My research investigated whether nitrogen (N) fertilizer application rates, with or without compost, impact nitrous oxide (N₂O) emissions in commercial lettuce fields. I conducted field sampling in two iceberg lettuce systems—one in Salinas (Dec–Apr) and one in Soledad (Mar–May)—focusing on emissions 8 days before and 10 days after fertilizer applications. Using LI-COR gas analyzers, I compared four treatments: Conservation N (CN), CN+Compost, Grower Standard (GS), and GS+Compost. I found that N₂O emissions were higher in the Salinas field, likely due to increased water from rainfall and irrigation. Across both sites, treatments with compost consistently produced higher N₂O emissions, suggesting that reducing fertilizer rates and water input may help lower greenhouse gas emissions in lettuce production.