Spatial variability of N2O emissions and soil parameters of an arable silt loam -: a field study

The spatial in situ variability of soil N2O emissions (measured by micro-chambers, radius 0.033 m), N2O content, water content, NO3-, NH4+, inorganic carbon and organic carbon concentrations was investigated on a silt loam by means of geostatistical methods and nonparametric statistics. The sampling grid consisted of different spacings between sampling points which ranged from 0.1 m to 50 m. There were no significant correlations between N2O emissions and soil parameters (P>0.1) when all the sampling points were considered. In the centre of the grid a "hot area" was localized with significantly higher N2O emissions, and NO, and NH4+ concentrations (P less than or equal to 0.05). Within this hot area the N2O soil content significantly correlated with N2O emissions (P less than or equal to 0.05). When semiovariograms were computed without data of the hot area samples, N2O emissions showed a weak spatial correlation (range: 4.3 m). The calculations including all data led to pure nugget effects for all parameters except for soil water content (range >40 m) and N2O soil content (range 16.4 m).