Eykelbosh Angela Joy, Johnson Mark S, Santos de Queiroz Edmar, Dalmagro Higo José, Guimarães Couto Eduardo
Institute for Resources, Environment, and Sustainability, University of British Columbia (UBC), Vancouver, British Columbia, Canada.
Institute for Resources, Environment, and Sustainability, University of British Columbia (UBC), Vancouver, British Columbia, Canada; Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia (UBC), Vancouver, British Columbia, Canada.
PLoS One. 2014 Jun 4;9(6):e98523. doi: 10.1371/journal.pone.0098523. eCollection 2014.
In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing) on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w.) were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w.) raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w.) in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions.
在巴西，贫瘠的铁铝土退化限制了生产力，并促使农业扩张至原始地区。然而，以稳定形式将农业残留物归还土壤，即便在通常会导致碳流失的条件下，也可能为维持或改善土壤质量提供契机。我们研究了用滤饼（甘蔗加工的一种副产品）制成生物炭对热带耕地土壤理化性质的影响。滤饼在575°C下热解3小时，生成的生物炭相比原始滤饼表面积和孔隙率增加。滤饼生物炭主要由芳香碳组成，还含有一些残留的纤维素和半纤维素。在为期三周的实验室培养中，添加5%（干重，d.w.）生物炭的高度风化铁铝土土壤的二氧化碳排放量比仅土壤对照大约高四倍，但比添加5%（d.w.）原始滤饼的土壤的二氧化碳排放量低23倍。我们还将酒糟（生物乙醇生产中富含碳的废液，通常用作甘蔗土壤的肥料）施用于添加了滤饼和生物炭的土壤。添加生物炭的土壤因酒糟施用产生的总二氧化碳排放量仅为酒糟施用于添加原始滤饼土壤时排放量的5%。此外，在这种高度风化的热带土壤中添加5%或10%（d.w.）的生物炭混合物显著增加了植物有效范围内的保水性，还提高了养分有效性。因此，将甘蔗滤饼制成生物炭施用，无论是否添加酒糟，相比将滤饼以原始形式施用于土壤，可能更能满足土壤管理目标，并且可能有助于在甘蔗种植区增加土壤碳储量。
