Trace gas exchange of N2O, NO/NO2 and CH4 between soil and the atmosphere was measured in a typical Mediterranean pine (Pinus pinaster) forest during two intensive field campaigns in spring and autumn 2003. Furthermore, gross and net turnover rates of N mineralization and nitrification as well as soil profiles of N2O and CH4 concentrations were determined. For both seasons a weak but significan...

ÐChanges in land use and management of tropical systems are considered to be major factors in the recent upsurge in increases in atmospheric nitrous oxide (N2O) and methane (CH4). Studies were initiated in western Puerto Rico grasslands to determine the e€ect of plowing, or liming and fertilizing an acid Oxisol on the soil±atmosphere exchanges of N2O and CH4. Weekly ®eld ̄ux measurements and ®el...

The dynamics of the nitrogen intermediates N2O and NO2 in estuarine sediments were studied along a salinity gradient in the eutrophied Weser Estuary (Germany) using microsensors for N2O, NO2, NOx, and O2. During dark incubations in the laboratory of sediment samples from a freshwater site, a brackish water site with fluctuating salinity, and a marine site, the effects of environmental changes i...

The Denitrification-Decompostion (DNDC) model was used to estimate the impact of change in management practices on N2O emissions in seven major soil regions in Canada, for the period 1970 to 2029. Conversion of cultivated land to permanent grassland would result in the greatest reduction in N2O emissions, particularly in eastern Canada where the model estimated about 60% less N2O emissions for ...

Soil is a significant source of atmospheric N2O, and soil N2O emissions at a global scale are greatly affected by environment changes that include continuous deposition of atmospheric nitrogen and changing precipitation distribution. However, to date, field simulations of multiple factors that control the interaction between nitrogen deposition and precipitation on forest soil N2O emissions are...

Nitrous oxide (N2O) is a major radiative forcing and stratospheric ozone-depleting gas. Among natural sources, freshwater ecosystems are significant contributors to N2O. Although temperature key factor determining the N2O emissions, respective effects of on emitted dissolved in water column remain unclear. In this study, 48 h incubation experiments were performed at three different temperatures...

Carbon (C) sequestration potential of biochar should be considered together with emission of greenhouse gases when applied to soils. In this study, we investigated CO2 and N2O emissions following the application of rice husk biochars to cultivated grassland soils and related gas emissions tos oil C and nitrogen (N) dynamics. Treatments included biochar addition (CHAR, NO CHAR) and amendment (CO...

Arable soils are a large source of nitrous oxide (N2O) emissions, making up half of the biogenic emissions worldwide. Estimating their source strength requires methods capable of capturing the spatial and temporal variability of N2O emissions, along with the effects of crop management. Here, we applied a process-based model, CERES, with geo-referenced input data on soils, weather, and land use ...

Nitrous oxide is soluble and can accumulate in soil solution when gaseous diffusion is restricted. The importance of N losses via degassing of N2O from groundwater entering surface streams is unknown. Measurements of N2O in soil solution revealed patterns of seasonal and spatial variation that were consistent with ecosystem regulation of denitrification. The highest concentrations were observed...

Nitrous oxide emissions during freeze/thaw periods contribute significantly to annual soil N2O emissions budgets in middle- and high-latitude areas; however, the freeze/thaw-related N2O emissions from waterlogged soils have hardly been studied in the Hulunber Grassland, Inner Mongolia. For this study, the effects of changes in land use/cover types on N2O emissions during freeze-thaw cycles were...