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Emissions of CH4 and N2O under different tillage systems from double-cropped paddy fields in Southern China.

Zhang HL, Bai XL, Xue JF, Chen ZD, Tang HM, Chen F - PLoS ONE (2013)

Bottom Line: Compared with other treatments, NT significantly reduced CH4 emission among the rice growing seasons (P<0.05).Conversion of CT to NT significantly reduced the cumulative CH4 emission for both rice seasons compared with other treatments (P<0.05).The mean value of global warming potentials (GWPs) of CH4 and N2O emissions over 100 years was in the order of NT<RT<CT, which indicated NT was significantly lower than both CT and RT (P<0.05).

View Article: PubMed Central - PubMed

Affiliation: College of Agronomy and Biotechnology, China Agricultural University, Key Laboratory of Farming System, Ministry of Agriculture, Beijing, China. hailin@cau.edu.cn

ABSTRACT
Understanding greenhouse gases (GHG) emissions is becoming increasingly important with the climate change. Most previous studies have focused on the assessment of soil organic carbon (SOC) sequestration potential and GHG emissions from agriculture. However, specific experiments assessing tillage impacts on GHG emission from double-cropped paddy fields in Southern China are relatively scarce. Therefore, the objective of this study was to assess the effects of tillage systems on methane (CH4) and nitrous oxide (N2O) emission in a double rice (Oryza sativa L.) cropping system. The experiment was established in 2005 in Hunan Province, China. Three tillage treatments were laid out in a randomized complete block design: conventional tillage (CT), rotary tillage (RT) and no-till (NT). Fluxes of CH4 from different tillage treatments followed a similar trend during the two years, with a single peak emission for the early rice season and a double peak emission for the late rice season. Compared with other treatments, NT significantly reduced CH4 emission among the rice growing seasons (P<0.05). However, much higher variations in N2O emission were observed across the rice growing seasons due to the vulnerability of N2O to external influences. The amount of CH4 emission in paddy fields was much higher relative to N2O emission. Conversion of CT to NT significantly reduced the cumulative CH4 emission for both rice seasons compared with other treatments (P<0.05). The mean value of global warming potentials (GWPs) of CH4 and N2O emissions over 100 years was in the order of NT

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Soil porosity of different tillage treatments in 2008 (A for the early rice season and B for the late rice season).Data are means of three replications; means followed by different letters are significantly different at P<0.05.
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pone-0065277-g002: Soil porosity of different tillage treatments in 2008 (A for the early rice season and B for the late rice season).Data are means of three replications; means followed by different letters are significantly different at P<0.05.

Mentions: Soil porosity decreased with soil depth among all the treatments (Fig. 2). For the early rice season, SP at 0−5 cm depth was 68.48%, 63.18% and 61.03% for NT, CT and RT, respectively. Tukey HSD statistical test showed that SP for NT and CT significantly differed with that of RT (0−5 cm, df = 8 F = 69.651 P<0.05; 5−10 cm, df = 8 F = 18.589 P<0.05; 10−20 cm, df = 8 F = 10.393 P<0.05). The order of SP at depths of 5−10 cm and 10−20 cm varied with CT>RT> NT; and SP for CT and RT were 11.5% and 8.9% higher than that of NT, respectively. The trend of SP in the late rice season varied similarly with that of the early rice season (0−5 cm, df = 8 F = 30.167 P<0.05; 5−10 cm, df = 8 F = 195.166 P<0.05; 10−20 cm df = 8 F = 6.957 P<0.05). Conversion of traditional tillage to NT, SP at 5−10 cm depth was higher 1.83% and 7.27% than that for CT and RT, respectively. Compared with NT, SP for CT significantly increased at 10−20 cm depth in the early rice season. During the early rice growing season, SP at 5−10 cm depth varied in the order of CT>RT>NT (P<0.05). However, during the late rice season, SP at 5−10 cm depth followed in the order of NT>RT>CT (P<0.05) and 9.84% and 6.35% higher for NT and RT than for CT, respectively.


Emissions of CH4 and N2O under different tillage systems from double-cropped paddy fields in Southern China.

Zhang HL, Bai XL, Xue JF, Chen ZD, Tang HM, Chen F - PLoS ONE (2013)

Soil porosity of different tillage treatments in 2008 (A for the early rice season and B for the late rice season).Data are means of three replications; means followed by different letters are significantly different at P<0.05.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672096&req=5

pone-0065277-g002: Soil porosity of different tillage treatments in 2008 (A for the early rice season and B for the late rice season).Data are means of three replications; means followed by different letters are significantly different at P<0.05.
Mentions: Soil porosity decreased with soil depth among all the treatments (Fig. 2). For the early rice season, SP at 0−5 cm depth was 68.48%, 63.18% and 61.03% for NT, CT and RT, respectively. Tukey HSD statistical test showed that SP for NT and CT significantly differed with that of RT (0−5 cm, df = 8 F = 69.651 P<0.05; 5−10 cm, df = 8 F = 18.589 P<0.05; 10−20 cm, df = 8 F = 10.393 P<0.05). The order of SP at depths of 5−10 cm and 10−20 cm varied with CT>RT> NT; and SP for CT and RT were 11.5% and 8.9% higher than that of NT, respectively. The trend of SP in the late rice season varied similarly with that of the early rice season (0−5 cm, df = 8 F = 30.167 P<0.05; 5−10 cm, df = 8 F = 195.166 P<0.05; 10−20 cm df = 8 F = 6.957 P<0.05). Conversion of traditional tillage to NT, SP at 5−10 cm depth was higher 1.83% and 7.27% than that for CT and RT, respectively. Compared with NT, SP for CT significantly increased at 10−20 cm depth in the early rice season. During the early rice growing season, SP at 5−10 cm depth varied in the order of CT>RT>NT (P<0.05). However, during the late rice season, SP at 5−10 cm depth followed in the order of NT>RT>CT (P<0.05) and 9.84% and 6.35% higher for NT and RT than for CT, respectively.

Bottom Line: Compared with other treatments, NT significantly reduced CH4 emission among the rice growing seasons (P<0.05).Conversion of CT to NT significantly reduced the cumulative CH4 emission for both rice seasons compared with other treatments (P<0.05).The mean value of global warming potentials (GWPs) of CH4 and N2O emissions over 100 years was in the order of NT<RT<CT, which indicated NT was significantly lower than both CT and RT (P<0.05).

View Article: PubMed Central - PubMed

Affiliation: College of Agronomy and Biotechnology, China Agricultural University, Key Laboratory of Farming System, Ministry of Agriculture, Beijing, China. hailin@cau.edu.cn

ABSTRACT
Understanding greenhouse gases (GHG) emissions is becoming increasingly important with the climate change. Most previous studies have focused on the assessment of soil organic carbon (SOC) sequestration potential and GHG emissions from agriculture. However, specific experiments assessing tillage impacts on GHG emission from double-cropped paddy fields in Southern China are relatively scarce. Therefore, the objective of this study was to assess the effects of tillage systems on methane (CH4) and nitrous oxide (N2O) emission in a double rice (Oryza sativa L.) cropping system. The experiment was established in 2005 in Hunan Province, China. Three tillage treatments were laid out in a randomized complete block design: conventional tillage (CT), rotary tillage (RT) and no-till (NT). Fluxes of CH4 from different tillage treatments followed a similar trend during the two years, with a single peak emission for the early rice season and a double peak emission for the late rice season. Compared with other treatments, NT significantly reduced CH4 emission among the rice growing seasons (P<0.05). However, much higher variations in N2O emission were observed across the rice growing seasons due to the vulnerability of N2O to external influences. The amount of CH4 emission in paddy fields was much higher relative to N2O emission. Conversion of CT to NT significantly reduced the cumulative CH4 emission for both rice seasons compared with other treatments (P<0.05). The mean value of global warming potentials (GWPs) of CH4 and N2O emissions over 100 years was in the order of NT

Show MeSH
Related in: MedlinePlus