DIFFERENT TYPES OF FERTILIZERS &

MANURES USED IN AQUACULTURE.

PRESENTED BY : APARNA KUMARI L-2014-F-07-M

INTRODUCTION Primary production of aquaculture ponds can be

augmented by increasing the availability of plant nutrients through fertilizer/manure applications.

Greater primary productivity leads to a higher abundance of natural food organisms i.e Planktons.

With the production of primary producers, the whole food chain is activated which enhances the aquaculture productivity.

Substances that increase nutrient concentrations to enhance the growth of primary producers are called fertilizers or manures.

IN PONDS WITH PLANKTON BLOOMS, SECCHI DISK IS AN INDICATOR FOR ASSESING FERTILIZATION REQUIREMENT

SDT Bloom condition

Pond productivity status

>40 cm Poor bloom Non productive- needs manuring/fertilization

20-40 cm Normal bloom Productive and fertile- need no additional manuring/fertilization

<15cm Thick bloom Highly productive and fertile. Bloom is required to be removed and no fertilization required

CHOICE OF FERTILIZERSTHE CHOICE OF FERTILIZERS IS DECIDED ON THE BASIS OF SOIL QUALITY Sandy or sandy loamy soils with low organic matter

Organic manures

Sandy or sandy loamy soils with low organic matter.

Organic manures

Loamy soils with medium organic matter

Combination of organic manures and inorganic fertilizers

Clayey or clayey loam soils with high organic matter

Inorganic fertilizers

VARIETY OF ORGANIC MANURES AND INORGANIC FERTILIZERS USED IN FISH POND

Organic manuresLivestock wasteCow dungPoultry droppings or duck droppingsPig dungCompost(decomposed organic manures)Made from variety of livestock waste and plant materials , e.g vermicompost Liquid manuresBiogass slurry Animal shed washings like cattle sheds, pigsitesTreated sewage waterGreen manuresLeguminous plants are grown at the pond bottom and ploghed into soil before filling waterIn situ killing of existing aquatic weeds Bio fertilizers( live fertilizers)Application of azolla- an N-fixing aquatic fern

Inorganic fertilizers

N- FertilizersUrea- for acidic to neutral soils Calcium Ammonium Nitrate –for acidic soilsAmmonium sulphate- for alkaline soilsP- fertilizers Single Super phosphate(SSP)Di-ammonium phosphate(DAP)K-FertilizersMurrate of potash Potassium sulphate

MANURESADVANTAGES•Easily available and cheap.•Provides all the essential nutrients.•Nutrients available for longer period of time.•Improves bottom soil i.e. increases the water holding capacity.•Reduces turbidity.

DISADVANTAGES•Required in large quantity.•Slow release of nutrients hence cannot keep pace with plankton production during growth phase.•Can lead to DO depletion also.•Pollute water.•Risk of pathogens-disease occurrence.

FERTILIZERS

ADVANTAGES•Nutrients readily available.•Quick in action.•Accurate amount of nutrients can be applied.•No oxygen depletion.

DISADVANTAGES•Very costly.•Not easily available.•Combinations of fertilizers required.•No carbon source.•Effective for short period cause of nutrient loss through seepage.

QUANTITY/COMPOSITION N,P,K, ORGANIC CARBON, C/N RATIOManures

Organic Carbon

C:N Ratio

N P K

Cow dung

1.47% 16 0.02% 1.2% 0.4%

Pig dung 0.845% 10-20 0.08% 0.7% 0.5%

Poultry droppings

5-15 1.0-1.8% 1.4-1.8% 0.8-0.9%

Slurry 35-38.40%

25-30 1.4-1.8% 1.10-1.72%

0.84-1.34

vermicompost

12-15 1.5-2.5% 1.25-2.25%

TOTAL MANURING/FERTILIZATION SCHEDULE FOR NEW PONDORGANIC MANURES

Manures Total dose kg/acre/yr

Pre-stocking dose kg/acre(1/4th of total)

Post- stocking doseKg/acre/fortnight

Cow dung 8000 2000 250Poultry drooping(PD)

4000 1000 125

CD+PD(1:1) 6000 1500 200Pig dung 8000 2000 250Vermicompost 7000 1750 200-225Biogass slurry 8000 2000 250-300 L

OR20L daily

INORGANIC FERTILIZERSFertilizers Total dose

kg/acre/yrPre-stocking dose kg/acre

Post –stocking dose kg/acre/month

Urea+SSP 80+100-120 80+50 0+5-6

DAP 40-50 20 2

Potash 15-20 15-20 0

FERTILIZERS VS MANURES Fertilizers Manures

Nutrients from artificial sources. Nutrients from natural sources.

Mineral origin. Natural or organic origin.

High nutrient content. Low nutrients compare to fertilizers

Simple salts. Very complex

Only specific nutrient. Organic nutrients contain all nutrients.

Very costly and not easily available.

Cheap and easily available.

Nutrients readily available. Slow release of nutrients.

METHOD OF APPLICATION Broadcasting

Platforms and bags

BROADCASTING METHOD Solid, granular fertilizers often are broadcast over

pond surfaces

Fertilizers do not dissolve completely while settling through the water, but they finish dissolving while laying on the pond bottom.

This favours adsorption of phosphate by the soil, and if water circulation in ponds is not good, nutrients that dissolve into the bottom water may not enter the illuminated upper layers for use by phytoplankton.

Instantly soluble fertilizers can be braodcast over the entire surfaces of ponds. The particles will dissolve before settling out of the epilimnon.

PLATFORMS AND BAGS This method prevents phosphorus fertilizer

from settling to the pond bottom,apparently decreasing the rate at which phophorus from the fertilizer is adsorbed by bottom muds.

This method reduces fertilizer requirements by 20-40%.

Platforms should be about 30cm underwater and one platform with an area of about 4m.sq. is adequate for 2-4 ha of pond area.

Fertilizer is poured onto the platform and water currents distribute nutrients as they dissolve.

Platforma also are sutaible for exposing controlled release fertilizers to the water.

Fertilizers also have been placed in porous bags and suspended in pond water st different places in the pond.

The nutrients disslove and seep out of the bags to be mixed by water currents.

Plastic bags of fertilizer can be laid on the pondbottom, and upper surface of the bag cut away to expose the fertilizer to the water.

Platforms are superior to either of the bag techniques mentioned above, but their construction requires more effort than the use of bags.

THANK YOU.