
According to Defra's Green Code, you are Not allowed to spray within a meter of the top of dikes or hedgerows. Most farmers leave at least a meter round the field for wildlife. but that doesnt stop the drift.
Unfortunatly he is not doing anythig wrong,
In an ideal world he would go round to anyone that lives near his field and let them know.
In REALITY, he will not have the time for this, as trapsing round notifying people of you spraying takes up alot of time, believe me I know LOL, and this is not a legal stipulation.
The white foam stuff, could just be what is called a Wetter, the stuff you add to the spray just rto help the spray adhere to the crops better.
The best thing to do it to ring the farmer up and ask him. Just make sure if you do, say you have no problems with him spraying you would just like to know because of the dogs. I am sure he will oblige seeing as you have said in the past he is fine about you having the dogs :) :)
HTH
Lea :) :)