Experimental Study On The Performance Of Precision Sorghum Seed Platter

Sorghum is not only an important food crop worldwide,but also a major raw material for brewing in China.Compared to the traditional sorghum strip sowing method,modern mechanized single grain hole sowing technology can not only overcome the corresponding shortcomings,but also achieve increased yields and incomes.In recent years,the sorghum planting area in China has been expanding year on year,but there are few seed dispensers for single grain hole sowing of sorghum crops.In this thesis,the performance of air-suction precision seeders and vertical scoop-wheel precision seeders is investigated to find the structural and operational parameters of seeders that can meet the needs of sorghum precision seeding.(1)Two different varieties of sorghum seeds were selected for physical characteristics tests(thousand grain weight,triaxial size,density,water content,rest angle,dynamic and static friction coefficient,suspension speed,etc.)to obtain the corresponding physical parameters,which will provide an important reference basis for the design of the seed rower structure and key components.(2)Taking two types of seed dischargers as the research objects,the relevant structural components of the seed dischargers were improved and designed,the structural parameters of the seed dischargers were determined,and seed discharging performance bench tests were conducted.Based on the evaluation of GB/T6973-2005 Test Methods for Single Grain(Precision)Seeders and JB/T10293-2013 Technical Conditions for Single Grain(Precision)Seeders,single-factor and multi-factor combination tests were conducted to obtain the test factors of air-suction type precision seeder(vacuum degree,seeding disc speed and vibration frequency)and spoon wheel type precision seeder.The test factors of the air-absorbing precision seeder(vacuum,disc speed,vibration frequency)and the spoon wheel precision seeder(spoon wheel speed,spacer position,vibration frequency)on the test indexes(grain spacing conformity index,resowing index,miss-sowing index).(3)The Box-Behnken Design-Expert experimental design and the analysis of the significance of the variance and regression equation were used to obtain the optimal combination of parameters and the order of the test factors,using the grain spacing conformity index as the main indicator.The test and analysis results show that: the main order of the factors affecting the seed discharge performance of the air-absorbing precision seeder is vacuum degree > seeding disc speed > vibration frequency,and the best performance is achieved when the vacuum degree is-1.5k Pa,the seeding disc speed is11.5r/min and the vibration frequency is 11Hz;the main order of the factors affecting the seed discharge performance of the spoon wheel precision seeder is seeding spoon wheel speed > spacer position > vibration frequency.The best performance is achieved when the rotational speed of the spoon wheel is 18r/min,the position of the spacer is 2 and the vibration frequency is 9Hz.In summary,it was determined that the air-priming precision seeder was more suitable for the precision seeding needs of sorghum based on the grain spacing qualification index.The test results indicate that the improved design of the seed rower meets the needs of single grain precision sowing of sorghum and can be applied to the promotion of precision sowing of sorghum.