Crop residue incorporation alters soil nitrous oxide emissions during freeze—thaw cycles

Abstract

Pelster, D. E., Chantigny, M. H., Rochette, P., Angers, D. A., Laganiere, J., Zebarth, B. and Goyer, C. 2013. Crop residue incorporation alters soil nitrous oxide emissions during freeze-thaw cycles. Can. J. Soil Sci. 93: 415-425. Freeze-thaw (FT) cycles stimulate soil nitrogen (N) and carbon (C) mineralization, which may induce nitrous oxide (N2O) emissions. We examined how soybean (Glycine max L.) and corn (Zea mays L.) residue incorporation affect N2O emissions from high C content (35 g kg-1) silty clay and low C content (19 g kg-1) sandy loam soils over eight 10-d FT cycles, as a function of three temperature treatments [constant at +1°C (unfrozen control), +1 to -3°C (moderate FT), or +1 to -7°C (extreme FT)]. In unamended soils, N2O emissions were stimulated by FT, and were the highest with extreme FT. This was attributed to the increased NO3 availability measured under FT. Application of mature crop residues (C:N ratios of 75 for soybean and 130 for corn) caused rapid N immobilization, attenuating ...