The present invention relates to the use of a quaternary ammonium glycoside surfactant as an adjuvant for fertilizers or pesticides, such as herbicides. The surfactant contains at least one hydrocarbon group with 6-24 carbon atoms and at least one quaternary ammonium group where at least one substituent is an alkyleneoxy containing group which is connected to a saccharide residue by a glycosidic bond. Also compositions containing pesticides or fertilizers are described. These quaternary ammonium glycoside surfactants have an essentially improved biodegradability. They also improve the uptake and efficacy of fertilizers and herbicides.
