464 FORAGE PLANTS AND THEIR CULTURE 



grown in the rotation, such as sorghum, cowpeas, sorghum 

 and cowpeas, soybeans, peanuts, etc. 



Common vetch is not well adapted to rotating with 

 cotton unless used merely as a green manure. The vetch 

 cannot be harvested soon enough to permit the early 

 planting of cotton, even when the seed is sown between 

 the rows of cotton. 



Common vetch is somewhat inclined to persist when 

 once grown, especially where the winters are mild. Ex- 

 amples are known of its reseeding itself in pastures for 

 five years. In cultivated fields it volunteers readily, 

 which is especially objectionable in the wheat crop, owing 

 to the difficulty of separating the vetch seed from the 

 wheat. There is no danger of volunteer vetch unless a 

 seed crop is grown or at least some of the seed allowed to 

 ripen. In such cases, to avoid volunteer vetch, the best 

 plan is to follow with a crop of vetch and oats for hay, 

 pasturing the stubble, so that no seed is allowed to ripen. 

 A cultivated crop should be grown the next season, and 

 then the land can be planted to wheat without any danger 

 of the vetch volunteering. 



560. Fertilizers. Information concerning the best 

 fertilizers for common vetch is very limited. Barnyard 

 manure is nearly always beneficial, and dairy farmers 

 especially find it profitable to use on vetch fields. 



In western Oregon, it is now a common practice to apply 

 gypsum, or land plaster, and special machines are often 

 used to apply it. It is commonly applied at the rate of 

 75 to 150 pounds to the acre. At the Oregon Experiment 

 Station, 100 pounds of gypsum to the acre increased the 

 yield from 7394 to 9031 pounds of hay to the acre. 



In the South, a fertilizer containing phosphoric acid and 

 potash is often used, a common rate of application being 



