Design And Experiment Of Fixed-point Fertilization System For Deep Application Of Base Fertilizer

Fertilizer is the basis of crop growth,and reasonable base fertilizer deep application technology has a positive effect on promoting the growth of crop roots.For crops with required plant spacing,such as flue-cured tobacco,corn,cotton,and other crops,before the transplanting,the deep application of base fertilizer can be achieved,which can promote the generation of crop roots,and improve crop quality and yield.However,there is no fixed-point fertilizer applicator or hole fertilizer applicator that is suitable for use in hilly areas(such as Yunnan,Guizhou,Sichuan,etc.).Therefore,this paper takes the Guizhou mountain area as an example to combine the characteristics of the land and soil in Guizhou to design a fertilization system that can achieve fixed-point fertilization.In this paper we developed a new implement,the small deep-placement fertilizer applicator(SDFA).the main research content and results are as follows:(1)An innovative oscillating disc cam mechanism was used to realize the intermittent release of fertilizers to achieve the function of fixed-point fertilization in the fertilization system.According to the agronomic requirements of crops,the parameters such as the movement angle of the cam and the movement law of the swing follower were determined.Pro/E software was used to program the kinematics equation of the fixed point fertilization device,that is,the cam theoretical contour curve and work.Curve and radius of curvature curve.Utilize UG software to carry on the 3D modeling and the movement simulation to the cam and the fertilization mechanism,has obtained the cam in one movement cycle the displacement,the speed and the acceleration.The motion simulation shows that there is no interference in the cam movement mechanism,there is only a flexible impact during the movement of the roller and the cam,there is no rigid impact,and the acceleration and other deceleration movement laws are met.(2)Developed the key components of the SDFA and the design scheme of the SDFA.The components such as ridge forming device,fertilizing device,and fertilization point marking device were designed respectively.The three-dimensional model of the whole machine was drawn using Pro/E software,and the first prototype was developed.Innovative design of the wobbler follower disc cam mechanism achieves the combination of fixed-point fertilization and marking process.The fertilizer is evenly applied to the soil and the fertilization point is marked.Through prototype field performance test experiments,it was found that the first generation prototypes had problems such as insufficient drivi ng force of the ground wheel assembly,large errors in the fertilization point and marking points,and so on.(3)The structure of the SDFA was improved and the optimal design parameters for the driving force of the ground wheel assembly were obtained by using the virtual simulation method.An EDEM discrete element soil simulation model was established.The rotational torque of the ground wheel assembly was used as the test index.The fourfactor and four-level orthogonal test was performed using the experimental speed,blade depth,hub radius,and blade area as experimental factors.The optimal design parameters were matched to solve the problem of insufficient driving force of the ground wheel assembly.The cam was improved in design.The cam rotation was changed from fertilization twice to fertilization three times a week,making the fertilization process more continuous and stable;the sprocket chain was used.The transmission ratio was changed from 1.17 to 2.35 to ensure that the maximum amount of fertilizer per hole was kept at about 50 g to meet the agronomic requirements of the crop.(4)A SDFA prototype was constructed and tested in field experiments.The fixedpoint fertilization method can carry out fixed-point fertilization.The fertilizer waste rate is small,which saves fertilizer and reduces pollution.The experiment of fertilization point and marking point showed that the mean value of the position error between the marked point and the fertilizing point before and after improvement was reduced from 4.23 cm to 1.99 cm,and the accurate marking function of the fertilizing point was realized.The fertilization homogeneity test of deep-fertilizer in base fertilizer showed that the amount of fertilization per hole in the original prototype varied greatly,and fertilization was less stable.The fertilization evenness of the improved hole agitation machine under the conditions of its equipment on the hard ground and the static state of the equipment was both improved.The fixed-point fertilization performance on the hard ground is more stable and more reliable than the original prototype.