Hi, Sorry for the late reply, but we have been doing this for 14 years, and don’t plan on stopping anytime soon. We love it. From what we have seen, we calculate about a 4.2:1 efficiency factor when applying solubilized urea as a foliar compared to 46-0-0 in the ground. This initially was backed by Dr. Bill Hamman in his 3 year trial back about 15 years ago. Since then, there have been others like Joel WIlliams and Graeme Sait who have used ratios of 7:1 or 9:1. We did up a tutorial video back in 2011 about the process here- https://youtu.be/zm-gcURfi9A?si=R6n36Mokl21mvvOp. We have tried 28-0-0 UAN as a foliar and do not recommend it, as it is nowhere near the results of solubilized urea as a foliar. We apply it at herbicide time and then one more time at about flag leaf time with other foliar nutrition and biology. We don’t use it in the furrow as a starter N, as it is too hard to make the product with our cold water up here in spring when it’s go time. Instead we opt for UAN in furrow with the seed. As far as burning is concerned, we don’t see any with a 5 gallon application of 18-0-0 (final solubilized result) which is 10 lb of actual N. When applied with herbicide, it CAN cause burning if you are using a contact mode of action herbicide. In that case we pull back the rate of herbicide 25% and still get great results, as the urea heats up the herbicide. Systemic mode of action herbicide is full rate. Melissa Werkema from Future Analytics claims that if you are able to used solubilized urea in furrow, it is more efficient as far as ppm that the plant sees and utilizes, as well as less salt in furrow. With regards to biuret, we don’t have to worry about that up here as we get most of our 46-0-0 from CF Industries in Medicine Hat, but a safe rule of thumb is a maximum of 1% biuret in the solution. Humic acid is a great idea UNLESS you are using a herbicide with it. If that’s the case, switch to fulvic acid, as the humic acid will tied up the active ingredient of your herbicide and your field will look like you applied about 15-20% of the recommended rate of herbicide As I said, we have been using this concept for 14 years and with this formulation (and a few other things) we have been able to consistently raise a bushel of corn, barley, or wheat on 0.52-54 lb of N, not the 1.6-2.1 lbs. that current agronomic advice suggests.

Good Luck!

Patrick