welcome to northern iowa/ southern minnesota/ illinois where they put in tile rather than pivots.  I dont know if this is irrigated ground you are talking about, but nebraskans irrigate too much in wet years imho.  I have a gravity irrigated field that was in alfalfa last year, the ground had no moisture at all in it this spring.  so much so that I planted corn in the dust, but it started raining may 16 or so.   i ridged it, and layed out pipe and never pumped a gallon on it and it looks fantastic.  still half green.  we had over 18 inches of rain from may 15- sept 20.  and it all soaked in!