Urea (Nitrogen Supplement) for Mushroom Compost

Urea is a concentrated nitrogen source (46 % N by weight) used to kick‑start thermophilic activity in mushroom compost piles and fine‑tune the C:N ratio for button, portobello and other compost‑loving species.

Why Use Urea?

• Supplies fast, plant‑available nitrogen that feeds heat‑producing microbes and raises compost temperature quickly.
• Higher nitrogen per gram than chicken or horse manure, so lower application rates reduce bulk and odour.
• Dissolves easily in water, ensuring even distribution through straw or manure mixes.

Recommended Rates

• Phase I compost: 0.3‑0.5 % of wet substrate weight (3‑5 g per kg) or about 4‑5 kg per metric ton of compost.
• Supplemental feed: If nitrogen drops during turning, dissolve 30 g urea in 10 L water and sprinkle over each 100 kg compost.

Exceeding 0.7 % can lead to excess ammonia and delayed pinning. Adjust based on compost analysis.

Basic Use

1. Weigh the required urea.
2. Dissolve in the water you plan to add during initial wetting.
3. Mix thoroughly with straw, manure and gypsum, then follow your usual piling and turning schedule.

Pack Size

1kg resealable pouch. Stored sealed and dry, urea remains stable for up to two years.

Tips

• Monitor ammonia smell during Phase I. If strong, delay spawning until levels drop.
• Pair with gypsum (5‑10 %) to buffer pH and supply calcium.
• Keep moisture at 65‑70 %. Too wet inhibits the microbes that convert urea to microbial protein.

Legal & Safety

For cultivating legal mushroom species only. Wear gloves and a dust mask when handling powder. Not for human or animal consumption. Keep out of reach of children and pets.