Emissions of CH4 and CO2 from paddy fields as affected by tillage practices and crop residues in central China

• Published in: Paddy and water environment 2016-01, Vol.14 (1), p.85-92
• Main Authors: Zhang, Zhi-Sheng, Cao, Cou-Gui, Guo, Li-Jin, Li, Cheng-Fang
• Format: Article
• Language: English
• Subjects: Agricultural practices; Agricultural production; Agriculture; Biomedical and Life Sciences; Carbon dioxide; Crop residues; Crop rotation; Crop yield; Dry matter; Ecotoxicology; Emissions; Experiments; Geoecology/Natural Processes; Grain; Growing season; Hydrogeology; Hydrology/Water Resources; Life Sciences; Methane; Rice; Soil Science & Conservation; Tillage
• ISSN: 1611-2490; 1611-2504
• DOI: 10.1007/s10333-015-0480-4

A field experiment was conducted to investigate effects of tillage practices [no-tillage (NT) and conventional intensive tillage (CT)] and oilseed rape residue returning levels (0, 3000, 6000, 9000 kg dry matter ha −1 ) on methane (CH 4 ) and carbon dioxide (CO 2 ) emissions and grain yield from paddy fields during the 2011 rice growing season after 2 years oilseed rape-rice rotation in central China. The experiment was established following a split-plot design of a randomized complete block with tillage practices as the main plots and residue returning levels as the sub-plots. NT significantly decreased CO 2 and CH 4 emissions by 38.8 and 27.3 % compared with CT, respectively. Residue returning treatments released significantly more CO 2 and CH 4 by 855.5–10410 and 51.5–210.5 kg ha −1 than no residue treatments, respectively. The treatments of 3,000 and 6,000 kg ha −1 residue returning significantly increased rice grain yield by 37.9 and 32.0 % compared with the treatment of no residue returning, respectively. Compared with NT, CT increased yield-scaled emissions of CH 4 and CO 2 by 16.0 %. The treatments of 6,000 and 9,000 kg ha −1 residue returning significantly increased yield-scaled emissions of CH 4 and CO 2 by 18.1 and 61.5 %, respectively, compared with the treatment of no residue returning. Moreover, the treatment of NT in combination with 3,000 kg ha −1 residues had the lowest yield-scaled emissions of CH 4 and CO 2 across tillage and residue treatments. In this way, this study revealed that the combination of NT with 3,000 kg ha −1 residues was a suitable strategy for optimizing carbon emissions and rice grain yield.