Inorganic fertilizers for aquaculture of fishes. Benefits of inorganic fertilizers e. g Na, K etc,

1. INORGANIC
FERTILIZERS
PRESENTED BY : MUZNA KASHAF
ROLL NO. : 16261514-030

2. CONTENTS
 INTRODUCTION
 NITROGEN FERTILIZER
 Efficiency of Nitrogen fertilizers
 Common Nitrogen fertilizers
 MAGNESIUM FERTILIZER
 TRACE ELEMENTS
 COMBINED USE OF CHEMICAL FERTILIZER

3. INTRODUCTION
 Feeding of fish and fertilization of water is essential part of pond
and reservoir management.
 The main objective is to direct all the primary, secondary and
tertiary levels of productivity towards maximum yield of fish.
 Fertilizers are divided into inorganic, organic and organo-
chemical fertilizers.
 Inorganic fertilizers consists of Limestone and lime, Phosphorus,
Potassium, Nitrogen, Magnesium and Trace elements.

4. NITROGEN FERTILIZER
 Most important elements required by plants and animals.
 In nature, it is available in free state in air and in the form of
compounds as nitrates, nitrites and ammonium salts.
 Free molecular nitrogen is in abundance but organisms use it
in water soluble form i.e. nitrates.
 Few bacteria and blue-green algae convert nitrogen into
nitrites or nitrates.

5. EFFICIENCY OF
NITROGEN FERTILIZER
 It is difficult to measure efficiency of nitrogen fertilizer.
 It gives extra production which can reach 50% level when used
alone or in combination with phosphate and potash fertilizers.
 Huet recommends the employment of nitrogen fertilizer for new
ponds which are either poor in nitrogen or without mud.
 If a pond has muddy bottom it will provide nitrogen itself and
the application of nitrogen fertilizer will be of no use and
uneconomical.

6. COMMON NITROGEN FERTILIZERS
 Common nitrogen fertilizers are:
 Ammonium nitrate (35% N)
 Ammonium sulphate (20% N)
 Ammonia water (20% N)
 Sodium nitrate (16% N)
 Synthetic urea (45% N)
 Most widely used fertilizer throughout the world is Ammonium
sulphate.
 Its application gives rise to phytoplankton blooms and stimulate
growth of benthic fauna and zooplankton.
 N-fertilizers should not be applied to waters having pH above
7.5 or when aquatic plants are in full bloom.

7. MAGNESIUM FERTILIZER
 Magnesium plays an important role in algal photosynthesis.
 It rarely limits the growth of distribution of aquatic biota,
because this element is usually present in large amounts in
aquatic systems.
 It may prove beneficial in fish ponds where the soil is
deficient of Mg, particularly in peaty mud.

8. TRACE ELEMENTS
 Trace elements are those elements which are required in very
small quantity.
 These includes; cobalt, zinc, manganese, copper, boron,
molybdenum etc.
 Cobalt is absorbed and retained by silt deposit for a long time
and is gradually included in biological cycle.
 Zinc at conc. of 0.5ppm gave the highest plankton volume of
primary productivity.
 Treatment of boron and molybdenum at very low rate has also
enhanced fish productivity.
 Application of manganese with super-phosphate gives far
superior phytoplankton than super-phosphate alone.

9. COMBINED USE OF CHEMICAL
FERTILIZERS
 Mineral fertilizers used in different combinations are more
reactive.
 More dependable results can be obtained compared to organic
manure.
 As chemical fertilizer contain a known quantity of biogenic
elements, their influence on productivity can be determined
more precisely.
 Also, inorganic fertilizers are easy to store, transport and apply
as compared to organic ones.

10. CONTINUE…
 Common 4 basic elements required to raise fertility of water
are nitrogen, phosphorus, calcium and potassium.
 The common fertilizers available in market are in the form of
nitrates, phosphates, muriate of potash and limestone.
 While using complex inorganic fertilizer, correct proportion of
N:P is important in most effective utilization of substance.
 It(proportion) may vary from place to place depending on
chemical composition of soil and water, stocking density and
technique of pond management.

11. CONTINUE…
 Maximum ratio of nitrogen to phosphorus is in the range
of 4:1 to 8:1 (N:P).
 Swingle reported that ponds fertilized with 8:8:4 (N:P:K)
at 123.5 kg/ha resulted in the rise of fish yield.
 So, high yield can be obtained by using these fertilizers
in combined form.

12. ADVANTAGES AND DISADVANTAGES
OF CHEMICAL FERTILIZERS

13. REFERENCES
 Boyd CE. Bottom Soils, Sediment, and Pond
Aquaculture.
 Chapman and Hall, New York, NY, USA; 1995.
 Boyd CE, Tucker CS. Pond Aquaculture and
WaterQuality Management. Kluwer Academic
Publishers, Boston, MA, USA; 1998.
 Jones US. Fertilizers and Soil Fertility. Reston
Publishing Company, Reston, VA, USA; 1979.
 Lorimor J. Manure Characteristics. Midwest Plan
Service, Iowa State University, Ames, IA, USA;
2004