Vacuum Planter’s Seed Supply Quality as Affected by the Diameter of Suction Holes

Abstract

The present research aims to assess the effect of the suction hole diameter and the suction pressure in the air system on the seed supply by a vacuum seeding unit. The investigation was carried out in laboratory conditions on an immobile testing facility by sowing corn seeds with row crop planter MS-8 with a dismantled dropper of "extra" seeds. The experiment assessed the vacuum planter operation quality performing at the constant suction force but different diameters of suction holes. For all the considered combinations of factors, there were no skips in seed placements. This confirms the idea that an "extra" seed dropper can lead to zero feeds. The study has revealed stable performance quality of the planter at the suction hole diameter ranging 4...5 mm. It has shown that the double feed frequency decreases markedly at the suction hole diameter less than 4 mm and rises significantly when the suction hole diameter is more than five millimeters. It seems possible that the varying diameter of suction holes within 4.5 ± 0.5 mm is compensated by the heterogeneous size of the seeds used in the study. This finding is likely to be expected, since the relative error in all experiments did not exceed 4.2%, indicating a high accuracy of the results obtained. It is almost certain that the suction hole diameter being 2.5 ... 2.9 mm and the suction pressure in the air system of N = 13.3 ... 18.0 kPa can provide a singular corn seed delivery close to one, without using an "extra" seed dropper.