46 GRASSES AND HOW TO GROW THEM. 



renovated by breaking them up occasionally with the 

 plough and then in due time following with the harrow. 

 Included in the number are quack grass (Agropyrum re- 

 pens), Russian brome (Bromus inermis), Johnson grass 

 (Sorghum halapense) and Bermuda grass (Cynodon 

 dactylon). It will be observed that these all have the 

 power to multiply by pushing root-stalks through the 

 soil, but all grasses which have such power may not be 

 renewed thus. Because of this quality these grasses 

 are much liable to become sod bound; that is to say, so 

 thick that free growth is hindered. By breaking them 

 up occasionally, as referred to above, they start off with 

 renewed vigor. The frequency with which they should 

 be thus ploughed, the season for doing the work and the 

 method of doing it will be influenced by such conditions 

 as climate and soil. Since experience in renovating 

 pastures thus is limited ; the precise methods to be fol- 

 lowed are as yet but imperfectly understood. 



Grasses as Soil Improvers. Grasses, unlike clovers 

 and other legumes do not bring fertility to land. 

 On the other hand, they remove it in the hay, which 

 they furnish as in the case of non-leguminous cereals, 

 unless fed upon the farm which produced them and 

 the manure thus made is returned to the land. Even 

 when pastured there is a loss of fertility unless the 

 animals grazed upon the pasture remain upon them by 

 night as well as by day. But since inert fertility is 

 being gradually liberated in all soils, and since grasses 

 not only gather more or less of this in the processes 

 of growth, but actually hasten such liberation while 

 they are growing, the soil upon which they grow grad- 



