State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
AgResearch Limited, Ruakura Research Centre, Hamilton 3240, New Zealand.
Sci Total Environ. 2020 Nov 15;743:140500. doi: 10.1016/j.scitotenv.2020.140500. Epub 2020 Jul 3.
Biochar and inhibitors applications have been proposed for mitigating soil greenhouse gas emissions. However, how biochar, inhibitors and the combination of biochar and inhibitors affect CH emissions remains unclear in paddy soils. The objective of this study was to explore the effects of biochar application alone, and in combination with urease (hydroquinone) and nitrification inhibitors (dicyandiamide) on CH emissions and yield-scaled CH emissions during three rice growing seasons in the Taihu Lake region (Suzhou and Jurong), China. In Suzhou, N fertilization rates of 120-280 kg N ha increased CH emissions compared to no N fertilization (Control) (P < 0.05), and the highest emission was observed at 240 kg N ha, possibly due to the increase in rice-derived organic carbon (C) substrates for methanogens. Biochar amendment combined with N fertilization reduced CH emissions by 13.2-27.1% compared with optimal N (ON, Suzhou) and conventional N application (CN-J, Jurong) (P < 0.05). This was related to the reduction in soil dissolved organic C and the increase in soil redox potential. Addition of urease and nitrification inhibitor (ONI) decreased CH emissions by 15.7% compared with ON treatment. Combined application of biochar plus urease, nitrification and double inhibitors further decreased CH emissions by 22.2-51.0% compared with ON and CN-J treatment. ON resulted in the highest yield-scaled CH emissions, while combined application of biochar alone and in combination with the inhibitors decreased yield-scaled CH emissions by 12.7-54.9% compared with ON and CN-J treatment (P < 0.05). The lowest yield-scaled CH emissions were observed under combined application of 7.5 t ha biochar with both urease and nitrification inhibitors. These findings suggest that combined application of biochar and inhibitors could mitigate total CH and yield-scaled CH emissions in paddy fields in this region.
生物炭和抑制剂的应用已被提议用于减少土壤温室气体排放。然而，在稻田中，生物炭、抑制剂以及生物炭和抑制剂的组合如何影响 CH 排放仍不清楚。本研究的目的是探索在太湖地区（苏州和句容）的三个水稻种植季节中，单独应用生物炭以及与脲酶（对苯二酚）和硝化抑制剂（双氰胺）联合应用对 CH 排放和产量标准化 CH 排放的影响。在苏州，与不施氮肥（对照）相比，120-280kgNha 的氮肥施用量增加了 CH 排放（P<0.05），在 240kgNha 时观察到最高排放，可能是由于甲烷菌的水稻衍生有机碳（C）底物增加。与最佳氮（ON，苏州）和常规氮施用量（CN-J，句容）相比，生物炭施肥与氮施肥结合减少了 13.2-27.1%的 CH 排放（P<0.05）。这与土壤溶解有机碳的减少和土壤氧化还原电位的增加有关。与 ON 处理相比，添加脲酶和硝化抑制剂（ONI）减少了 15.7%的 CH 排放。与 ON 和 CN-J 处理相比，生物炭加脲酶、硝化抑制剂和双重抑制剂的联合应用进一步减少了 22.2-51.0%的 CH 排放。ON 处理导致产量标准化 CH 排放最高，而单独和联合应用生物炭以及抑制剂与 ON 和 CN-J 处理相比，降低了 12.7-54.9%的产量标准化 CH 排放（P<0.05）。在同时施用 7.5tha 生物炭和脲酶和硝化抑制剂的情况下，观察到最低的产量标准化 CH 排放。这些发现表明，在该地区的稻田中，联合应用生物炭和抑制剂可以减少总 CH 和产量标准化 CH 排放。
