Fertiliser Application During the Rainy Season: Best Time and Best Practices

by | Jul 26, 2026 | Crop Production, Production | 0 comments

Fertiliser

Introduction

The rainy season is one of the most important periods for crop production in Nigeria. It is also the time when many farmers apply fertilisers to improve crop growth and increase yields. However, applying fertiliser at the wrong time or using the wrong method can reduce its effectiveness and lead to unnecessary losses.

Heavy rainfall can wash fertilisers away before crops absorb the nutrients. On the other hand, delaying fertiliser application can slow crop growth and reduce yields. Knowing when and how to apply fertiliser is therefore essential for every farmer.

Whether you are growing maize, rice, cassava, soybean, vegetables, or other crops, following the right fertiliser practices can help you maximise your investment and achieve a better harvest.

Why Fertiliser Is Important During the Rainy Season

Healthy crops need nutrients to grow properly. Although soils naturally contain some nutrients, continuous cultivation often reduces soil fertility over time.

Fertilisers replace essential nutrients that crops remove from the soil during growth. The three primary nutrients required by most crops are:

  • Nitrogen (N): Promotes leafy growth and healthy green plants.
  • Phosphorus (P): Encourages strong root development and early plant growth.
  • Potassium (K): Improves crop strength, disease resistance, and grain or fruit quality.

Applying fertiliser correctly helps crops develop faster, produce healthier leaves, and achieve higher yields.

When Is the Best Time to Apply Fertiliser?

Timing is one of the most important factors in fertiliser application.

Many farmers believe fertiliser should be applied immediately after planting, but this is not always the best approach.

For most crops, fertiliser should be applied when seedlings are well established and actively growing. This allows plants to absorb nutrients efficiently without risking fertiliser wastage.

For example:

  • Maize: Apply the first fertiliser about 2 to 3 weeks after planting, followed by a second application at 5 to 6 weeks if required.
  • Rice: Apply according to the crop growth stage, often in split applications to improve nutrient use.
  • Cassava: Apply fertiliser 4 to 8 weeks after planting, depending on soil fertility and variety.
  • Vegetables: Apply smaller amounts at regular intervals throughout the growing season.

Following crop-specific recommendations produces better results than applying fertiliser based on guesswork.

Avoid Applying Fertiliser Before Heavy Rainfall

One of the biggest mistakes farmers make during the rainy season is applying fertiliser just before a heavy downpour.

Heavy rainfall can wash nutrients away through surface runoff or carry them deep into the soil beyond the reach of crop roots. This process, known as nutrient leaching, reduces fertiliser efficiency and increases production costs.

Instead, farmers should monitor weather conditions and apply fertiliser when light or moderate rainfall is expected. Gentle rainfall helps dissolve fertiliser and move nutrients into the soil without causing excessive losses.

Apply Fertiliser to Moist Soil

Fertiliser performs best when the soil contains adequate moisture.

Dry soil limits nutrient movement, while waterlogged soil increases nutrient losses and may damage plant roots.

The ideal time to apply fertiliser is when the soil is moist but not saturated. This allows nutrients to dissolve properly and become available for crop uptake.

Use the Right Fertiliser for Your Crop

Different crops require different nutrient combinations.

Using the wrong fertiliser can reduce crop performance and waste money.

Common fertilisers used by Nigerian farmers include:

  • NPK compound fertilisers
  • Urea
  • Single Super Phosphate (SSP)
  • Muriate of Potash (MOP)

Before purchasing fertiliser, farmers should consider:

  • The crop being grown.
  • Soil fertility.
  • Previous fertiliser applications.
  • Recommendations from agricultural extension officers.

Where possible, conducting a soil test before planting provides valuable information about nutrient deficiencies and helps farmers choose the most suitable fertiliser.

Apply the Correct Fertiliser Rate

More fertiliser does not always produce better yields.

Excessive fertiliser application may:

  • Burn crop roots.
  • Increase production costs.
  • Pollute nearby water sources.
  • Encourage excessive vegetative growth instead of grain or fruit production.

Farmers should always follow the recommended application rate for each crop and fertiliser type.

Applying the right amount improves nutrient efficiency while protecting both crops and the environment.

Split Fertiliser Application Improves Efficiency

Instead of applying all fertiliser at once, many agronomists recommend split application.

This involves dividing the total fertiliser requirement into two or more applications during the growing season.

Split application offers several advantages:

  • Reduces nutrient losses.
  • Improves nutrient uptake.
  • Matches nutrient supply with crop demand.
  • Increases fertiliser efficiency.

For maize, for example, the first application supports early vegetative growth, while the second application supplies nutrients during rapid growth and grain formation.

Place Fertiliser Correctly

The placement of fertiliser is just as important as timing.

Fertiliser should not be placed directly against plant stems because concentrated nutrients may damage young roots.

Instead, fertiliser should be applied a short distance away from the plant and lightly covered with soil where appropriate.

Proper placement reduces nutrient loss and improves absorption by plant roots.

Combine Organic and Inorganic Fertilisers

Healthy soils benefit from both organic and inorganic nutrient sources.

Organic materials such as compost, poultry manure, and well-decomposed farmyard manure improve soil structure, increase organic matter, and enhance water retention.

Chemical fertilisers provide nutrients more quickly.

Combining both sources often produces better long-term results than relying on one method alone.

Integrated soil fertility management helps maintain productive soils for future farming seasons.

Common Mistakes Farmers Should Avoid

Many fertiliser-related problems result from simple management errors.

Avoid the following mistakes:

  • Applying fertiliser before heavy rainfall.
  • Applying fertiliser to waterlogged fields.
  • Using the wrong fertiliser for the crop.
  • Applying excessive fertiliser.
  • Broadcasting fertiliser carelessly.
  • Ignoring soil testing.
  • Applying fertiliser too close to plant stems.
  • Delaying fertiliser application until crops show severe nutrient deficiency.

Correcting these mistakes can significantly improve fertiliser performance.

Signs Your Crops May Need Fertiliser

Farmers should regularly inspect their crops for signs of nutrient deficiency.

Common symptoms include:

  • Yellowing leaves.
  • Stunted growth.
  • Weak stems.
  • Poor root development.
  • Slow growth.
  • Low grain or fruit production.

However, these symptoms may also result from pests, diseases, or poor drainage. Where possible, seek advice from an agricultural extension officer before making major fertiliser decisions.

Conclusion

Applying fertiliser during the rainy season is one of the most important investments farmers make each year. However, achieving good results depends not only on the type of fertiliser used but also on proper timing, correct application methods, and careful nutrient management.

Applying fertiliser to moist soil, avoiding heavy rainfall, using recommended rates, practising split application, and selecting the right fertiliser for each crop can significantly improve crop growth and increase yields.

As production costs continue to rise, every bag of fertiliser should be used as efficiently as possible. By following these best practices, Nigerian farmers can reduce nutrient losses, improve soil fertility, and achieve healthier crops and more profitable harvests.

 

OTHER RELATED ARTICLES