Evaluation of Five Gas Diffusion Models Used in the Gradient Method for Estimating CO2 Flux with Changing Soil Properties

The gradient method used to estimate soil CO2 flux is distinctive because it can provide additional information about production and consumption of profile. However, choosing an appropriate gas diffusion model with confidence the a big challenge. There no universal optimal but only most suitable in specific soils. This paper evaluates applicability five commonly models laboratory changing properties forest farm, respectively. When moisture, bulk density fertility status were changed laboratory, was discussed. Moreover, this shows diurnal variation estimated by under four different climatic conditions also analyzed. Both experimental results confirm that estimating accuracy Moldrup highest, followed Millington–Quirk model, while those Penman, Marshall Penman–Millington–Quirk are poor. Furthermore, indicate highly sensitive insensitive changes properties. In general, be as practical, cost-effective tool study respiration when first determined.