I'm trying to find a (possibly spray) fertilizer with a N-P-K concentration like this one: 20-2-20 and possibly with Ca (about 20), Mg (about 10), Cu, Zn and B.
I know that it is a strange concentration, so I ask if you know a similar one, or a multiple but it is important that the N and K concentration are similar and the the P concentration is very low than N and K concentrations.
Possibly a international brand...
I will use it on Pistacia Vera and I got these concentrations basing on data found in internet.
I know it is possible to make a custom fertilizer with individual elements but I do not really understand how to make a perfect concentration with not pure products.
For example, if I have pure urea (46N) and I want a fertilizer with 20N, what have I to do?
