It is indeed becoming curiouser and curiouser (to quote Alice in Wonderland) that this discussion should focus so one-sidedly on our lowly alfalfa crop. Even the National Geographic article implies that the quantity of 'water' exported with alfalfa (billions of gallons) is miniscule in relationship to the amount of virtual 'water' exported for years in other crops (trillions of gallons) ---remember, a trillion is a thousand billion. I haven't done a complete calculation, but it is likely that alfalfa is less than 1% of the total exported 'water' (if you will) from the US from agriculture.
Yet the focus is on alfalfa. Why not cut off the exports of cotton (by the way, our cotton goes to Indonesia and Bangladesh before it comes back as a t-shirt), wheat, soybeans or corn Strawberries, rice, citrus, fruits, almonds, apples, canned tomatoes, blueberries or walnuts? Wines or cheese? Beef, chicken, hog, or dairy products? Fresh lettuce, spinach, onions, broccoli and cauliflower 'exported' to frozen New York or Tokyo from the Imperial Valley Desert wheat from Imperial grown for pasta made in Italy. The list goes on and on. All of these are exported from irrigated or rain-fed farming regions to the benefit of farmers and consumers in cities, foreign or domestic (and, I should add, to the benefit of the US economy as a whole). These crops account for vastly greater amounts of virtual water than alfalfa hay.
This would tend to support the view that the focus on alfalfa is primarily due to a gut feeling ("utter disbelief") or lack of appreciation of hay, rather than a careful analysis of the quantities of water, nor the economic impacts involved.
Farmers and extension agronomists are working hard to figure out how to produce crops during this year's severe drought in California, which in the case of alfalfa includes deficit irrigation strategies as suggested in the NatGeo article.
