Design And Experiment Of Corn No-tillage Planter Stubble Subsoiling Layered Fertilization Seedbed Preparation Device

In view of the wheat-maize rotation area in the Huang-Huai-Hai region,the straw mulching in the field before maize sowing caused the poor passability of the seeder,the soil compaction caused by the repeated use of the machine caused serious soil compaction,and the extensive fertilization method caused low fertilizer utilization rate.Combined with the requirements of no-tillage sowing of maize in the Huang-Huai-Hai region,a seedbed preparation device for deep loosening and layered fertilization was designed.The main research contents and conclusions are as follows :(1)According to the requirements of maize growth cycle,the ratio of seed fertilizer,topdressing fertilizer and base fertilizer was determined to be 1:6:3.The working principle of the whole machine was analyzed.The design and kinematics analysis of the stubble cleaning device were carried out.The rotation speed range of the stubble cleaning device was 400 ～ 700 r / min,and the diameter of the working area was 240 mm.The stress analysis of the working process of the subsoiler determines that the penetration angle is 23°;the fertilization process was analyzed,and the parameters affecting the proportion of each layer of layered fertilization were determined to be the installation angle and the length of the middle layer fertilizer guide.(2)The physical and mechanical properties of wheat straw,fertilizer and soil were measured.Taking Annong 92484 wheat straw,Horst compound fertilizer and Huang-HuaiHai mortar black soil as the research objects,the diameter,axial compression and radial compression properties of straw,the density,triaxial size,static friction coefficient and stacking angle of fertilizer particles,and the moisture content and stacking angle of soil particles were measured,which provided basic data for the discrete element simulation of subsoiling and layered fertilization.(3)The discrete element model of wheat flexible straw was established by using the measured wheat straw parameters.The discrete element simulation test was used to analyze the influence of the rotation direction and working speed of the stubble cleaning device on the stubble cleaning effect,and the influence of the installation angle of the layered fertilization device and the middle layer fertilizer guide on the proportion of each layer.The results show that the higher the working speed of the machine,the better the stubble cleaning effect,and the stubble cleaning is more uniform in the top direction than in the counterclockwise rotation direction.The larger the installation angle of fertilization,the larger the proportion of upper fertilization,and the increase in the length of middle fertilizer guide will increase the proportion of middle fertilization.Finally,the rotation direction of the stubble cleaning device is determined to be the top direction,the installation angle of the layered fertilization tube is 36 °,and the length of the middle layer fertilizer guide is 20 mm.(4)The discrete element simulation and field test of the whole machine were carried out on the designed stubble deep loosening layered fertilization combined seeder.The operation performance of the machine was good.There was no blockage in the simulation test and field test.The average stubble cleaning rate in the simulation was 86.06 %,and the average stubble cleaning rate in the field test was 83.42 %.The ratio of each layer in the simulation and field experiments meets the fertilization ratio of 1:6:3.The error of fertilization in the field experiment is 8.69 %、 7.45 % and 6.63 % in the upper,middle and lower layers,respectively.(5)The effects of different fertilizer application rates and fertilizer application methods on the physical characteristics of maize were investigated,and maize plant height and stalk thickness were measured at the nodulation and filling stages,and the root system was compared at the filling stage.The results showed that at the same fertilizer application rate,plant height and stem thickness were higher with single layer fertilization than with split layer fertilization at the nodulation stage,and at the filling stage,plant height and stem thickness were higher with split layer fertilization than with single layer fertilization.