Placing the compound at a greater depth can minimize its emission into the air during soil fumigation. The studies also showed that disking and surface-packing closed the cracks in the soil above the injection sites. This, along with increasing the water content at the surface, helped reduce total methyl bromide emissions. Degradation Degradation, or the breaking down, of methyl bromide in the soil keeps it from escaping into the atmosphere. Yates and colleagues found that less methyl bromide escaped from soils high in organic matter.
Organic matter enhances degradation by providing a way for the chemical to uncouple.
Once this occurs, the part of primary co cern, bromine, remains in the soil as bromide. Therefore, increasing the organic matter in the soil allows less of the chemical to escape. If new ways to enhance methyl bromide's effectiveness could be developed, the quantity needed for agricultural uses would be reduced, thereby reducing the amount released into the atmosphere, Yates says. In general, the amount and depth of injection depends on soil conditions and the type and distribution of target organisms. Therefore, the ideal injection depth for pest control differs for these two crops.