摘要 : The spatial variability of soil chemical properties and their relationships with N₂O emissions were studied in a lowland soil cropped to onion in Mikassa, Hokkaido (Japan). Soil air for the determinations of N<sub>2</su... 展开 The spatial variability of soil chemical properties and their relationships with N₂O emissions were studied in a lowland soil cropped to onion in Mikassa, Hokkaido (Japan). Soil air for the determinations of N₂O emissions and soil samples for chemical properties analyses were collected in 100 by 100 m and 60 by 60 m grids in 1999 and 2000, respectively with samples taken at 10 m spacing. Soil chemical properties studied were pH, electrical conductivity (EC), nitrite (NO₂^-), nitrate (NO₃^-), ammonia (NH₄⁺), sulfate (SO₄^2-), phosphate (PO₄^3-), chloride (Cl^-), total carbon (TC), C/N ratio and total nitrogen (TN). Results showed that in both years, soil chemical properties fitted to either linear, exponential or spherical variogram models. In 1999, soil chemical properties showed positive first degree surface trends, but removing them resulted in decreasing the range of spatial variability (Ao) and R² values. However, there was no positive trend in 2000. N₂O emissions were directly related with NO₂^-, PO₄^3- and soil temperature. However, correlations between other soil chemical properties and N₂O emissions were possible only after transforming the data into logarithmic scale. The highest correlations were obtained between N₂O emission and PO₄^3- (p=0.0001, r=0.61), followed by the sum of N-radicals NO₃^-+NH₄⁺ (p=0.003, r=0.48). This study confirms that, besides those traditionally studied, other soil chemical properties might as well correlate with N₂O emissions. In depth studies of the relationship between N₂O emissions and these soil chemical properties are needed. 收起