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United States Department of Agriculture

Agricultural Research Service

Title: The Impact of Nitrogen Placement and Tillage on No, N20, Ch4 and Co2 Fluxes from a Clay Loam Soil.

Authors
item Liu, X - CHINA AG UNIV., BEIJING
item Mosier, Arvin
item Halvorson, Ardell
item Zhang, F - CHINA AG UNIV., BEIJING

Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 6, 2005
Publication Date: March 3, 2006
Citation: Liu, X.J., Mosier, A.R., Halvorson, A.D., Zhang, F.S. 2006. The impact of nitrogen placement and tillage on NO, N2O, CH4 and CO2 fluxes from a clay loam soil. Plant and Soil Journal 280 (1-2): 177-188.

Interpretive Summary: Fertilizer N induced trace gas emission from arable soils is an environmental issue worldwide. Predictions of trace gas emissions from soils are difficult and confounded by different management practices such as tillage and fertilization techniques. The impact of deep N placement and no-till (NT) practice on the emissions of nitric oxide (NO), nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) from soils was evaluated by conducting two N placement experiments within a long-term tillage study in northeastern Colorado in 2004. Trace gas flux measurements were made 2-3 times per week, in zero-N fertilizer plots cropped continuously to corn under conventional-till (CT) and NT. Three N fertilizer placement depths (5, 10 and 15 cm in Exp.1 and 0, 5 and 10 cm in Exp.2, respectively) were used in both experiments. Liquid urea-ammonium nitrate at 224 kg N ha-1 was injected to the desired depth in the CT- and NT-soils. The NO and N2O emissions decreased linearly with increased depth of N placement while CH4 and CO2 emissions were not affected by N placement in either experiments. Trace gas fluxes were also significantly affected by tillage practice. Generally, NT decreased NO emission and CH4 oxidation but greatly increased N2O and CO2 emissions in both experiments compared with CT. The study results suggest that N placement ³10 cm could be an effective option for reducing NO and N2O emissions from N fertilized CT- and NT-soils.

Technical Abstract: Fertilizer N induced trace gas emission from arable soils is an environmental issue worldwide. Predictions of trace gas emissions from soils are difficult and confounded by different management practices such as tillage and fertilization techniques. To evaluate the impact of deep N placement and no-till (NT) practice on the emissions of NO, N2O, CH4 and CO2 from soils, we conducted two N placement experiments in a long-term tillage experiment site of northeastern Colorado in 2004. Trace gas flux measurements were made 2-3 times per week, in zero-N fertilizer plots that were cropped continuously to corn (Zea mays L.) under conventional-till (CT) and NT. Three N placement depths, replicated four times (5, 10 and 15 cm in Exp.1 and 0, 5 and 10 cm in Exp.2, respectively) were used in both experiments. Liquid urea-ammonium nitrate (UAN, 224 kg N ha-1) was injected to the desired depth in the CT- or NT-soils in each experiment. NO and N2O emissions decreased linearly with increased depth of N placement while CH4 and CO2 emissions were not affected by N placement in either experiments. Trace gas fluxes were also significantly affected by tillage practice. Generally, NT decreased NO emission and CH4 oxidation but greatly increased N2O and CO2 emissions in both experiments compared with CT. The study results suggest that N placement ³10 cm could be the effective option for reducing trace gaseous emissions from fertilized CT- and NT-soils.

Last Modified: 11/28/2014