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Evaluating annual soil carbon emissions under biochar-added farmland subjecting from freeze-thaw cycle.
Zhang, Ruxin; Qu, Zhongyi; Yang, Wei; Li, Junjie; Wang, Liping; Liu, Qi; Zhang, Dongliang; Qiao, Tian; Zhao, Yibo.
Afiliación
  • Zhang R; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
  • Qu Z; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China; Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River, Hohhot, 010018, C
  • Yang W; College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, 010018, China; Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River, Hohhot, 010018, Chin
  • Li J; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
  • Wang L; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China; Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River, Hohhot, 010018, C
  • Liu Q; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
  • Zhang D; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
  • Qiao T; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
  • Zhao Y; College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
J Environ Manage ; 365: 121506, 2024 Aug.
Article en En | MEDLINE | ID: mdl-38901319
ABSTRACT
Straw biochar is a commonly recognized agricultural amendment that can improve soil quality and reduce carbon emissions while sequestering soil carbon. However, the mechanisms underlying biochar's effects on annual soil carbon emissions in seasonally frozen soil areas and intrinsic drivers have not been clarified. Here, a 2-y field experiment was conducted to investigate the effects of different biochar dosages (0, 15, and 30, t ha-1; B0 (CK), B15, and B30, respectively) on carbon emissions (CO2 and CH4) microbial colony count, and soil-environment factors. The study period was the full annual cycle, including the freeze-thaw period (FTP) and the crop growth period (CP). Structural equation modeling (SEM) was developed to reveal the key drivers and potential mechanisms of biochar on carbon emissions. Biochar application reduced soil carbon emissions, with the reduction rate positively related to the biochar application rate (B30 best). During FTP, the reduction rate was 11.5% for CO2 and 48.2% for CH4. During CP, the reduction rate was 17.9% for CO2 and 34.5% for CH4. Overall, compared with CK, B30 treatment had a significant effect on reducing total soil carbon emissions (P < 0.05), with an average decrease of 16.7% during the two-year test period. The study also showed that for soils with continuous annual cycles (FTP and CP), carbon emissions were best observed from 1000-1300. After two years of freeze-thaw cycling, biochar continued to improve soil physical and chemical properties, thereby increasing soil microbial colony count. Compared with B0, the B30 treatment significantly increased the total colony count by 74.3% and 263.8% during FTP and CP (P < 0.05). Structural equation modeling (SEM) indicated that, with or without biochar application, the soil physicochemical properties directly or indirectly affected soil CO2 and CH4 emission fluxes through microbial colony count. The total effects of biochar application on CO2 emission fluxes were 0.50 (P < 0.05) and 0.64 (P < 0.01), respectively, but there was no significant effect on CH4 emission fluxes (P > 0.05). Among them, soil water content (SWC), soil temperature (ST) and soil organic carbon (SOC) were the main environmental determinants of CO2 emission fluxes during the FTP and CP. The total effects were 0.57, 0.65, and 0.53, respectively. For CH4, SWC, soil salinity (SS) and actinomycete colony count were the main environmental factors affecting its emission. The total effects were 0.50, 0.45, 0.44, respectively. For freeze-thaw alternating soils, the application of biochar is a feasible option for addressing climate change through soil carbon sequestration and greenhouse gas emissions mitigation. Soil water-heat-salt-fertilization and microbial communities are important for soil carbon emissions as the reaction matrix and main participants of soil carbon and nitrogen biochemical transformation.
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Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Suelo / Carbono / Carbón Orgánico Idioma: En Revista: J Environ Manage Año: 2024 Tipo del documento: Article País de afiliación: China

Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Suelo / Carbono / Carbón Orgánico Idioma: En Revista: J Environ Manage Año: 2024 Tipo del documento: Article País de afiliación: China