Research was conducted on the leachability and dissipation of sodium azide applied to soil as a solution or as granules with various coatings. The sodium azide leached readily from all formulations, leaving sections of the soil profile with insufficient concentrations to stimulate germination of dormant wild oat (Avena fatua L.) seed. Sodium azide-impregnated clay granules coated with 5% (w/w) polyethylene glycol increased germination of wild oat seed two-fold over uncoated granules at a rate of 5.6 kg sodium azide/ha in field experiments. The polyethylene glycol coating reduced the rate of sodium azide dissipation from the soil in growth chamber experiments. Formulation of sodium azide has potential for increasing wild oat germination stimulation under field conditions.
