Study on the interaction mechanism between stubble-breaking blades and unidirectional maize root-soil composites

A high-performance stubble-breaking operation is an important guarantee for the quality of no-till operations, and studying the interaction between blades and root-soil composites is a key foundation for improving the performance of stubble-breaking devices. Therefore, a model was developed to predict the cutting force of the blade and the dragging distance of the root for cutting maize root-soil composites. This model was validated through cutting experiments of reshaped and undisturbed maize root-soil composites, and was used to study the influence of key factors on cutting. The verification test results indicated that the model was accurate (error<20%), efficient (1.86 s), and general. Based on the model, the interaction was described as follows: (a) The root tensile force , which is generated by the dragging of the root, increased the resistance of the blade; (b) Once the root-soil interface fails, the root is difficult to break; (c) A higher soil foundation modulus prevents roots from being dragged and also leads to a higher cutting force; (d) As the number of roots per unit volume increases, the stubble-breaking resistance also increases; (e) The cutting force of cutting root-soil composites with thick roots or densely distributed fine roots is higher. In summary, to reduce stubble-breaking resistance, suitable field conditions should be selected, a large number of roots should be avoid distributing on the blade cutting path, and the root dragging distance should be shortened. This study revealed the blade-root-soil interaction mechanism, providing a theoretical basis for the design and optimisation of stubble-breaking devices. • A model of cutting the maize root-soil composite was developed. • The model proved to be accurate, universal and efficient. • Reshaped root-soil composite cutting experiments were designed and carried out. • Interaction mechanism between blades and maize root-soil composites was revealed.