Land application of biochar reportedly provides many benefits, including reduced risk of nutrient transport, greenhouse gas (GHG) emission mitigation, and increased soil C storage, but additional field validation is needed. We evaluated the effectiveness of biochar in controlling the lability of nutrients in agricultural land. This study was designed to evaluate the impacts of biochar co-applied with various N and P sources on GHG fluxes from a subtropical grassland. Nutrients (inorganic fertilizer and aerobically digested Class B biosolids) were surface applied at a rate of 160 kg plant available N ha-1 yr-1 with or without biochar (applied at 20 Mg ha-1 ). Greenhouse gas (CO2 , CH4 , and N2 O) fluxes were assessed using static chambers and varied significantly, both temporally and with treatments. Greenhouse gas fluxes ranged from 1,247 to 23,160, -0.7 to 42, and -1.4 to 376 mg m-2 d-1 for CO2 , N2 O, and CH4 , respectively. Results of the 3-yr field study demonstrated strong seasonal variability associated with GHG emissions. Nutrient source had no effect on soil CO2 and CH4 emissions, but annual and cumulative (3-yr) N2 O emissions increased with biosolids (8 kg N2 O ha-1 yr-1 ) compared with inorganic fertilizer (5 kg N2 O ha-1 yr-1 ) application. Data suggested that environmental conditions played a more important role on GHG fluxes than nutrient additions. Biochar reduced CO2 emissions modestly (<9%) but had no effects on N2 O and CH4 emissions.

中文翻译：

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生物炭对亚热带草原土壤养分动力学的影响——第二部分。温室气体排放

据报道，生物炭的土地应用提供了许多好处，包括降低养分运输的风险、减缓温室气体 (GHG) 排放和增加土壤碳储存，但需要额外的现场验证。我们评估了生物炭在控制农田养分不稳定方面的有效性。本研究旨在评估生物炭与各种 N 和 P 源共同应用对亚热带草原温室气体通量的影响。营养物（无机肥料和需氧消化的 B 类生物固体）以 160 kg 植物有效氮 ha-1 yr-1 的比率进行表面施用，有或没有生物炭（以 20 Mg ha-1 施用）。温室气体（CO 2 、CH 4 和N 2 O）通量使用静态室进行评估，并且随时间和处理变化显着。温室气体通量范围从 1,247 到 23，CO2、N2O 和 CH4 分别为 160、-0.7 至 42 和 -1.4 至 376 mg m-2 d-1。为期 3 年的实地研究结果表明，与温室气体排放相关的季节性变化很大。营养源对土壤 CO2 和 CH4 排放没有影响，但与无机肥料（5 kg N2 O ha-1）相比，年和累积（3 年）N2 O 排放量随生物固体（8 kg N2 O ha-1 yr-1）而增加1 年-1 ) 申请。数据表明，环境条件对温室气体通量的影响比养分添加更为重要。生物炭适度减少了 CO2 排放（<9%），但对 N2 O 和 CH4 排放没有影响。营养源对土壤 CO2 和 CH4 排放没有影响，但与无机肥料（5 kg N2 O ha-1）相比，年和累积（3 年）N2 O 排放量随生物固体（8 kg N2 O ha-1 yr-1）而增加1 年-1 ) 申请。数据表明，环境条件对温室气体通量的影响比养分添加更为重要。Biochar 适度减少了 CO2 排放 (<9%)，但对 N2 O 和 CH4 排放没有影响。营养源对土壤 CO2 和 CH4 排放没有影响，但与无机肥料（5 kg N2 O ha-1）相比，年和累积（3 年）N2 O 排放量随生物固体（8 kg N2 O ha-1 yr-1）而增加1 年-1 ) 申请。数据表明，环境条件对温室气体通量的影响比养分添加更为重要。Biochar 适度减少了 CO2 排放 (<9%)，但对 N2 O 和 CH4 排放没有影响。