## 1 Introduction  
In most soil-engaging parts in tillage and planting tools, the soil slides tangentially along the tool surface. The sliding resistance along the soil-tool interface is determined by three forces that interact: (i) structural resistance to soil particle displacement, (ii) frictional resistance to transfer between individual soil particles, and (iii) resistance produced by soil-tool adhesion [1]. Soil adhesion to the tool surface can cause a change in surface shape and substantially increase the sliding resistance. Soil adhesion is the force of attraction between soil particles and the surface contacting the soil; this attraction often occurs due to the surface tension and viscosity of the interfacial water film (a few molecules thick) forming on the tool surface [2]. Soil-tool adhesion can have various implications for agricultural operations, including lowering germination rates [3], increasing energy consumption per unit soil operation [4], and restricting the use of no-tillage planting in sticky soils [5]. Another consequence of soil adhesion phenomena is a considerable reduction in the work efficiency of loading and excavation equipment [6]. According to [PERSON]'s theory, the sliding resistance along the soil-tool interface could be described as a function of the normal load applied to the soil-tool interface, the soil-tool contact area, soil-tool adhesion, and soil-tool friction as per Equation (1) [7],  
\[\tau=a\ C+N\tan\varphi \tag{1}\]  
Here, \(\tau\) is the sliding resistance in the tangential direction, (N), \(a\) is the contact area, (cm\({}^{2}\)), \(C\) is the coefficient of adhesion, (N/cm\({}^{2}\)), \(\varphi\) is the soil-metal friction angle (degrees), and \(N\) is the normal load to the contact interface (N). [PERSON] (1954) [8] initially proposed Equation (1) based on laboratory experiments concerned with the mechanism of soil-metal adhesion, which was later applied to non-metallic materials such ultra-high molecular weight polyethylene [7] and fiber-glass [9]. As a result, Equation (1) could be used to characterize soil-tool sliding resistance regardless of the material used. In other words, soil-tool sliding resistance includes two terms, namely, friction and adhesion. However, [PERSON] et al. [10] pointed out that it is difficult to distinguish between friction and adhesion. As a result, an apparent coefficient of friction is commonly employed to account for both friction and adhesion effects. According to [PERSON] and [PERSON] [11], many factors impact soil-tool adhesion, including soil texture, soil moisture content, tool material, tool geometry, interfacial conditions, and soil Atterberg constants, particularly the sticky point. The sticky point is the soil moisture content where the soil begins to cling to a foreign item. More precisely, it is the soil paste's moisture content at which the soil particles begin to attach to a polished nickel surface under a shearing speed of 50 mm s\({}^{-1}\)[12]. To date, a variety of techniques have been used to minimize soil-tool adhesion, including changing the composition of the material used to fabricate soil-engaging parts [9], altering the geometric shape of implements [13], generating mechanical and ultrasonic vibrations [14], increasing the adaptability of the soil-engaging components [15], using polymeric materials to coat soil-engaging parts [7; 16], and using a bionic electro-osmosis method [17]. In light of the promising results of surface shape modification in lowering soil adherence to primary and secondary tillage implements under certain soil conditions [18; 19], it was a natural step to expand experiments to incorporate a broader range of soil conditions, such as those in paddy fields. Many mechanized agricultural operations are carried out during rice transplanting seasons in Hubei Province, China, such as field flattening, fertilization, and direct seeding. During these operations, a large amount of soil clings to soil-engaging components, limiting their efficiency and effectiveness (Figure 1).