Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Formation and release of non-extractable C-14-Dicamba residues in soil under sterile and non-sterile regimes.
AU - Gevao, Bondi
AU - Jones, Kevin C.
AU - Semple, Kirk T.
PY - 2005/1
Y1 - 2005/1
N2 - The role of native soil microorganisms in the formation and release of non-extractable C-14-residues, previously treated with C-14- Dicamba, was investigated to examine their significance to the longer-term environmental effects on non-extractable pesticide residues. A 90 d study compared the fate of Dicamba under sterile and non-sterile regimes. In addition, soils were aged for 30 d and repeatedly extracted with a 0.01 M CaCl2 Solution, to an extraction end point, to produce non-extractable residues. The extracted soil containing non-extractable residues was mixed with clean soil that had been freshly spiked with non-labeled Dicamba at 0.2 mg kg(-1) to increase the bulk volume of the soil and stimulate microbial activity. Sub-samples were then introduced into microcosms to compare the extent of microbially facilitated release and mineralisation with release rates in sterile microcosms. The results show that microorganisms play a significant role in the formation and release of non-extractable Dicamba residues. The release of C-14-activity in sterile microcosms was linked to physical mixing of the extracted soil with field soil prior to the beginning of the incubations. The released C-14-activity may be further mineralized, reincorporated into humus, or taken up by plants or other soil inhabiting biota. (C) 2004 Elsevier Ltd. All rights reserved.
AB - The role of native soil microorganisms in the formation and release of non-extractable C-14-residues, previously treated with C-14- Dicamba, was investigated to examine their significance to the longer-term environmental effects on non-extractable pesticide residues. A 90 d study compared the fate of Dicamba under sterile and non-sterile regimes. In addition, soils were aged for 30 d and repeatedly extracted with a 0.01 M CaCl2 Solution, to an extraction end point, to produce non-extractable residues. The extracted soil containing non-extractable residues was mixed with clean soil that had been freshly spiked with non-labeled Dicamba at 0.2 mg kg(-1) to increase the bulk volume of the soil and stimulate microbial activity. Sub-samples were then introduced into microcosms to compare the extent of microbially facilitated release and mineralisation with release rates in sterile microcosms. The results show that microorganisms play a significant role in the formation and release of non-extractable Dicamba residues. The release of C-14-activity in sterile microcosms was linked to physical mixing of the extracted soil with field soil prior to the beginning of the incubations. The released C-14-activity may be further mineralized, reincorporated into humus, or taken up by plants or other soil inhabiting biota. (C) 2004 Elsevier Ltd. All rights reserved.
KW - pesticides
KW - non-extractable residues
KW - microbial activity
KW - extractability
U2 - 10.1016/j.envpol.2004.04.007
DO - 10.1016/j.envpol.2004.04.007
M3 - Journal article
VL - 133
SP - 17
EP - 24
JO - Environmental Pollution
JF - Environmental Pollution
SN - 0269-7491
IS - 1
ER -