TY - JOUR
T1 - Influence of commercial formulation on leaching of four pesticides through soil
AU - Khan, Majid Ali
AU - Brown, Colin David
N1 - © 2016 Published by Elsevier B.V. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. Embargo period : 12 months
PY - 2016/12/15
Y1 - 2016/12/15
N2 - Studies with small soil columns (2 cm i.d. x 5.4
cm depth) compared leaching of four pesticides added either as technical
material or as commercial formulations. Pesticides were selected to give a
gradient of solubility in water between 7 and 93 mg L-1, comprising
azoxystrobin (emulsifiable concentrate, EC, and suspension concentrate, SC),
cyproconazole (SC), propyzamide (SC) and triadimenol (EC). Columns of sandy
loam soil were leached with 6 pore volumes of 0.01M CaCl2 either 1
or 7 days after treatment. Separate experiments evaluated leaching of
triadimenol to full breakthrough following addition of 18 pore volumes of 0.01M
CaCl2. The mass of pesticide leached from columns treated with
commercial formulation was significantly larger than that from columns treated
with technical material for all compounds studied and for both leaching
intervals (two-sided t-tests, p<0.001). This difference was conserved when
triadimenol was leached to full breakthrough with 79 ± 1.2 and 61 ± 3.1% of
applied triadimenol leached from columns treated with formulated and technical
material, respectively. There were highly significant effects of formulation
for all pesticides (two-way ANOVA, p<0.001), whereas leaching interval was
only significant for azoxystrobin EC formulation and cyproconazole (p <0.001
and 0.021, respectively) with greater leaching when irrigation commenced 1 day
after treatment. Leaching of azoxystrobin increased in the order technical
material (6.0% of applied pesticide) < SC formulation (8.5-9.1% of applied) <
EC formulation (15.8-21.0% of applied). The relative difference between
leaching of formulated and technical pesticide increased with pesticide
solubility in water, increasing from a factor of 1.4 for the SC formulation of
azoystrobin to 4.3 for the SC formulation of triadimenol. Experimental systems
differ markedly from field conditions (small columns with intense irrigation).
Nevertheless, results indicate the need to consider further the influence of
co-formulants in pesticide formulations on behaviour of the active ingredient
in soil.
AB - Studies with small soil columns (2 cm i.d. x 5.4
cm depth) compared leaching of four pesticides added either as technical
material or as commercial formulations. Pesticides were selected to give a
gradient of solubility in water between 7 and 93 mg L-1, comprising
azoxystrobin (emulsifiable concentrate, EC, and suspension concentrate, SC),
cyproconazole (SC), propyzamide (SC) and triadimenol (EC). Columns of sandy
loam soil were leached with 6 pore volumes of 0.01M CaCl2 either 1
or 7 days after treatment. Separate experiments evaluated leaching of
triadimenol to full breakthrough following addition of 18 pore volumes of 0.01M
CaCl2. The mass of pesticide leached from columns treated with
commercial formulation was significantly larger than that from columns treated
with technical material for all compounds studied and for both leaching
intervals (two-sided t-tests, p<0.001). This difference was conserved when
triadimenol was leached to full breakthrough with 79 ± 1.2 and 61 ± 3.1% of
applied triadimenol leached from columns treated with formulated and technical
material, respectively. There were highly significant effects of formulation
for all pesticides (two-way ANOVA, p<0.001), whereas leaching interval was
only significant for azoxystrobin EC formulation and cyproconazole (p <0.001
and 0.021, respectively) with greater leaching when irrigation commenced 1 day
after treatment. Leaching of azoxystrobin increased in the order technical
material (6.0% of applied pesticide) < SC formulation (8.5-9.1% of applied) <
EC formulation (15.8-21.0% of applied). The relative difference between
leaching of formulated and technical pesticide increased with pesticide
solubility in water, increasing from a factor of 1.4 for the SC formulation of
azoystrobin to 4.3 for the SC formulation of triadimenol. Experimental systems
differ markedly from field conditions (small columns with intense irrigation).
Nevertheless, results indicate the need to consider further the influence of
co-formulants in pesticide formulations on behaviour of the active ingredient
in soil.
U2 - 10.1016/j.scitotenv.2016.09.076
DO - 10.1016/j.scitotenv.2016.09.076
M3 - Article
SN - 0048-9697
VL - 573
SP - 1573
EP - 1579
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -