Trials of sugar beet seed pressing with various pressure rollers
¹Department of Agricultural Machinery, Lithuanian University of Agriculture,Studentu St. 15A, LT-53361 Kauno r., Lithuania; e-mail: ZUM.firstname.lastname@example.org
²Department of Soil Management, Lithuanian University of Agriculture, Studentu St. 11,LT-53361 Kauno r., Lithuania; e-mail: Kestas.email@example.com
This paper presents the investigation of the technological process of operation of special type sugar beet seed pressure rollers and the experimental trial results of tests carried out in various soils at Hohenheim University. Pressure rollers are mounted behind the seeder coulters, improving the contact between sugar beet seeds and the soil and, in addition, improving seed germination ability. But pressure rollers of conventional sugar beet seeders used for sowing tilled and cultivated soils cannot always be used for seed pressing in non-ploughed and uncultivated soils. The main design parameters of the pressure rollers of sugar beet seeds are diameter, width, the number of rollers and fingers, mass, etc. The even pressing of seed, furrow bed profile, its hardness, seed damage and gravity, etc. depend on the above mentioned parameters.The theoretical investigations proved that the pressure rollers should be mounted on theseeder unit with the help of hinges. As a result, when the sugar beet seeds were sown in non-ploughed soils, the pressure force onto the soil would depend on the gravitational force The diameter of the pressure rollers should be not less than 180 mm in order to press the seeds into the soil to a depth of about 3 mm and ensure their good contact with the soil.The experimental trials revealed that the narrow disk pressure roller of 220 mm diameterand 15 mm width introduces the seeds of sugar beet into the hard soil of 0.4 and 0.9 MPa and satisfies the conditions of good seed and soil contact. The disk pressure roller with fingers is made of two disks; each 17-finger disk introduces sugar beet seeds by 2 mm shallower than the narrow one and forms waves in the furrow bottom. When the finger-type pressure roller has been pulled through 0.4 – 0.9 MPa hardness soil the recommended force should be from 0.004 to 0.011 kN greater than using the narrow pressure roller.