Takeoffs and climbs from soft fields require the use of operational techniques for getting the airplane airborne as quickly as possible to eliminate the drag caused by tall grass, soft sand, mud, and snow, and may or may not require climbing over an obstacle.
AFH Ch-05 (11) Soft/Rough-Field Takeoff and Climb
Cessna SOPM 2-14 Soft-Field Takeoff and Climb
Private Pilot ACS Page 22 Task C. Soft-Field Takeoff and Climb