SIMILAR N2O FLUX FROM SOIL MEASURED WITH DIFFERENT CHAMBER TECHNIQUES

N2O flux from an arable soil was measured using two types of closed chamber and one open chamber system. The results were compared. Average N2O flux from the closed chambers did not depend on chamber design. Fifteen replicate chambers of 0.78 dm2 and four chambers of 49 dm2 gave average fluxes of 0.63 and 0.66 mug N2O-N dm-2 h-1, respectively, with a higher variability from the small chambers (coefficient of variation, CV = 77%) than from the large chambers (CV = 40%). Six open chambers operating over the same period gave an average N2O flux of 1.16 mug N2O-N dm-2 h-1 with CV = 64%. The general agreement between the methods suggests that within the achievable precision, limited by spatial and temporal variability, they are all adequate for measuring N2O flux.