Would depend a lot on the spread soil type and moisture situation after planting. Be it a inch wide rows or a 6 inch band. I’ve gone from a band to a 3/4 inch disc cut slot and I’d never consider any more that 10 units an acre. And that’s only because it’s with the phosphate. polymer Coated urea would be another story but I doubt many will find it now.Dad used to put 4 hundy weights an acre of 20.10.10 down the spout back in the day . That would be 100kgN/h by my maths so don't see why urea would be any different as it's slower releasing anyway
25kg/ha of N or product?Be very careful.
Urea is hard on seeds.
If memory serves it forms a toxic alkaline area around the fertiliser, something to do with all the ammonia.
Maximum rate of 25kg/ha in wheat.
Perfect placement in my opinion. Roots go down and the seed is safe. Would be intresting to dig down at the theee to four leaf stage and see if there is any hot zone that the roots have not grown into. Have seen canola on 10 inch rows that had a full dose of NPS mid row banded so 5 inches away. Even after a month not even weeds grew over the fert row. Phosphate was of little use in a no go zone for roots.I’ll be putting 200kg/ha of 33N, 30S as a urea/AS blend down the spout but 3-4” below the seed.
When you said 12.5 cm rows. How wide is each rows spread. If it’s an inch I’d think you’ll Be much happier throwing the whole lot on and drill thru it to mix it in.100kg/ha of 46% urea ok?