12 GRASSES AND HOW TO GROW THEM. 



urably so. When these are weedy when first laid down, 

 the tendency is that they shall become more so as they 

 become older, much depending of course upon the kind 

 or kinds of the weeds that infest them, and when weeds 

 increase in them they cannot be got rid of without great 

 labor. The tendency with biennial and perennial weeds 

 is to increase, especially the latter. But there are some 

 kinds of weeds more commonly of the annual class, and 

 which are eaten by live stock, that decrease in pastures. 

 Such are wild oats. And some kinds of grasses crowd 

 out not a few of the forms of weed life. Such are 

 Kentucky blue grass (Poa pratensis) and Russian brome 

 (Bromus inermis). Because of this power, there may 

 be instances in which these grasses can be sown on 

 weedy ground. 



When grasses thus follow cultivated crops, if sown 

 on ground that has been prepared to receive the seed 

 by stirring the surface and pulverizing without having 

 ploughed it, the further advantage follows: viz., that 

 the land will be firm and consequently would lose less 

 by surface evaporation than if it had been prepared in 

 the ordinary way. This, in dry areas, is a matter of 

 much importance. When such lands are not ploughed 

 after the removal of the crop, the further advantage fol- 

 lows, that the weed seeds in the lower sections of the 

 cultivated soil are brought to the surface. In many in- 

 stances these will perish before the grass crop will be 

 broken up again. 



Some grasses may follow immediately on the removal 

 of forests, as soon as the brush and valueless parts 

 of the trees have been burned. Kentucky blue grass 



