Last week I attended the Illinois Crop Management Conference in Mt. Vernon. One of the presentations was by Emerson Nafziger. Dr. Nafziger is the senior agronomist at the University of Illinois. He discussed his latest research on nitrogen management and use efficiency. He was looking at the effects of such things as split applications or late applications. He explained the value of the N-Rate calculator which I have previously discussed.
His results were sort of spotty. In some cases, the split rate did as well as the full rate applied in spring. In some cases, split rates did better. His point was, that later in the season application rates can get expensive and troublesome considering extra machinery required and weather issues. He says you should think twice before jumping in with both feet. His results were not necessarily consistent with what others have found.
One of the flaws in his study that I caught, was that he equated dribbling UAN in the middle of the row with using Y-drops. This misses the point of Y-drops entirely. The Y-drops put the UAN neat the base of the plant where there is at least theoretically a little extra moisture to stabilize the UAN and maybe help with uptake. I thought Emerson made some good points, but his research results were only from one year.
My bottom line is that you should not draw any conclusions from the U of I work at this time. If you are using some sort of split application method, don't let these results deter you. If you are considering a big purchase however, I would hold off on it especially in these lean times.