°C). After each step, the quantity of soluble-N and extraction efficiency compared to the Control was determined. Tannins produced the greatest reductions of soluble-N with stronger effects on pasture soil. Little soluble-N was extracted with cool water but hot water released large amounts in patterns influenced by the previous treatments. The results of this study indicate hydrolyzable tannins like PGG reduce the solubility of labile soil-N more than condensed tannins like sorghum procyanidin (SOR) and suggest tannin effects will vary with land management. Because they rapidly reduce solubility of soil-N and can also affect soil microorganisms, tannins may have a role in managing nitrogen availability and retention in agricultural soils.

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Influence of repeated applications of glyphosate on its persistence and soil bioactivity

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2003001100012 ◽

2003 ◽

Vol 38 (11) ◽

pp. 1329-1335 ◽

Cited By ~ 53

Author(s):

Mara Mercedes de Andréa ◽

Terezinha Bonanho Peres ◽

Luiz Carlos Luchini ◽

Sheila Bazarin ◽

Solange Papini ◽

...

Keyword(s):

Dehydrogenase Activity ◽

Half Life ◽

Soil Microorganisms ◽

Pesticide Degradation ◽

14Co2 Production ◽

Repeated Applications ◽

Degradation Studies ◽

Herbicide Glyphosate

Pesticide degradation studies are essential to evaluate its impact in the environment and on non-target organisms. The effect of repeated soil applications of the herbicide glyphosate on its dissipation and on soil microorganisms was studied by radiometric and microbial techniques. Results indicated fast dissipation of the [14C]-glyphosate or [14C]metabolites extractable residues (half-life of 0.92±0.29 month), but increasing half-lives of total mineralization ranging from 2.2 to 3.4 months as the number of applications increased from 1 to 4. No significant correlation was found between 14CO2 production and dehydrogenase activity.

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Populations of EPTC-Degrading Microorganisms in Soils by Accelerated Rates of EPTC Degradation

Weed Science ◽

10.1017/s0043174500074518 ◽

1988 ◽

Vol 36 (1) ◽

pp. 96-101 ◽

Cited By ~ 14

Author(s):

Thomas B. Moorman

Keyword(s):

Soil Microorganisms ◽

Most Probable Number ◽

Silt Loam ◽

Probable Number ◽

Herbicide Degradation ◽

Silt Loam Soil ◽

Loam Soil ◽

Previously Treated ◽

Repeated Applications ◽

Degrading Microorganism

Reduced effectiveness of carbamothioate (thiocarbamate) herbicides in certain soils has been attributed to rapid herbicide degradation by soil microorganisms. Studies were conducted to determine if greater populations of EPTC (S-ethyl dipropyl carbamothioate)-degrading microorganisms were responsible for increased rates of degradation observed following repeated applications of EPTC to a Grenada silt loam soil. EPTC-degrading microorganism populations, measured with a14C-MPN (most-probable-number) technique, were not larger in soils with accelerated rates of EPTC degradation, and degrader populations did not increase after application of 6 mg EPTC/kg of soil. Degrader populations increased after application of 60 mg EPTC/kg of soil only in soil previously treated for 6 yr with EPTC. Increased rates of metabolism of EPTC were apparently responsible for the increased rates of degradation, rather than increased populations of degraders.

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Changes on polystyrene surface and biofilm formation as indication of biodegradation by soil microorganisms

10.1055/s-0037-1608184 ◽

2017 ◽

Author(s):

F Mohd Fadhil Mohd ◽

M Sharifah Aminah Syed ◽

J Siti Norazura

Keyword(s):

Biofilm Formation ◽

Soil Microorganisms ◽

Polystyrene Surface

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Soil response to chemicals used in a field experiment

International Agrophysics ◽

10.2478/v10247-012-0080-0 ◽

2013 ◽

Vol 27 (2) ◽

pp. 151-158 ◽

Cited By ~ 6

Author(s):

S. Jezierska-Tys ◽

A. Rutkowska

Keyword(s):

Alkaline Phosphatase ◽

Enzymatic Activity ◽

Field Experiment ◽

Soil Microorganisms ◽

Block Design ◽

Soil Samples ◽

Alkaline Phosphatases ◽

Soil Response ◽

Negative Effect ◽

Set Up

Abstract The effect of chemicals (Reglone 200 SL and Elastiq 550 EC) on soil microorganisms and their enzymatic activity was estimated. The study was conducted in a field experiment which was set up in the split-block design and comprised three treatments. Soil samples were taken six times, twice in each year of study. The results showed that the application of chemicals generally had no negative effect on the number of soil microorganisms. The application of Reglone 200 SL caused an increase of proteolytic and ureolytic activity and affected the activity of dehydrogenases, acid and alkaline phosphatases in the soil. The soil subjected of Elastiq 550 EC was characterized by lower activity of dehydrogenases, protease, urease and alkaline phosphatase.

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