Compaction Performance of Biomimetic Press Roller to Soil

The compaction characteristics of biomimetic press roller with ridge structures, inspired from the geometrical features of the ventral surface of dung beetle （Copris ochus Motschulsky）, were investigated in this work. Field tests were carried out at three weights （300 N, 500 N and 700 N） and two forward velocities （0.64 m·s^-1 and 1.04 m·s^-1） for biomimetic press roller and conventional press roller. To determine compaction performance, rolling resistance, soil bulk density, soil moisture content, emergence rate and percent change of plant spacing were measured. Roller weight was proved to be the major contributory factor on soil compaction. Biomimetic press roller decreased rolling resistance by 2.98% -17.69% at the velocity of 0.64 m·s^-1, and by 6.59% -18.57% at the velocity of 1.04 m·s^-1 compared with the conventional press roller. Both biomimetic roller and conventional roller can achieve proper bulk density for corn seeds under the experimental conditions. However, compared with the conventional roller, biomimetic roller helped soil conserve more moisture. The highest emergence rate was found when the biomimetic roller worked with a weight of 700 N and velocity of 0.64 m·s^-1. Percent change of plant spacing was lower using the biomimetic press roller compared with that using the conventional roller, because that adjacent ridge structures of the biomi- metic roller can well constrain the flow of soil during compacting process.