The scientific application of fertilizers not only helps in conserving resources more efficiently but also enhances the effectiveness of nutrient use and reduces the risk of fishery accidents. Therefore, it is essential to master the key principles of proper fertilization.
1. **Assess Water Condition Before Fertilizing**: It’s important to evaluate the water’s clarity and nutrient content before applying fertilizer. Methods like visual inspection, oil film observation, and chemical testing are commonly used. If the water is already rich in nutrients, fertilization may be temporarily avoided. If the water is too clear, measures should be taken to control dominant species. In cases where the water is thin, appropriate fertilization should be applied based on water quality, soil condition, and environmental factors.
2. **Determine Fertilizer Quantity Based on Conditions**: The amount of fertilizer needed depends on the soil composition, pond conditions, water clarity, depth, and farming practices. Adjustments should be made accordingly to ensure optimal results.
3. **Timing Is Key**: Fertilization should follow the principle of “small amounts, frequent applications†to maximize efficiency and reduce waste. When the water temperature reaches 15°C, base fertilizer should be applied, and when it rises to 20–30°C, a larger amount of nutrients is required due to increased plankton growth. Fertilization should be done on sunny days to ensure better absorption.
4. **Adjust Application Frequency**: The frequency of fertilizer application varies depending on the type of fertilizer, the species being raised, pond conditions, and water color. Typically, applications are spaced 7–10 days apart at temperatures between 20–25°C, and every 4–5 days at 25–30°C.
5. **Proper Fertilization Technique**: When using "Tianchen Fishery Fertilizer," it should first be dissolved in a container with water (for about 5–10 minutes) before being evenly distributed. It is best applied during sunny afternoons, avoiding rainy days. When mixing nitrogen and phosphate fertilizers, apply phosphate first, then nitrogen, followed by "Tianchen" — never reverse this order or mix them simultaneously. Combining these can produce harmful substances like metaphosphoric acid, reducing fertilizer effectiveness and potentially harming aquatic life.
6. **Use Organic and Inorganic Fertilizers Wisely**: Some fertilizers can be combined, such as inorganic superphosphate with organic ones. However, acidic and alkaline fertilizers should not be mixed, as they can react, causing gas release, sedimentation, or toxic byproducts like NH3 or H2S. "Tianchen Fishery Fertilizer" can be used alone or with carbon and ammonia sources, but urea should be applied separately.
7. **Ten Important Fertilization Taboos**:
- **Avoid Fertilizing During Rain**: Rainy weather reduces light, weakens phytoplankton photosynthesis, increases organic matter, dilutes fertilizer, and leads to loss.
- **Avoid Fertilizing in Hot Weather**: High temperatures lower dissolved oxygen levels, increasing the risk of fish suffocation.
- **Avoid Fertilizing in Turbid Water**: Excessive clay particles can adsorb fertilizer components, reducing their availability.
- **Avoid Using Only Chemical Fertilizers**: A balanced ratio of N, P, K (typically 4:4:2) is essential for effective nutrient uptake.
- **Avoid Blind Mixing**: Certain combinations can cause gas release, precipitation, or toxicity. Wait 3–5 days if mixing for disease control.
- **Avoid Fertilizing in High Temperatures**: Fertilization should occur between May and October, with ideal temperatures around 22–30°C. Avoid above 35°C.
- **Avoid Dry Application of Solid Fertilizers**: Solid fertilizers tend to sink and get trapped in sludge, reducing effectiveness. Always dissolve first.
- **Avoid Fertilizing When Animals Are Not Eating Well or Diseased**: This can lead to plankton blooms and poor water quality.
- **Avoid Over-Fertilizing**: Excess ammonium can poison fish, while too much organic matter can cause oxygen depletion. Follow the “small and frequent†rule.
- **Avoid Draining Surface Water After Fertilizing**: Plankton needs time to develop. Surface water drainage can reduce fertilizer impact.
Mastering these techniques ensures that the water becomes rich in beneficial plankton without compromising dissolved oxygen levels. By following these ten rules, aquaculturists can achieve efficient, safe, and sustainable fertilization practices.
Yancheng Rongtai Labware Co.,Ltd , https://www.rongtailab.com