330 FIELD CROP8 



crop, though the pasture is of short duration, because the 

 grass does not stand grazing well. Like other grasses with 

 strong stolons, it produces larger yields of pasture or hay if 

 the sod is broken every two or three years. The growth of 

 the plant is confined almost entirely to the South Atlantic 

 and Gulf states, though it is also found to some extent in 

 California. It is not a troublesome weed where the ground 

 ordinarily freezes to a depth of 6 inches or more. 



417. Eradication. To eradicate Johnson grass, it is 

 necessary to prevent it from producing seed and to guard 

 against the introduction of seed to the field by hay, manure, 

 or any other carrier. The easiest method of eradicating it is 

 to pasture the field for a year or two, when the roots will all 

 be close to the surface. Then if the sod is broken late in the 

 fall very shallow, not more than 3 or 4 inches, so that these 

 roots are just turned over, many of them will be killed by 

 frost. In the spring, the land should be worked frequently 

 enough with the disk harrow to prevent all top growth. 

 About the first of June, it should be planted to cotton or 

 some other crop which can be given thorough cultivation, 

 to prevent top growth from the few Johnson grass roots which 

 remain, or some rank-growing crop like cowpeas may be 

 sown to smother out the grass. Another method which is 

 recommended is to plow the land thoroughly in the spring 

 and cultivate it at intervals during the spring and summer, 

 thus smothering the roots by preventing them from produ- 

 cing top growth. By this method, the use of the land is lost 

 for a year. Thorough cultivation and a good rotation will 

 most effectively keep Johnson grass in check, as they will 

 any other weed, and it is an open question whether the 

 Southern farmer will not yet find that Johnson grass is a 

 very useful plant and one which he has little reason to fear 



