conditions of the rotavators. The flow of tilled soil was the largest in the plow-type rotavator, and followed by the crank-type and rotary-type rotavators in order. Table 6 shows the other tillage characteristics, i.e. soil pulverizing ratio and inversion ratios, for each rotavator and operational condition. In the most commonly used gear ranges of L2 and L3, the average soil pulverizing ratio of the rotary-type, the crank-type and the plow-type rotavators were 97.87%, 90.04% and 78.85%, respectively. The rotary-type rotavator showed the highest soil pulverizing ratio and followed by the crank-type and plow-type rotavators in order. The soil inversion ratio also showed better performance in the rotary-type rotavator than in the crank-type and plow-type rotavators. Especially, in the gear L2 and L3, the rotary-type and the crank-type rotavators showed 100% of soil inversion ratio while the plow-type rotavator showed 80%. Figure