What is Humus or Humic Acid?
The term "humus" dates back to the time of the
Romans, when it was frequently used to designate the soil as a whole. It was
later applied to the organic matter of soils and composts, or to different
fractions of this organic matter; as well as, to complexes formed from a variety
of natural organic substances. Humus compounds are complex natural organic
compounds that are formed in soils from plant residues, by a process of
"humification". Humus materials are complex aggregate of brown to dark colored
amorphous substances, which have originated during the decomposition of plant
and animal residues by microorganisms, under aerobic and anaerobic conditions,
in soils, composts, peat bogs, and water basins. Chemically, humus consists of
certain constituents of the original plant material resistant to further
decomposition; of substances undergoing decomposition; of complexes resulting
from decomposition, either by processes of hydrolysis or by oxidation and
reduction; and of various compounds synthesized by microorganisms.
“Humic
acid ” is the commercial term often used to refer to the combined humic and
fulvic acid content found in these naturally occurring deposits. Humic acid is
known to be among the most bio-chemically active materials found in soil.
Why Use Humic Acid?
Today, there is a recognized and increasing use of
humic acids for their beneficial impact on the growth and cultivation of crops
(vegetable & non-vegetable), citrus, turf, flowers, and particularly in
organically-deficient soils. Humic acid is not a fertilizer as it does not
directly provide nutrients to plants, but is a compliment to fertilizer.
Benefits include:
- Addition of organic matter to
organically-deficient soils
- Increase root vitality
- Improved nutrient uptake
- Increased chlorophyll synthesis
- Better seed germination
- Increased fertilizer retention
- Stimulate beneficial microbial activity
- Healthier plants and improved yields
How Does Humic Acid Improve Soil?
When applied to clay soils, humic acid can help break
up compacted soils, allowing for enhanced water penetration and better root zone
growth and development. When applied to sandy soils, humic acid adds essential
organic material necessary for water retention thus improving root growth and
enhancing the sandy soil's ability to retain and not leach out vital plant
nutrients.
How Does Humic Acid Improve Plant
Growth?
As mentioned above, one way plant growth is improved
is through the structural improvement of both clay and sandy soil allowing for
better root growth development.
Plant growth is also improved by the ability of the
plant to uptake and receive more nutrients. Humic acid is especially beneficial
in freeing up nutrients in the soil so that they are made available to the plant
as needed. For instance if an aluminum molecule is binded with a phosphorus one,
humic acid detaches them making the phosphorus available for the plant. Humic
acid is also especially important because of its ability to chelate
micronutrients increasing their bio-availability.
How Does Humic Acid Effect Microbial Activity
and What is its Role?
The activities of beneficial soil microbes are
crucial for the sustainability of any soil and plant growth. Humic acid
stimulates microbial activity by providing the indigenous microbes with a carbon
source for food, thus encouraging their growth and activity. Soil microbes are
responsible for solubilizing vital nutrients such as phosphorus that can then be
absorbed by the humic acid and in turn made available to the plant.
Additionally, microbes are responsible for the continued development of humus in
the soil as it continues to break down not fully decomposed organic matter. This
in-situ production of humus continues to naturally add to the humic acid base
and its benefits.
Humic Acid's Role in Fertilization
Humic acid is technically not a fertilizer, although
in some walks people do consider it that. Humic
acid is an effective agent to use as a complement to synthetic or organic
fertilizers. In many instances, regular humic acid use will reduce the need for
fertilization due to the soil's and plant's ability to make better use of it. In
some occurrences, fertilization can be eliminated entirely if sufficient organic
material is present and the soil can become self sustaining through microbial
processes and humus production.
