Soil Biogeochemistry, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Soil Biogeochemistry, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Sci Total Environ. 2024 Dec 1;954:176340. doi: 10.1016/j.scitotenv.2024.176340. Epub 2024 Sep 18.
Organic soil amendments (OSA) with long residence times, such as biochar, have a high potential for soil organic carbon (SOC) sequestration. The highly aromatic structure of biochar reduces microbial decomposition and explains the slow turnover of biochar, indicating long persistence in soils and thus potential SOC sequestration. However, there is a lack of data on biochar-induced SOC sequestration in the long-term and under field conditions. We sampled two long-term field experiments in Germany, where biochar was applied 12 and 14 years ago. Both locations differ in soil characteristics and in the types and amounts of biochar and other OSA. Amendments containing compost and 31.5 Mg ha of biochar on a loamy soil led to a SOC stock increase of 38 Mg ha after OSA addition. The additional increase is due to non-biochar co-amendments such as compost or biogas digestate. After eleven years, this SOC stock increase was still stable. High biochar amount additions of 40 Mg ha combined with biogas digestate, compost or synthetic fertilizer on a sandy soil led to an increase of SOC stocks of 61 Mg ha; 38 Mg ha dissipated in the following four years most likely due to lacking physical protection of the coarse soil material, and after nine years the biochar-amended soils showed only slightly higher SOC stocks (+7 Mg ha) than the control. Black carbon stocks on the same soil increased in the short- and mid-term and decreased almost to the original stock levels after nine years. Our results indicate that in most cases the long-term effect on SOC and black carbon stocks is controlled by biochar quality and amount, while non-biochar co-amendments can be neglected. This study proves that SOC sequestration through the use of biochar is possible, especially in loamy soils, while non-biochar OSA cannot sequester SOC in the long term.
有机土壤改良剂（OSA）具有较长的停留时间，如生物炭，具有很大的土壤有机碳（SOC）固存潜力。生物炭的高芳香结构降低了微生物的分解作用，解释了生物炭的缓慢转化，表明其在土壤中具有较长的持久性，因此具有潜在的 SOC 固存能力。然而，关于生物炭在长期和田间条件下引起的 SOC 固存，目前数据还很缺乏。我们在德国的两个长期田间试验中进行了采样，这两个地点的土壤特性、生物炭和其他 OSA 的类型和数量都不同。在壤土上施用含有堆肥和 31.5 Mg/ha 的生物炭，导致添加 OSA 后 SOC 储量增加了 38 Mg/ha。这种额外的增加是由于非生物炭共添加物，如堆肥或沼气消化物。经过 11 年，这种 SOC 储量的增加仍然稳定。在沙质土壤上，高生物炭添加量（40 Mg/ha）与沼气消化物、堆肥或合成肥料结合使用，导致 SOC 储量增加了 61 Mg/ha；在接下来的四年中，40 Mg/ha 的生物炭有 38 Mg/ha 消散，这可能是由于粗土壤物质缺乏物理保护，而在九年之后，添加生物炭的土壤的 SOC 储量仅比对照略高（+7 Mg/ha）。在同一种土壤上，黑碳储量在短期和中期增加，在九年之后几乎减少到原始储量水平。我们的结果表明，在大多数情况下，SOC 和黑碳储量的长期影响受生物炭质量和数量控制，而非生物炭共添加物可以忽略不计。这项研究证明，通过使用生物炭来固存 SOC 是可行的，特别是在壤土中，而在长期内，非生物炭 OSA 不能固存 SOC。
