Studies have shown a positive and strong arnica's reaction to humic
acids application in the formof leonardite contained in PowhumusWSG
85 preparation on sandy soil. A significant increment of flowering stems’
number and inflorescences per plant along with increased leonardite
doses (from 2 to 6 kg∙ha−1) was observed. As a consequence rawmaterial
yield's increment was obtained. Regardless of dose, leonardite
application positively influenced enzymes’ activity catalyzing the
transformation of the most important soil organic matter processes.
In response to higher leonardite application doses (4 and 6 kg∙ha−1)