While there is no set amount of land needed for a farm, M. D. Creekmore from The Survivalist Blog states that about 8,000 square feet is needed to provide a complete vegetarian diet for one person. This number assumes 100 percent crop yield and four growing seasons per year. Since an acre is 43,560 square feet, land in these conditions could sustain about five people per acre.
Land needed for cattle varies based on soil fertility, volume of rainfall, and pasture quality. According to Living the Country Life, most areas of Missouri require three to four acres per cow-calf pair for grazing purposes. The amount of land needed also depends on whether the cattle are grazing or confined. During the winter, cows eat about 2 percent of their body weight and need about 3,600 pounds of hay when grazing is unavailable, depending on climate.
According to Walter Jeffries from Sugar Mountain Farm, pigs kept on pasture need about 2,000 square feet of space per pig. The quality of pasture also affects how many pigs can subsist on the land. Jeffries keeps 200 pigs on 10 acres, but also feeds the pigs on whey from cheese and butter-making, bread, cottage cheese and excess milk. Land requirements for pigs may be up to four times greater without these supplements.