Journal
JOURNAL OF ENVIRONMENTAL SCIENCES
Volume 26, Issue 3, Pages 581-592Publisher
SCIENCE PRESS
DOI: 10.1016/S1001-0742(13)60453-2
Keywords
N-15 tracing model; N2O; NO; NO/N2O; nitrification; denitrification
Categories
Funding
- Sino-German collaborative project: Innovative nitrogen management technologies to improve agricultural production and environmental protection in intensive Chinese agriculture
- Chinese Ministry of Science and Technology (MOST) [2007DFA30850]
- German Ministry of Education and Research [BMBF FKZ: 0330800C]
Ask authors/readers for more resources
Rice-paddies are regarded as one of the main agricultural sources of N2O and NO emissions. To date, however, specific N2O and NO production pathways are poorly understood in paddy soils. N-15-tracing experiments were carried out to investigate the processes responsible for N2O and NO production in two paddy soils with substantially different soil properties. Laboratory incubation experiments were carried out under aerobic conditions at moisture contents corresponding to 60% of water holding capacity. The relative importance of nitrification and denitrification to the flux of N2O was quantified by periodically measuring and comparing the enrichments of the N2O, NH4+-N and NO3--N pools. The results showed that both N2O and NO emission rates in an alkaline paddy soil with clayey texture were substantially higher than those in a neutral paddy soil with silty loamy texture. In accordance with most published results, the ammonium N pool was the main source of N2O emission across the soil profiles of the two paddy soils, being responsible for 59.7% to 97.7% of total N2O emissions. The NO3--N pool of N2O emission was relatively less important under the given aerobic conditions. The rates of N2O emission from nitrification (N2On) among different soil layers were significantly different, which could be attributed to both the differences in gross N nitrification rates and to the ratios of nitrified N emitted as N2O among soil layers. Furthermore, NO fluxes were positively correlated with the changes in gross nitrification rates and the ratios of NO/N2O in the two paddy soils were always greater than one (from 1.26 to 6.47). We therefore deduce that, similar to N2O, nitrification was also the dominant source of NO in the tested paddy soils at water contents below 60% water holding capacity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available