I’ve read time and time again how unsustainable it is to continue to raise cows for beef due to their water consumption. The argument is, cows consume so much more water than it takes to grow a comparable amount of crop-derived calories, that its unsustainable to rasie beef to feed the population. Some of the numbers representing water consumption by cows were so large it made me question their accuracy. Those who claim this in their articles also never list their assumptions. How they arrive at the number of gallons of water that go into producing beef. They just throw a number out there – BAM!

Most of these numbers are cited by those who would rid the world of the consumption of all animal proteins and make us eat the darling of the high protein plant world – soy. So I set out to see if these numbers were accurate and here’s what I found.

In the case of soy

A one-acre crop of soybeans takes approximately 6 months from planting to harvesting. Irrigation requirements are determined by the depth in which each watering saturates the soil. This varies by climate as well as seasonal rainfall. A publication I found published by Mississippi Agriculture and Forestry shows the average water needed must saturate the soil to ¼ inch depth every day. But daily irrigation may be wasteful due to evaporation so it’s suggested that it be done every 4 days to a depth of 1 inch as opposed to every day in an effort to avoid wasting the water and more ends up getting invested into the soil.

To water an acre of land to the requisite 1-inch depth every 4 days requires 27,154.3 gallons of water. Over the course of the 6-month growing season this yields 45.5 watering days. This is a total seasonal water consumption of 1,235,521 per acre of soybeans.

According to Perdue University, the expected bushel yield of an acre of soybeans is between 20 and 30 bushels. I used the higher yield number to give soybeans a fair playing field. A bushel of soybeans yields 60 pounds of soybeans. So right here we’re at 22.88 gallons of water per pound of soybeans.

If we take this down to a 3 ounce “serving size” since we are talking about food here, this is 3.81 gallons of water per serving of soybeans.

So beef has to be a lot thirstier than soybeans, right?

In the case of beef

According to Explore Beef Organization’s Modern Beef Production Fact Sheet a cow is raised for 22 months to reach a top weight of 1,400 pounds before being processed. Like soybeans, season and rain also offset how much water a cow drinks each day. The average daily water consumption of a cow is between 5 and 7 gallons a day year-round – I used the higher 7-gallon number to be fair. There are 669 days in the 22 months of raising a cow to processing weight. Total water consumption over the life of the cow is 4,684 gallons.

Not all of the cow is edible. A cow will yield around 64% of its “on the hoof” weight in what is considered retail beef. This puts the edible beef of a 1,400 pound cow right around 896 pounds. If we divide the total gallons of water consumed over 22-month life of that cow we arrive at 5.22 gallons of water per pound of edible beef. Wait… that can’t be right!? 

So if we reduce this to a 3 ounce serving size we have the burden of water consumed to produce that serving of beef right at 0.87 gallons! Less than a gallon of water per serving of beef!?

I must be wrong. How could it be that so many journalist quote “a pound of beef requires a whopping 1,851 gallons of water to produce” like Maria Speck of the Washington Post? It took me 20 minutes using Google to find the answers and make the calculation to discover the real figures. Doesn’t anyone care about the truth anymore? I guess the truth is expendable when you have an agenda to support.

But cows eat feeds that require water to produce

This is not completely true. When you look at modern beef production, cows will spend the initial 16 to 18 months of their life grazing pastures. The land used for grazing are generally areas that are not suited for growing crops. These areas grow grasses and do not require conventional irrigation. They are irrigated by whatever rainfall occurs. The last 4 to 6 months of a cows life is where “feeds” are introduced. These feeds have only on purpose, to add fat to the cow before processing. This is called the finishing phase. It’s only Feed Lots that feed cow’s corn and grains to finish them before processing. Cows that are finished on grass require no corn or grains and thus the beef produced is considered “grass fed” because it was not finished on corn or grains. For 10 years now I have espoused eating only beef that is finished on grass. For that reason I am not estimating the impact of what amount of water is used to grow feed crops. Instead I suggest that people choose beef finished on grass if they’re concerned about sustainability.

After publishing this blog

Someone claimed we could not produce the amount of beef we produce without cows eating corn, grains and soy. They claimed there's not enough range and pasture land to feed cows. This is simply a lie. According to the USDA's own website range and pasture lands used for grazing cattle make up the largest amount of land in the USA. Here is their quote:

"Range and pasture lands are located in all 50 states of the US.   Privately owned range and pasture lands makes up over 27% (528 million acres) of the total acreage of the contiguous 48 states, and these lands constitute the largest private lands use category, exceeding both forest land (21%) and crop land (18%)."

So its not true that we need feed crops to raise cows for beef.

So what does this mean?

A 3 ounce serving of beef provides 578 Kcals and a 3 ounce serving of soybeans 382 Kcals so just from an energy standpoint beef wins. When you factor in that it requires 4 times as much water to produce that serving of soybeans, soybeans lose hands down. And as for high quality protein, nothing compares to beef. And beef has many vitamins and minerals you won’t find in soybeans. 

So let’s endl this perpetuation of misinformation about beef production being unsustainable. In fact, I think I just uncovered why it may actually be the soybean that’s unsustainable for us to produce!

sources:

http://www.explorebeef.org/cmdocs/explorebeef/factsheet_modernbeefproduction.pdf

http://www.noble.org/ag/livestock/waterconcerns/

http://igrow.org/livestock/beef/how-much-meat-can-you-expect-from-a-fed-steer/

http://commodities.about.com/od/profilesofcommodities/a/soybean-growing.htm

http://msucares.com/pubs/publications/p2185.htm

http://mathcentral.uregina.ca/QQ/database/QQ.09.05/patti1.html

https://hort.purdue.edu/newcrop/articles/ji-beans.html

https://www.unc.edu/~rowlett/units/scales/bushels.html