Performance Evaluation of Biomimetic-Designed Rotary Blades for Straw Incorporation in an Intensive Tillage System

A rotary tiller is a common tillage tool for straw incorporation in an intensive tillage system. However, rotary tillage for seedbed preparation in dense-straw mulching conditions experiences high torque and poor performance of straw incorporation. Nowadays, a great deal of studies have been focused on mimicking the morphological features of low-resistance animals to improve the performance of soil-engaging tools. Accordingly, the present study investigated the performance of three C-type rotary blades (i.e., conventional, serrated, and biomimetic) under three straw lengths (50, 100, and 150 mm) for incorporation of straw into the field using an in situ field tillage testing bench. Compared to the conventional and serrated blades, the biomimetic blade had lower straw displacement (decreased by an average of 50 mm and 7 mm, respectively), higher straw burying rate (increased by an average of 5.2% and 7.8%, respectively), better straw distribution (decreased by an average of 9.1% and 10.4% on the coefficient of variation, respectively), as well as lower torque and power (decreased by an average of 3.3 N·m and 4.4 N·m, respectively) under all straw lengths. The improved performance of the biomimetic blade could be attributed to the fact that its typical teeth configuration was designed by mimicking the smooth arc of the mole-rat’s claw. These results demonstrated that the biomimetic-designed blade could be a better option for incorporating dense straw into the field conditions.