A farming systems trial has been conducted at the Rodale Institute Research Center in Kutztown, Pennsylvania since 1981. Over time, the organic rotation has changed to reflect improved knowledge and experience. The current, three-year rotation (hairy vetch/corn, rye/soybeans, and wheat) focuses on mechanical tillage for weed control and year-round live plant cover for pest control and nutrient supply. We constructed long-term enterprise budgets for the organic and conventional cash grain rotations and compared returns earned during the first years of the study, which for the organic rotation involved investment in soil capital, with returns during two later 5-year periods. The organic rotations during these two later periods produced com and soybean yields comparable with the conventional rotation, but grew higher-value crops less frequently and required more family labor and management. The differences in the profitability of the conventional and organic farming systems depend on whether the analysis includes the initial investment in building up the soil and the value of family labor.