Gerald J. - 6/14/2016 09:20

There used to be an ISU extension bulletin dating from the 1970s that said corn planted after plowing under mature alfalfa didn't need any nitrogen the first year because the yield didn't increase by adding nitrogen, and that it might not need nitrogen the second corn year. In the 90s I raised decent corn after three year old alfalfa. I quit the alfalfa and went to buying 32% because the "free" nitrogen cost too much money in not growing and selling corn those three alfalfa years. I was doing a 6 year rotation, three years of alfalfa with oats nurse crop the first year, then corn, beans, corn. It did work but grain income for only half the place (I broke the farm into 6 patches each a different year of the rotation) wasn't all that profitable even though I only applied MAP for each corn year.

I haven't detected that ISU extension bulletin in the last 15 years.

Gerald J.