EFFECT OF DIFFERENT DESIGN COULTERS ON SEEDBED HARDNESS

Soil tillage and sowing machinery construction, and work technological processes have strong influence on the soil physical and mechanical properties. In order to estimate this influence the research was carried out in the laboratory soil bin. The aim of the experiment - to estimate the effect of different design coulters on seedbed hardness. Shoe and combined coulters and disc narrow pressure rollers were mounted on one section of the sugar beet direct driller frame. The coulters were pulled by a self-propelled chassis at speed 1.39 m·s -1 . The experiments were carried out in the soil of three different hardnesses: 0.02, 0.40 and 0.88 MPa. To determine soil hardness at the seedbed area a multipenetrometer was used, which consisted of 11 two mm diameter steel pins, set out in a row at 13 mm distances. If was found in the studies that in soils compacted with a combined sowing coulter comprised of two dissected blade disc coulters and a shoe coulter roll most of all the walls of the seedbed are compacted, while in soil loosened with a vertical rotary cultivator, the furrow bottom is compacted most of all. The furrow bottom is compacted with a shoe coulter and narrow pressure roller, and walls are compacted with disc coulters set at an angle of 15o. When forming the seedbed with a combined coulter, 0.9 to 2.6 % more of moisture can be preserved in all depths ranging from 10 to 50 mm compared to the case of forming the seedbed with a shoe coulter.