UAN-28

UAN-28 is a liquid nitrogen fertilizer containing 28% total nitrogen in three forms:

• nitrate (NO₃⁻) – rapidly absorbed by plants but easily leached;
• ammonium (NH₄⁺) – slower uptake, less prone to leaching;
• amide (NH₂) – gradually converted in soil into ammonium form, ensuring prolonged action.

Compared to UAN-32, UAN-28 has a lower nitrogen concentration, making it safer for foliar applications and more efficient under limited moisture conditions. Its superior crystallization resistance (–17 °C) allows safe storage and transportation during cold seasons. The product is fully water-soluble, free from undissolved particles and sediment, and does not clog nozzles. It has a neutral to slightly alkaline pH (~7) and is non-acidifying, making it suitable for most soil types.

Key advantages:

• reduced risk of phytotoxicity during foliar feeding;
• higher frost resistance — crystallization temperature down to –17 °C;
• low salt stress for crops;
• fully compatible with micronutrients, stimulants, and pesticides (subject to compatibility testing);
• easy application — uniform distribution via sprayers, fertigation, or drip irrigation systems;
• effective even under challenging weather conditions.

Application:

• base application — prior to sowing, particularly into moist soil;
• pre-sowing application — with incorporation into the soil;
• top dressing during vegetation — via sprayers (preferably streamer nozzles);
• fertigation — for vegetables and field crops;
• foliar application — in diluted form (8–12%).

Limitations and warnings:

• avoid application during hot hours — apply in the morning or evening;
• do not apply to wet foliage without prior dilution;
• crystallization temperature: –17 °C;
• precipitation or partial crystallization may occur at temperature extremes.