AN ACRE A MEAL? - MEAT: A Benign Extravagance - page 28

And again:
The amount of meat, milk or eggs produced from a unit of land is a function of
crop yield as well as conversion rate by the animal. A crop such as alfalfa (lucerne),
for example, yields much more tonnage than any food crop that might replace it …
As shown by the table below, in California, more human food energy and protein (of
higher quality) is obtained per hectare from growing alfalfa and feeding it to dairy
cows than by growing wheat. The alfalfa requires more water but less nitrogen fertil-
izer. 27
Although they certainly have a point, I am a bit sceptical about the CAST scientists'
examples, because the yields they give for wheat are so low. Their yield for maize on ir-
rigated land in Nebraska is 7.41 tonnes per hectare, while the yield given for wheat on the
same land is 3.49 tonnes. But an average yield for wheat in the UK is 8.25 tons or 7.5 tons
milled, which is comparable with the Nebraskan maize. Either the Nebraskans aren't very
good wheat farmers or else Nebraska isn't a particularly good place for growing high yield
wheat, but is part of the corn belt - in which case perhaps the Nebraskans should jolly well
learn to eat corn, like Mexicans do. There is a sense in which CAST's ostensibly scientif-
ic analysis reflects a mission to persuade all the world to eat wheat, in the same way that
the world is being induced to eat burgers and wear trainers and baseball caps. On the other
hand, I was brought up on wheat, and if I moved to Omaha, Nebraska, I'd no doubt contin-
ue to eat it; so maybe that's not a very good line of argument.
The case for lucerne is also suspect, because its abundant yield depends upon large
amounts of water, which in California cannot be provided without levels of irrigation which
many environmentalists predict are unsustainable. According to Marc Reisner, in 1986
California used as much water for cow pasture as all 27 million people in the state used,
including for their swimming pools and lawns. 28 And here again, the CAST scientists are
comparing these rather artificial lucerne harvests to wheat yields of only four tonnes per
hectare.
In Britain, where rainfall is abundant and wheat yields are twice as high, lucerne or
clover yields can reach 14 tonnes of dry matter per hectare without irrigation. Lucerne has
a 20 per cent protein content, nearly twice as high as wheat, so a hectare of high yielding
lucerne would produce about 2.8 tonnes of protein, over three times as much as a hectare of
high yielding wheat or barley, while red clover is only slightly less productive. 29 Since both
lucerne and red clover are legumes which add nitrogen to the soil, their use in a well man-
aged dairy farm can produce nearly as much protein for human consumption per hectare
as a hectare of grain, economizes on fossil fuel derived fertilizers, and being a perennial
probably secures more carbon in the soil.