title: Diuron mineralisation in a Mediterranean vineyard soil: impact of moisture content and temperature.
abstract: BACKGROUND
  The diuron-mineralising ability of the microbiota of a Mediterranean vineyard soil exposed each year to this herbicide was measured. The impact of soil moisture and temperature on this microbial activity was assessed.
  
  
  RESULTS
  The soil microbiota was shown to mineralise diuron. This mineralising activity was positively correlated with soil moisture content, being negligible at 5% and more than 30% at 20% soil moisture content. According to a double Gaussian model applied to fit the dataset, the optimum temperature/soil moisture conditions were 27.9 degrees C/19.3% for maximum mineralisation rate and 21.9 degrees C/18.3% for maximum percentage mineralisation. The impact of temperature and soil moisture content variations on diuron mineralisation was estimated. A simulated drought period had a suppressive effect on subsequent diuron mineralisation. This drought effect was more marked when higher temperatures were used to dry (40 degrees C versus 28 degrees C) or incubate (28 degrees C versus 20 degrees C) the soil. The diuron kinetic parameters measured after drought conditions were no longer in accordance with those estimated by the Gaussian model.
  
  
  CONCLUSIONS
  Although soil microbiota can adapt to diuron mineralisation, its activity is strongly dependent on climatic conditions. It suggests that diuron is not rapidly degraded under Mediterranean climate, and that arable Mediterranean soils are likely to accumulate diuron residues.
authors: INRA, Université de Bourgogne, UMR Microbiologie du Sol et de l'Environnement, Dijon, France.
authors: Talaat
authors: T
authors: El Sebaï
authors: Marion
authors: M
authors: Devers
authors: Bernard
authors: B
authors: Lagacherie
authors: Nadine
authors: N
authors: Rouard
authors: Guy
authors: G
authors: Soulas
authors: Fabrice
authors: F
authors: Martin-Laurent
mesh_terms: D004237:Diuron / Q000378:metabolism*; D007700:Kinetics; D019083:Mediterranean Region; D054892:Metagenome; D008903:Minerals / Q000378:metabolism*; D010575:Pesticides / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D013696:Temperature; D014867:Water / Q000032:analysis*; D014920:Wine
chemical_list: D008903:Minerals; D010575:Pesticides; D012987:Soil; D014867:Water; D004237:Diuron