"David Hare-Scott" wrote in message
u...

"Dave Chalton" wrote in message
om...
Thought this may be worth a little discussion, especially for all of
you who are convinced that land is better put to crops for human
consumption than for animals.

I heard it postulated today, in a Crop Mechanisation lecture, that the
power consumption of a powered forage harvester giving a precision (or
metered) chop, working width maybe three metres, in
chemical-energy-required terms, would, in one years use on one farm,
consume enough energy (chemical) to feed 3000 people for a year.

If we feed people 3000 kilocalories a day, 3000 people need about
13,800,000 (3000*3000*365*4.2/1000) megajoules a year. Burning
hydrocarbon fuel we get about 46 megajoules per kilogram, so the
equivalent energy is about 300,000 kg of fuel.

Now I don't know forage harvester from a framistan but does it take 300
tons of fuel a year to run one? According to other posts here nothing
like it by several orders of magnitude.

I wonder if your lecturer has done their own sums?

Putting up wet forage is more costly than putting up dry forage but properly
ensiled wet forage is more nutritious than dry forage and it comes out a
push or slightly in favor of silage.

Local conditions have a great deal to do with how one puts up forage. In my
part of the world it is not uncommon to cut alfalfa at 10 in the moring and
bale it at ten that night in August. In parts of the UK if you tried to make
hay the world might end before it got dry enough to bale.

There are a very many factors that go into raising animal and to reduce it
to fuel equlivents takes a very knowledgably person a long time to get it
right. When he does get it right it is only good for a small area. The
factors on farms sitting side by side can be different depending on the
management level of the farmer and comfort with risk of the farmer and the
landlord. One size does not fit all in farming. One size only fits one once.
--
Gordon

Gordon Couger
Stillwater, OK
www.couger.com/gcouger