『Abstract
　Nitrogen oxides (NOx) are involved in acid rain and ozone formation, as well as destruction. NOx are climate-relevant trace gases in the atmosphere. Atmospheric NOx originate from anthropogenic emissions (mainly combustion processes). NO from natural processes derives from thunderstorm and soil microbial processes. They may play a crucial role in soil-atmosphere feedback processes. This study aims to investigate NOx-emissions from soils under different land use, geographical and meteorological conditions. NOx-emissions were quantified in both field and laboratory experiments with a closed static chamber. Disturbed soil samples have been used for laboratory experiments. A climate chamber was used to regulate soil temperature of the samples. Field experiments showed that NO-soil emissions strongly depend on soil temperature. NO-emissions from a soil under meadow showed significantly daily variations, unlike soil below spruce forest. Peak emission values were 18μg NO-N m^-2 h^-1 above meadow and 1.3μg NO-N m^-2 h^-1 under forest canopy. In addition, NO-emissions of meadow and forest soil were studied in a climate chamber, enhanced by an additional experiment with agricultural soil. These experiments revealed strong exponential correlations of NO-emissions and soil temperature. Maximum values reached above 400μg NO-N m^-2 h^-1 from agricultural soils at soil temperatures above 50℃. This study shows that soil NO-emissions strongly depend on temperature, vegetation type and geographical position. Consequently, NO-emissions may have a positive feedback effect on climate change.

Keywords: Soil emissions; Nitric oxide; Nitrification; Closed static chamber; Climate change』

Introduction
Materials and methods
　Site description
　Experimental setup
　　Field experiments
　　Laboratory experiments
Results
　Field measurements
　　Meadow
　　Forest
　Laboratory experiments
Discussion
　Field experiments
　　Meadow
　　Forest
　Laboratory measurements
Conclusions
Acknowledgments
References