Straight fertilizer:
Any fertilizers having
a declarable content of only one of the primary plant nutrients i.e., Nitrogen,
Phosphorus or Potassium, Urea, TSP.
Compound
fertilizer:
According to ISO
(International Organization for Standardization), a fertilizer has a declarable
content of at least two of the primary plant nutrients e.g. N, P and K obtained
chemically or by blending, or both. It may also contain one or more of the
secondary and micronutrient elements. In the United States, the term “mixed
fertilizers” is synonymous with “Compound fertilizers”. In some European
countries, compound fertilizers are further subdivided into “mixed fertilizers” and “complex
fertilizers” according to whether chemical reactions are involved in the mixing
process or not.
Complex
fertilizer:
A compound fertilizer
containing two or more essential primary plant nutrients that have undergone
chemical reaction during the production process.
E.g. DAP: %N (21.19),
%P2O5 (53.76)
MAP: %N (12.17), %P2O5 (61.71)
Elaboration of
some important fertilizer:
DAP = Di-Ammonium
Phosphate
MAP = Mono-Ammonium
Phosphate
MoP = Muriate of Potash
SSP = Single Super
Phosphate
TSP = Triple Super
Phosphate
Mixed
fertilizer:
The term applied to a
fertilizer that is physical mixture of two or more of the straight fertilizer.
Mixed fertilizer may be powdered or granulated.
Ex. DAP+MoP: %N (12),
%P2O5 (32), %K2O (16)
Granular
fertilizer:
A fertilizer of
particles, sized between an upper and lower limit or between two screen sizes,
usually within the range of 1-4 mm often more closely sized. Most of the
particles size (about 90%) will be 4 mm. E.g. Urea, TSP
Prilled fertilizer:
Prilled fertilizer may
be defined as a type of smooth granular fertilizer of near spherical shaped
made by solidification of free falling droplets in air or other fluid medium.
This fertilizer is only sprayed by machine. E.g. Urea.
Non-granular
(powder) fertilizer:
A fertilizer containing
fine particles, usually with some upper limit such as 3 mm but no lower limit
is called non-granular or powder fertilizer. E.g. SSP (Single Super Phosphate),
Borax (Na2B4O7.10H2O)
Crystals:
Particles that have flat side and sharp edges and corners resembling the
particle shape of sugar and table salt. E.g. MOP, Ammonium Sulfate [(NH4)2SO4]
Coated fertilizer:
A
granular fertilizer that has been coated with a thin layer of nutrient
containing substance to prevent caking or formation or to control dissolution
rate, i.e. Sulfur coated Urea.
Conditioned fertilizer:
Fertilizer treated with an additive/filler to improve physical condition or prevent caking. The conditioning agent maybe applied as a coating or incorporated in the product. E.g. Polymer (Plastic or resin) coated fertilizer
Bulk fertilizer (Unpacked fertilizer):
Bulk-blended fertilizer or Blended fertilizer:
Two
or more granular fertilizers of similar size mixed together to form a compound
fertilizer is called Bulk-blended fertilizer.
Controlled-Release fertilizer:
Fertilizer
in which one or more of the nutrients have limited solubility in the soil
solution, so that they become available to the growing plant over a controlled
period are called controlled-release fertilizer. E.g. Gelatin encapsulated
fertilizer, polymer plastic coated fertilizer.
Advantages of
compound fertilizer:
i) Compound fertilizers
contain more than one of the three major primary plant nutrients.
ii) Lower cost per unit of
plant production.
iii) Lower transportation
cost.
iv) Less storage space
required.
v) Less labor required for
storage and loading shipment.
vi) Less labor required for
applying to the soil.
Disadvantages of
compound fertilizer:
i) Primary investments are
high.
ii) Modern technologies are
required.
iii) For maximum benefit,
nitrogenous fertilizers must be applied in split. So, nitrogenous straight
fertilizers are good.
Liquid/Fluid fertilizer:
The
term liquid or fluid fertilizer is a general term usually including fertilizers
wholly or partially in solution that can be handled as a liquid. This includes
clear liquid and liquid containing solid in suspension.
Liquid
fertilizers are usually classified into two distinct types:
i)
Solution fertilizer: Solutions are
defined as fluids, the ingredients of which are in solution that is aquatic
liquid fertilizer free from solids. These are clear or of a particular color.
Sometimes a coloring agent is added so that a particular liquid can be
distinguished from another liquid.
ii)
Suspension fertilizer: A
suspension fertilizer is defined as a saturated solution with small particles
of nutrient bearing materials suspended in saturated solution. The solids may
be water soluble materials in a saturated solution or they may be insoluble.
Advantages of Liquid/Fluid fertilizers:
1.
Low cost materials are used in manufacturing of fluid fertilizers.
2.
They can be distributed more accurately than solid fertilizers.
3.
They can be placed where needed in the soil by injection under pressure.
4.
Less fertilizer is usually required.
5.
They allow the efficient use of plant nutrients to minimize environmental
problems.
6.
The injury to new roots of seedlings from heavy application of dry fertilizer
can be avoided.
7.
Fluid fertilizers are excellent carrier of micro-nutrient because a small
amount of micro-nutrients can be homogenously dispersed in the fluid.
8.
They are excellent carrier of pesticides and are widely used in the application
of herbicides.
9.
Fertilizers of poor physical condition can be utilized.
10.
Maximum crop response may be obtained during dry weather.
11.
Light applications may be applied according to plant needs.
12.
Problems of physical properties such as hygroscopicity and caking are absent.
13.
Liquid fertilizer can be applied in irrigation water.
14.
Liquid fertilizers are adoptable to foliar application which is sometimes more
efficient than soil fertilization.
15.
They are usually much easier to handle than solid fertilizers.
Disadvantages of Liquid/Fluid fertilizers:
1.
Specialized equipment is needed for storage and transport of liquid fertilizers
such as tanks, barrels, rail or road tankers, ships, barrages and pipelines
also are needed.
2.
Expensive and sophisticated equipment’s are sometimes required for application
of liquid fertilizers.
3.
Liquid fertilizers are less concentrated than solids, therefore shipping or
transportation cost are increased.
4.
When solutions are cooled, crystals may form and settle. To guard this liquids
should be formulated to with stand the lowest temperature.