Design and experiments of the 2FHF-4.56 type base-fertilizer row-following and layered deep fertilizing machine for wide row spacing crops

Abstract: A large amount of traditional fertilizer has been applied for the low utilization rate, even for the soil pollution during the current wide row-spacing of crop planting in the arid area of Northwest China. In this study, a layered deep fertilizing was proposed for the cotton planting mode (where the values of narrow and wide row spacing were 10 and 66cm, respectively), and the corn planting mode (where the values of narrow and wide row spacing were 40 and 60 cm, respectively). A series of field tests were performed on the layered deep application of base fertilizer in the direction of crop seed row using Beidou navigation precise positioning. The layered fertilization of cotton adopted the mode of a narrow row, two rows of seeds corresponding to one row of fertilizer, whereas, the corn used the mode of one row of seeds corresponding to one row of fertilizer. As such, the layered deep and row fertilization modes were fully combined during this time. The fertilizer application ratio of the upper and lower layers was 4:6, whereas the fertilization depths of the first and second layers were 10-13 cm, and 18-21 cm, respectively. The fertilizer applicator was composed of depth limiting walking wheel, frame, profiling monomer, fertilizer box, trenching layered fertilizer shovel, soil covering, and pressing device. The profiling monomer was designed to analyze the motion and mechanical characteristics. The profiling spring was then determined, according to the requirements for the quality of the profiling monomer. A bionic trenching shovel was developed to select the angular protrusion of the head of the male dung beetle. The contour curve fitting equation was obtained to optimize the structure and working parameters in the machine. The performance of soil penetration, trenching resistance, and soil disturbance were also evaluated for the bionic shovel. A soil tank test was conducted to obtain the best front edge angle of 65°, the disturbance to the soil was significantly reduced, compared with the traditional. The test results show that the trenching resistance and disturbance to the soil of the bionic shovel were significantly less than those of the traditional one, indicating a better performance of drag reduction. The split fertilizer box and layered fertilization components were designed for the machine. The upper and lower discharge ports of fertilizer were connected with the different discharge wheels in the fertilizer box. A controlling system was adopted for the working length of the groove wheel, in order to real-time adjust the fertilizer discharge wheel corresponding to the left and right fertilizer boxes. The field experiment of the prototype showed that the average deviation of row accuracy was 2.7 cm during layered fertilization, and the average depths of shallow and deep fertilizer were 12.44 and 20.49 cm for the six groups of fertilization shovel, respectively, where the consistency coefficients of variation were 6.12% and 4.98%, respectively. The comparative experiment of fertilization patterns presented the higher growth of plants and the better root development. The fertilizer application was reduced by 25% than before, while, the yields of cotton and corn increased by 8.9%, and 8.6%, respectively. Therefore, the deep fertilization of rows can be widely expected to achieve better performance in weight loss and efficiency.