C. Perrin-ganier et al., Effect of sludge-amendment or nutrient addition on the biodegradation of the herbicide isoproturon in soil, CHEMOSPHERE, 44(4), 2001, pp. 887-892
Adding sludge to agricultural soil results in added organic matter, nutrien
ts and metallic and/or organic pollutants. These components may modify the
behaviour of pesticides in the soil. We monitored possible changes in the d
egradation of the herbicide isoproturon (production of CO2 and degradation
products) in soil amended with sludge, heavy metals or nitrogen and phospho
rus. The treated and control soils were incubated under controlled conditio
ns for 60 days. The nitrogen and phosphorus had the greatest effect on isop
roturon degradation, independent of the presence of pollutants. Mineralisat
ion of the herbicide to CO2 was slow and seemed to be linked to a fast degr
adation and to the accumulation of a complex degradation product that was n
either catabolized nor adsorbed, 4,4 ' -diisopropylazobenzene. This degrada
tion pathway also produced smaller amounts of non-extractable residues. Sew
age sludge had no significant effect on isoproturon degradation, despite a
large increase of organic matter mineralisation (factor 2). (C) 2001 Elsevi
er Science Ltd. All rights reserved.