Humic substances (HS) are carbon-rich organic materials derived from the microbial and abiotic breakdown and transformation of dead plant tissues through a process called humification. They occur in soil, sediments, and water. Additional sources from which HS are obtained for commercial purposes include peats, brown coals, oxidized lignite coals (i.e., Leonardite), and oxidized sub-bituminous coals.
When added to soil or applied to plants foliarly, HS act as natural biostimulants that enhance and support plant growth.
