The researchers studied the physical quality of agricultural soils in Bacau county. They looked at properties like bulk density, penetration resistance, and water retention. They found that high penetration resistance and bulk density can create a compacted layer in the soil. The top layers of soil had better water flow and porosity compared to deeper layers. Organic matter, clay content, and bulk density affect soil quality. The S index can predict soil quality, and pedotransfer functions can help with this prediction.