
%0 Journal Article
%A Sparling, Graham 
%A Dragten, Robert 
%A Aislabie, Jackie 
%A Fraser, Rhonda 
%T Atrazine mineralisation in New Zealand topsoils and subsoils: influence of edaphic factors and numbers of atrazine-degrading microbes
%J Soil Research
%D 1998/06/30
%V 36
%N 4
%P 557-570
%K microbial degradation, subsoil.
%R https://doi.org/10.1071/S97065
%U https://www.publish.csiro.au/paper/S97065 
%X The mineralisation of 14C-ring-labelled atrazine to 14CO2 was measured in 3 contrasting New Zealand soils under controlled conditions of temperature and moisture. The numbers of atrazine-degrading organisms were measured by a most probable number technique. Decomposition rates were slow, with a maximum of 41% of atrazine being mineralised over 263 days. Mineralisation was generally very low in subsoils and was much reduced by low moisture content. However, one subsoil from 60&#8211;90 cm depth had unusually high numbers of atrazine-degrading microbes and showed mineralisation greater than or equivalent to the surface soil. Mineralisation was approximately doubled by a 10&#176;C rise in temperature over the range 16&#8211;28&#176;C. In general, the rate of atrazine mineralisation over 7&#8211;96 days could be predicted from the number of atrazine-degrading microbes and the cation exchange capacity of the soil (R2 = 0&#183;86). A large amount (54&#8211;77%) of 14C remained in the soil as non-extractable residues after 263 days, but only trace amounts of the added atrazine or the decomposition products de-ethyl atrazine and de-isopropyl atrazine were detected by extraction in organic solvent. 
