Pond Fertilization Regime

A pond fertilization regime is the planned schedule of nutrient inputs (inorganic N-P-K fertilizers, manure, or compost) designed to build and maintain the natural food web in extensive and semi-intensive ponds. Fertilization stimulates phytoplankton, which feeds zooplankton and benthic organisms that fish and shrimp graze directly, supplementing or replacing expensive feed. Typical inorganic doses range from 2 to 10 kg N and 0.5 to 3 kg P per hectare per week, adjusted to secchi disk readings (target 25-40 cm visibility) and chlorophyll-a levels (roughly 20-80 µg/L). Over-fertilization causes algal crashes, oxygen depletion, and ammonia spikes; under-fertilization leaves the pond underproductive and fish growth stalls. Regimes usually start with a base dose before stocking, then follow-up applications weekly, often split to avoid peroxide-like bloom flushes. The correct regime depends on soil pH, water hardness, temperature, and target species: filter feeders such as tilapia and silver carp respond strongly, while carnivores gain little beyond improved water quality. Integrating fertilization with feed trays and regular water monitoring is the core of profitable extensive production.