Hi Viz.
Sounds like you could be shooting over ground which is quite open?
Most planted fields are a waste of time shooting, as they are normaly planted edge to edge, no verges to work.
But.....when they are harvested, there should be some good pigeon action, and a bit of bunny activity.
All I could suggest is....keep the wind/breeze in your face, approach your permission/ quarry accordingly, dont wear deoderant/aftershave,wash your kit in rain water no soap or detergents etc, break up your shape, be carful of your silohete, use the natural cover if possible, i.e.stay tight to hed