How Many People Can Be Fed on an Acre of Land Used to Grow Beef Cattle
With the holiday flavour behind united states many are feeling the effects of eating a bit too much and are working on a New year's resolution to shed some pounds. This reminds me of a question I take been asked numerous times, i.east., "How much state does it accept to feed somebody for a yr?" To rid you lot of any suspense, I normally give the respond equally about ane acre when referring to the U.S. today.
For those who desire to sympathize why, what follows is an explanation.
Start with the Nutrition
A precise answer is impossible considering and then many variable factors are at play, including the productivity of the agricultural land. Only really, the commencement step in answering this is to know the nutrition being considered (including any big holiday turkeys consumed).
The current U.S. diet is shown nicely in the graph below from Visual Economics.
To summarize, the average American consumes about 2000 lbs of nutrient per year, which works out to nearly 5.5 lbs and 2700 calories per day–or almost your unabridged trunk weight in nutrient per month. Carve up those daily 2700 calories by 5.5 lbs and you get 490 calories per pound of food, on average.
There are differences in the quality of various parts of the diet that are important to appreciate, including caloric density. Fruits and vegetables are abundant in the diet by weight and requite the states the flavors, fiber, vitamins and minerals nosotros crave, merely merely typically provide 50-150 calories per pound. By contrast, a single slice of my favorite staff of life (pictured below) has 110 calories and simply weighs a tenth of a pound. Oils and fats are about three to four times more dense, calorie-wise, than bread. Meat tends to accept slightly fewer calories per pound than loftier starch foods. For example, boneless lamb chops without the edge fat are effectually 976 calories per pound, co-ordinate to the USDA'due south Food-A-Pedia, which I could peruse for hours. Low-fat milk, which is more often than not h2o, still has most 200 calories per pound (almost a pint).
Converting to Expanse
If we take the average U.S. diet as our starting point, we can convert each component of this nutrition into the area needed to produce it by using average U.Due south. harvest yields. For case, the USDA reported recently that the average corn harvest was 147 bushels per acre, or almost 8250 lbs. It takes a truthful professional to sort out how much of this corn gets into the man food supply, since corn is normally eaten in highly processed and modified forms. The vast majority of corn is roughly dissever between ethanol factories and animal feed, with perhaps 10% or less used for food directly (due east.g., polenta) and via nutrient processing (e.g., gummy bears).
This sort of complexity is why I must rely on others to brand the diet to surface area conversion. The nigh recent studies I am aware of were done for the state of New York past a team of Cornell scientists led by Christian Peters. Hither's a link to one of the published papers, but a more than accessible review is likewise available and highly recommend for those who hunger for more information.
Below I have posted a key summary graphic from the paper. Along the Y-axis is land area in hectares needed to feed ane person for a twelvemonth, which is dependent upon the model diets shown along the X-axis. Each model diet is labeled by two dietary factors: meat and fat.
Adding Meat Feeds More than People
The finding that gained headlines from this written report some years agone had to do with the fact that adding some meat and dairy to the nutrition, while increasing country area, really fed more people. This is because much land is not suited to annual crops but can exist sown in pasture (well-nigh of the "perennial crops" shown in the bar graph are pasture). Cutting the average meat consumption roughly in one-half, which would de-emphasize hogs and poultry in the diet as these rely on grains, actually feeds more than people than a vegetarian diet.
And the Answer Is…
Since the area of production needed is most sensitive to meat and fat consumption, nosotros can see which of the model diets in the Cornell study is closest to the typical American diet to estimate the per capita area given current habits. To gauge the boilerplate, wait at the middle of the chart above the 190 grams of meat per solar day and you'll see that this converts to about 0.45 hectares, which is just a bit over one acre.
It is fair to ask if New York is representative of the U.Southward. in terms of agricultural potential. I actually think it is pretty "average" having a mix of both good and poor soils, mountains and plains and a climate that is neither the nearly benign nor most farthermost. Certainly California and Iowa are not boilerplate then we shouldn't exist extrapolating from those best cases.
It would be nice, and possibly disquisitional, to have this sort of enquiry done more than extensively. To that end, the Cornell group has a grant to develop a Local Foodshed Mapping Tool. It is beingness created for New York simply the methods should be applicable anywhere.
Connecting Issues
Those who are savvy nearly how nutrient is produced will have many follow-upwardly questions to this direction of idea. For case, crop yields are no longer a uncomplicated function of Nature's endowment of soil, the blessings of good weather, and irrepressible seed germination. Near all farmers rely on a steady stream of exterior inputs in forms such as ammonia-nitrate and super phosphate. These derive from concentrated below ground sources of energy and raw materials deposited over geologic time. As I've explored before on this blog, food supply is over-correlated for my comfort zone with oil supply. Over the past few years I've also written most techniques for de-linking nutrient production from massive external inputs. Simply that is a long word that has no like shooting fish in a barrel reply either.
I'll only add that addressing the exterior inputs conundrum makes ane consider the part that well-managed grazing systems have in an agriculture that tin can sequester carbon, make clean h2o, and build soil fertility more endemically. And for those who claim nosotros don't accept the land area to practise this, have a expect at the acres of corn sown each yr (virtually 100 million acres) and how much of that is used for directly human consumption (well-nigh 10 million acres) in the U.South. Looking at the numbers clearly shows we take a problem of too much artificially created demand. Why not put pasture on ninety million acres of cropland and allow the ruminants eat their evolved diet?
Nigh people are not looking forrad to a 10 minute lecture when they inquire me a supposedly elementary question. So while there are many variables and lots of imprecision when answering "How much country is needed to feed a person," for today'southward American nutrition, with today'due south agricultural system, I'll stick with most one acre .
Source: https://www.farmlandlp.com/2012/01/one-acre-feeds-a-person/
0 Response to "How Many People Can Be Fed on an Acre of Land Used to Grow Beef Cattle"
Post a Comment