Impact of maize formulated herbidcides, Mesotrione and S-Metolachlor, applied alone and in mixture, on soil microbial communities

Pierre Joly (1) , Pascale Pascale Besse, P. Besse-Hoggan Besse-Hoggan (2) , Frédérique Bonnemoy (1) , Isabelle Batisson (1) , Jacques Bohatier (1) , Clarisse Mallet (1)

1 LMGE - Laboratoire Microorganismes : Génome et Environnement
2 SEESIB - Synthèse et étude de systèmes à intêret biologique

In order to reduce the amounts of pesticides used, and thereby their associated risks, new generations of less environmentally dangerous molecules with lower weight are currently being used in the mixtures sprayed on crops. Few studies have been made, however, to analyse their impact on the soil, and more particularly on the microorganisms living in the soil which maintain the essential functions of this ecosystem. By taking a microcosmic approach, we were able to assess the impact of the maize herbicides "cocktail" Mesotrione and S-metolachlor on global soil microbial activity, biomass, and structures, by using the formulated compounds, respectively, Callisto and Dual Gold (both registered brands of Syngenta). Our results highlighted a synergetic effect in "cocktail" microcosms resulting in an increase in the Mesotrione herbicide dissipation time and in an impact on the microbial community at onefold field rate equally to more than a single herbicide used at tenfold field rate.

Pierre Joly, Pascale Pascale Besse, P. Besse-Hoggan Besse-Hoggan, Frédérique Bonnemoy, Isabelle Batisson, Jacques Bohatier, et al.. Impact of maize formulated herbidcides, Mesotrione and S-Metolachlor, applied alone and in mixture, on soil microbial communities. International Scholarly Research Network, ISRN Ecology, 2012, vol. 2012, ID 329898 (9 p.). ⟨hal-00679861⟩