With expanding turf areas and increased costs for developing water resources in urban, it has become very important to research irrigation requirements. Water moves into turfgrass roots from soil. The irrigation rate should be not equal in each season because the depth of root system decided the intensity for using soil water. The experiment on soil moisture dynamic and root system growth of Kentucky bluegrass turf was conducted. The results showed that: (a) Acuteness of soil water content change was differ...