Soil emissions of nitric oxide and nitrous oxide from injected anhydrous ammonium and urea

This study characterizes soil emissions of NO and N{sub 2}O from banded applications of anhydrous ammonium (AA) and urea over the period from 6 May 1994 to 12 September 1994 from a losses soil in western Tennessee. The N application rate for both sources was 168 kg ha{sup {minus}1}. Fertilizer type strongly influenced emissions of N{sub 2}O (F = 231; P = 0.0001) and NO (F = 69; P = 0.0001). During the 129 d measurement period, the AA treatment lost 12.33 Kg of N{sub 2}O-N or 7.33% of the applied N. The N{sub 2}O-N loss from the urea treatment was about one-half that from AA; 6.34 kg ha{sup {minus}1} or 3.77% of the applied N. Loss of NO-N from both treatment was small compared with N{sub 2}O-N loss. The urea treatment lost 0.27 kg ha{sup {minus}1} as NO-N and the AA treatment lost 0.2 kg ha{sup {minus}1} during the study period. While the measured loss rate of N{sub 2}O-N from AA is similar to previous literature estimates, our values for urea are 20 to 40 times greater than the current literature reports of N{sub 2}O-N loss of 0.1 to 0.2% of the urea applied. Higher N{sub 2}O losses frommore » urea in this study may be related to the fact that urea was banded below the soil surface, whereas urea has been broadcast on the soil surface in other N{sub 2}O emissions studies. 31 refs., 5 figs., 2 tabs.« less