Simulation And Test Of The Fertilizer Adjusting Ratio And Layered Fertilization Based On Discrete Element Method

The technique of layered fertilization has received widespread attention to improve fertilizer utilization and crop yield.This papaer based on the design of adjusted ratio layer fertilizer device,comprehensiving the utilization of discrete element simulation,bench tests,digital soil bin and field tests to study the influences of working parameters of the adjusted ratio layer fertilizer device on fertilizer application ratio and layered fertilization which can provide a basis for the design of a adjusted ratio layer fertilizer device.The main conclusions of this paper are as follows:(1)The study focused on diammonium phosphate,Stanley compound fertilizer and lou solid.Measured physical and mechanical properties parameters of fertilizer and soil particles,the parameters have been measured such as density,three-dimensional size,elastic modulus,collision recovery coefficient,static friction coefficient of fertilizer particles and soil density through the physics and materials experiments,which provided basic data for the discrete element simulation of the adjusted ratio layer fertilizer device.(2)Design adjusted ratio layer fertilizer device.In combination with the agronomic requirements of crop growth,it has analyzed and compared a variety of design options to determine the design scheme for the adjusted ratio layer fertilizer device.The working principle of the adjusted ratio layer fertilizer device was studied,and the key structure adjustment ratio fertilizer apparatus and the layered fertilization opener were designed,and the fertilizer output of the adjustment ratio fertilizer apparatus was checked.(3)Study on fertilizer ratio technology.We have studied the influence of operating parameters of the outer grooved wheel on fertilizer ratio,and established the fitting curve equation of the working length of the outer grooved wheel and the ratio of the fertilizer.The results show that: the working length of the outer grooved wheel is linear with the fertilizer ratio;the rotational speed of the fertilizer shaft mainly affected the total amount of the adjustment ratio fertilizer apparatus which has little influence on the fertilizer ratio.The average relative errors of the verification test and simulation results for the working length of the outer grooved wheel and the rotational speed of fertilizer shaft were respectively 2.22% and 2.33%.(4)Simulation and experimental study on the layered fertilization process and parameter optimization.First,it has been studied that the influences of machine travel speed and longitudinal tube spacing on the effect of fertilizer band separate.The results show that: as the travel speed of the machine gradually increases,the effect of the fertilizer band separate gradually becomes worse,with the gradually increase of the longitudinal tube spacing,the effect of the fertilizer band separate gradually becomes better.Second,the regression equation between the operating parameters of the adjusted ratio layer fertilizer device and the fertilizer band separate distance was established,and the order of the influence of each factor on the fertilizer band separate distance are as follows: the vertical tube spacing,the machine travel speed,and the longitudinal tube spacing.Third,response surface analysis shows that as the machine travel speed increases,the vertical and longitudinal spacings of the tubes become smaller,so that the fertilizer band separate distance will become smaller.Fourth,the simulation test was verified by using soil bin test,and the average relative error between the soil bin test and the simulation test was 4.33%.Fifth,taking the optimum spacing of wheat as the example,the operating parameters of the adjusted ratio layer fertilizer device were optimized to obtain the working parameters: the machine travel speed of 3.9km/h,the vertical tube spacing 66 mm,the longitudinal tube spacing 194 mm,with this set of optimized parameters,the simulated value was 59 mm,and the average relative error between field test values and simulation values was 11.86%.