186 DRY FARMING 



emphasizes the value of intertilled crops such as corn 

 and potatoes, and such leguminous crops as peas. The 

 effect of perennial legume and grass crops was studied 

 only in the year 1917 when the yield of every crop was 

 greater after these than after any annual crop or on 

 fallow. In this test the alfalfa land yielded slightly more 

 than the grass land. 



The following yields are reported from trials made 

 with wheat at the Brandon Experimental Farm in 

 1915 :— After alfalfa 61 bus. 10 lbs. ; after red clover 58 

 bus. 30 lbs.; after alsike clover 57 bus. 40 lbs.; after 

 western rye grass 49 bus. 40 lbs. ; after red top 47 bus. 

 20 lbs.; after timothy 43 bus. 60 lbs.; after Kentucky 

 blue 38 bus. ; after brome grass 29 bus. 20 lbs. 



146. Advantages of Suitable Crop Rotations. — (1) A 



rotation including different crops reduces the risk of a 

 complete failure. In this climate where drought, frost 

 or hail occasionally causes a partial or complete loss of 

 the grain crop a greater diversification of crops is less 

 likely to result in serious loss than where only one class 

 of crops is grown. This is particularly true where 

 forage crops are used and where live stock is kept. 



(2) A good rotation aids in fighting weeds. When 

 grain crops only are grown, certain weeds, such as wild 

 oats and mustard, that ripen earlier than the grain, 

 spread rapidly. When hay crops only are grown certain 

 perennial weeds, such as thistles and daisies, have op- 

 portunity to spread. If grass and cereals are alternated, 

 and particularly if a fallow or an intertilled crop is 

 added, all of these weeds can be more easily controlled. 

 The use of perennial grasses for hay has in many parts 

 proven a very efficient means of controlling wild oats. 



