Investigation into the Effects of Straw Retention and Nitrogen Reduction on CH4 and N2O Emissions from Paddy Fields in the Lower Yangtze River Region, China

Straw retention is a widely used method in rice planting areas throughout China. However, the combined influences of straw retention and nitrogen (N) fertilizer application on greenhouse gas (GHG) fluxes from paddy fields merits significant attention. In this work, we conducted a field experiment in the lower Yangtze River region of China to study the effects of straw retention modes and N fertilizer rates on rice yield, methane (CH4) and nitrous oxide (N2O) emission fluxes, global warming potential (GWP), and greenhouse gas intensity (GHGI) during the rice season. The experiments included six treatments: the recommended N fertilizer—240 kg N·ha−1 with (1) no straw, (2) wheat straw, (3) rice straw, and (4) both wheat and rice straw retentions; in a yearly rice–wheat cropping system (N1, WN1, RN1, and WRN1, respectively); as well as both wheat and rice straw retentions with (5) no N fertilizer and (6) 300 kg N·ha−1 conventional N fertilizer (WRN0, WRN2). The results showed that CH4 emissions were mainly concentrated in the tillering fertilizer stage and accounted for 54.2%–87.5% of the total emissions during the rice season, and N2O emissions were primarily concentrated in the panicle fertilizer stage and accounted for 46.7%–51.4% total emissions. CH4 was responsible for 87.5%–98.5% of the total CH4 and N2O GWP during the rice season, and was the main GHG contributor in the paddy field. Although straw retention reduced N2O emissions from paddy field, it significantly increased CH4 emissions, which resulted in a significant net increase in the total GWP. Compared with the N1 treatment, the total GWP of WN1, WRN1, and RN1 increased by 3.45, 3.73, and 1.62 times, respectively; and the GHGI increased by 3.00, 2.96, and 1.52 times, respectively, so the rice straw retention mode had the smallest GWP and GHGI. Under double-season’s straw retentions, N fertilizer application increased both CH4 and N2O emissions, and the WRN1 treatment not only maintained high rice yield but also significantly reduced the GWP and GHGI by 16.5% and 30.1% (p < 0.05), respectively, relative to the WRN2 treatment. Results from this study suggest that adopting the “rice straw retention + recommended N fertilizer” mode (RN1) in the rice–wheat rotation system prevalent in the lower Yangtze River region will aid in mitigating the contribution of straw retention to the greenhouse effect.

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Comparison of carbon footprint and net ecosystem carbon budget under organic materials retention combined with reduced mineral fertilizer

10.21203/rs.3.rs-51084/v2 ◽

2021 ◽

Author(s):

Ying Liu ◽

Haiying Tang ◽

Pete Smith ◽

Chuan Zhong ◽

Guoqin Huang

Keyword(s):

Rice Straw ◽

Carbon Footprint ◽

Carbon Budget ◽

Mineral Fertilizer ◽

Chemical Fertilizer ◽

N Fertilizer ◽

Utilization Efficiency ◽

Astragalus Sinicus ◽

Straw Retention ◽

Rice Season

Abstract Background: Excessive application of chemical fertilizer has resulted in lower nitrogen uptake and utilization efficiency of crops, decreasing soil fertility, increasing greenhouse gas emissions, and worse environment pollution. Organic material retention is regard as the key to solve these problems. he objective of this study is to conduct an assessment of carbon budget under Astragalus sinicus L. and rice straw retention combined with reduced mineral fertilizer based on the two-year field experiment in a paddy field in the south of China. The experiment was randomized complete block design including four treatments with triplicates: control CK (winter follow, 120 kg ha-1 N fertilizer for each rice season) and three treatments with Astragalus sinicus L. and rice straw retention named RA, RB, and RC (reduced N fertilizer by 15%, 27.5%, and 40% in each rice season). Results: Treatments RA, RB, and RC increased greenhouse gases emissions by 9.30%~101.25%, among which CH4 accounted for more than 60%; Carbon input of crops from treatments RA, RB, and RC increased by 2.25%~12.10% compared with control CK over the two years. Though treatments RA, RB, and RC enhanced CO2 emissions, however, treatment RB decreased carbon footprint and became carbon sink.Conclusions: The results of this study reveal that treatment RB (Astragalus sinicus L. and rice straw retention with reduced N fertilizer by 27.5%) is better in reducing chemical fertilizer amount, increasing crop yield and carbon input, which is more conductive to sustainable development of agriculture.

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Comparison of carbon footprint and net ecosystem carbon budget under organic material retention combined with reduced mineral fertilizer

Carbon Balance and Management ◽

10.1186/s13021-021-00170-x ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Ying Liu ◽

Haiying Tang ◽

Pete Smith ◽

Chuan Zhong ◽

Guoqin Huang

Keyword(s):

Greenhouse Gas ◽

Rice Straw ◽

Carbon Footprint ◽

Organic Material ◽

Carbon Budget ◽

Mineral Fertilizer ◽

N Fertilizer ◽

Astragalus Sinicus ◽

Straw Retention ◽

Rice Season

Abstract Background Excessive application of chemical fertilizer has resulted in lower nitrogen uptake and utilization efficiency of crops, decreasing soil fertility, increasing greenhouse gas emissions, and worse environmental pollution. Organic material retention is regard as the key to solve these problems. The objective of this study is to conduct an assessment of carbon budget under Astragalus sinicus L. and rice straw retention combined with reduced mineral fertilizer based on the 2-year field experiment in a paddy field in the south of China. The experiment was randomized complete block design including four treatments with triplicates: control CK (winter follow, 120 kg ha−1 N fertilizer for each rice season) and three treatments with Astragalus sinicus L. and rice straw retention named RA, RB, and RC (reduced N fertilizer by 15%, 27.5%, and 40% in each rice season). Results Treatments RA, RB, and RC increased greenhouse gas emissions by 9.30–101.25%, among which CH4 accounted for more than 60%; Carbon input of crops from treatments RA, RB, and RC increased by 2.25–12.10% compared with control CK over the 2 years. Though treatments RA, RB, and RC enhanced CO2 emissions, treatment RB decreased carbon footprint and became carbon sink. Conclusions The results of this study reveal that treatment RB (Astragalus sinicus L. and rice straw retention with reduced N fertilizer by 27.5%) is better in reducing chemical fertilizer amount, increasing crop yield and carbon input, which is more conductive to sustainable development of agriculture.

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Effects of N Fertilizer Application Rates on N2O Emissions from a Vegetable Field in Wuhan, China - A Lysimeter Study

2010 4th International Conference on Bioinformatics and Biomedical Engineering ◽

10.1109/icbbe.2010.5515422 ◽

2010 ◽

Author(s):

Weihong Qiu ◽

Jinshan Liu ◽

Chengxiao Hu

Keyword(s):

Fertilizer Application ◽

N Fertilizer ◽

N2o Emissions ◽

Vegetable Field ◽

Application Rates

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Shallow Crustal Structure of the Middle‐Lower Yangtze River Region in Eastern China from Surface‐Wave Tomography of a Large Volume Airgun‐Shot Experiment

Seismological Research Letters ◽

10.1785/0220170232 ◽

2018 ◽

Vol 89 (3) ◽

pp. 1003-1013 ◽

Cited By ~ 12

Author(s):

Yuyang She ◽

Huajian Yao ◽

Qiushi Zhai ◽

Fuyun Wang ◽

Xiaofeng Tian

Keyword(s):

Surface Wave ◽

Crustal Structure ◽

Large Volume ◽

Yangtze River ◽

Eastern China ◽

Surface Wave Tomography ◽

River Region ◽

Wave Tomography ◽

Lower Yangtze

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Using stratified Bayesian model averaging in probabilistic forecasts of precipitation over the middle and lower Yangtze River region

Meteorology and Atmospheric Physics ◽

10.1007/s00703-021-00799-w ◽

2021 ◽

Author(s):

Haixia Qi ◽

Xiefei Zhi ◽

Tao Peng ◽

YongQing Bai ◽

Chunze Lin ◽

...

Keyword(s):

Bayesian Model ◽

Yangtze River ◽

Bayesian Model Averaging ◽

Model Averaging ◽

Probabilistic Forecasts ◽

River Region ◽

Lower Yangtze

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Nitrogen Fate and Efficiency of Fertilizer Application under a Rapeseed–Wheat–Rice Rotation System in Southwest China

Agronomy ◽

10.3390/agronomy11020258 ◽

2021 ◽

Vol 11 (2) ◽

pp. 258

Author(s):

Peng Ma ◽

Yan Lan ◽

Tengfei Lyu ◽

Feijie Li ◽

Zhiyuan Yang ◽

...

Keyword(s):

Southern China ◽

Fertilizer Application ◽

Application Rate ◽

N Fertilizer ◽

Management Model ◽

Fertilizer Management ◽

Rotation System ◽

Residual N ◽

Rice Season ◽

Stable Yield

To evaluate the efficient use of nitrogen (N) for rice in a rapeseed–wheat–rice rotation system, a pot experiment was conducted. The results indicated that in the conventional 15N-labeled (Nc) and reduced 15N-labeled (Nr) urea applications, absorbed N and soil residual N was higher in rapeseed than in wheat. In the rice season, the higher accumulation of 15N was achieved with an Nr application rate during the rapeseed season and an N fertilizer management model (40% as basal fertilizer, 40% as tillering fertilizer, and 20% as panicle fertilizer) during the rice season (PrNrM3). A high 15N accumulation was also achieved under the Nc application rate during the wheat season and the N fertilizer management model during the rice season (PwNcM3). The accumulation of 15N in PrNrM3 and PwNcM3 accounted for 21.35% and 36.72% of the residual N under the Nr application rate in the rapeseed season and the Nc application rate in the wheat season, respectively. Compared with the Nc application rate in the rapeseed season and M3 N management in the rice season (PrNcM3), the N agronomy efficiency (NAE) and the N partial factor efficiency (NPFP) of rice were increased by 23.85% and 1.59%, respectively, in PrNrM3. The annual crop yield was 3.95% lower in PrNrM3, which was not significant. PrNrM3 was a stable yield, N-saving application rate for rapeseed-rice rotation systems in southern China.

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