ABSTRACT 

Application of biochar to soil has been suggested as a nonstructural best management practice to mitigate runoff potential and soil loss. However, empirical data substantiating these effects are still scarce. Rainfall was presently simulated under controlled conditions to study the effects of biochar on erosion and runoff potential with sandy loam soil sampled from a field experiment 2 years after biochar amendment (2 kg m⁻²). The field experiment comprised four untreated and four biochar-treated plots that were amended with biochar produced from birchwood. In the laboratory, aggregate stability and organic carbon (OC) in topsoil (0–0.2 m) were analyzed. Soil loss and runoff were measured during a 3.5-h rainfall simulation using a round flume setup. Organic C was also determined in the eroded sediment, soil crust, and bulk soil of each flume after simulations. While runoff was not affected by treatment, biochar-treated soils showed significantly lower soil loss rates compared with untreated soils, reducing the cumulative soil loss by 41%. This was attributed to the aggregating effects of OC from the biochar application and delayed crust formation. The reduced erosion of OC from biochar-treated soils also resulted in lower OC enrichment ratios in the sediment and thus less OC export than from untreated soils. The results illustrated that biochar application already in the short term (2 years) can lead to an improvement of soil aggregation, thereby enhancing aggregate stability and leading to a reduction in soil loss. However, extrapolation of these positive results must be done with caution because the scale of the flume limited the erosive forces acting on the soil. Before an extrapolation of the results, an upscaling of erosion tests to field scale is therefore required.

中文翻译：

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降雨径流模拟中生物炭施用对土壤流失的短期影响

摘要 

已建议将生物炭应用于土壤是一种非结构性的最佳管理方法，可减轻径流潜力和土壤流失。但是，仍缺乏证实这些影响的经验数据。目前，在受控条件下模拟了降雨，以研究生物炭对土壤侵蚀和径流潜力的影响，该砂土是从生物炭改良后2年（2 kg m ^-2）的田间试验中取样的。现场实验包括四个未经处理和四个经过生物炭处理的地块，并用桦木生产的生物炭进行了修改。在实验室中，骨料的稳定性和有机碳分析了表土（0-0.2 m）中的（OC）。在3.5小时的降雨模拟中，使用圆形水槽设置测量了土壤流失和径流。模拟后，还确定了每种水槽的侵蚀沉积物，土壤结皮和散装土壤中的有机碳。尽管径流不受处理的影响，但生物炭处理过的土壤与未处理过的土壤相比，土壤流失率明显降低，累计土壤流失减少了41％。这归因于生物炭施用过程中OC的聚集作用和结壳的延迟。生物炭处理过的土壤中OC侵蚀的减少也导致沉积物中的OC富集率降低，因此与未经处理的土壤相比，OC的出口减少。结果表明，生物炭在短期内（2年）内施用可改善土壤团聚体，从而增强团聚体稳定性并减少土壤流失。但是，对这些积极结果的推断必须谨慎进行，因为水槽的水垢限制了作用在土壤上的侵蚀力。因此，在对结果进行外推之前，需要将腐蚀试验的规模升级到现场规模。