The pilot of the multi-engine airplane reported that, while utilizing a short field takeoff technique on a private, dirt airstrip, the airplane encountered soft patches of dirt. He rotated the airplane to initiate a climb, but the airplane could not climb higher than ground effect and the stall horn sounded. He lowered the nose to gain airspeed, but the landing gear impacted the gravel berm, which sheared off the landing gear and the airplane came to rest in the dirt field. The pilot also reported that, before takeoff, he walked the airstrip and determined there was about 5,000 ft of usable runway and he estimated he needed 3,800 ft. The airport elevation was about 5, 000 feet and the density altitude was about 8,000 ft. After the accident, the pilot used Google Earth to measure the runway. According to Google Earth the runway length was about 3,500 ft. The airplane sustained substantial damage to the left wing and right horizontal stabilizer. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot reported that the wind was light and variable, visibility 10 statute miles, temperature 72°F. The airplane was departing to the south. The airport elevation was about 5,500 ft mean sea level (msl). The calculated density altitude was 7,400 ft. The calculated takeoff distance on a level, hard surface, dry runway was 2,240 ft and the takeoff distance over a 50 ft obstacle was 2,930 ft. The calculated maximum rate of climb was 1,400 ft/min.