/* Style Definitions */
table.MsoNormalTable
{mso-style-name:"Table Normal";
mso-style-parent:"";
line-heigh t:115%;
font-size:11.0pt;
font-family:" Calibri","sans-serif";
mso-bidi-font-family:"TimesNew Roman";}
Source of natural organic matter in the soil fertile substance derived from
humus (humic substances), which usually accumulates in the upper layer of soil
(top soil). The
main active substance or content of humus that contribute to soil fertility is
the Humic Acid compounds (humic acid) and fulvic acid. These compounds are
stable organic matter and the end result of decomposition of organic materials.
Humic
acid and fulvic acid is different from the organic substances contained in
organic matter such as compost and manure are generally in the form of organic
substances are easily decomposed by soil microbes and eventually will run out. Humic
acid content in the topsoil is generally higher than in the fulvic acid. Therefore,
the main components of humus is often referred to simply humic acid alone,
although it also contains fulvic acid.
Humic
acid is an organic substance that has a complex molecular structure with high
molecular weights (macromolecules) or can be referred to as an organic polymer
containing an active group. In
nature, humic acids are formed through a process of physics, chemistry, and
biology of ingredients derived from plants and animals, a process called humifications.
Therefore,
the structure of humic acids consist of a mixture of aliphatic and aromatic
organic compounds (such as indicated by an active carboxylic acid groups and
quinoid), the humic acid has the ability to stimulate and activate the
biological and physiological processes in living organisms in the soil.
Several
other important properties of humic acids associated with its role in improving
soil conditions and plant growth is Cation Exchange Capacity (cation Exchange
Capacity) high, has the ability to bind water (Water Holding Capacity) is
large, as a complexing agent (Chelating / Complexing Agent ), and
the ability to bind (fixation) of pollutants in the soil.
From
the excellence of its properties, here are some benefits to be gained from the
use of humic acid:
•
Increase input (uptake) through the conversion of nutrients into forms
available nutrients and increase the permeability of plant membranes.
•
Binding and regulate the release of nutrients (slow release) in accordance with
the needs of plants so as to increase the effectiveness of the use of
fertilizers and reduces nutrient loss due to dissolved or evaporated.
•
Stimulate plant growth and accelerate the growth of roots or young shoots, so
the plants grow faster and increase the yield and crop quality.
•
Improve soil structure in physics and chemistry (friability, pH, water binding,
colloidal properties, organic catalysts, etc..) So that can sustain good plant
growth and plant stress is not easy.
•
Stimulate an increase in microbiological activity of soil favorable for the
growth of plant roots.
• And others.
1. Humic ACID EFFECT ON SOIL
PHYSICAL PROPERTIES
• humic
acid has the ability arbsorsi about 80-90% water. So
that the water movement vertically (infiltration) rather than horizontally
growing, useful for reducing the risk of soil erosion. It also
increases the ability of soil to hold water.
•
humic acid acts as a granulator or improve soil structure. Occurs
because the soil is easy to form a complex with humic acid, due to increased
soil microorganism populations, such as mold, fungi and bacteria. Because
humic acid is used as a constituent of the body and its energy sources. Fungus
is able to unite the land into grain aggregates. While
the bacteria serves as the cement that unites the aggregate, while fungi can
improve the physical grain quality. The
result is a more friable soil crumb structure and relatively lighter.
•
• Improve soil aeration as a result of the increase in soil pores (porosity)
due to the formation of aggregates. In
soil pores is generally dominated by the gases O2, N2, and CO2. It
is important for breathing (respiration) soil micro-organisms and plant roots.
•
Darken the color became dark brown soil, thereby increasing the absorption of
solar radiation that will increase the soil temperature becomes warmer.
2. Humic ACID EFFECT ON SOIL
CHEMICAL PROPERTIES
Increasing the cation
exchange capacity (CEC). Such
improvements increase the ability of soil to withstand the elements nutrient. Humic
acid form a complex with micro elements to protect the elements from leaching
by rain water. Elements
N, P, and K bound in organic form or in the body so that microorganisms can be
maintained and at times can be absorbed by plants. So it can
improve the efficiency of the use of chemical fertilizers.
·
humic acid
can bind heavy metals (forming compounds khelate) then precipitate there by
reducing soil toxicity
·
Increase
the pH of acidic soil due to the use of chemical fertilizers continuously. Especially land that
contains aluminum. Because
humic acid complex binds Al as a difficult compound soluble in water
(insoluble) so it can not be hydrolyzed
·
The bond of
complex that occurs between the humic acid with Fe and Al is the anticipation
of bonding that occurs between elements of P (phosphorus) with Al and Fe, so
the element of P can be maximally absorbed by plants
3. Humic ACID EFFECT ON THE
NATURE OF BIOLOGICAL SOIL
·
Due to the
influence of humic acid on soil chemical and physical properties, thereby
creating a conducive ground situation to stimulate the development of soil
microorganisms that function in the decomposition process that produces humus
(humification).
·
Activity of
microorganisms in the ground will produce growth hormones such as auxin,
cytokinins., And giberillin
Auxin, function:
• Stimulate the process of
seed germination;
• Stimulates
root formation and growth process;
•
Stimulate plant shoots and roots will not develop into a thriving again.
Cytokines, function:
•
Stimulates cell division and enlargement so as to spur growth;
• Stimulate the formation
of new shoots;
• Prevent
damage to the crop, making it more durable.
Gibberellins, function:
• Improve flowering and
fruiting;
• Increase the
percentage of finished flowers and fruit;
• Reduce the loss of flowers
and fruit;
•
Encourage partenokarphy without pollination or fertilization.
ts.