Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Management Practices to Mitigate Global Climate Change, Enhance Bio-Energy Production, Increase Soil-C Stocks & Sustain Soil Productivity...

Location: Soil Plant Nutrient Research (SPNR)

Title: Soil Carbon Dynamics for Irrigated Corn under Two Tillage Systems

Authors
item Follett, Ronald
item Jantalia, Claudia -
item Halvorson, Ardell

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 6, 2012
Publication Date: April 5, 2013
Repository URL: http://doi:10.2136/sssaj2012.0413
Citation: Follett, R.F., Jantalia, C.P., Halvorson, A.D. 2013. Soil Carbon Dynamics for Irrigated Corn under Two Tillage Systems. Soil Science Society of America Journal. 77:951-963.

Interpretive Summary: Conventional plow tillage (CT) with high N rates is commonly used to grow irrigated, continuous corn (Zea mays L.) in the central Great Plains. Less common than CT is to instead use continuous no-till (NT). Both systems, with optimum irrigation and N fertilization, produce similar corn stover yields with similar stover carbon:nitrogen (C/N) ratios. We compared effects of tillage and N for their potential to maintain or sequester soil organic C (SOC) near the surface (0 to 30 cm) and deeper within the soil profile (30 to 120 cm). Stable C isotope techniques were used to understand the dynamics of soil C gains and losses. This technique provided information about the fate of C added to the soil by continuous corn (C4-C) and of the residual C3-C from cool-season plants grown prior to beginning the study. We determined change in SOC stocks under NT and CT management and relative contributions of C4-C and C3-C to change in total SOC stocks after eight crop years. No-till was superior to CT in maintaining SOC stocks. The C4-C from continuous corn was maintained under both NT and CT. Most of the change in SOC dynamics of CT vs. NT resulted from greater loss of C3-C stocks under CT throughout all sampling depths. N fertilization slowed losses of C3-C stocks and maintained C4-C stocks. Soil sampling to only 30cm may result in incomplete information about SOC sequestration. Deep soil sampling and use of stable C isotope techniques were important to the overall evaluation of soil C dynamics.

Technical Abstract: Conventional plow tillage (CT) with high N rates is commonly used to grow irrigated, continuous corn (Zea mays L.) in the central Great Plains. Less common than CT is to instead use continuous no-till (NT). Both systems, with optimum irrigation and N fertilization, produce similar corn stover yields with similar stover carbon:nitrogen (C/N) ratios. We compared effects of tillage and N for their potential to maintain or sequester soil organic C (SOC) near the surface (0 to 30 cm) and deeper within the soil profile (30 to 120 cm). Stable C isotope techniques were used to understand the dynamics of soil C gains and losses. This technique provided information about the fate of C added to the soil by continuous corn (C4-C) and of the residual C3-C from cool-season plants grown prior to beginning the study. We determined change in SOC stocks under NT and CT management and relative contributions of C4-C and C3-C to change in total SOC stocks after eight crop years. No-till was superior to CT in maintaining SOC stocks. The C4-C from continuous corn was maintained under both NT and CT. Most of the change in SOC dynamics of CT vs. NT resulted from greater loss of C3-C stocks under CT throughout all sampling depths. N fertilization slowed losses of C3-C stocks and maintained C4-C stocks. Soil sampling to only 30cm may result in incomplete information about SOC sequestration. Deep soil sampling and use of stable C isotope techniques were important to the overall evaluation of soil C dynamics.

Last Modified: 12/24/2014
Footer Content Back to Top of Page