YIELD 417 



8 or 10 bushels were considered normal. There was no rotation of crops, 

 and little or no manure was applied to the soil, which was worn out and 

 poorly cultivated. 



When the soil became exhausted the land was fallowed and allowed 

 to lie idle for a whole year, during which period it was ploughed several 

 times. After this treatment returns of 8 to 10 times the amount of seed 

 sown (i.e. 16-20 bushels) were not infrequently obtained. The ground 

 was thereafter cropped annually, the yields diminishing until no more 

 than a three- or four-fold return was secured, when the fallowing process 

 was again repeated. 



With the introduction of stock-raising in the early part of the seven- 

 teenth century a greater amount of manure became available, and the 

 land was better cultivated, average yields rising to 12 or 14 bushels per 

 acre. 



Improvement continued slowly during the seventeenth century, and 

 at its close average yields of 1 8 to 20 bushels were estimated by contem- 

 porary writers. 



In the eighteenth century further progress was made, and the average 

 of 23 or 24 bushels per acre is given for the wheat crop by the authors of 

 the county agricultural surveys carried out for the whole of Great Britain 

 during the last few years of the eighteenth and the first ten years of the 

 nineteenth centuries. 



In the middle of the nineteenth century Pusey, Caird, and others 

 estimated the yield at 26 or 27 bushels ; at the end it had risen to 30 

 bushels. 



The average yield per acre during the first twenty years of the twentieth 

 century has been 31 bushels per acre. 



It can be safely assumed that the increase in the yield from an average 

 of 8 bushels in the fourteenth century to one of 27 bushels in the middle 

 of the nineteenth century was a real improvement in the average yield per 

 acre, due chiefly to an extended application of manures and more efficient 

 cultivation of the soil. 



Regarding the more recent advance of 3 or 4 bushels in the yield per 

 acre during the last sixty or seventy years, there is less certainty in respect 

 of its real character and cause. It is probable that the increase is not due 

 to improvement in cultivation or general management, but to the fact 

 that land which gave poor return has been utilised for other purposes, 

 only that specially suited to wheat being retained for this crop. Under 

 such circumstances the average yield per acre would rise even if the 

 manuring, cultivation, and seasons remained unchanged or were worse 

 than before. 



Real progress is only made when the increase in the yield per acre is 

 obtained from the same area, and it is doubtful if any material improve- 



2E 



