What predicts nitrous oxide emissions and denitrification N‐loss from European soils?

Abstract

Abstract N 2 0 emissions and denitrification N‐losses. precipitation, air temperature, soil moisture, bulk density and content of mineral N were monitored in 9 different agricultural soils in 6 European countries throughout the vegetation period (April to September) 1992 and 1993. N 2 O emissions and denitrification N‐losses were log‐normal distributed, reflecting high temporal changes. While small flux rates (< 2 g N ha −1 d −1 ) were detectable every day, high rates (> 10 g N ha −1 d −1 ) were measured after fertilization. An attempt to relate the emission variables to climate and soil variables was made through the use of correlation analysis. The mean N 2 0 emissions from soil were significantly correlated with the soil properties clay, organic C and mineral N content and the amount of applied mineral N fertilizer. The best prediction of the N 2 O emission rates (r 2 = 0.734) was achieved by multiple linear regression using the soil parameter clay and mineral N. Only 50% of the observed variation could be explained by the factors C org and mineral N, which describe the substrate availability for microbial processes. No successful statistical model was found for the prediction of denitrification N‐losses.