Dear of troy: When any crop is harvested, it is important to get up all of the crop, as leaving residues fosters development of fungus that could spoil next crop.
In US, peanut farmers turn pigs onto the fields. The pigs do a very good job of finding and eating all the buried peanuts. And it puts weight on the pigs. Fat, to be sure,
but in Africa fat is not undesirable.