The influence of winter soil cover on spring nitrous oxide emissions from an agricultural soil

In temperate regions, a majority of N(2)O is emitted during spring soil thawing. We examined the influence of two winter field covers, snow and winter rye, on soil temperature and subsequent spring N(2)O emissions from a New York corn field over two years. The first season (2006-07) was a cold winter (2309 h below 0 degrees C at 8 cm soil depth), historically typical for the region. The snow removal treatment resulted in colder soils and higher N(2)O fluxes (73.3 vs. 57.9 ng N(2)O-N cm(-2) h(-1)). The rye cover had no effect on N(2)O emissions. The second season (2007-08) was a much milder winter (1271 h below freezing at 8 cm soil depth), with lower N(2)O fluxes overall. The winter rye cover resulted in lower N(2)O fluxes (5.9 vs. 33.7 ng N(2)O-N cm(-2) h(-1)), but snow removal had no effect. Climate scenarios predict warmer temperature and less snow cover in the region. Under these conditions, spring N(2)O emissions can be expected to decrease and could be further reduced by winter rye crops. (C) 2011 Published by Elsevier Ltd.