Effects of Biomimetic Press Roller Type, Material, Velocity, and Packing Force on Soil Compaction Characteristics

Highlights The performance of biomimetic rollers was better than that of a conventional roller. The biomimetically ridged roller had better soil compaction performance. The resistance order of rollers with different materials was: Fe360A steel > UHMWPE > enamel coating. Packing force was the most significant factor. Abstract . To reduce soil adhesion and rolling resistance during seeding and improve the uniformity of plant spacing, a biomimetically ridged press roller (BRPR) and a biomimetically polyhedral press roller (BPPR) were designed. Moreover, hydrophobic materials, i.e., ultra-high molecular weight polyethylene (UHMWPE) and enamel coating, were applied and compared with uncoated Fe360A steel. Field experiments were conducted to test the effects of the biomimetic press roller type, material, velocity, and packing force on soil compaction characteristics. A conventional press roller (CPR) was used as a reference. Traction resistance (TR), soil bulk density (SBD), soil moisture content (SMC), emergence rate (ER), and percent change of plant spacing (PCPS) were measured. The packing force was the most significant factor affecting each index. For all rollers, the TR, SBD, ER, and PCPS increased with increasing packing force, while the loss of SMC decreased. The TR and SBD decreased with increasing velocity. All rollers achieved proper SBD for corn seeds. The biomimetic press rollers had a significant effect on TR, PCPS, and SMC on the third day after sowing. The BRPR had lower PCPS and TR than the BPPR and higher SMC than the BPPR on the third day after sowing. Compared with the CPR, the PCPS for all biomimetic rollers decreased, and the ER and SMC increased. The BPPR with Fe360A steel had a slightly higher TR than the CPR, but the other biomimetic rollers had a lower TR than the CPR. The BRPR decreased the TR by 2.13% to 22.30%, while the BPPR decreased the TR by 0.35% to 18.59%. Moreover, both types of biomimetic press rollers had the highest TR values when using Fe360A steel, followed by UHMWPE, and the enamel coating had the lowest TR values. The BRPR decreased the PCPS by 19.46% to 48.34%, while the BPPR decreased the PCPS by 9.69% to 36.99%. The biomimetic rollers increased the ER by 2.17% to 11.36%. On the 18th day after sowing, the SMC was 4.21% to 7.75% higher for the biomimetic press rollers compared to the CPR when the packing force was 700 N. This study can provide a reference for the biomimetic design, material, and force selection of press rollers. Keywords: Biomimetics, Compaction characteristics, Enamel coating, Press roller, UHMWPE.