In message , The Natural Philosopher
writes
dennis@home wrote:
"Tim Lamb" wrote in message
. ..

Now for the arithmetic.... Most arable crops need to be grown as
part of a rotation to reduce the build up of pests and diseases. Let
us say you grow it one year in four. That is 1.8tons x 0.4 /4 = 0.18
tons of oil/ha.
A bit too simple.. you can grow other oil plants in the rotation,
like rape.

No dennis, you cant. Not to go up on yield significantly anyway.

Like solar panels plants need light.

And like solar panels that means they do best in summer.

At our latitudes the best you will ever manage is about 3 crops in two
years which is not enough to make any significant difference

And to do even that needs a lot of rain and added fertiliser. Which
uses oil to make and diesel to spread.

I think Dennis probably meant you could grow other oil seeds to shorten
the rotation.

In practice, oil seeds are grown to provide a break in cereal cropping
and not because they are hugely profitable themselves. I have never
heard of anyone attempting continuous rape or even a sunflower
succession.

Nobody has yet mentioned Lupins. The Russians developed a white flowered
variety which is an annual but I don't know of anyone growing it here.

While wheat is so valuable, nobody is going to **** about with niche
crops:-)

regards


--
Tim Lamb