Regulatory Mechanism Dataset of Organic Carbon Fraction Characteristics and Soil-like Fertility Formation under Different Stability Organic Material Additions in Lithium Slag Matrix

Four gradient treatments were established: control (CK), 0.5% (LS1, LS4), 1.0% (LS2, LS5), and 1.5% (LS3, LS6). The biological activator was set at two levels: without addition and with addition. A total of seven experimental treatments were established, with three replicates for each treatment.

Specific treatments are shown in Table 1. After thorough mixing of all treatments, an appropriate amount of deionized water was added, and the moisture was adjusted to approximately 70% of field water-holding capacity. After the substrate was fully moistened, it was mixed uniformly again.

Subsequently, the lepidolite slag soil-like substrate was placed in a constant temperature incubator at 25 °C for 6 months of incubation. Deionized water was added every 3–5 days to maintain relatively constant moisture content. After incubation, samples were collected, and the physicochemical properties of the substrate, organic carbon fractions, microbial biomass, and related enzyme activity indicators were determined.

The main equipment and tools used included: microplate spectrophotometer (for enzyme activity determination), Excel 2021, SPSS 27, and Origin 2024. The dataset is stored in tabular format, with row labels representing each treatment group and column labels representing each measured indicator. Specific indicators and their meanings are as follows: soil physicochemical properties include pH (dimensionless, measured by pH meter at soil-to-water ratio of 2.5:1), soil organic carbon SOC (g/kg), total nitrogen TN (g/kg), total phosphorus TP (g/kg), dissolved organic carbon DOC (g/kg), particulate organic carbon POC (g/kg), and mineral-associated organic carbon MAOC (g/kg); microbial biomass includes microbial biomass carbon MBC (mg/kg), microbial biomass nitrogen MBN (mg/kg), microbial biomass phosphorus MBP (mg/kg), and their stoichiometric ratios (such as SOC:TN, SOC:TP, MBC:MBN, MBC:MBP, dimensionless).

Soil enzyme activities include β-glucosidase BG, cellobiohydrolase CBH, leucine aminopeptidase LAP, alkaline phosphatase AKP, and β-N-acetylglucosaminidase NAG, all in units of nmol·g⁻¹·h⁻¹. Vector Length calculated based on enzymatic stoichiometry (characterizing carbon limitation degree, dimensionless) and Vector Angle (in degrees °, characterizing nitrogen and phosphorus nutrient limitation; angles >45° indicate phosphorus limitation, <45° indicate nitrogen limitation); microbial carbon use efficiency CUE (dimensionless, range 0–1).

Data errors mainly originate from systematic errors of indoor instrument determination and random errors introduced by micropipette operations. Enzyme activity determination may introduce slight deviations due to substrate incubation time and color development reaction time. This dataset contains 1 data file in standard .xlsx format, which can be directly read and processed using software such as Microsoft Excel and WPS.

The file content is divided into 3 main Sheets: (1) Soil Chemical Properties: includes treatment types, all soil chemical property indicators, and microbial biomass carbon, nitrogen, phosphorus and their ratios; (2) Hydrolytic Enzyme Activity: includes 6 enzyme activities, enzymatic stoichiometric ratios, vector length, vector angle, and microbial carbon use efficiency (CUE).