Granular Humic Acids May increase micronutrient uptake by plantsDown To Earth’s Granular Humic Acids is a highly concentrated source of humic substances that is ideal for use on fields, turf and vegetable gardens. Carefully mined from one of the world’s richest deposits, DTE Granular Humic Acids is derived from the ancient remains of decomposed organic plant materials. Naturally occurring, unaltered oxidized lignite, DTE Granular Humic Acids are crushed, screened and graded to a particle size of 1-3mm.