The strategic role of potassium nitrate in autumn turf nutrition

Autumn is a physiological transition period for natural sports fields: the turf must recover energy after the intense summer season and prepare for winter dormancy. At this time, nutrition should focus not on vegetative growth, but on rebuilding reserves, strengthening tissues, and improving the turf’s response to mechanical stress from play and maintenance.

To meet these specific needs, DUO – 18-0-15 + 2Mg, a fertilizer from the Turf-on® line, is designed to deliver a balanced input that aligns with the seasonal phase of sports turf.

The value of potassium from potassium nitrate (KNO₃)

All the potassium in DUO comes from potassium nitrate (KNO₃)—a highly soluble, stable, and fully available source. Compared with other forms (such as potassium sulfate or potassium chloride), KNO₃ offers higher efficiency and complete physiological compatibility with plant tissues.

Potassium supplied as potassium nitrate:

• increases the mechanical strength of leaf blades and culms;

• improves osmotic regulation, reducing cellular dehydration under thermal stress;

• stabilizes photosynthesis and sugar metabolism, supporting the accumulation of carbohydrate reserves;

• enhances low-temperature tolerance, improving the turf’s winter resilience.

In addition, the nitrate (NO₃⁻) associated with potassium ensures a quick response even in cool soils, enabling rapid root uptake in the weeks leading up to vegetative dormancy.

Nitrogen balance and continuous nutrition

DUO provides 18 units of total nitrogen, delivered in forms with different release dynamics:

• nitrate (for immediate effect),

• ammoniacal (for an intermediate effect),

• methylene urea (for a prolonged effect).

This composition prevents excessive top growth and ensures steady, uniform nutrition—supporting root metabolism without stimulating undesirable leaf growth at this time of year.

The result is a dense, elastic, and durable turf with balanced physiology and an active root system, even under sub-optimal temperatures.

Directions for use

Application of DUO – 18-0-15 + 2Mg (Turf-on®) is recommended:

• from late September to November, before winter growth slowdown;

• at a rate adjusted to soil texture and maintenance intensity, typically 30–35 g/m²;

• on sports turfs, golf courses, and ornamental surfaces subject to heavy traffic.

Regular autumn use increases structural strength, maintains color, and improves the turf’s spring response at green-up.

DUO is a precision nutrition technology for autumn turf management. The balance between modulated nitrogen and potassium nitrate—combined with the total absence of phosphorus—helps the turf face the cold season with plants that are stronger, more resilient, and physiologically balanced.

👉 For detailed technical specifications and application protocols, visit www.comagricola.com or contact the Comagricola technical team for personalized advice on turf nutrition.