PKOBLEM OF CROP PRODUCTION 371 



there is too much in the soil. Under such conditions the 

 removal of the surplus by artificial surface or under- 

 ground drainage is just as necessary as the addition of 

 of water to dry lands. Outside a few local areas and on 

 low, flat lands and alkaline soils, land drainage is not a 

 serious problem in the Prairie Provinces, 



333. Tillage. — ^^Tillage is the greatest means at man's 

 disposal for controlling the conditions that at the present 

 time are causing low yields on the farms of Western Can- 

 ada. It is also by far the largest single item on the cost 

 side of the crop account. Tillage is a universal practice, 

 but on account of the great variation in soil, temperature 

 and moisture conditions in different countries and in dif- 

 ferent parts of the same country, the various methods 

 employed art still fruitful of debate and somewhat dif- 

 ficult to determine satisfactorily. At the present time in 

 the West, tillage is one of the most important subjects 

 connected with crop growing, yet it is one upon which 

 conclusive data concerning the relative value of different 

 pi actices is not available for more than a few sections of 

 the country. In the dry year of 1914 the yields of Mar- 

 quis wheat at Saskatoon ranged from six bushels per 

 acre to thirty-two. In the wet year of 1915 they ranged 

 from seventeen to forty-seven. The range in yield in each 

 of these seasons was due entirely to the different tillage 

 practices followed. This subject is discussed at some 

 length in chapters VII to X. 



334. Crop Rotations.— The most reliable information 

 the world affords on the value of crop rotations shows 

 that land in England when cropped continuously to 

 wheat for sixty years produced an average of fourteen 

 bushels per acre, and when grown in a rotation of turnips 

 barley, clover and wheat it produced twenty-five bushels 



