N2O EMISSIONS FROM A CULTIVATED MOLLISOL: OPTIMAL TIME OF DAY FOR SAMPLING AND THE ROLE OF SOIL TEMPERATURE

作者：Noemi Cosentino Vanina Rosa; Lilia Fernandez Patricia; Figueiro Aureggi Santiago Andres; Angel Taboada Miguel

来源：Revista Brasileira de Ciencia do Solo, 2012, 36(6): 1814-1819.

DOI：10.1590/S0100-06832012000600015

• soil N2O fluxes
• climate change
• GHG sampling

The correct use of closed field chambers to determine N2O emissions requires defining the time of day that best represents the daily mean N2O flux. A short-term field experiment was carried out on a Mollisol soil, on which annual crops were grown under no-till management in the Pampa Ondulada of Argentina. The N2O emission rates were measured every 3 h for three consecutive days. Fluxes ranged from 62.58 to 145.99 mu g N-N2O m(-2) h(-1) (average of five field chambers) and were negatively related (R-2 = 0.34, p %26lt;0.01) to topsoil temperature (14 - 20 degrees C). N2O emission rates measured between 9:00 and 12:00 am presented a high relationship to daily mean N2O flux (R-2 = 0.87, p %26lt; 0.01), showing that, in the study region, sampling in the mornings is preferable for GHG.

• 出版日期2012-12