By going early, you have a chance to visit with them and ask their permission to hunt on their property. Most of the time, the farmers do not mind dove hunters as much as they do deer hunters with high powered rifles. I guess they realize that a shotgun does not pose the danger that a rifle does and therefore are more willing to let you hunt their property for doves. Most of the time, they do not hunt doves and don't seem to mind if you do. The main reason I scout the area, is to locate the fly ways of the doves, in order to get a good shooting position on opening day.
Doves are very predictive in their movements.
If you find a concentration of birds a couple of weeks before the season opens, there is a very good chance that they will still be there on opening day. Once you locate the birds, the second thing is to pattern the birds so that you know where to hunt in the field you are working. Doves fly the same flyway in the field over and over again. If you see a dove fly along a fence row and turn at a certain corner and fly over a certain tree line, you can almost be certain that other doves will use the same path, almost as if they were following each other. If you watch several doves cross a field or follow a tree line, you can get in the path and you will get lots of shots that you would otherwise not get 50 or 100 yards from that spot.