TY - JOUR
T1 - Impacts of early- and late-terminated cover crops on gas fluxes
AU - Ruis, Sabrina J.
AU - Blanco-Canqui, Humberto
AU - Jasa, Paul J.
AU - Ferguson, Richard B.
AU - Slater, Glen
N1 - Funding Information:
Acknowledgments This research work was funded by the Nebraska Environmental Trust through Grant no. 16-189. The authors acknowledge the field assistance, maintenance, and coordination by Stuart Hoff at the University of Nebraska–Lincoln’s Roger’s Memorial Farm and many student employees.
Publisher Copyright:
© American Society of Agronomy.
PY - 2018/11/1
Y1 - 2018/11/1
N2 - Cover crops (CCs) could alter soil processes, but the effects of early versus late termination of CCs on gas fluxes are not well known. We evaluated temporal changes in fluxes of CO 2 , N 2 O, and CH 4 and related soil properties in no-till corn (Zea mays L.) with and without winter rye (Secale cereale L.) CCs that were terminated early (30 d before planting) or late (at planting) in a rainfed silty clay loam and an irrigated silt loam in Nebraska from April 2016 to June 2017. Gas fluxes, soil temperature, and soil water content were measured biweekly to monthly, and wet aggregate stability and particulate organic matter concentrations were measured seasonally. We also compared our results with a global literature review. Late-terminated CCs did not affect CH 4 fluxes but increased daily CO 2 fluxes by 59% compared with no CC at both sites and N 2 O fluxes by 92% at the rainfed site only. Early termination did not affect gas fluxes. Termination date did not affect cumulative fluxes and had minimal effects on soil properties. The literature review supports our study results, which indicate that CC effects on (i) CO 2 fluxes are driven by plant respiration during the CC growing period, and (ii) N 2 O and CH 4 fluxes are minimal under grass CCs. Overall, under no-till, CC termination date has small effects on N 2 O and CH 4 fluxes, but late CC termination can increase CO 2 fluxes in spring due to greater biomass yield compared with early termination.
AB - Cover crops (CCs) could alter soil processes, but the effects of early versus late termination of CCs on gas fluxes are not well known. We evaluated temporal changes in fluxes of CO 2 , N 2 O, and CH 4 and related soil properties in no-till corn (Zea mays L.) with and without winter rye (Secale cereale L.) CCs that were terminated early (30 d before planting) or late (at planting) in a rainfed silty clay loam and an irrigated silt loam in Nebraska from April 2016 to June 2017. Gas fluxes, soil temperature, and soil water content were measured biweekly to monthly, and wet aggregate stability and particulate organic matter concentrations were measured seasonally. We also compared our results with a global literature review. Late-terminated CCs did not affect CH 4 fluxes but increased daily CO 2 fluxes by 59% compared with no CC at both sites and N 2 O fluxes by 92% at the rainfed site only. Early termination did not affect gas fluxes. Termination date did not affect cumulative fluxes and had minimal effects on soil properties. The literature review supports our study results, which indicate that CC effects on (i) CO 2 fluxes are driven by plant respiration during the CC growing period, and (ii) N 2 O and CH 4 fluxes are minimal under grass CCs. Overall, under no-till, CC termination date has small effects on N 2 O and CH 4 fluxes, but late CC termination can increase CO 2 fluxes in spring due to greater biomass yield compared with early termination.
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U2 - 10.2134/jeq2018.02.0066
DO - 10.2134/jeq2018.02.0066
M3 - Article
C2 - 30512049
AN - SCOPUS:85056709982
SN - 0047-2425
VL - 47
SP - 1426
EP - 1435
JO - Journal of Environmental Quality
JF - Journal of Environmental Quality
IS - 6
ER -