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

2003 ◽  
Vol 38 (11) ◽  
pp. 1329-1335 ◽  
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.

Inexpensive soil flask for 14C-pesticide degradation studies

1980 ◽  
Vol 12 (6) ◽  
pp. 583-585 ◽  
Author(s):  
Michael A. Loos ◽  
Arnold Kontson ◽  
Philip C. Kearney
Keyword(s):  
Pesticide Degradation ◽  
Degradation Studies

scholarly journals Changes in Soluble-N in Forest and Pasture Soils after Repeated Applications of Tannins and Related Phenolic Compounds

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Jonathan J. Halvorson ◽  
Javier M. Gonzalez ◽  
Ann E. Hagerman
Keyword(s):  
Soil Microorganisms ◽  
Nitrogen Availability ◽  
Extraction Efficiency ◽  
Agricultural Soils ◽  
Hot Water ◽  
Land Uses ◽  
Soil N ◽  
Water Control ◽  
Cool Water ◽  
Repeated Applications

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.

scholarly journals Potential of biochar after the biological activation by native soil microflora

2021 ◽  
Vol 26 (3) ◽  
pp. e2219
Author(s):  
Helena Dvorackova ◽  
Jaroslav Záhora ◽  
Lubica Pospíšilová ◽  
Vítězslav Vlček
Keyword(s):  
Dehydrogenase Activity ◽  
Soil Microorganisms ◽  
Mineral Fertilizer ◽  
Statistical Test ◽  
Soil Microflora ◽  
Mineral Fertilizers ◽  
Activated Biochar ◽  
Native Soil ◽  
Negative Effect ◽  
And Control

Objective. Dehydrogenase activity after the biological activation of biochar by the native soil microorganisms was studied. The main aim was to improve biochar properties by activation and make it more friendly for the soil microflora. Materials and methods. The activation was reached by aerating with the soil solution for two weeks. No special inoculum of microorganisms was applied. The following treatments in four replicates were prepared: conventional raw biochar (BR), activated biochar (BA), mineral fertilizer DAM 390 (NF), and control (C). A statistical test for comparing treatments means (Fisher p≤0.05; program STATISTICA 12.0; StatSoft software Inc., Tulsa, Oklahoma, USA) was used. Results. Statistically significant differences in the dehydrogenase activity between the treatments BR, BA, and C were found. Application of mineral fertilizers had a negative effect and increasing of nitrogen leaching was observed. Conclusions. Activating of biochar is suitable metods for impove soil biota conition compared with convention biochar.

scholarly journals Degradation dynamics and dissipation kinetics of an imidazole fungicide (Prochloraz) in aqueous medium of varying pH

2008 ◽  
Vol 1 (3-4) ◽  
pp. 203-205 ◽  
Author(s):  
Md. Aktar ◽  
Dwaipayan Sengupta ◽  
Swarnali Purkait ◽  
Madhumita Ganguly ◽  
M. Paramasivam
Keyword(s):  
Aqueous Medium ◽  
Water Samples ◽  
Half Life ◽  
Residue Analysis ◽  
Uv Detector ◽  
Dissipation Kinetics ◽  
Degradation Studies ◽  
Kinetics Of

Degradation dynamics and dissipation kinetics of an imidazole fungicide (Prochloraz) in aqueous medium of varying pHLaboratory degradation studies were performed in water at pH 4.0, 7.0 and 9.2 using Prochloraz (450 EC) formulation at the concentration of 1.0 (T1) and 2.0 (T2) μg/mL. Water samples collected on 0 (2 h), 3, 7, 15, 30, 45, 60 and 90 days after treatments were processed for residue analysis of Prochloraz by HPLC-UV detector. In 60 days, dissipation was 89.1-90.5% at pH 4.0, 84.1-88.2% at pH 7.0, and 92.4-93.8% at pH 9.2 in both treatments. The results indicate that at pH 7.0 the degradation of Prochloraz was much slower as compared to other two. Between pH 4.0 and 9.2 the degradation of compound is little faster at pH 9.2. The half-life periods observed were 18.35 and 19.17 days at pH 4.0, 22.6 and 25.1 days at pH 7.0 and 15.8 and 16.6 days at pH 9.2 at T1and T2doses respectively.

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

Weed Science ◽  
1988 ◽  
Vol 36 (1) ◽  
pp. 96-101 ◽  
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.

Responses of Soil Microorganisms and Enzymes to Repeated Applications of Chlorothalonil

2006 ◽  
Vol 54 (26) ◽  
pp. 10070-10075 ◽  
Author(s):  
Yun Long Yu ◽  
Min Shan ◽  
Hua Fang ◽  
Xiao Wang ◽  
Xiao Qiang Chu
Keyword(s):  
Soil Microorganisms ◽  
Repeated Applications

scholarly journals Degradation and sorption of fipronil and atrazine in Latossols with organic residues from sugarcane crop

2016 ◽  
Vol 46 (7) ◽  
pp. 1172-1177 ◽  
Author(s):  
Raquel de Oliveira Silva ◽  
Rômulo Penna Scorza Júnior ◽  
Maricy Raquel Lindenbah Bonfá ◽  
Maria Fernanda Zaneli Campanari ◽  
Ieda de Carvalho Mendes
Keyword(s):  
Half Life ◽  
Field Capacity ◽  
Organic Residues ◽  
Pesticide Degradation ◽  
Mato Grosso ◽  
Sugarcane Crop ◽  
Degradation Rates ◽  
Life Values ◽  
Mato Grosso Do Sul ◽  
Atrazine Degradation

ABSTRACT: Organic residues from sugarcane crop and processing (vinasse, boiler ash, cake filter, and straw) are commonly applied or left on the soil to enhance its fertility. However, they can influence pesticide degradation and sorption. The objective of this study was to assess the effect of adding these organic residues on the degradation and sorption of fipronil and atrazine in two soils of the State of Mato Grosso do Sul, MS, Brazil. The degradation experiment was carried out with laboratory-incubated (40 days; 28°C; 70% field capacity) soils (0-10cm). The batch equilibration method was used to determine sorption. Fipronil (half-life values of 15-105 days) showed to be more persistent than atrazine (7-17 days). Vinasse application to the soil favored fipronil and atrazine degradation, whereas cake filter application decreased the degradation rates for both pesticides. Values for sorption coefficients (Kd) were determined for fipronil (5.1-13.2mL g-1) and atrazine (0.5-1.5mL g-1). Only straw and cake filter residues enhanced fipronil sorption when added to the soil, whereas all sugarcane residues increased atrazine sorption.

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