Net N2O production from soil particle size fractions and its response to changing temperature - 土壤碳循环与地膜覆盖课题组

Previous studies demonstrated that finer soil particles have smaller rates of CO2 emission but the larger Q10 values (the proportionate increase in the rate for a warming of 10 oC) than coarser particles. However, it has not been tested whether there is a regular pattern for rates and Q10 for N2O emission (net production) across soil particle size fractions, considering the known positive correlation between soil CO2 and N2O emissions. A short-term incubation study with different soil particle fractions was conducted for soils from a grassland, a forest, an upland (including organic manure (OM) and chemical nitrogen, phosphorus, and potassium fertilizers (NPK) treatments), and a paddy (including manure plus chemical fertilizer (MNPK) and NPK treatments) under a series of increasing and decreasing temperatures between 5°C and 30°C with 5°C intervals. For all the soils, net N2O production per unit mass of soil N was smaller from the silt (2–50 μm) fraction than from the sand (>50 μm) and clay (