Data of Vegetation Sampling Record Form for the Black Soil Region, 2023

Here is the translation: --- **This dataset comprises field survey and laboratory analysis records of maize leaf chlorophyll obtained through random sampling within the typical black soil region of Northeast China (covering the three northeastern provinces and the four eastern leagues of Inner Mongolia) during the 2023 growing season. It includes five temporal sampling campaigns, covering key maize growth stages (seedling, jointing, tasseling, and maturity stages).

For each sampling event, the following core information was recorded:** **Physical parameters of leaf samples:** Including sample fresh weight (g), number of leaves, and sample ID, for subsequent area- or mass-normalization in chlorophyll content calculations. **Field measurement records:** Some files (e.g., "Field Measurement Record Form") contain in-situ observations of plant growth indicators (such as plant height, leaf area, etc.) and geographic/environmental information of the sampling sites. **Spectral/biochemical data:** Including absorbance measurements of leaf extracts in the visible light bands (especially at 663 nm and 645 nm), used for calculating chlorophyll concentration. **The sampling points are not fixed to a single county or district but are randomly distributed across the entire black soil cultivation area based on crop planting patterns, to ensure statistical representativeness and generalizability of the data at the regional scale.