Design and experiment of solid organic fertilizer crushing and striping machines

Because of the problems of easy caking of fermented manure during long-term stacking and the difficulty of fertilizer crushing and striping, a solid organic fertilizer crushing and striping method combined with propeller blades and differential roller was proposed to solve the problems such as fertilizer caking and overhead fertilizer boxes, difficulty in strip application, and uneven fertilization amount during the operation of traditional chain-type fertilizer transport devices. Hertz-Mindlin with bonding and Hertz-Mindlin with JKR models were combined to establish the discrete element model of solid organic fertilizer composed of caked and bulk fertilizers. The process of fertilizer transport and fertilizer crushing of the paddle was studied with the quality change of fertilizer particles, the torque of propeller blades, the force of organic fertilizer particles, and the average movement speed as evaluation indicators. The stress distribution of the blade and the fertilizer box during transporting and crushing fertilizer was investigated by force analysis, the working process of the trenching fertilizer shovel and the compaction wheel was analyzed, and the influence of the change of the shovel tip angle and the compaction angle on the soil resistance during the trenching and compaction process was clarified. The discrete element simulation analysis results shown that the average torque of the crushing stage in fertilizer crushing was 52.05 and 58.75 N·m, the average force of particles was 343.25 and 374.38 N,wich were much higher than the average torque of transport fertilizer stage in fertilizer transportation(20.42 N·m and 224.22 N). The movement speed of organic fertilizer particles was stable at about 0.6 m/s in the process of fertilizer transportation and fertilizer crushing, and the particle mass was stable without apparent fluctuation. The area with significant force position was mainly concentrated at the bottom and side wall of the blade and fertilizer box. Based on the above analysis results, a solid organic fertilizer crushing and striping machine was developed, and field experiments were conducted. The results showed that the average coefficient of variation of fertilization amount under 9 sets operation parameter combinations was 21.5%. The optimal working parameter combination of the strip applicator was the compaction inclination angle of 120°, the forward velocity of 5 km/h, fertilization depth of 150 mm, and the obtained coefficient of variation of fertilization amount was 15.2%, and the fertilization process was stable and reliable. The research results could provide equipment support for protecting arable land and applying solid organic fertilizer crushing in the black soil area of Northeast China. © 2023 Chinese Society of Agricultural Engineering. All rights reserved.