A novel whole-greenhouse static chamber method for quantifying ecosystem respiration and nitrous oxide emissions in greenhouse cultivation systems

We present a novel and cost-effective whole-greenhouse static chamber method for quantifying nighttime ecosystem respiration (carbon dioxide emissions in the dark) and nitrous oxide (N₂O) emissions in greenhouse cultivation systems. This method leverages routine nighttime sealing practices-such as closing vents and deploying thermal quilts-to create an enclosed environment for gas accumulation. Gas concentrations can be monitored either automatically using in situ sensors or manually via gas-tight sampling bags. In both approaches, linear regression of gas concentration versus time yields robust accumulation rates, which are then converted into fluxes based on greenhouse volume and temperature. Validation using a high-precision Picarro analyzer demonstrated strong linearity (R² > 0.95) in carbon dioxide (CO₂) and N₂O accumulation curves across 15 greenhouses, confirming the method's reliability. As both approaches produce comparable results, we recommend manual sampling for its simplicity and cost-efficiency. The method integrates emissions from soil, plants, and other surfaces, overcoming spatial limitations of small chambers. With minimal equipment and labor requirements-especially when using manual sampling-it offers a practical solution for routine monitoring of greenhouse gas (GHG) emissions in controlled-environment agriculture.•Allows for whole-ecosystem CO₂ and N₂O flux estimation using manual sampling and gas chromatography.•Demonstrates strong agreement with continuous online measurements in multi-site validation.•Provides a low-cost, scalable solution for GHG quantification in protected cropping systems.