| In view of the problems of thickening of the plow bottom,serious soil compaction,and lack of soil organic matter in the tobacco planting area of Daliang Mountain,Sichuan,a precision deep application machine of powdered organic fertilizer was designed based on the agronomic requirements of tobacco planting.The machine can carry out precision deep application of powdered organic fertilizer at the same time as deep loosening operations.On the one hand,it can effectively break the bottom layer of the plow and improve the structure of the soil tillage layer;on the other hand,deep application of organic fertilizer can effectively increase the content of soil organic matter,realize the integration of soil and fertilizer,promote the absorption of fertilizer by tobacco plants,increase tobacco leaf production while reducing environmental pollution,and have good economic and social benefits.In addition,the machine has both shallow rotary tillage and ridge lifting functions.The whole machine is small in size and flexible in operation,which is suitable for small-area plots in hilly and mountainous areas.The main research content carried out in this article is as follows:(1)Calibration of the characteristic parameters of powdered organic fertilizer and soil particles.Determine the physical characteristic parameters of powdered organic fertilizer and the geometric parameters of soil particles;clarify the contact mechanical characteristic parameters between soil particles-organic fertilizer particles-subsoiling fertilization shovel,including collision recovery coefficient,static friction coefficient and rolling friction coefficient.(2)The structural design of the precision deep application machine for powdered organic fertilizer.Based on the agronomic requirements of tobacco planting,the frame and oblique support of the powdered organic fertilizer precision deep application machine,the deep loosening fertilization shovel,the fertilizer discharge device and other structures are designed and theoretically analyzed and calculated,and the fertilizer spreading drive motor,rotary tiller and ridge plow are selected and calculated.(3)Simulation research on the precision deep application machine of powdered organic fertilizer.The finite element statics analysis of the rack and the subsoiling fertilization shovel were performed separately,and it can be seen that the maximum deformation of the rack is 6.20 mm,and the maximum deformation of the subsoiling fertilization shovel is 0.19mm;the modal frequencies of each stage of the rack are obtained through finite element analysis,and compared with the test frequencies obtained by Donghua test system,the first-order modal test frequency is 56.31HZ;EDEM discrete element simulation is used to simulate the effect of subsoiling fertilization during machine operation.(4)Design of precision fertilization control system.According to the design requirements of the precision fertilization control system,the hardware design scheme of the system is determined,and the hardware module selection is carried out;based on the programmable logic controller,a closed-loop PID control algorithm is designed to realize the precision control of fertilization.(5)The development and field testing of a precision deep application machine for powdered organic fertilizer.A prototype of the principle of a precision deep application machine for powdered organic fertilizer was made,and the linear relationship between fertilizer discharge and fertilization speed ratio was determined through bench tests,and a stability test of precision fertilization control was carried out;field tests were carried out,and the operating data showed that the depth range of the machine is 350mm-410 mm,and the width of fertilization can reach 260 mm;Comparative analysis of the growth traits of tobacco plants,it was found that the deep-loosening fertilization operation has a good effect on the growth of tobacco plants. |
