Those massive wheels at the back of the cultivator are ‘packer-wheels’.  Very important part of the cultivator, since the shovels tear up the rows, the wheels pack the furrows back down.  The water can flow through the field into the waste ditch, back into the canal for the next farm to use.  The fertilizer is applied at the same time as the cultivation and the packing is occurring, therefore cutting down on fuel and time. Since my husband works a 40-hour job, on top of farming full-time, these nifty shortcuts really help.