RUSSIAN BROME GRASS. 175 



Ij until experience has thrown more light upon this ques- 

 tion, but it will probably be found that it would not 

 be advisable to take more than two crops of hay and 

 one or two of pasture, before breaking up the sod. In 

 any event, the sod should not be allowed to become so 

 filled with the roots of the grass before this is done as to 

 preclude the possibility of making a good seed bed- for 

 corn or other crops on the overturned sod without too 

 great an expenditure of labor. 



In areas where crops of grain are regularly grown, 

 and more especially in those in which a regular rota- 

 tion is attempted, brome grass may come anywhere in 

 the rotation, but as with other grasses, a stand is more 

 assured on land that is clean. But, if not smothered 

 by weeds when the plants are young, this grass has more 

 power to crowd them out later than most other grasses. 

 When once established, if not broken up for a number 

 of years, in certain of the prairie soils the roots will fill 

 these so completely that when the ground is ploughed 

 the furrow slice is a mass of roots so bound together that 

 pulverization cannot be secured without great labor. Be- 

 cause of this, in such areas, the sod should be ploughed 

 before it became so filled with the interlacing roots. 

 The number of years required to induce such a condition 

 will vary with soils and with the precipitation. Us- 

 ually the grass may be cut two seasons and pastured 

 one before the sod becomes so stiff as to become thus dif- 

 ficult of pulverization. But when it does occur, it is 

 probable that rape, or flax, or buckwheat sown on it 

 would aid in more quickly reducing the sod. 



In all arable areas deficient in rainfall, where this 



