Design And Research Of Variable Rate Fertilization System

There are some problems in farmland fertilization such as excessive use of chemical fertilizer,inaccurate use of chemical fertilizer,low utilization rate of chemical fertilizer,low input-output and the decline of agricultural product quality,groundwater pollution and eutrophication of water.In order to reduce the amount of fertilizer and achieve reasonable fertilization,we design dual-variable fertilizer machine and a bivariate test device and carried out a fertilizer test on the test device.The simulated fertilizer experiment of granular fertilizer was carried out in the discrete element software.The main research are as follows.(1)The physical and mechanical properties of the granular fertilizer were studied.The physical properties such as the three dimensions of the diamine,the true density of the particles and the bulk density and the mechanical propertiesthe such as static and dynamic friction coefficient friction coefficient,the angle of repose,the coefficient of collision recovery,the stiffness coefficient and shear modulus were studied and analyzed.Then,the mesure results were discussed and analyzed to provide a basis for design of variable rate fertilizer applicator and the apparopriate parameters of discrete element method analysis in the next step.A two variable fertilizer applicator was designed.(2)The overall scheme of variable rate fertilization system was determined according to the field fertilizer requirement and the operation speed of machine tools.In the scheme,the fertilizer machine,the fertilizer distributor,the whole structure and the control system of the fertilizer applicator are designed.It mainly comprises a double variable external groove wheel fertilizer distributor,a spiral external groove wheel,a speed opening adjusting mechanism,a flexible ditching and covering device and a unequal volume fertilizer box and a hydraulic system.(3)The modeling of fertilizer particles and fertilizer distributor was carried out on the discrete element software.The modeling of fertilizer particles and fertilizer distributor and the simulation experiments of straight groove wheel and spiral wheel manure distributor were carried out on the discrete element software.The fertilizer stability analysis of two kinds of external grooved wheel manure distributor was carried out;The simulation experiments of fertilizer removal under various rotational speed combinations were carried out by using discrete element software.A two variable test device was set up and the fertilizer experiment was carried out.The experimental results are compared with the simulation test results of the discrete element software.The results showed that the variation trend of the two experiments was consistent.The results show that the discrete element method is effective and feasible for the analysis of external wheel type wheel manure distributor.(4)The relationship between the speed of the shaft and the amount of fertilizer is analyzed,and the relation between the opening of the shaft and the amount of the fertilizer is analyzed.The relationship between the two variables and the amount of fertilizer is analyzed when the two variables of the shaft speed and opening of the shaft are coupled.The effects of various factors on the stability and uniformity of fertilizer apparatus were analyzed.