Wednesday, June 21, 2006

Working further on the hemp vs. cotton water issue (see postings on 19 & 20 June), I did find some figures for cotton's water consumption. One source gave out that one acre needed 800,000 gallons, while Maha Devi Design's website stated that 22,000 litres of water were what it took to produce 1 kilogram of cotton.
An acre of cotton produces between 2-3 bales of cotton, a bale weighing either 480 lbs. or 500 lbs. Using the higher weight for a bale, and averaging the two figures at 2.5, which seems a bit more than average after looking at cotton figures for the last day or two, we can calculate that cotton produces 1,250 lbs. per acre. This is is about 568 kilograms per acre. Dividing that into 800,000 gallons, we arrive at an approximate figure of 1,450 gallons per kilogram.
Comparing that to Maha Devi Design's figure of 22,000 litres of water, which is roughly 5,500 gallons, we can see a great divergence of opinion. By those figures, an acre of cotton needs 3,300,000 gallons of water.
I'll have to keep picking some figures to be able to put up something definitive; for now I admit that there is great variation in opinion, although all parties agree that cotton is water intensive and it is clearly obvious that this is destroying the environment in places.
Once again, I appeal to anyone with solid figures to contact me at:

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