NITROUS OXIDE EVOLUTION RATES FROM FERTILIZED SOIL: EFFECTS OF APPLIED NITROGEN

Authors:
  • DMD. J. McKENNEY
    D. J. McKENNEY
  • KSK. F. Shuttleworth
    K. F. Shuttleworth
  • WFW. I. Findlay
    W. I. Findlay

Abstract
Nitrous oxide emission from agricultural soil has been measured in two relatively long-term studies over two different soil types, Brookston clay and Fox sandy loam, located at Woodslee and Harrow Ontario, respectively. The clay plots treated with various amounts (0–366 kg N∙ha−1) of ammonium nitrate, potassium nitrate, or urea were routinely monitored for periods up to 1 yr. Extreme variability in rates within the range 109–1013 molecules∙cm−2∙s−1 was observed (1 × 109 molecules∙cm−2∙s−1 = 4.02 = 10−4 kg N∙ha−1∙day−1 = 1.68 μg N∙m−2∙h−1). Over sandy loam, rates which were lower and more uniform (108–1011 molecules∙cm−2∙s−1) showed a strong correlation with amount of NH4NO3 applied. About 0.25% of applied fertilizer was released as N2O within 80 days following treatment.