Greenhouse gas budget and methane dynamics in a no tillage chronosequence Research Project Indiana University and Ohio State University United States Department Of Agriculture Cooperative State Research Education And Extension Service USA OMB Approved No 0524 0039 Research Assistant 2009 2012 3 years Bu projede gorev almak icin 6 ay sure ile TUBITAK tarafindan USA da 6 ay sure ile gorevlendirildim


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Bilen S. , Dick W. A.

Universities of Other Countries Supported Project, 2008 - 2011

  • Project Type: Universities of Other Countries Supported Project
  • Begin Date: May 2008
  • End Date: May 2011

Project Abstract

Abstract

Nearly a quarter of all cropland in the US is under no-till (NT) - a management practice with well-documented positive effects on soil C sequestration, and soil quality maintenance. Although widespread adoption of no-tillage farming can help mitigate the global warming effect, there is a paucity of field-based data regarding the long-term impact of NT on greenhouse gas (GHG) fluxes. Accumulation of crop residue on soil surface increased soil moisture and availability of labile organic substrates could stimulate the emission of carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) from NT systems. Conversely, long-term adoption of no-tillage could lead to the evolution of a more active population of methanotrophs, increase soil macroporosity and ultimately improve the CH4 sink strength of croplands. Our primary hypothesis in this study is that the longer no-tillage is continuously applied to soil, the greater becomes the soil’s ability and potential to oxidize CH4. We also recognize that expression of the CH4 oxidation potential of NT soils could be hindered by other soil factors. Thus, there is a need to examine discrepancies between biological potential and actual CH4 fluxes in NT soils. Based on these considerations, the proposed research will address the following three objectives:

 

(1) Assess the impact of long-term no-tillage on GHG fluxes, and examine relationships between gas fluxes and biophysical properties of NT soils.

(2)  Evaluate the link between soil drainage characteristics and the impact of long-term no-till on GHG fluxes.

(3) Characterize the CH4 oxidation potential of NT soils, and identify factors limiting expression of that potential.  

 

Although CH4 is a major focus, the proposed research is a comprehensive assessment encompassing all three major soil-derived GHG (CO2, N2O, and CH4) in order to fully appraise the global warming mitigation potential (GWMP) of no-tillage farming. We will monitor GHG fluxes (2 full years) at research stations and farmers’ fields in similar soil types and under no-tillage for up to 46 years. Detailed studies using the kinetic approach, stable C isotope, and selective inhibition techniques will be conducted in order to characterize the community of CH4-oxidizers in NT soils and assess the effect of no-tillage duration and soil drainage characteristics on GHG dynamics. These experiments will be conducted to determine the potential for no-tillage soils to oxidize CH4 and to provide guidance as to management options that can be used to achieve this potential. Our goal is to provide a basis to enhance and project the contribution of no-till farming to regional GHG inventory under various scenarios of conservation tillage adoption in US agriculture. The proposed research addresses several priorities of the Air Quality program and most specifically priority #2 “increase adoption of best management practices to reduce agricultural emissions”.