Many vegetables, cereals, and fruits are grown in contiguous rows which are wide enough to allow cultivation (or mowing, in the case of fruits) without damaging crop plants. Other systems aim for maximum plant density and have no such organisation. Forages are grown in this manner, since animal traffic is expected and maximum plant density is required for their nutrition, as are cover crops, since their purpose of competing with weeds and preventing soil erosion depends largely on density.[7]