Nitrogen, Tillage, and Crop Rotation Effects on Carbon Dioxide and Methane Fluxes from Irrigated Cropping Systems
- Francesco Alluvionea,
- Ardell D. Halvorson *b and
- Stephen J. Del Grossob
- a Dep of Agronomy, Forest and Land Management, Univ. of Turin, via L. da Vinci 44, 10095 Grugliasco (TO), Italy
b USDA–ARS, 2150 Centre Ave., Bldg. D, Suite 100, Fort Collins, CO 80526-8119. Contribution from USDA-ARS, Fort Collins, CO. The U.S. Department of Agriculture offers its programs to all eligible persons regardless of race, color, age, sex, or national origin, and is an equal opportunity employer. Mention of trade names or proprietary products does not indicate endorsement by USDA and does not imply its approval to the exclusion of other products that may be suitable
Long-term effects of tillage intensity, N fertilization, and crop rotation on carbon dioxide (CO2) and methane (CH4) flux from semiarid irrigated soils are poorly understood. We evaluated effects of: (i) tillage intensity [no-till (NT) and conventional moldboard plow tillage (CT)] in a continuous corn rotation; (ii) N fertilization levels [0–246 kg N ha−1 for corn (Zea mays L.); 0 and 56 kg N ha−1 for dry bean (Phaseolus vulgaris L.); 0 and 112 kg N ha−1 for barley (Hordeum distichon L.)]; and (iii) crop rotation under NT soil management [corn-barley (NT-CB); continuous corn (NT-CC); corn-dry bean (NT-CDb)] on CO2 and CH4 flux from a clay loam soil. Carbon dioxide and CH4 fluxes were monitored one to three times per week using vented nonsteady state closed chambers. No-till reduced (14%) growing season (154 d) cumulative CO2 emissions relative to CT (NT: 2.08 Mg CO2–C ha−1; CT: 2.41 Mg CO2–C ha−1), while N fertilization had no effect. Significantly lower (18%) growing season CO2 fluxes were found in NT-CDb than NT-CC and NT-CB (11.4, 13.2 and 13.9 kg CO2–C ha−1d−1 respectively). Growing season CH4 emissions were higher in NT (20.2 g CH4 ha−1) than in CT (1.2 g CH4 ha−1). Nitrogen fertilization and cropping rotation did not affect CH4 flux. Implementation of NT for 7 yr with no N fertilization was not adequate for restoring the CH4 oxidation capacity of this clay loam soil relative to CT plowed and fertilized soil.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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