Open AccessEffects of Winter Cover Crops Straws Incorporation on CH4 and N2O Emission from Double-Cropping Paddy Fields in Southern China
Author(s) -
Haiming Tang,
Xiaoping Xiao,
Wenguang Tang,
Ke Wang,
Jian Sun,
Weiyan Li,
Guibiao Yang
Publication year - 2014
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0108322
Subject(s) - agronomy , paddy field , growing season , lolium multiflorum , oryza sativa , multiple cropping , environmental science , randomized block design , cropping system , field experiment , greenhouse gas , straw , biology , crop , sowing , ecology , biochemistry , gene
Residue management in cropping systems is believed to improve soil quality. However, the effects of residue management on methane (CH 4 ) and nitrous oxide (N 2 O) emissions from paddy field in Southern China have not been well researched. The emissions of CH 4 and N 2 O were investigated in double cropping rice ( Oryza sativa L.) systems with straw returning of different winter cover crops by using the static chamber-gas chromatography technique. A randomized block experiment with three replications was established in 2004 in Hunan Province, China, including rice–rice–ryegrass ( Lolium multiflorum L.) (Ry-R-R), rice–rice–Chinese milk vetch ( Astragalus sinicus L.) (Mv-R-R) and rice–rice with winter fallow (Fa-R-R). The results showed that straw returning of winter crops significantly increased the CH 4 emission during both rice growing seasons when compared with Fa-R-R. Ry-R-R plots had the largest CH 4 emissions during the early rice growing season with 14.235 and 15.906 g m −2 in 2012 and 2013, respectively, when Ry-R-R plots had the largest CH 4 emission during the later rice growing season with 35.673 and 38.606 g m −2 in 2012 and 2013, respectively. The Ry-R-R and Mv-R-R also had larger N 2 O emissions than Fa-R-R in both rice seasons. When compared to Fa-R-R, total N 2 O emissions in the early rice growing season were increased by 0.05 g m −2 in Ry-R-R and 0.063 g m −2 in Mv-R-R in 2012, and by 0.058 g m −2 in Ry-R-R and 0.068 g m −2 in Mv-R-R in 2013, respectively. Similar result were obtained in the late rice growing season, and the total N 2 O emissions were increased by 0.104 g m −2 in Ry-R-R and 0.073 g m −2 in Mv-R-R in 2012, and by 0.108 g m −2 in Ry-R-R and 0.076 g m −2 in Mv-R-R in 2013, respectively. The global warming potentials (GWPs) from paddy fields were ranked as Ry-R-R>Mv-R-R>Fa-R-R. As a result, straw returning of winter cover crops has significant effects on increase of CH 4 and N 2 O emission from paddy field in double cropping rice system.