保持土壤健康是确保作物高产优质、土壤生态系统平衡和环境可持续发展的基础。而土壤有机质作为土壤健康的关键属性，驱动土壤结构建成和土壤健康发展，在低碳绿色健康农业及其可持续发展方面具有巨大的潜力。土壤团聚体固碳与土壤有机质分子组成的关系是认识土壤健康的前沿方向，而生物质炭对土壤健康的调控作用是当今低碳绿色农业研究的热点。从生物质炭影响土壤结构与养分有效性、改变土壤有机质组分和提高微生物活性等方面入手，探讨生物质炭基有机培肥下耕作土壤有机质分子组成与团聚体发育的演进关系，可以提升土壤健康管理的科学认识。

本研究选取江苏省南京市溧水浮山小籽花生专业合作社黄棕壤旱地花生农田，设计实施实物施用量1吨/亩的土壤有机培肥试验处理，包括常规施肥（CK）和施用常规有机肥（OM）、玉米秸秆生物质炭（MB）、玉米秸秆生物质炭基有机肥（MBSC）、木质生物质炭（WB）和木质生物质炭基有机肥（WBSC）6个处理，于2021年春季花生播种前施入并混合于耕作层。于当年花生收获时分别采集不同处理小区耕作层（0~15cm）土壤样品，测定土壤的基本性质、有机质分子组成、胞外酶活性和磷脂脂肪酸含量，对比不同处理下土壤结构、有机质含量、微生物活性和微生物群落的变化。同时，采用湿筛法分离出宏团聚体（2000~250 µm）、微团聚体（250~53 µm）和粉黏粒（<53 µm）三级土壤水稳性团聚体粒径组分，分析这些团聚体组分的有机质分子丰度变化与胞外酶活性差异。主要研究结果如下：

（1）与CK相比，生物质炭和炭基有机肥均显著提高土壤pH值，并显著增加土壤有机碳含量和土壤有效磷等养分含量。与OM处理相比，MB提升养分效果炭优于WB。尽管土壤容重处理间无明显差异，但生物质炭和炭基有机肥处理下宏团聚体质量分数显著提高4%~16%。总体上，炭基改良处理下显著提高了土壤团聚体的平均重量直径。团聚体结合态有机碳总量以生物质炭>炭基有机肥>OM>CK。

（2）不同有机培肥处理间有机质提取态分子丰度及多样性具有显著差异。首先，炭基改良处理均提升本体土壤和团聚体中各级提取态有机质的丰度及其分子多样性，且各级提取态有机质分子总丰度与分子多样性呈正相关关系；各级提取态有机质分子在宏团聚体中富集，但在粉黏粒组分中大幅度减少。此外，炭基改良处理下显著提升宏团聚体组分的植物源有机分子丰度与微生物源有机分子丰度比（P/L比）和长链脂肪酸与短链脂肪酸比（RLS比），而玉米炭及其炭基有机肥处理下还提升了微团聚体和粉黏粒中这些比值。在各粒级团聚体中，MB和MBSC处理下的木质素单体总量显著高于其他处理。同时，木质素单体总丰度随团聚体粒径减小而呈现下降趋势，提示宏团聚体在土壤固碳中的重要意义。

（3）不同处理下花生土壤胞外酶活性存在较大差异，炭基改良处理均显著提高了土壤胞外酶活性和酶活性多样性指数（4%~19%）及氮循环与磷循环酶活性比值。就本体土壤来说，玉米炭基有机肥处理下土壤酶活性总体显著高于其他各处理，而硫酸酯酶和多酚氧化酶在各处理间无显著差异。与CK相比，MBSC处理下过氧化物酶活性显著提高了42%~66%，在其他炭基改良处理下无明显变化趋势。与CK比，WBSC处理下氮循环酶活性与磷循环酶活性比值升高。而团聚体水平的酶活性分布则与本体土壤不同，特别是硫酸酯酶在团聚体中表现出明显差异。

（4）土壤磷脂脂肪酸总量在生物质炭和炭基有机肥处理下均显著增加29%~76%，以MB和MBSC处理下增幅最高。土壤放线菌PLFAs含量在MB和MBSC处理下显著高于WB、OM与CK等处理，而其他各处理间均无显著差异。与CK相比，玉米生物质炭（MB）及其炭基有机肥（MBSC）和木质生物质炭基有机肥（WBSC）处理下F/B分别显著提升44%、39%和28%，与OM相比，MBSC和MB处理下F/B显著增加32%和37%。不过，不同处理间G⁺/G^－均无显著变化趋势。

综上所述，生物质炭在提高土壤肥力和改善土壤结构的同时，还能提高团聚体数量，促进植物源土壤有机质快速积累，提升土壤胞外酶活性及酶活性多样性指数，改善土壤微生物群落结构。从分子水平来讲，生物质炭促进花生地土壤提取态有机质的增加与植物源有机质的贡献，而有机质分子总丰度的增加伴随着有机质分子多样性升高。并且，玉米生物质炭优于木质生物质炭，玉米炭基有机肥优于木质炭基有机肥，更优于常规有机肥。本研究将土壤健康提升到土壤有机质-团聚体-微生物同一健康，进一步说明了生物质炭对于土壤健康和农业健康可持续发展具有巨大应用潜力。

Maintaining soil health is fundamental to ensuring high yield and quality of crops, balance of soil ecosystems, and sustainable environmental development. Soil organic matter, as a key attribute of soil health, drives the construction of soil structure and the development of soil health, holding immense potential in low-carbon, green, and healthy agriculture and its sustainable development. The relationship between soil aggregate carbon sequestration and the molecular composition of soil organic matter is a cutting-edge direction for understanding soil health, and the regulatory role of biochar on soil health is a hot topic in current low-carbon, green agricultural research. By exploring how biochar affects soil structure and nutrient availability, alters the composition of soil organic matter, and enhances microbial activity, the evolution of the relationship between the molecular composition of soil organic matter and the development of soil aggregates under biochar-based organic fertilizer can be enhanced, thereby improving the scientific understanding of soil health management.

This study selected the peanut farmland with yellow-brown soil in Fushan Village, Lishui District, Nanjing City, Jiangsu Province, and implemented a soil organic fertilization experiment with a application rate of 1 ton/mu. The experiment included six treatments: control check, conventional organic fertilizer, maize straw biochar, maize straw biochar-based organic fertilizer, wood biochar, and wood biochar-based organic fertilizer. These treatments were applied and mixed into the tillage layer before peanut sowing in the spring of 2021. Soil samples from the tillage layer (0~15cm) of different treatments were collected at peanut harvest in the same year. Soil basic properties, organic matter molecular composition, extracellular enzyme activity, and microbial PLFAs content were measured. The effects of different treatments on soil structure, dynamic characteristics of organic matter, microbial activity, and microbial community were compared, and their changes and differences were analyzed. Additionally, the wet sieving method was used to separate macroaggregates (2000~250 µm), microaggregates (250~53 µm), and silt-clay fraction (<53 µm) as three levels of soil water-stable aggregates, and the changes in organic matter molecular abundance and enzyme activity differences of these aggregate components were analyzed. The main research results obtained are as follows:

（1）Compared to CK, both biochar and biochar-based organic fertilizer significantly increased soil pH and substantially enhanced soil organic carbon content, as well as nutrient contents such as available phosphorus. In comparison with the organic matter treatment (OM), the nutrient enhancement effect of maize biochar was superior to that of the wood biochar. Although there were no significant differences in soil bulk density among the treatments, the mass fraction of macro-aggregates significantly increased by 4% to 16% under biochar and biochar-based organic fertilizer treatments. Overall, the average weight diameter of soil aggregates was notably enhanced under biochar-based amendment treatments. The total amount of occluded organic carbon in aggregates followed the order of biochar > biochar-based organic fertilizer > organic matter > control.

（2）Significant differences were observed in the abundance and diversity of extractable organic matter among different organic fertilization treatments. Firstly, biochar-based amendments uniformly enhanced the abundance and molecular diversity of extractable organic matter at all levels in both the bulk soil and aggregates. Moreover, there was a positive correlation between the total abundance of extractable organic matter molecules at all levels and their molecular diversity; these molecules were enriched in macro-aggregates but significantly decreased in the fine particle fraction. Additionally, biochar-based amendments significantly elevated the ratio of plant-derived organic molecules to microbial-derived organic molecules (P/L ratio) and the ratio of long-chain fatty acids to short-chain fatty acids (RLS ratio) in the macro-aggregate fraction. The maize straw biochar and its biochar-based organic fertilizer treatments also increased these ratios in micro-aggregates and fine particles. Among the aggregates of different sizes, the total amount of lignin monomers was significantly higher in the MB and MBSC treatments compared to other treatments. Concurrently, the total abundance of lignin monomers showed a decreasing trend with the reduction of aggregate size, highlighting the significant role of macro-aggregates in soil carbon sequestration.

（3）Significant differences in peanut soil extracellular enzyme activity were observed among different treatments. Biochar-based amendments significantly enhanced soil extracellular enzyme activity and the enzyme activity diversity index (by 4% to 19%), as well as the ratio of nitrogen cycle to phosphorus cycle enzyme activities. For the bulk soil, the overall soil enzyme activity in the maize straw biochar-based organic fertilizer treatment was significantly higher than in other treatments, while there were no significant differences in the activity of sulfatase and polyphenol oxidase among treatments. Compared to CK, the peroxidase activity significantly increased by 42% to 66% under the MBSC treatment, with no clear trend of change under other biochar-based amendments. The ratio of nitrogen cycle enzyme activity to phosphorus cycle enzyme activity increased under the WBSC treatment compared to CK. The distribution of enzyme activity at the aggregate level, however, differed from that of the bulk soil, especially for sulfatase, which showed distinct differences in the aggregates.

（4）The total amount of soil phospholipid fatty acids significantly increased by 29% to 76% under biochar and biochar-based organic fertilizer treatments, with the highest increase observed in the maize straw biochar (MB) and maize straw biochar-based organic fertilizer (MBSC) treatments. The content of actinomycete PLFAs in the soil was significantly higher in the MB and MBSC treatments compared to WB, OM, and CK treatments, while no significant differences were observed among the other treatments. Compared to CK, the F/B ratio significantly increased by 44%, 39%, and 28% under the maize biochar (MB), maize biochar-based organic fertilizer (MBSC), and wood biochar-based organic fertilizer (WBSC) treatments, respectively. Compared to the conventional organic fertilizer (OM), the F/B ratio significantly increased by 32% and 37% under the MBSC and MB treatments, respectively. However, there were no significant trends in the G+/G- ratio among different treatments.

In summary, biochar not only enhances soil fertility and improves soil structure but also increases the quantity of aggregates, promotes rapid accumulation of plant-derived soil organic matter, boosts soil extracellular enzyme activity and enzyme activity diversity index, and improves the structure of soil microbial communities. From a molecular perspective, biochar promotes the increase of extractable organic matter in peanut field soil and the contribution of plant-derived organic matter, with an increase in the total abundance of organic matter molecules accompanied by an increase in organic matter molecular diversity. Moreover, maize biochar is superior to wood biochar, and maize biochar-based organic fertilizer is more effective than wood biochar-based organic fertilizer, which in turn is more effective than conventional organic fertilizer. This study elevates soil health to the same level of health for soil organic matter, aggregates, and microbes, further demonstrating the great potential of biochar for soil health and the sustainable development of healthy agriculture.