Runoff, soil erosion and grain yields were measured from five corn and soybean tillage systems implemented up-and-down hill and on the contour in a Tama silt loam soil in northwestern Illinois. The tillage systems evaluated were 1) moldboard plow, 2) chisel plow, 3) ridge-till, 4) strip-till, and 5) no-till. The greatest runoff and soil loss was observed from the up-and-down hill moldboard tillage. Contouring the moldboard tillage or substituting a chisel plow for a moldboard plow reduced soil loss significantly. Soil loss from the ridge-, strip- and no-till systems was significantly less than from the moldboard tillage. No one tillage system produced the greatest grain yields each year, and the two to four year average grain yields were not significantly affected by tillage system. A farm machinery selection program was used to calculate partial cost budgets for each of the tillage systems. The ridge- and no-till systems appeared to have the lowest fixed and operating costs.