98 LAND FOR FOOD PRODUCTION 



crops per acre, taking the average yields of the last ten years, 

 is as follows: Barley, grain and straw, 1,716; oats, grain and 

 straw, 1,576; roots, 2,418; rotation grass, 840; permanent 

 grass, 645. The average for arable land may thus be 

 taken at 1,800 Ib. of starch equivalent per acre. The starch 

 equivalents per cwt. of barley, oats and maize (grain only) 

 are 79, 67 and 91 Ib. respectively. 60 Ib. of starch equiva- 

 lent have to be consumed to produce 14 Ib. of live weight 

 increase or 8 Ib. of meat (average of beef, mutton and pork). 

 This figure is somewhat high, being true for the increase in 

 adult animals, whereas young stock make a bigger increase 

 on the same weight of food. The arable land is assumed to 

 produce 4,000 Ib. of milk per acre, equal to 150 Ib. of butter 

 or 350 Ib. of cheese. A deduction has also to be made for the 

 food value of the separated milk and whey produced as by- 

 products in butter and cheese making, and also for the straw 

 and the offal obtained with the wheat. Only 10 per cent, of 

 the offal is allowed for because the bulk of the wheat is 

 imported as grain ; its offals now come into the country, and 

 only the offals corresponding to the flour imports would be 

 added to the cattle food of the country if the wheat was 

 grown at home. 



Thus a total of 16 million acres of arable land 

 would be required to grow the main items of the food 

 we import. Nor would this 16 millions be enough, 

 because when they have been taken from the grass land 

 in order to grow the imports we shall still have lost the 

 cattle food that they were previously producing as grass. 

 A further calculation shows that this 16 millions would 

 have to be increased to 24 million acres of arable land 

 in order both to replace the imports and maintain the 

 cattle food at present derived from the grass. 



This means that nearly the whole of the culti- 

 vated area in the United Kingdom, 47 million acres, 



