To day in market liquid N/P/K fertilizers available, but my opinion is that it is OK for N and K but plant can not absorb phosphorus through leaves or any aerial part, it is only by root.
The use of humic/fluvic acids can improve the absorption of most mineral nutrients. They possess growth regulatory activity and are effective at low dose 50 to 150 ppm very effective. The growth regulator response beside stimulating the mineral absorption also helps the defensive responses rooting and chlorophyll content.