The study looked at different types of soil in Tancheng County to see how they affect soil line parameters. They found that soil types and organic matter content can change the slope and intercept of the soil line. Different soil types have different soil lines, with fluvo-attic soil having the steepest slope. As organic matter content increases, the slope of the soil line goes up but the intercept goes down. The slope of the soil line changes from west to east and north to south, showing a pattern. In the same soil type, the slope increases from the center to the edge, while the intercept decreases with more organic matter.