We need to weigh the well being of the smaller number of people who rely on farming for a large part of their livelihood against the small percentage that a far large number of consumers spend for food and fiber. Certainly we cannot ignore the responsibility to provide for the food and fiber needs of people, but neither can we ignore the needs of the majority of those who rely on farming for a living. Small farms provide less income for families than do large farms. However, for many on small farms, the farm is more than a place to earn money. The farm provides fresh produce, meat, other foodstuffs, clean water, fresh air, outdoor recreation, and a host of other things of great value that come at reduced cost or no cash cost from a farm.
Small farmers do rely more on non-farm income than do large farmers.
There are relatively few households, on farms or in cities, that rely on only one source of income, farming or otherwise, for their livelihood these days. That question can't be answered from available survey data. First, we must recognize that small farms must be different from large farms if they are to provide for the needs of the family. They must generate more dollar sales and more net income per acre of land and per dollar of invested. Small farms, by any common sense definition, have less land and less capital, so they have to earn more per acre of land and dollar invested to have a comparable return.