Soil temperature controls gaseous nitrogen losses through nitrous oxide (N<sub>2</sub>O) and ammonia (NH<sub>3</sub>) fluxes. Eight surface soils from agricultural fields across the United Stat...Soil temperature controls gaseous nitrogen losses through nitrous oxide (N<sub>2</sub>O) and ammonia (NH<sub>3</sub>) fluxes. Eight surface soils from agricultural fields across the United States were incubated at 10<span style="white-space:nowrap;">°</span>C, 20<span style="white-space:nowrap;">°</span>C, and 30<span style="white-space:nowrap;">°</span>C, and N<sub>2</sub>O and NH<sub>3</sub> flux were measured twice a week for 91 and 47 d, respectively. Changes in cumulative N<sub>2</sub>O and NH<sub>3</sub> flux and net N mineralization at three temperatures were fitted to calculate Q<sub>10</sub> using the Arrhenius equation. For the majority of soils, Q<sub>10</sub> values for the N<sub>2</sub>O loss ranged between 0.23 and 2.14, except for Blackville, North Carolina (11.4) and Jackson, Tennessee (10.1). For NH<sub>3</sub> flux, Q<sub>10</sub> values ranged from 0.63 (Frenchville, Maine) to 1.24 (North Bend, Nebraska). Net soil N mineralization-Q<sub>10</sub> ranged from 0.96 to 1.00. Distribution of soil organic carbon and total soil N can explain the variability of Q<sub>10</sub> for N<sub>2</sub>O loss. Understanding the Q<sub>10</sub> variability of soil N dynamics will help us to predict the N loss.展开更多
文摘Soil temperature controls gaseous nitrogen losses through nitrous oxide (N<sub>2</sub>O) and ammonia (NH<sub>3</sub>) fluxes. Eight surface soils from agricultural fields across the United States were incubated at 10<span style="white-space:nowrap;">°</span>C, 20<span style="white-space:nowrap;">°</span>C, and 30<span style="white-space:nowrap;">°</span>C, and N<sub>2</sub>O and NH<sub>3</sub> flux were measured twice a week for 91 and 47 d, respectively. Changes in cumulative N<sub>2</sub>O and NH<sub>3</sub> flux and net N mineralization at three temperatures were fitted to calculate Q<sub>10</sub> using the Arrhenius equation. For the majority of soils, Q<sub>10</sub> values for the N<sub>2</sub>O loss ranged between 0.23 and 2.14, except for Blackville, North Carolina (11.4) and Jackson, Tennessee (10.1). For NH<sub>3</sub> flux, Q<sub>10</sub> values ranged from 0.63 (Frenchville, Maine) to 1.24 (North Bend, Nebraska). Net soil N mineralization-Q<sub>10</sub> ranged from 0.96 to 1.00. Distribution of soil organic carbon and total soil N can explain the variability of Q<sub>10</sub> for N<sub>2</sub>O loss. Understanding the Q<sub>10</sub> variability of soil N dynamics will help us to predict the N loss.
