TY - JOUR
T1 - Soil greenhouse gas responses to biomass removal in the annual and perennial cropping phases of an integrated crop livestock system
AU - Christenson, Elizabeth
AU - Jin, Virginia L.
AU - Schmer, Marty R.
AU - Mitchell, Robert B.
AU - Redfearn, Daren D.
N1 - Funding Information:
This research was funded by the United States Department of Agriculture-NIFA as a Coordinated Agricultural Project (CAP), Award no. 2016-68004-24768. Research was also supported by the United States Department of Agriculture-Agricultural Research Service (USDA-ARS). The authors gratefully acknowledge the contributions of the many student workers, technicians, and support scientists who were instrumental in maintaining this experiment, collecting data, and providing analytical laboratory support. A special thanks to Ben Fann and David Walla, and to UNL?s Agronomy and Horticulture farm crew and Animal Science folks for their logistic support of farming and livestock operations. The USDA, University of Nebraska, and Nebraska Extension are equal opportunity employers and providers. These groups prohibit discrimination in their programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status. Additionally, family status, parental status, religious preference, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual?s income is derived from any public assistance program has no effect on program delivery. Mention of trade names or specific commercial products in this publication is solely for the purpose of providing specific information and neither endorses nor implies recommendation or endorsement by the USDA, University of Nebraska, or Nebraska Extension.
Funding Information:
Funding: This research was funded by the United States Department of Agriculture-NIFA as a Coordinated Agricultural Project (CAP), Award no. 2016-68004-24768. Research was also supported by the United States Department of Agriculture-Agricultural Research Service (USDA-ARS).
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/7
Y1 - 2021/7
N2 - Diversifying agronomic production systems by combining crops and livestock (i.e., Integrated Crop Livestock systems; ICL) may help mitigate the environmental impacts of intensive single-commodity production. In addition, harvesting row-crop residues and/or perennial biomass could increase the multi-functionality of ICL systems as a potential source for second-generation bioenergy feedstock. Here, we evaluated non-CO2 soil greenhouse gas (GHG) emissions from both row-crop and perennial grass phases of a field-scale model ICL system established on marginally productive, poorly drained cropland in the western US Corn Belt. Soil emissions of nitrous oxide (N2O) and methane (CH4) were measured during the 2017–2019 growing seasons under continuous corn (Zea mays L.) and perennial grass treatments consisting of a common pasture species, ‘Newell’ smooth bromegrass (Bromus inermis L.), and two cultivars of switchgrass (Panicum virgatum L.), ‘Liberty’ and ‘Shawnee.’ In the continuous corn system, we evaluated the impact of stover removal by mechanical baling vs. livestock grazing for systems with and without winter cover crop, triticale (x Triticosecale neoblaringhemii A. Camus; hexaploid AABBRR). In perennial grasslands, we evaluated the effect of livestock grazing vs. no grazing. We found that (1) soil N2O emissions are gener-ally higher in continuous corn systems than perennial grasslands due to synthetic N fertilizer use; (2) winter cover crop use had no effect on total soil GHG emissions regardless of stover management treatment; (3) stover baling decreased total soil GHG emissions, though grazing stover significantly increased emissions in one year; (4) grazing perennial grasslands tended to increase GHG emissions in pastures selected for forage quality, but were highly variable from year to year; (5) ICL systems that incorporate perennial grasses will provide the most effective GHG mitigation outcomes.
AB - Diversifying agronomic production systems by combining crops and livestock (i.e., Integrated Crop Livestock systems; ICL) may help mitigate the environmental impacts of intensive single-commodity production. In addition, harvesting row-crop residues and/or perennial biomass could increase the multi-functionality of ICL systems as a potential source for second-generation bioenergy feedstock. Here, we evaluated non-CO2 soil greenhouse gas (GHG) emissions from both row-crop and perennial grass phases of a field-scale model ICL system established on marginally productive, poorly drained cropland in the western US Corn Belt. Soil emissions of nitrous oxide (N2O) and methane (CH4) were measured during the 2017–2019 growing seasons under continuous corn (Zea mays L.) and perennial grass treatments consisting of a common pasture species, ‘Newell’ smooth bromegrass (Bromus inermis L.), and two cultivars of switchgrass (Panicum virgatum L.), ‘Liberty’ and ‘Shawnee.’ In the continuous corn system, we evaluated the impact of stover removal by mechanical baling vs. livestock grazing for systems with and without winter cover crop, triticale (x Triticosecale neoblaringhemii A. Camus; hexaploid AABBRR). In perennial grasslands, we evaluated the effect of livestock grazing vs. no grazing. We found that (1) soil N2O emissions are gener-ally higher in continuous corn systems than perennial grasslands due to synthetic N fertilizer use; (2) winter cover crop use had no effect on total soil GHG emissions regardless of stover management treatment; (3) stover baling decreased total soil GHG emissions, though grazing stover significantly increased emissions in one year; (4) grazing perennial grasslands tended to increase GHG emissions in pastures selected for forage quality, but were highly variable from year to year; (5) ICL systems that incorporate perennial grasses will provide the most effective GHG mitigation outcomes.
KW - Cover crop
KW - Grazing
KW - Integrated crop-livestock system
KW - Land-use change
KW - Methane
KW - Nitrous oxide
KW - Stover removal
KW - Switchgrass
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U2 - 10.3390/agronomy11071416
DO - 10.3390/agronomy11071416
M3 - Article
AN - SCOPUS:85111349215
VL - 11
JO - Agronomy
JF - Agronomy
SN - 2073-4395
IS - 7
M1 - 1416
ER -