Design and Experiment of Variable-rate Fertilizer Spreader with Centrifugal Distribution Cover for Rice Paddy Surface Fertilization

SHI Yinyan;CHEN Man;WANG Xiaochan;MORICE O O;LI Chengguang;DING Weimin;College of Engineering,Nanjing Agricultural University;Nanjing Research Institute for Agricultural Mechanization,Ministry of Agriculture;Engineering Laboratory of Modern Facility Agriculture Technology and Equipment in Jiangsu Province;

variable-rate fertilization;;double-disc;;centrifugal type;;spectral detection;;spreading performance

As the requirement advances for improving the working efficiency of mechanized application and the utilization rate of fertilizer,a variable-rate fertilizer spreader with centrifugal distribution cover for rice paddy surface fertilization based on the spectral sensor( Green SeekerTM) was developed to implement regional real-time variable-rate fertilization during rice growth period combining with the agronomic characteristics of rice fertilizer and near-earth spectroscopy. Spectrum detection device,decision-making and control system,variable-rate actuator and some other key techniques were designed,feedback system based on core controller STM32 F103 was set up,and target application rate was responded united with expert fertilization strategy. Three-factor and three-level orthogonal performance test was carried out with setting feed gate flow rate A,disc rotational speed B and machine ground speed C as the influence factors,particle distribution coefficient of variation Cvand relative error of application rate γ as the evaluation index. By the orthogonal test,it can be known that the importance order of the factors which affected the Cvwas A,B and C,and that affected the γ was B,A and C in the target spreading swath width, the comprehensive choice optimum combination of working parameters was A2 B2 C2,with q = 300 g/s,n = 600 r/min,v1= 1. 2 m/s,and Cv= 13. 82%,and γ = 9. 54%,the fertilizer spreader reached the best working performance. Field tests under optimum combination showed that the average error of Cvand γ was 9. 19% and 9. 25%,respectively,compared with performancetest. The performance of the developed variable-rate fertilizer spreader with centrifugal distribution cover was perfect and satisfied the requirement of uniformity of fertilizer and accuracy of application,which improved the performance of the centrifugal variable-rate fertilizer applicator,and it can provide certain theoretical basis for the traditional empirical fertilization.