Landing on fields that are rough or have soft surfaces, such as snow, sand, mud, or tall grass requires unique procedures. When landing on such surfaces, the objective is to touch down as smoothly as possible, and at the slowest possible landing speed. The pilot must control the airplane in a manner that the wings support the weight of the airplane as long as practical, to minimize drag and stresses imposed on the landing gear by the rough or soft surface.
AFH Ch-08 (21) Soft-Field Approach and Landing
Cessna SOPM 2-88 Soft-Field Approach and Landing
Private Pilot ACS Page 23 Task D. Soft-Field Approach and Landing