『Abstract
Despite many studies of the N2O emission,
there is a lack of knowledge on the role of subsoil for N2O emission, particularly in sandy soils. To obtain
insight into the entrapment, diffusion, convection and ebullition
of N2O in the soil, the N2O
concentration in the soil atmosphere was measured over a period
of 1 year in 4 lysimeters (agricultural soil monoliths of 1 m2×2
m) at 30, 50, 80, 155, and 190 cm depth with altogether 86 gas
probes. Additionally the N2O emission into
the atmosphere was measured in 20 closed chambers at the soil
surface. Concurrently the soil temperature and soil water content
were recorded in order to quantify their effects on the fate of
N2O in the soil. Results of the continuous
measurements between January and December 2006 were: N2O
concentrations were highest in the deeper soil; maximum concentration
was found at a depth of 80 cm, where the water content was high
and the gas transport reduced. The highest N2O
concentration was recorded after ‘special events’ like snowmelt,
heavy rain, fertilization, and grubbing. The combination of fertilization
and heavy rain led to an increase of up to 2,700 ppb in the subsoil.
Keywords: Lysimeter; N2O; Concentration』
1 Introduction
2 Methods
2.1 Research fields
2.2 Soil monoliths
2.3 Soil emissions
2.4 Soil gas concentration measurements
3 Results
4 Discussion
5 Conclusions
References