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Re: water for food

Hi folks,

Well, I got curious, because I remember being AMAZED at the amount of water
it took to grow corn (no pun intended 8->), but I couldn't remember just
how much that was.

So.....I got out my Wheat Health Management book (R. Cook and R. Veseth,
1991) and they say that wheat will produce 130 kg/ha grain yield on one
hectare-centimeter of water.  If I did my calculations correctly, that
comes to 769 L water/kg of wheat.  Pretty close to the 900 L listed below -
and this 769 L was production with water as the only limiting factor, in
other words, the most efficient use of water possible, and usually never
attained in reality.

I bet the list is accurate, and what's more, it appears that the data do
not contain the water involved in transportation/machinery/processing, etc.
which would add even more water use.

Finally, my understanding is that the New Scientist is a well-regarded
European Journal - on par with Science or Scientific American.


At 09:59 AM 7/23/97 -0500, you wrote:
>Friends and Colleagues,
>         I agree, the whole table looks suspicious. Perhaps, I should have
>added a qualifier: "The data cited in this post have not been independently
>verified (by me-maybe others have). 
>How about it SANnetters-does anyone have data to support or challenge the
>"New Scientist" data?
>At 10:04 AM 7/23/97 -0400, you wrote:
>>C'mon, get serious.  500 liters of water for a kilo of potatoes?
>>100,000 liters for a kilo of beef?  Strains credulity, well past my
>>breaking point.
>>Whoever is responsible for this chart owes all of us a closer look at
>>how these figures were derived.
>>Looks cooked up to me, in a plot to pile on animal agriculture in
>>general, and beef producers in particular.
>>Beef takes a bum rap.  Under grazing systems, cattle utilize forages
>>unsuitable for human consumption, reducing tillage, benefitting water
>>quality and erosion control.
>>I challenge anyone to justify these remarkable estimates.  Until someone
>>does, all of us should consider them BS.
>>On 07/21/97 at 15:01:18 Douglas B. Johnson said:
>>>Friends and Colleagues,
>>>	I thought this might interest you.
>>>>To: infoterra@cedar.univie.ac.at
>>>>Date: Mon, 21 Jul 1997 13:57:39 GMT
>>>>Subject: INFOTERRA: Water for food
>>>>Priority: normal
>>>>Sender: owner-infoterra@cedar.univie.ac.at
>>>>I thought this data might provide food for thought:
>>>>Litres of water required to produce 1kg of food:
>>>>Potatoes       500
>>>>Wheat          900
>>>>Alfalfa           900
>>>>Sorghum     1110
>>>>Maize          1400
>>>>Rice            1910
>>>>Soya beans 2000
>>>>Chicken      3500
>>>>Beef       100,000
>>>>Source: New Scientist 1.2.97
>>>>message sent by infoterra@cedar.univie.ac.at
>>>>to signoff from the list, send an email to
>>>>the message body should read
>>>>unsubscribe infoterra your@email.address
>Best Wishes,
>Douglas B. Johnson, Ph.D.
>Outreach Specialist, Quality of Life Project
>CSARE (Consortium for Sustainable Agriculture Research and Education
>c/o CIAS (Center for Integrated Agricultural Systems
>University of Wisconsin-Madison
>1450 Linden Drive, Room 146
>Madison, WI 53706
>(608) 262-9997