Sub-bituminous coal and Leonardite are both naturally occurring materials with agricultural value, particularly in soil improvement. Subbituminous coal is a lower-grade coal that contains a moderate amount of carbon and is sometimes processed for Humic substances. Leonardite, derived from oxidized lignite (brown coal), is especially rich in Humic and ulvic acids—organic compounds known to enhance nutrient uptake, improve soil structure, and stimulate microbial activity. In agriculture, Leonardite is widely used as a soil conditioner and organic fertilizer additive to support plant growth and increase soil fertility.
Humic Acid Powder Specification Sheet
