Dinitrogen and N(2)O emissions in arable soils: Effect of tillage, N source and soil moisture

作者：Liu Xuejun J^*; Mosier Arvin R; Halvorson Ardell D; Reule Curtis A; Zhang Fusuo S

来源：Soil Biology and Biochemistry, 2007, 39(9): 2362-2370.

DOI：10.1016/j.soilbio.2007.04.008

• no-till
• WFPS
• (15)SN-labeled fertilizer
• denitrification
• nitrification
• nitrous oxide emission

A laboratory investigation was performed to compare the fluxes of dinitrogen (N(2)), N(2)O and carbon dioxide (CO(2)) from no-till (NT) and conventional till (CT) soils under the same water, mineral nitrogen and temperature status. Intact soil cores (0-10 cm) were incubated for 2 weeks at 25 degrees C at either 75% or 60% water-filled pore space (WFPS) with (15)N-labeled fertilizers (100 mg N kg(-1) soil). Gas and soil samples were collected at 1-4 day intervals during the incubation period. The N(2)O and CO2 fluxes were measured by a gas chromatography (GC) system while total N(2) and N(2)O losses and their (15)N mole fractions in the soil mineral N pool were determined by a mass spectrometer. The daily accumulative fluxes of N(2) and N(2)O were significantly affected by tillage, N source and soil moisture. We observed higher (P < 0.05) fluxes of N(2)+N(2)O, N(2)O and CO(2) from the NT soils than from the CT soils. Compared with the addition of nitrate (NOD, the addition of ammonium (NH(4)(+)) enhanced the emissions of these N and C gases in the CT and NT soils, but the effect of NH(4)(+) on the N(2) and/or N(2)O fluxes was evident only at 60% WFPS, indicating that nitrification and subsequent denitrification contributed largely to the gaseous N losses and N(2)O emission under the lower moisture condition. Total and fertilizer-induced emissions of N(2) and/or N(2)O were higher (P < 0.05) at 75% WFPS than with 60% WFPS, while CO(2) fluxes were not influenced by the two moisture levels. These laboratory results indicate that there is greater potential for N(2)O loss from NT soils than CT soils. Avoiding wet soil conditions (> 60% WFPS) and applying a NO(3) form of N fertilizer would reduce potential N(2)O emissions from arable soils.

• 出版日期2007-9
• 单位中国农业大学