Fibrophos is certainly abrasive & corrosive but I'm unsure of how "hot" it is on the crop. My predecessors have killed cotyledon stage osr by applying 0.12.12 but what isn't clear is whether it was from the abrasion or any toxicity. I'd be wary of putting it in a seed hopper unless is was totally dry & there was good agitation to prevent it bridging.
@tw15 - does your drill put the fertiliser down a separate spout away from the seed or is it dropped into the same airstream?
@tw15 - does your drill put the fertiliser down a separate spout away from the seed or is it dropped into the same airstream?