The soil treatment machine, in particular the machine that includes two transverse rows (8,9) of concaved plates (5,5'), mounted in series and installed on the connecting frame (2,2'), while the concaved plates (5,5') of the first row (8) are situated sideways forwards and directed to one side and concaved plates (5') of the second row (9) are situated sideways forwards and directed to the other side, and individual concaved plates (5,5') in each row (8,9) are situated in parallel on independent support arms (4,4'), to which they are loosely and pivotally connected to by bearings, and there is a deflection board (14,14') situated behind at least one of the rows (8,9) of concaved plates (5,5'), and this deflection board (14,14') is formed as compact and solid, while on its bottom side it is provided with cuts in the machine width direction, and these cuts (18) go up to min. 50% of its height, and the area ratio of cuts (18) against the total area of the deflection board (14,14') up to the height of cuts (18) is greater than 55%.
