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Soil Emissions of Nitric Oxide and Nitrous Oxide from No‐till Corn
Author(s) -
Thornton Frank C.,
Valente Ralph J.
Publication year - 1996
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1996.03615995006000040024x
Subject(s) - loam , nitrous oxide , soil water , zoology , ammonium , nitrate , fertilizer , ammonium nitrate , nitrogen , environmental science , zea mays , no till farming , chemistry , agronomy , soil science , soil fertility , biology , organic chemistry
Fertilized agricultural soils can be a significant source of emissions of NO and N 2 O into the atmosphere. This study was conducted to determine the influence of N rate on the emissions of these gases in a no‐till corn ( Zea mays L.) crop grown in western Tennessee. The influence of N rate was assessed for a 210‐d period on replicated plots receiving 0, 140, and 252 kg N ha −1 (0N, 140N, and 252N) as ammonium nitrate (AN). Plots were located on a Routon silt loam (fine‐silty, mixed, thermic Typic Ochraqualf) at the West Tennessee Agricultural Experiment Station in Jackson, TN. Gas fluxes were measured by static chamber boxes located on plots. The measurement technique was automated and replicate chamber estimates were made eight times daily for the entire study period. Fertilizer application significantly affected both NO and N 2 O emission rates. The cumulative N 2 O‐N lost from the fertilizer treatments was from 10 to 20‐fold that of NO. On an areal basis, the 140N treatment emitted 4.23 kg N 2 O‐N and 0.19 kg ha −1 of NO‐N whereas the 252N treatment emitted 6.56 kg N 2 O‐N and 0.50 kg ha −1 NO‐N. Soil parameters of water‐filled pore space (WFPS), NO 3 − and NH 4 + , were correlated with N 2 O emissions but only soil NO 3 − was correlated with NO flux. Our data, and more recent data in the literature, suggest that N 2 O emissions from fertilized soil may be considerably higher than previously thought. Emissions of N 2 O were 2.6 to 3.0% of the fertilizer amounts applied. These higher emissions may, in part, explain some of the reason for the shortfall in the global N 2 O budget.