Soil classification systems define soil with an organic matter content of less than 1% as having extremely low fertility, i.e., as impoverished soil. In China, the area of impoverished soil accounts for 2/5 of the total arable land. One of the key priorities for improving the quality of impoverished arable land is to increase soil organic matter content and promote the formation of humic aggregate structures. Soil aggregates are the basic structural units for the formation of soil humus and the formation rate of soil humus is a critical indicator that directly determines the level of soil organic matter. Investigating the changing characteristics of the precursor substances for soil humus formation is significant for studying the formation of soil humus and changes in soil fertility. This chapter, using traditional organic fertilizer (TF) and chemical fertilizer (HF) as reference objects, clarifies the mechanism by which the synergistic and high-efficiency conditioner (SHF) affects the formation of humus in infertile arable soil and evaluates its effect on the management of the carbon pool in low-quality arable land.