SE IL and SW IN | ehoff - 12/16/2014 07:53
So for you agronomists out there ...... what minimum soil N level is adequate at planting ahead of corn? 20ppm? 30ppm?
I wish someone could answer that question with solid research back-up. I do know that we measured N in some ARG/radish plots in 2012/13 and lowered the N to <10ppm. I was of the opinion that we did not recover from that even with 5 gal 6-24-24 and 50# N in a 2X2 at planting. We repeated this exercise again this spring and again left some yield on the table simply due to lack of early available N.
There is something about residual N from an organic source that a corn plant likes early in its life. Most soils have an ability to mineralize some N so this phenomenon is not readily obvious, but in our light soils, I will be more careful to not push the cover crop in the spring, and leave some residual N for the corn crop. |