dc.description.abstract | One of alternatives that can be used to increase the nutrient elements release from igneous rocks is reaction with humic substances. This research aims to study the ability of humic substances to increase the nutrient elements release and improve the release from igneous rocks. The humic substances, in the form of salt and acid, are extracted from peat and lignite. Three kinds of igneous rocks were treated i.e. basalt porphyry, diorite porphyry and trachyte porphyry with three grain size i.e. 60 - <2000 μm, <60μm and (1x1x0,3)cm3 . the rocks were impregnated with humic substances for 5 weeks. The result showed that the peat humic substances in the form of peat humate can increase the nutrient elements release from igneous rocks in size <1000μm. Nutrient elements release in basalt porphyry showed better results than diorite porphyry and trachyte porphyry. Release process of element from minerals in igneous rocks occur in the field boundaries between crystals, crystals cleavage, and the crystals surface. | en |