Tests were conducted in the University of Hawaii Soil Dynamics Laboratory. Two geometrically similar moldboard plows having cutting depth of 6 in. and 8 in. were used. Two types of soil were used: Wahiawa and Molokai. A rotary tiller was used to pulverize and mix the soil and an 18-in. diameter roller covered with high-density plastic sheeting was used to compress the soil. The 6-in. moldboard plow was used exclusively in the Wahiawa soil test series.