Agricultural Productivity in relation to Population 
kilograms of feed, equivalent to about 4 kilograms of cereals, if 
we take into account the agricultural value of protein and other 
supplements included in the feed. On these figures, therefore, 
we could provide 45 kilograms of meat from the cereals grown 
on 580 square metres. 
To produce 45 kilograms in the form of mutton and beef 
would require 20,000 square metres (5 acres) on the “rough 
grazings”’ of this country. This land is about as productive as 
if we did not farm it at all, but merely trapped the rabbits, deer 
and other wild animals it carried. Farmers improve pasture 
land by fertilizing, weed destruction, reseeding and controlled 
grazing. ‘There are many good farmers in Britain who 
would produce this amount of meat on 2,000 square metres 
(0:5 acre). The Grassland Research Station has a number of 
examples of carefully managed grasslands in this country where 
the figure has been reduced to 1,000 square metres, that is, 
1 ton of meat liveweight, or a little over halfa ton of meat dead- 
weight per hectare per year. With good management it is 
believed that a ton of meat, live weight, should be obtainable 
from the consumption of 7 tons of grass (dry weight measure). 
The best fertilized grasslands at the Hannah Institute in 
Scotland (likewise grass in New Zealand) have yielded 15 tons 
dry weight per hectare per year, which should be capable of 
giving double the above meat yield. At this rate we could obtain 
45 kilograms of mutton and beef from only 400 square metres. 
Americans now consume milk at the rate of 285 kilograms 
per person per year, including the milk equivalent of dairy 
products; but their doctors have been telling them that they 
consume too much, particularly in middle age, when they 
heighten the risk of coronary trouble; we may take 250 kilo- 
grams per person per year as an objective. The average British 
or North American cow yields 3 tons and, fed entirely on grass, 
hay and silage, needs 5-5 tons dry weight per year. To allow 
for the cost of breeding replacement stock, and with a small 
credit for the meat from old cattle, we may raise this figure to 
7°5 tons, or the produce of 5,000 square metres under the best 
conditions. One person’s milk requirements (at 250 kilograms 
33 
