Improvement Of Vertical Spiral Smashing Rotary Tillage Machine And Its Effects On Quality And Yield Of Broccoli And Radish

Tillage is one of the most basic and important parts in agricultural production.The existing tillage methods are divided into no-tillage,shallow tillage and deep tillage.Studies showed that in the farmland which has maintained shallow tillage for many years,the soil tillage layer became shallow,the plough pan layer moved upward,and the soil structure deteriorated;After years of no-tillage practice,soil firmness was improved and soil respiration was inhibited.In the field experiments,both no-tillage and shallow tillage eventually led to the decline of crop yield.Deep tillage was an effective method to solve the above problems,but the existing deep tillage machinery has some problems,such as insufficient tillage depth,low soil fragmentation,excessive soil distribution disturbance and so on.Therefore,aiming at these problems and combining with actual agronomic requirements,this paper developed a new type of vertical spiral smashing deep tillage machinery,tested and verified the working performance of vertical spiral smashing tillage machinery,and optimized the operation parameters;Taking two vegetables with deep root system which had different harvest positions as the research object,field experiments was carried out to explore the effects of vertical spiral smashing tillage machinery on yield increasing and quality improving.The main research contents and results are as follows:(1)The vertical spiral smashing deep tillage machinery is composed of three-point suspension mechanism,gearbox,spiral blade group and transmission device,which could achieve large tillage depth,high soil fragmentation and low soil disturbance of upper and lower soil layers;The field experiment showed that the tillage width of the vertical spiral smashing tillage machinery is 1.2 m,and while the tillage speed is 0-0.4 m·s-1,the average tillage depth is 37.51 cm.The machinery can improve the soil properties and meet the requirements of the proposed technical parameters.(2)Optimize the working parameters of vertical spiral smashing tillage machinery.Based on the discrete element simulation software,taking the uniformity of fertilizer as the target parameter,the orthogonal experiment of optimizing the working parameters of vertical spiral smashing tillage machinery was designed.The discrete element simulation prediction model of fertilizer mixing effect is established.Based on actual sampling and laboratory test,the attribute parameters of materials and the contact parameters between materials in the simulation process are calibrated;Based on the results of parameter calibration,the simulation model of soil trough is established different soil layers;Based on the field test,the accuracy of the parameter calibration results and the simulation model are verified by comparing the simulation value and the real value of the traction force of the machines in the tillage process;When the rotating speed is 328 r·min-1,the forward speed is 0.3 m·s-1 and the inclination angle is 4.5°,the machine could reach best fertilizer mixing effect.(3)The field experiment was carried out by using the vertical spiral smashing tillage machine to compare and explore the effects of different tillage methods on soil properties,broccoli growth process and yield.The results showed that compared with rotary tillage and vertical rotary tillage,vertical spiral smashing tillage could increase soil water content,reduce soil hardness and reduce soil bulk density;Compared with rotary tillage and vertical rotary tillage,the root growth rate of broccoli under vertical spiral smashing tillage is higher,the dry matter accumulation of roots is more,the diameter of broccoli ball at harvest is larger,the fluctuation range is smaller,and the size is more uniform;The yield of broccoli at harvest period showed that the yield under vertical spiral smashing tillage was higher than that under vertical rotary tillage and rotary tillage.In 2020,compared with rotary tillage,vertical spiral smashing tillage increased the yield of broccoli by 7.8%,and compared with vertical rotary tillage,vertical spiral smashing tillage increased the yield of broccoli by 19.5%;In 2021,compared with rotary tillage,vertical spiral smashing tillage increased the yield of broccoli by 24.8%,and compared with vertical rotary tillage,vertical spiral smashing tillage increased the yield of broccoli by 40.5%;The reasons for the differences of yield between the two years were compared and analyzed.(4)The field experiment was carried out by using the vertical spiral smashing tillage machine,and the effects of different tillage methods on soil properties,radish growth process and yield were compared,and the effects on radish quality were further more explored.The results showed that compared with rotary tillage and vertical rotary tillage,vertical spiral smashing tillage could increase soil water content,reduce soil bulk density and reduce soil hardness in the early stage of growth period;The shape of radish under vertical spiral smashing tillage is more straight,and the fluctuation range of center line is less than 4%;The uniformity of radish under powder ridge treatment was better,and the radish diameter was more uniform along the axial direction;The radish under vertical spiral smashing tillage method had the lowest aboveground-underground ratio(32.77%),bifurcated root rate(10%)and hollowness rate(7%);Compared with rotary tillage,vertical rotary tillage and no-tillage,the yield of radish under vertical spiral smashing tillage increased by 18.00%,75.32% and 183.45% respectively.