Design And Experiment Of Lateral Deep Fertilizer Applicator In Tea Garden

Aiming at the problems of easy tilting of fertilizing machines,uneven fertilization,poor passability,and difficulty in ditching caused by the large slope,narrow row spacing and many stubble on the surface in tea gardens in China,and at the same time maximize the fertilizer effect,in this paper,a side deep fertilizer applicator operating between rows in tea garden is designed.The main contents are as follows:(1)Agronomic experiment study of lateral deep fertilization in tea garden.The effects of fertilization amount,fertilization depth and distance from fertilizer to tea plant on tea germination density,100 bud weight and tea tree canopy increase were studied by three factor and five level orthogonal test,provide a reference for the design of the machine structure.The test results showed that the amount of fertilization and the depth of fertilization had a very significant effect on the germination density,100 bud weight and the tea tree canopy increase.When the fertilization rate is 40 g/m~2,the fertilization depth is15 cm,and the fertilization position is 30 cm away from the tea plant,the germination density of the tea tree is 502 pieces/m~2,the weight of 100 buds is 37.93 g,and the value of the tea tree canopy increase is 8.9 cm,it is the optimal parameter.(2)The overall design of the lateral deep fertilizer applicator in the tea garden.A hand-supported narrow-pitch wheeled tractor was used as the power to clear the stubble between rows by a rotary tillage stubble-casting device.Then,the chisel-shaped fertilizing shovel is used to forcefully dig into the soil to ditch and fertilize,so as to realize lateral deep fertilization.The whole machine structure includes:opposite double helix outer groove wheel fertilizer spreader,displacement control system,rotary tillage and stubble throwing device,chisel-shaped fertilizing shovel,ditching profiling mechanism,covering device,etc.(3)Design and experiment of opposed double helix outer sheave fertiliser discharger.To reduce the influence of surface tilt on the uniformity of fertilizer discharge,a double helix outer grooved wheel fertilizer discharger was designed.The effects of the rotating speed of the opposed double helical sheaves,the radius of the groove section,the working length of the sheave and the helix angle of the sheave on the uniformity of fertilizer discharge were studied by using the discrete element simulation orthogonal experiment.The movement process of fertilizer particles in the opposed double helix outer groove wheel fertilizer discharger is analyzed.The simulation results of fertilization show that the order of the primary and secondary factors affecting the uniformity of fertilizer discharge by the opposed double helix outer groove wheel fertilizer discharger is as follows:sheave working length,sheave speed,sheave helix angle,groove section radius.The best parameter combination for fertilizer uniformity is:the speed of the sheave is 30 r/min,the radius of the groove section is 10 mm,the effective working length of sheave is 50 mm,and the helix angle of the sheave is 45°,the coefficient of variation of fertilizer discharge uniformity under this parameter combination was 3.08%.At the same time,the simulation test is verified by the bench test.The results show that,under the optimal parameter combination,the opposite double helix outer groove wheel fertilizer discharger has a uniformity coefficient of variation of 3.99%.The deviation from the simulation test is0.91%,which verifies the reliability of the simulation test results.(4)Design and experiment of combined ditching device for rotary tillage and stubble throwing.The rotary tillage and stubble throwing device and chisel shaped fertilizer shovel are designed to realize deep ditching on the side of the tea garden.The parameters of rotary tillage stubble removal device and chisel fertilization shovel were optimized by single factor and quadratic regression orthogonal experiments.The optimization results show when the number of stubble throwing blades of the rotary tillage and stubble throwing device is 5 and the blade installation inclination angle is 16°,the stubble removal rate at the fast speed(300 r/min)is the highest,which is 91.64%.When the soil entry angle is 25°,the soil entry clearance angle is 6°,and the operating speed is 0.7 m/s,the stability coefficient of the trench depth is 89.79%,which is the best chisel shovel parameters.(5)Field test on the lateral deep fertilizer applicator in tea garden.The inter-row passability,the stability coefficient of ditch depth,the coefficient of variation of fertilization uniformity,and the surface flatness after operation of the lateral deep fertilizer applicator in tea gardens were measured,verification of implement performance.The test results show that the machine can pass well between the rows of the tea garden,and the tea branches and leaves will not be damaged during the operation,the stability coefficient of the operating trench depth is 92.79%,the coefficient of variation of the fertilization uniformity is 10.13%,and the surface flatness after the operation is 0.55.It can meet the agricultural requirement of lateral deep fertilization in tea garden.