How to Fertilize During El Niño Drought Conditions

What Is El Niño And Why It Affects Crop Nutrition

El Niño is a systemic shift in climate patterns caused by warming sea surface temperatures in the Pacific Ocean. In many agricultural regions, El Niño is associated with reduced rainfall, higher temperatures, and increased evapotranspiration.

For growers, the immediate concern is water. But from a nutrition standpoint, the real challenge is what follows. As nutrients rely on water to move through the soil and into the plant, when soil moisture drops, this transport system breaks down. As a result, even well-supplied soils can behave like nutrient-deficient systems.

How Drought Impacts Nutrient Dynamics

Reduced soil moisture slows nutrient diffusion, limits root growth, and weakens the continuous flow of nutrients toward the root surface. Inside the plant, lower transpiration further reduces the movement of key nutrients. The outcome is a clear drop in NUE: nutrients remain present in the soil, but the plant cannot access or utilize them efficiently.

Which Nutrient Requires Special Attention in Dry Conditions?

Among all nutrients, potassium plays a central role in maintaining plant growth under dry conditions. Unlike nitrogen or phosphorus, potassium is directly involved in regulating plant water relations. It controls stomatal activity, improves water-use efficiency, and helps maintain turgor pressure during stress.

In practical terms, adequate potassium nutrition allows plants to:

• maintain photosynthesis under limited water
• regulate water loss more efficiently
• sustain nutrient transport processes
• better utilize available nitrogen

This makes potassium a critical driver of nutrient efficiency under drought. Ensuring sufficient potassium supply is therefore one of the most effective ways to protect yield potential when water is limited.

How to Adjust Fertilizer Programs for El Niño Conditions

Under El Niño drought conditions, fertilization is no longer about how much nutrient is applied but about how much is available and can be effectively used. Understanding these changes allows growers to adapt their nutrition programs before drought conditions become severe.

Maintaining NUE requires:

• aligning nutrient supply with reduced plant uptake capacity
• avoiding large, poorly timed applications
• ensuring nutrients remain accessible within the active root zone

Frequent monitoring of soil moisture, irrigation performance, and crop development can help growers make more informed fertilizer decisions.

Why Fertigation Becomes More Valuable During Drought

Where irrigation is available, fertigation becomes one of the most powerful tools to maintain NUE in dry conditions. It allows growers to supply nutrients together with irrigation water and make adjustments as conditions change.

Compared with large fertilizer applications made before drought develops, fertigation offers greater flexibility. By combining water and nutrients, growers can:

• place nutrients exactly where roots are active
• adjust nutrient supply dynamically
• avoid accumulation of unused nutrients in dry zones

ICL’s water-soluble fertilizer ranges such as Nova^® and Nova NPK^®are specifically designed for this level of precision. Their reliability and flexibility enable growers to respond quickly to changing field conditions, ensuring that nutrients remain available even when water is limiting.

Why And How Support Plant Performance

Nutrition is only one part of drought management. Under drought stress, the plant’s ability to absorb and utilize nutrients becomes just as important as nutrient availability itself. Root growth, metabolic activity, and stress tolerance all directly influence nutrient use efficiency.

Biostimulants such as BEOZ^® Adamite, combining seaweed extracts and amino acids, are designed to:

• stimulate root development
• support plant physiology under drought stress
• improve nutrient uptake efficiency

By helping the plant remain active, they ensure that available nutrients are effectively converted into growth.

Building Long-Term Nutrient Availability

Under prolonged drought conditions, maintaining a consistent and balanced nutrient supply becomes essential for sustaining nutrient use efficiency. This is not only about keeping nutrients available, but also about ensuring that they are supplied in forms and patterns that align with the plant’s reduced uptake capacity.

Polysulphate^® a key role in this context. As a natural polyhalite mineral, it delivers potassium, sulfur, calcium, and magnesium from a single source, with a gradual and sustained release pattern. This prolonged dissolution helps match nutrient availability with crop demand over time while minimizing the risk of losses and supporting overall NUE throughout the growing season. Additionally, the nutrients in Polysulphate^® promote better root development, as observed in multiple pot and field trial done globally.

At the same time, controlled release fertilizers can complement this strategy by providing an additional level of stability. Their coated structure regulates nutrient release over time, reducing immediate exposure of nutrients to the soil environment and helping maintain availability across longer periods. However, because their release dynamics are still influenced by soil temperature and moisture, their role under drought conditions is best seen as supportive rather than primary.

Together, these technologies illustrate an important principle: improving NUE under challenging conditions is not based on a single product, but on combining solutions that stabilize nutrient availability from different angles.

Conclusion

El Niño seasons often include alternating periods of excessive rainfall and dry weather, that destabilize the entire nutrient cycle. The drought conditions do not remove nutrients from the system but they reduce the plant’s ability to use them.

This makes nutrient use efficiency the central objective of any fertilization strategy.

Successful programs focus on:

• strengthening potassium nutrition to support water regulation and nutrient use
• improving nutrient availability rather than increasing input
• using fertigation for precision and adaptability
• supporting plant resilience and root activity

In a season defined by limited water, the most effective growers are those who ensure that every kilogram of nutrient applied is positioned, timed, and supported to deliver maximum return.

Through careful assessment, targeted nutrient management, and solutions such as Nova^®, BEOZ^®, and Polysulphate^®, growers can rebuild nutrient availability, support crop recovery, and improve fertilizer efficiency throughout El Niño-affected seasons.