Plant nitrogen (N) use is a key component of the N cycle in terrestrial ecosystems. The supply of N to plants affects community species composition and ecosystem processes such as photosynthesis and carbon (C) accumulation. However, the availabilities and relative importance of different N forms to plants are not well understood. While nitrate (NO3-) is a major N form used by plants worldwide, ...

Variability in seasonal soil moisture (SM) and temperature (T) can alter ecosystem/atmosphere exchange of the trace gases carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). This study reports the impact of year-round SM status on trace gas fluxes in three semiarid vegetation zones, mesquite (30 g organic C kg soil), open/ forb (6 g organic C kg soil), and sacaton (18 g organic C kg s...

Eddy covariance and static chambers are different-scale methods for monitoring agricultural N2O that, when used together on heterogeneous agricultural landscapes, can help identify flux sources and sinks and evaluate the effect of management interventions on landscape-scale N2O emissions. This study compared the N2O flux data obtained by eddy covariance and static chambers during a short-term N...

Nitrification inhibitors may be potential management strategy to reduce N2O emissions in irrigated rice (Oryza sativa L.). A field experiment was conducted to evaluate chemically synthesized as well as locally available neem plant products on N2O emissions, from an irrigated rice at New Delhi, India. Emission of nitrous oxide (N2O) was monitored during 70 days by closed chamber method in rice (...

Nitrous oxide (N2O) emissions from N fertilizer applied to row crops makes up a large portion of the greenhouse gas loading atmosphere. Guayule (Parthenium argentatum A. Gray) is desert perennial shrub being promoted for Central Arizona farmers as source natural rubber and hypoallergenic latex. Emissions N2O crop uptake have not been previously quantified in this multi-year cropping system. A 2...

Groundwater contamination was characterised using a methodology which combines shallow groundwater geochemistry data from 17 piezometers over a 2 yr period in a statistical framework and hydrogeological techniques. Nitrate-N (NO3-N) contaminant mass flux was calculated across three control planes (rows of piezometers) in six isolated plots. Results showed natural attenuation occurs on site alth...

To evaluate spatial variability of nitrous oxide (N2O) emissions and to elucidate their determining factors on a field-scale basis, N2O fluxes and various soil properties were evaluated in a 100- x 100-m onion (Allium cepa L.) field. Nitrous oxide fluxes were determined by a closed chamber method from the one-hundred 10- x 10-m plots. Physical (e.g., bulk density and water content), chemical (e...

Nutrient deposition to tropical forests is increasing, which could affect soil fluxes of nitrous oxide (N2O), a powerful greenhouse gas. We assessed the effects of 35–56 months of moderate nitrogen (N) and phosphorus (P) additions on soil N2O fluxes and net soil N-cycling rates, and quantified the relative contributions of nitrification and denitrification to N2O fluxes. In 2008, a nutrient man...

In the present research, effects of UV-B radiation (5.00 kJ·m−2) on chemical composition Azolla were investigated, and decomposition residues after radiation, nitrogen form, enzyme activity, bacterial community in paddy soil analyzed. Compared to natural light treatment, total content was significantly increased by 17.0% under treatment. returned grown light, rate cellulose, lignin, increased, ...

Understanding forest carbon cycling responses to atmospheric N deposition is critical to evaluating ecosystem N dynamics. The natural abundance of N (dN) has been suggested as an efficient and non-invasive tool to monitor N pools and fluxes. In this study, three successional forests in southern China were treated with four levels of N addition. In each treatment, we measured rates of soil N min...