A satellite-guided tractor will plant a northeast Iowa cornfield today. Clay Mitchel, a farmer near Buckingham — which is just south of Waterloo — will host the demonstration.Mitchel says an “auto-pilot” will use Global Positioning technology to steer the tractor. He says this system’s more accurate than other G-P-S units now used by farmers. Mitchel says the unit operates with “centimeter-level accuracy.” Mitchel sought out the technology which is getting its test-run today.The demonstration’s open to the public and anyone can ride in the tractor to see how it works. Eighty acres of corn will be planted. Mitchel says the tractor’s steering system will be automatically guided in consistent rows.