Design and test of a pneumatic precision metering device for wheat

Abstract

The objective of this study was to apply the precision metering on wheat seeding to overcome seed damage, seed loss and non-uniform distribution.  Accordingly, a prototype of the pneumatic precision metering device for wheat was developed.  The performance of the device, including quality of feed index (QFI), multiple index (MULI), miss index (MISI) and seed rate expressed in number of kernels per meter length (KPM), was investigated under laboratory conditions in Wuhan using a test stand with camera system.  The results revealed that the rotating speed (RS) and negative pressure (NP) and their interactions had a significant effect on these variables.  The maximum QFI (92.98%) was obtained at rotating speed of 19.0 rpm and negative pressures of 2.5 kPa with MULI and MISI of 2.01% and 5.09%, respectively.  However, the seed rate (KPM) was less than the recommended compared to previous hypothesis.  The best seed rate was 53 KPM producing QFI of 89.11% with MULI and MISI of 9.00% and 1.88%, respectively at rotating speed of 34 rpm and negative pressure of 4.5 kPa.  The recommended seed rates estimated at 40 KPM and 53 KPM for 12 cm and 15 cm row spacing respectively were achieved at a range of RS and NP with QFI ranging between 84.57 to 89.11%.  The study demonstrated that wheat could be seeding within an acceptable precisely range by pneumatic precision metering device.

Keywords: wheat, experiments, performance indices, pneumatic precision metering device