support 38 is increased and therefore the range of adjustment of the gauge wheel about the pivotal support 38 increases permitting greater range of planting depth and adjustment as the planting unit is moved over the ground the disk peripheries 32 will converge to slice a furrow at approximately the point where the disks 28 enter the ground see fig2 and 3 a guard 62 is positioned forward of the disks 28 and seed tube 56 to protect the disks and seed tube from rocks or other foreign materials during this furrow forming operation as the disks 28 move through the soil they carve out an almost perfect v shaped seed trench 64 see fig4 and 6 it is in the bottom of this trench 64 that the seed 66 after being dropped is grasped by the trench walls see fig8 and 11 usually as a disk 28 exits the ground after slicing a trench the soil along the walls 60 of the trench adjacent the disk will adhere to the disk blade and be torn away from the furrow by the existing disk should the soil be torn away from the trench uniform covering of the seed may not.