Source:http://linkedlifedata.com/resource/pubmed/id/11476506
Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4
|
pubmed:dateCreated |
2001-7-30
|
pubmed:abstractText |
Soil fumigation using shank injection creates high fumigant concentration gradients in soil from the injection point to the soil surface. A temperature gradient also exists along the soil profile. We studied the degradation of methyl isothiocyanate (MITC) and 1,3-dichloropropene (1,3-D) in an Arlington sandy loam (coarse-loamy, mixed, thermic Haplic Durixeralf) at four temperatures and four initial concentrations. We then tested the applicability of first-order, half-order, and second-order kinetics, and the Michaelis-Menten model for describing fumigant degradation as affected by temperature and initial concentration. Overall, none of the models adequately described the degradation of MITC and 1,3-D isomers over the range of the initial concentrations. First-order and half-order kinetics adequately described the degradation of MITC and 1,3-D isomers at each initial concentration, with the correlation coefficients greater than 0.78 (r2> 0.78). However, the derived rate constant was dependent on the initial concentration. The first-order rate constants varied between 6 and 10x for MITC for the concentration range of 3 to 140 mg kg(-1), and between 1.5 and 4x for 1,3-D isomers for the concentration range of 0.6 to 60 mg kg(-1), depending on temperature. For the same initial concentration range, the variation in the half-order rate constants was between 1.4 and 1.7x for MITC and between 3.1 and 6.1x for 1,3-D isomers, depending on temperature. Second-order kinetics and the Michaelis-Menten model did not satisfactorily describe the degradation at all initial concentrations. The degradation of MITC and 1,3-D was primarily biodegradation, which was affected by temperature between 20 and 40 degrees C, following the Arrhenius equation (r2 > 0.74).
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/1,3-dichloro-1-propene,
http://linkedlifedata.com/resource/pubmed/chemical/Allyl Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Herbicides,
http://linkedlifedata.com/resource/pubmed/chemical/Insecticides,
http://linkedlifedata.com/resource/pubmed/chemical/Isothiocyanates,
http://linkedlifedata.com/resource/pubmed/chemical/methyl isothiocyanate
|
pubmed:status |
MEDLINE
|
pubmed:issn |
0047-2425
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
30
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
1278-86
|
pubmed:dateRevised |
2006-11-15
|
pubmed:meshHeading |
pubmed-meshheading:11476506-Allyl Compounds,
pubmed-meshheading:11476506-Fumigation,
pubmed-meshheading:11476506-Herbicides,
pubmed-meshheading:11476506-Insecticides,
pubmed-meshheading:11476506-Isothiocyanates,
pubmed-meshheading:11476506-Kinetics,
pubmed-meshheading:11476506-Models, Theoretical,
pubmed-meshheading:11476506-Temperature
|
pubmed:articleTitle |
Degradation of soil fumigants as affected by initial concentration and temperature.
|
pubmed:affiliation |
USDA-ARS, Soil Physics and Pesticides Research Unit, George E Brown Jr Salinity Lab, Riverside, CA 92507, USA.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, Non-P.H.S.
|