I agree with buck about the fresh planted corn. Not being able to walk the land personally and just a guess from the picture. I would say that field slopes to lower elavations running to the creek. I would set myself up on the creek and glass the field for a few days if you have the time. Turkeys are a creature of habit and if their are birds there they will enter the field from the same spot and about the same time every day. Leave the turkey calls at home but, you could try a crow call a few times for location, don't over do it.

After you see where and when they are entering the field, watch for Toms, hopefully there is more than 1 with the flock. Set yourself up a hundred or so yards from where they enter the field on the fields edge but, not crossing their route to do so. Light purrs and some yelps should get you a bird. Do not overcall. They will hear you before you can hear them so have your game face on and come up shooting!!