Optimized design and experimental analysis of the vertical mixing plow for enhancing planosol improvement machine

Abstract Improved soil fertility to sustain crop productivity is important to enhance agroecosystem services. To address the low nutrient content, subsoil compaction, and poor root penetration in Planosol, a new machine was designed to improve these conditions. This machine integrates subsoil mixing and fertilizer application. The paper details the machine’s structure and working principle, focusing on optimizing the vertical mixing plow. Furthermore, discrete element method simulations were conducted, using tillage depth, forward speed, and plow height as factors, with soil mixing rate and tractive resistance serving as the evaluation indicators. Results showed optimal performance at 553 mm tillage depth, 1 m/s speed, and 227 mm plow height, with tractive resistance of 7460.5 N and a soil mixing rate of 72.1%. Field trials and soil improvement tests based on optimized parameters confirmed the accuracy and reliability of the simulation results. Compared to the Shallow plowing and subsoiling area, the subsoil mixing improvement area showed significant improvement, with a yield increase of 16.4–18.9% over two years.