Best location for a pit in a field??

[sharpshooter]

Question for many of you field hunters:
We have three 40 acre fields that we will be flooding for the first time next year. They are all identical square fields. 40 acres is a little large to be shooting over, so I'd like to sink some pits in them. Where should I place the pits? (other than "wherever the ducks are"). 2 of the fields are bordered on 2 sides by trees, and one is completely open. I have been told by some that the middle of the field may not necessarily be the best location. Or, should I place one pit in the open field and just stand in the treelines on the others? The wariness of the ducks that we've shot at the last 2 years makes me want to just do that. Any suggestions would be helpful.

[Nitro Mag]

I'd put the pit on the shallow water side about 75-100 yards from the edge of the water or in the turn row. If you put in the field , put to where you can pull a levee across the field to each end. This will help breakup the outline of the pit. If you put it in the turnrow the top should be even with the turnrow. Then instead of a top just bundle some johnson grass or rice straw to cover the top. This will help keep a low profile and seems to work really well.