Farmland soil in Guanzhong area of Shaanxi was studied to understand how human activities affect soil quality. The researchers found that soil density was higher in deeper layers, making it hard for plant roots to grow. Soil compactness increased with depth, limiting plant growth. Soil compactness was linked to soil density and water content. Only the top 10cm of soil was suitable for planting, while deeper layers were compacted. Deep ploughing and scarification were suggested to improve soil quality.