I usually get a yield of 235 to 255 when I do yield checks.  I use the better part of the field for each hybrid I am checking. 

 When it is all said and done my total farm average last year was 220 bu.  (220 just happens to be my 5 total farm year average also.)This included the sand and clay spots, the hill that was terraced, the point rows, ect.  I keep a high fertility program I think on dry fert. and have my fields grid sampled and grid applied the past 8 years. 

Now if you go appox. 15 miles north of me the fields get much more level and even, in general and I would expect a higher total farm average. 

You get up around York, Ne. and along the  I 80 going to Grand Island and you will get better yields.

Not limited by irrigation water here.  Good rains in the latter 1/2 of the growing season.  I only watered my fields 3 times instead of 7-9 times in a normal year.