M.— AGRICULTURE. 261 



It is from these countries with the low yield per acre that wheat is 

 exported and their production determines the world market, with the 

 consequence that wheat production has been increasing in these and 

 similar countries while it has been shrinking in the European countries 

 with a higher yield per acre. 



The dominating factor has been cost of labour ; speaking broadly, it 

 may be said that increased yields per acre are associated with higher 

 expenditure per bushel for labour, and the great wheat-producing countries 

 with a low yield per acre are the countries with a correspondingly high 

 yield per man employed. It may be estimated that in England a man's 

 labour produces about 960 bushels of wheat, in Australia 1,500 bushels. 

 A more exact comparison shows that in England the labour cost amounts 

 to Is. per bushel of wheat, against 8d. in Canada, this with an average 

 wage rate of 30s. to 36s. a week in England as compared with 60s. in Canada. 



All this goes to show that intensification is only to be purchased at 

 the cost of labour and that in the past extending the cultivated area 

 has been a cheaper way of getting the wheat required by the world than 

 by higher farming. 



This general statement, however, does not tell the whole story ; par- 

 ticularly it disguises the intensification of yield that may be obtained 

 without a commensurate increase of labour. For example, the intro- 

 duction of more heavily cropping varieties, originated by the skill of the 

 plant-breeder, may add greatly to the production from a given area 

 without increasing costs other than those of harvesting and marketing. 



One must not, however, expect too much of the plant-breeder. Over 

 the greater part of the cultivated land of the world the gross amount of 

 production is limited by external factors such as water supply, temperature, 

 available fertility of the soil, etc. For example, the plant-breeder seems 

 to have had little or no power to increase the absolute production of Beta 

 vulgaris ; from all the forms of sugar-beet or fodder-beet (mangolds) on 

 a given soil there is much the same yield of dry matter per acre, though in 

 the well-bred sugar-beets the proportion that is in the useful form of sugar 

 is greatly enhanced. The wheats and barleys grown in England had long 

 been subjected to selection and improvement before the scientific methods 

 of plant-breeding were evolved, and the further steps in improvement are 

 going to be neither big nor easily won, depending as they do upon altering 

 what Dr. Beaven has called the migration ratio, whereby the plant will 

 convert more of the material obtained from the air into useful grain and 

 leave less as straw. The chief opportunities, in fact, lie in the elimination 

 of susceptibility to disease or destruction by frost, or general tenderness of 

 constitution, by which means the range of the high-yielding cereals or 

 even of cereal growth at all may be enormously extended. Absolute 

 yielding power is perhaps less in question than productive capacity in 

 relation to the environment. 



The general enhancement of production by processes which induce 

 improvements of the water supply or the temjierature, as by irrigation 

 and drainage, soil amelioration, cultivations, etc., suffers from the dis- 

 advantage of calling for labour, until it may prove far more costly than 

 the increased produce can repay. Fertilisers appear to offer more promise. 

 It may be recalled that the general level of production from English land 

 was raised by nearly 50 per cent, between 1840 and 1870. At the beginning 



