生物炭施用于石灰性农田对表土和底土中有机碳的稳定化作用。
Stabilization of organic carbon in top- and subsoil by biochar application into calcareous farmland.
机构信息
College of Land Science and Technology, China Agricultural University, Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Beijing 100193, China.
School of Materials Science and Engineering, University of New South Wales (NSW), Sydney, NSW 2052, Australia.
出版信息
Sci Total Environ. 2024 Jan 10;907:168046. doi: 10.1016/j.scitotenv.2023.168046. Epub 2023 Oct 27.
Biochar is recognized for its role in carbon sequestration and emission mitigation in farmland topsoil. However, the mechanisms by which biochar affects soil organic carbon (SOC), its composition, and stability, in the topsoil (0-20 cm) and subsoil (140-160 cm) remain unclear. Applying biochar to the calcareous farmland topsoil significantly increased the topsoil SOC contents by 33 % after a decade, with a 5 % increase in dissolved organic carbon (DOC) contents (topsoil) and a substantial increase of 162 % in subsoil DOC contents. Additionally, humic substances showed an increase of 24 % (topsoil), while low-molecular-weight water-extracted DOC exhibited a remarkable increase of 142 % in the subsoil. The application of biochar significantly increases the contents of SOC, DOC, and microbial biomass carbon (MBC) in the topsoil, as well as SOC and DOC contents in the subsoil. However, a slight decrease is observed for MBC content in the subsoil. Biochar-amended soil significantly suppressed enzyme activity in the topsoil and decreased α diversity in topsoil and subsoil while increasing the content of mineral-associated soil organic matter (MAOM). These observed changes are conducive to stabilizing SOC, emphasizing MAOM formation as a primary mechanism for carbon sequestration in both topsoil and subsoils. This study provides evidence that biochar contributes to the long-term organic carbon sequestration in calcareous farmland, highlighting the importance of considering both topsoil and subsoil when evaluating the dynamic impacts of biochar on SOC.
生物炭因其在农田表土中固碳和减排的作用而受到关注。然而，生物炭如何影响表土（0-20 厘米）和底土（140-160 厘米）中土壤有机碳（SOC）及其组成和稳定性的机制尚不清楚。将生物炭施用于钙质农田表土后，经过十年时间，表土 SOC 含量显著增加了 33%，其中溶解有机碳（DOC）含量增加了 5%（表土），底土 DOC 含量大幅增加了 162%。此外，腐殖质增加了 24%（表土），而低分子量水提取的 DOC 在底土中则显著增加了 142%。生物炭的施用显著增加了表土中 SOC、DOC 和微生物生物量碳（MBC）的含量，以及底土中 SOC 和 DOC 的含量。然而，底土中 MBC 含量略有下降。生物炭改良土壤显著抑制了表土中的酶活性，降低了表土和底土中 α 多样性，同时增加了矿物结合土壤有机质（MAOM）的含量。这些观察到的变化有利于 SOC 的稳定，强调了 MAOM 的形成是表土和底土中碳固存的主要机制。本研究提供了证据表明，生物炭有助于钙质农田的长期有机碳固存，强调在评估生物炭对 SOC 的动态影响时，需要同时考虑表土和底土。
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