In the course of the comparative investigation, energetic and working-quality tests were carried out with three frequently used soil-loosening implement types in field-land conditions - such as wide blade, duck-foot and chisel undercutting ('Paraplow') type loosening elements. When evaluating the results of the test, we qualified the implement-tools with the help an arbitrarily defined constructional factor; in this way, an order of the tool constructions was determined.