GENERAL PRINCIPLES. 13 



{Poa pratensis) is pre-eminently adapted to such a use, 

 as it will soon stibdue the growth of extraneous and com- 

 paratively useless products that once spring up as it were 

 spontaneously on such lands. Other grasses may be 

 sown in certain areas of the unbroken prairie for the 

 purpose of crowding out and supplanting the original 

 grasses which grew upon them. Such is Russian brome 

 (Bromus inermis), but this grass will not crowd out 

 and supplant all kinds of prairie grass or even the same 

 kind in all places. 



It is proper to follow grasses with such crops as 

 luxuriate in soils plentifully supplied with humus. 

 Such are corn, potatoes, flax and rape. Where the sod 

 is old, that is where grass has grown for several succes- 

 sive years, and is then broken up, it may be advanta- 

 geous to grow on it some such crop as peas or vetches 

 to aid in subduing the sod, that is, in hastening its de- 

 cay. Oats are also capable of growing in good form 

 after nearly all kinds of grass, as they are a strong feed- 

 ing plant. It is common and usually preferable to de- 

 fer the sowing of the other small grains, as wheat and 

 barley, until the following year. 



Preparing the Soil. — -When preparing the soil for 

 any kind of grass the aim should be to secure a moist, 

 firm and finely pulverized seed bed. These requisites 

 would seem to be more important relatively than depth 

 of tillage, since many kinds of grass when once started, 

 have much power to send their roots and rootlets down 

 into the soil below the line to which cultivation is ordi- 

 narily carried. 



Moisture in the soil is of course necessary to secure 



