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United States Department of Agriculture

Agricultural Research Service

Research Project: Technologies for Managing Water and Sediment Movement in Agricultural Watersheds

Location: Watershed Physical Processes Research Unit

Title: Response of carbon dioxide emissions to warming under no-till and conventional till systems

Authors
item Hou, Ruixing -
item Ouyang, Zhu -
item Wilson, Glenn
item Li, Yusheng -
item Li, Hanxia -

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 2013
Publication Date: November 1, 2013
Citation: Hou, R., Ouyang, Z., Wilson, G.V., Li, Y., Li, H. 2013. Response of carbon dioxide emissions to warming under no-till and conventional till systems. Soil Science Society of America Journal. doi:10.2136/sssaj2013.05.0184.

Interpretive Summary: No-tillage (NT) tends to have greater soil organic carbon (SOC) stored in the surface soil layer relative to (conventional tillage) CT but few studies have addressed the fate of this SOC under conditions of global warming. An open warming experiment was conducted in the North China Plain (NCP) by heating long-term management plots using infrared heaters to determine the effects of warming on soil carbon dioxide emissions and the relationship between these soil carbon losses to changes in soil temperature and soil moisture. This experiment was conducted over three wheat/corn double cropped growing seasons from February 2010 to June 2012 and included CT and NT plots with and without warming. The warming treatment increased soil temperature by 2.1' and 1.6' for CT and NT, respectively, and decreased volumetric soil-water content by 14% and 10% for CT and NT, respectively. The effects of warming on cumulative soil carbon dioxide emissions over the study period were not significant but the trend was that emissions were restricted under CT (decreased by 2.7% on average), and stimulated by warming under NT system (increased by 3.9% on average). Significantly (P<0.05) lower soil respiration was observed in warmed plots than control plots from May to June each wheat season, and this pattern of soil respiration was consistent with advanced reproductive period of wheat by warming. Our results suggested that continued accumulation of SOC at the surface of NT plots could eventually promote more soil carbon dioxide emissions under NT relative to CT under a warmer climate. There is a need to consider the differences in response between these tillage systems to global warming if one is to estimate the effects of climate change on SOC accumulation and the impacts of NT on climate change.

Technical Abstract: No-tillage (NT) tends to have greater soil organic carbon (SOC) stored in the surface soil layer relative to (conventional tillage) CT but few studies have addressed the stability of the SOC under conditions of global warming. An open warming experiment was conducted in situ by infrared heating of long-term management plots in the North China Plain (NCP) to determine the effects of warming on soil CO2 emissions and the correlation to changes in soil properties (soil temperature and moisture). This experiment was conducted over three wheat-maize growing seasons from February 2010 to June 2012 and included CT and NT plots with and without warming. Warming treatment increased soil temperature by 2.1' and 1.6', and decreased volumetric soil-water content by 14% and 10% for CT and NT systems on average, respectively. The effects of warming on cumulative soil CO2 emissions over the study period were not significant but the trend was that soil CO2 emissions were limited under CT (decreased by 2.7% on average), and stimulated by warming under NT system (increased by 3.9% on average). Significantly (P<0.05) lower soil respiration was observed in warmed plots than control plots from May to June each wheat season, and this pattern of soil respiration was consistent with advanced reproductive period of wheat by warming. Our results suggested that continued accumulation of SOC at the surface of NT plots could eventually promote more soil CO2 emission under NT relative to CT due to warming. There is a need to consider the differences in response between these tillage systems to global warming if one is to estimate the effects of climate change on SOC accumulation under NT and the impacts of NT on climate change.

Last Modified: 8/30/2014
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