Pond fertilization

• Aimed alt developing natural food and saving formulated feeds.
• Provides nutrients to encourage rapid growth of phytoplankton.
• Are used to increase the production of natural organism to be eaten by the fish.
• Are of two categories i) Organic fertilizers ii) Inorganic fertilizers

Organic fertilizers

• Are composite in nature and contain all the natural elements required for the metabolic cycle.
• Contain a mixture of organic matter and mineral nutrients.
• Are following types:

a) Livestock manure

b) Compost

c) Green manure

d) Night soil

Advantages of organic fertilizers

• Improves the pond soil structure, fertility and water holding capacity.
• Are relatively inexpensive.
• Readily available on-farm.
• Slow nutrients release for long time.
• Converts unusual surplus waste into useful products, so mitigates the problem of waste disposal.
• Besides N,P,K, organic matter is a potential source of micronutrients.
• Serves as direct source of food for certain fish species.
• Increases the effectiveness of any inorganic fertilizers by providing the necessary organic matter base.
• Encourages bacterial growth, which in turn favors better production of the zooplankton.
• May also help to clarify clay turbidity in pond water.

Disadvantages of organic fertilizer

• Difficult to transport
• Continual application reduces pond depth
• Low contents of primary nutrients
• Time consuming to collect and apply bulk materials to ponds on a routine basis.
• Results in unpredictable nutrient quality and high biological oxygen demand, which may cause oxygen depletion of pond water when applied at high rates.
• Unsuitable for intensive high-yield culture systems.
• Decomposing organic manures creates unhealthy conditions in the pond favoring incidence of some diseases as the gill rot.