GENERAL PRINCIPLES. 11 



states is much lower. Consequently, this grass should 

 be given a much more prominent place in the states 

 and provinces first named. Because of this difference 

 in adaptation it may be eminently proper in certain in- 

 stances to give the right of way in production to cer- 

 tain grasses that are intrinsically much inferior to 

 others, could they be grown. In this fact the justifica- 

 tion is found for growing under some conditions such 

 varieties as couch grass (Agropyrum repens), Johnson 

 grass {^Sorghum halapense) and Bermuda grass {Cyno- 

 don dactylon), all of wiich are weed pests of the most 

 perplexing type, when allowed to grow under other con- 

 ditions. It is not wise to attempt to grow grasses to 

 any considerable extent in any locality for which their 

 adaptation is lower than what may be considered as nor- 

 mal for them. Nor should valuable time and labor be 

 thrown away in the attempt to grow a large variety 

 of grasses in permanent pastures where the conditions 

 only favor the growth of a few varieties. 



Place in the Rotation. — The aim should be to sow 

 grasses on clean ground. They should, therefore, as a 

 rule, be sown after a cleaning crop, that is to say, after 

 such crops as are cultivated while they are growing or 

 after a summer-fallow. These crops include corn, sor- 

 ghum, the non-saccharine sorghums, potatoes, field roots, 

 rape, tobacco and cotton. When thus sown for hay, a 

 crop is secured that is usually entirely free, or, in the 

 main, free from extraneous products which would lessen 

 the value for feeding at home and to a still greater de- 

 gree for exposing for sale on the market. When thus 

 sown for pasture, the pastures will be clean or meas- 



