Agriculture Reference
In-Depth Information
In Table D I have assumed that one hectare out of every three arable hectares is used for
green manure - except for the pea crop which fixes its own nitrogen from the atmosphere.
This adds an extra 2.2 million hectares to the vegan organic land-take, with the result that it
requires 14 per cent more arable land than is in use today (including set-aside). This is not a
problem, since it can be taken from the pasture, for which the vegan diet has no use. I have
used the 33 per cent green manure ratio because that is the figure given in my main source,
the
Organic Farm Management Handbook
. Clearly, other rotations, as listed in Box 2 in
Chapter 8 would give a different result.
Organic Livestock: The High Yield Paradox
In organic mixed farming systems, nitrogen is provided by manure, and by leys - tem-
porary pasture including clover or other nitrogen fixing plants which after perhaps four or
five years is ploughed up for two or three years cropping, and then put back to ley. Essen-
tially these are green manures in which part of the nutrients pass through grazing animals
before finding their way back to the cropland - though a proportion are creamed off to
provide milk, meat, leather etc.
TABLE E: ORGANIC WITH LIVESTOCK
• 8.1 million hectares arable and ley
• 7.8 million hectares of pasture
• 2.6 million spare hectares
Population 60.6 million. Agricultural land 18.50 million ha. Forestry etc 3.69 million ha.
• One hectare of arable plus one of pasture feeds 7.5 people
In Table E, three hectares of ley is assumed to fertilize two hectares of cash crops. At
this rate the 1.9 million hectares of ley for dairy pasture, plus a small amount of manure
from the beef, does not provide enough fertility for all the crops grown and so the organic
livestock model also has to rely on 1.7 million hectares of green manure. If there were pigs
