Once or twice a week is a practical target for most active compost piles — enough to add nitrogen and moisture without tipping the pile into ammonia overload or creating odor problems.
Urine is roughly 95% water with a nitrogen concentration that makes it a usable "green" input — similar in function to adding diluted liquid fertilizer. For a GEOBIN pile running heavy on browns (dry leaves, cardboard, straw), weekly urine additions help rebalance the carbon-to-nitrogen ratio that stalls decomposition. The risk with overdoing it isn't toxicity — it's excess ammonia off-gassing, which produces odor and wastes the nitrogen before microbes can use it. Diluting urine 10:1 with water before applying reduces that risk if you're adding more frequently.
- Recommended frequency: 1–2 times per week directly on an active compost pile.
- Urine nitrogen content: approximately 11 grams of nitrogen per liter of undiluted urine.
- Recommended dilution ratio: 10 parts water to 1 part urine for more frequent or concentrated applications.
- Urine pH: typically 6.0–8.0, which is compatible with the microbial range in a healthy compost pile.
- Best use case: brown-heavy piles lacking nitrogen — dry leaves, cardboard, straw — where urine offsets added greens.