Author
Sainju, Upendra | |
LENSSEN, ANDREW - Iowa State University | |
Allen, Brett | |
Stevens, William - Bart | |
Jabro, Jalal - Jay |
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/21/2016 Publication Date: 12/1/2016 Citation: Sainju, U.M., Lenssen, A.W., Allen, B.L., Stevens, W.B., Jabro, J.D. 2016. Soil total carbon and crop yield affected by crop rotation and cultural practice. Agronomy Journal. 109(1):1-9. doi:10.2134/agronj2016.07.0402 Interpretive Summary: Stacked crop rotation where same crop types are grown successively for a number of years in the rotation has been used to manage weeds and pests compared with alternate-year rotation. Another practice to control weeds and pests is to alter cultural practice. Practices that use higher crop seeding rates, banded fertilization, and delayed planting and harvest have been effective in controlling weeds compared with recommended seeding rates, broadcast fertilization, and early planting and harvest. Information on the effects of stacked vs. alternate-year crop rotation and continuous monocropping as well as alteration in cultural practices on soil organic carbon storage and crop yields, however, is lacking. We evaluated the effects of stacked vs. alternate-year crop rotations and cultural practices on soil organic carbon at the 0- to 125-cm depth and annualized crop yields from 2005 to 2011 in the northern Great Plains. Stacked rotations included durum-durum-canola-pea ((D-D-C-P) and durum-durum-flax-pea (D-D-F-P). Alternate-year rotations were durum-canola-durum-pea (D-C-D-P) and durum-flax-durum-pea (D-F-D-P). Cultural practices were traditional (conventional till, recommended seed rate, broadcast N fertilization, and reduced stubble height) and ecological (no-till, increased seed rate, banded N fertilization, and increased stubble height). Annualized biomass residue (stems and leaves) returned to the soil and grain yield were greater with D-C-D-P and D-D-C-P than D-D-F-P and greater with the ecological than the traditional practice. Soil organic carbon at 5 to 10 cm was lower with D-D-C-P than other crop rotations and lower with the ecological than the traditional practice. At 20 to 50, 50 to 88, and 0 to 125 cm, soil organic carbon was lower with D-D-F-P than D-C-D-P and D-F-D-P. Regardless of treatments, soil organic carbon declined linearly from 2005 to 2011. Soil organic carbon at 0 to 125 cm increased linearly with annualized crop yield. Stacked rotation reduced soil organic carbon storage and crop yield compared with alternate-year rotation. Ecological cultural practice increased crop yield with minimum impact on soil organic carbon compared with the traditional practice. Alternate-year crop rotation can sustain soil carbon storage and crop yield compared with monocropping. As a result, alternate-year rotation may be used to sequester carbon in the soil, reduce carbon pollution in the atmosphere, enhance soil health and quality, sustain crop yield, reduce farm inputs, and claim carbon credit in dryland cropping systems. Technical Abstract: Stacked crop rotation and improved cultural practice have been used to control pests, but their impact on soil organic C (SOC) and crop yield are lacking. We evaluated the effects of stacked vs. alternate-year rotations and cultural practices on SOC at the 0- to 125-cm depth and annualized crop yields from 2005 to 2011 in the northern Great Plains. Stacked rotations were durum (Triticum turgidum L.)-durum-canola (Brassica napus L.)-pea (Pisum sativum L.) (D-D-C-P) and durum-durum-flax (Linum usitatissimum L.)-pea (D-D-F-P). Alternate-year rotations were durum-canola-durum-pea (D-C-D-P) and durum-flax-durum-pea (D-F-D-P). Cultural practices were traditional (conventional till, recommended seed rate, broadcast N fertilization, and reduced stubble height) and ecological (no-till, increased seed rate, banded N fertilization, and increased stubble height). Annualized biomass residue (stems and leaves) returned to the soil and grain yield were greater with D-C-D-P and D-D-C-P than D-D-F-P and greater with the ecological than the traditional practice. The SOC at 5 to 10 cm was lower with D-D-C-P than other crop rotations and lower with the ecological than the traditional practice. At 20 to 50, 50 to 88, and 0 to 125 cm, SOC was lower with D-D-F-P than D-C-D-P and D-F-D-P. Regardless of treatments, SOC declined linearly from 2005 to 2011. The SOC at 0 to 125 cm increased linearly with annualized crop yield (R2 = 0.58, P = 0.01). Stacked rotation reduced SOC storage and crop yield compared with alternate-year rotation. Ecological cultural practice increased crop yield with minimum impact on SOC compared with the traditional practice. |