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施肥是维持和增加农田土壤有机质的重要管理措施,其中,稳定性土壤有机碳库与长期碳截获密切相关。土壤中木质素对微生物具有高度的抗性,根据其水解性单体的变化,可指示土壤木质素动态、稳定性及其氧化程度。因此,研究利用肥料与肥力长期定位实验,采用碱性氧化铜氧化-气相色谱方法,根据土壤中各木质素单体含量和侧链基团的变化,探讨不同施肥处理对农田黑土中木质素积累和稳定性碳库的影响。实验结果表明,和对照处理(不施肥,CK)相比,化肥施用对0~20 cm的土壤木质素积累并未产生显著影响,但显著增加了20~40 cm土壤的木质素含量;长期施用有机肥使0~20 cm和20~40 cm的土壤中木质素的含量分别提高了197%~301%和306%~382%,均与施肥量正相关,同时使0~20 cm的木质素单体的酸醛比显著降低。相对于土壤有机碳来说,长期施用有机肥使0~20 cm和20~40 cm的木质素来源碳的相对含量分别提高了151%~187%和267%~285%,但是化肥施加仅对20~40 cm土壤有机碳中木质素来源碳含量产生显著影响。土壤木质素的积累特征和氧化程度在不同施肥处理间的差异表明,化肥施用增加了植物来源木质素的输入,也同时加速了木质素在耕层的周转,所以长期施用化肥并未导致木质素的积累;来源于有机肥的活性碳源的输入降低了木质素的微生物降解作用,有利于稳定性碳的积累,增加了土壤有机碳的可持续利用能力。
Fertilization is an important management measure to maintain and increase soil organic matter in farmland. Among them, stable soil organic carbon pool is closely related to long-term carbon sequestration. Soil lignin has a high degree of resistance to microorganisms, according to the changes of its hydrolyzable monomers, can indicate the dynamics of soil lignin, stability and degree of oxidation. Therefore, the long-term fertilization and fertilization experiments were conducted to study the effect of different fertilization treatments on the accumulation of lignin in farmland black soils based on the changes of the content of each lignin monomer and the side chain groups by using alkaline oxidation of copper oxide-gas chromatography And the impact of stable carbon stocks. The results showed that compared with CK (no fertilization, no CK), the application of chemical fertilizer had no significant effect on the accumulation of soil lignin at 0 ~ 20 cm, but significantly increased the lignin content in 20 ~ 40 cm soil. Organic manure increased the lignin content in soils from 0 to 20 cm and 20 to 40 cm by 197% to 301% and 306% to 382%, respectively, and was positively correlated with the amount of fertilizer application. The acid-aldehyde ratio of the monomer is significantly reduced. Compared with soil organic carbon, long-term application of organic manure increased the relative content of lignin-sourced carbons of 0-20 cm and 20-40 cm by 151% -187% and 267% -258%, respectively, but the application of chemical fertilizers was only The carbon content of lignin sources in 20 ~ 40 cm soil organic carbon had a significant effect. The differences in accumulation characteristics and degree of oxidation of soil lignin between different fertilization treatments indicate that the application of chemical fertilizers increased the input of plant-derived lignin and also accelerated the turnover of lignin in the tillage so that long-term application of fertilizers did not result in lignin The input of activated carbon source from organic fertilizers reduced the microbial degradation of lignin, contributed to the accumulation of stable carbon and increased the sustainable utilization of soil organic carbon.