Biochar, a material defined as charred organic matter applied in agriculture, is suggested as a beneficial additive and bulking agent in composting. Biochar addition to the composting feedstock was shown to reduce greenhouse gas emissions and nutrient leaching during the composting process, and to result in a fertilizer and plant growth medium that is superior to non-amended composts. However, the impact of biochar on the quality and carbon speciation of the organic matter in bulk compost has so far not been the focus of systematic analyses, although these parameters are key to determine the long-term stability and carbon sequestration potential of biochar-amended composts in soil. In this study, we used different spectroscopic techniques to compare the organic carbon speciation of manure compost amended with three different biochars. A non-biochar-amended compost served as control. Based on Fourier-transformed infrared (FTIR) and ¹³C nuclear magnetic resonance (NMR) spectroscopy we did not observe any differences in carbon speciation of the bulk compost independent of biochar type, despite a change in the FTIR absorbance ratio 2925 cm^− 1/1034 cm^− 1, that is suggested as an indicator for compost maturity. Specific UV absorbance (SUVA) and emission-excitation matrixes (EEM) revealed minor differences in the extractable carbon fractions, which only accounted for ~ 2–3% of total organic carbon. Increased total organic carbon content of biochar-amended composts was only due to the addition of biochar-C and not enhanced preservation of compost feedstock-C. Our results suggest that biochars do not alter the carbon speciation in compost organic matter under conditions optimized for aerobic decomposition of compost feedstock. Considering the effects of biochar on compost nutrient retention, mitigation of greenhouse gas emissions and carbon sequestration, biochar addition during aerobic composting of manure might be an attractive strategy to produce a sustainable, slow release fertilizer.

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生物炭改良剂对好氧复合肥后堆肥有机质组成的影响

生物炭，一种定义为用于农业的炭化有机物的材料，被建议作为堆肥中有益的添加剂和填充剂。堆肥原料中添加生物碳可减少堆肥过程中的温室气体排放和养分浸出，并产生优于未改良堆肥的肥料和植物生长培养基。然而，迄今为止，生物炭对散装堆肥中有机物的质量和碳形态的影响尚未成为系统分析的重点，尽管这些参数对于确定经修正的生物炭的长期稳定性和碳固存潜力至关重要。土壤中的堆肥。在这项研究中，我们使用了不同的光谱技术来比较用三种不同的生物炭改良的肥料堆肥的有机碳形态。以未经生物炭处理的堆肥为对照。基于傅立叶变换红外（FTIR）和¹³ C核磁共振（NMR）光谱尽管FTIR吸收比2925 cm ^-1 /1034 cm ^-1有所变化，但我们没有观察到堆肥的碳形态没有任何差异，而与生物炭类型无关，建议将其作为堆肥成熟度的指标。特定的紫外线吸收率（SUVA）和发射激发矩阵（EEM）显示可提取碳组分中的细微差别，仅占总有机碳的2-3％。经生物炭改性的堆肥的总有机碳含量增加仅归因于生物炭-C的添加，而不是堆肥原料-C的保存增强。我们的结果表明，在优化堆肥原料好氧分解的条件下，生物炭不会改变堆肥有机物中的碳形态。考虑到生物炭对堆肥养分保留，减轻温室气体排放和固碳的影响，在有氧堆肥过程中添加生物炭可能是生产可持续，缓释肥料的有吸引力的策略。