urea and nitrogen

[early]

I have heard from farming, that urine, which is high in urea kills terrestrial plants. Is the salts or the urea?

Here on OB, I have read it is best not to use fertilizer that has urea .

I have both a 30-10-10 and a 20-20-20 that has as part of the nitrogen, urea.

I need help figuring out if I need to buy a 20-20-20, which I am now using weakly in S/H, that has no urea the in fertilizer.