Acres Needed to Support a Family

Looking to the future, and a time when we will have to support ourselves, again, largely by agriculture-without-oil, I thought I’d look into this subject. Let me start with some U.S. Department of Agriculture data (link, see tables at the bottom of that page). These show historical farm acreage under cultivation. From these I’ve calculated “big picture” averages, thus how many acres supported a person in the past, do so now, and that number, multiplied by 4, provides some idea of what a family needs for support. Here is the tabulation:

Farm acreage per person and family of four
	Farm	U.S.	Acres	Acres
	Land	Population	per	per
Year	(000 acres)	(million)	person	4 People
1850	293,561	23.2	12.7	50.6
1860	407,213	31.4	13.0	51.8
1870	407,735	39.8	10.2	41.0
1880	536,082	50.2	10.7	42.7
1890	623,219	62.9	9.9	39.6
1900	838,592	75.2	11.1	44.6
1910	878,798	92.2	9.5	38.1
1920	955,884	106.0	9.0	36.1
1930	986,771	122.8	8.0	32.1
1940	1,060,852	132.2	8.0	32.1
2010	918,840	308.7	3.0	11.9

An interesting table. Notice that, with a population nearly three times greater than we had in 1920, we used fewer acres of farmland in 2010. Note that the number of acres needed to support a person declines as time passes, from a max of 13 in 1860 to a mere 3 acres in 2010. Similarly the acreage to support a family has shrunk by more than a factor of four between 1850 and 2010. What explains this? Fossil fuels—for doing the mechanical work, for increasing fertility, for controlling pests, for freezing, processing, and transportation.

In turn, the disappearance of such fuels means that, out in time, the need for acreage will either greatly increase or the population will have to shrink. Supposing that we needed 10.2 acres per person in 2010 (as we did in 1870). In that case we would’ve needed 3.1 billion acres under cultivation to support the population—nearly three times the maximum acreage (1.1 billion) we’ve ever cultivated in the United States (in 1940). Pondering that requirement will produce some interesting future scenarios. For starters, our current farm acreage includes some significant portion which requires fossil fuels to pump water to make it useful; such acreage will first fall away. How much naturally arable, rain-watered land do we have? I don’t know, but I’ll post something on that in the future.

Now for another kind of take on the subject, this time working from the bottom up, asking ourselves how many calories we need and what amount of acreage we might need to produce it. Here I’ve found a splendid article written by Nathan Lewis and published on a site called 24hgold.com (link). The article is long but well worth reading carefully if your thoughts are on the longer-term future. Lewis concludes that a family will need minimally 17 acres to sustain itself, operating organically, including having a horse. Now that just feeds the family. The farm does not, as yet, sell much of its product to others—just enough to buy the extras needed for survival. Interestingly, if the family had an 1850-level 50 acres, it would also be able to provide for two other families living in town and, say, sew clothes or shoe horses.

Difficulties loom ahead here, but this transition we will have to accomplish—and do it right. It will take all of our ingenuity, hard work, and dedication to get there—compared with which the making of a new hot version of a smart-phone will seem like the mere buzzing of a fly.