328 THE SMALL GRAINS 



354. Time of spring seeding. In general, the spring 

 isotherms and spring seeding move together northward, 

 while the autumn isotherms and fall seeding move south- 

 ward. Also fall seeding becomes later and spring seeding 

 earlier from the mountains toward the sea-coast. 



Usually spring seeding of small cereals should be done 

 just as early as weather conditions permit. True enough, 

 in the extreme South, that rule would make it practically 

 fall seeding, which, however, is as it should be, for spring 

 seeding, except for some special purpose, is not justified 

 in that latitude. Frosts or even freezes just after the 

 seed is sown rarely injure it. In fact, spring cereals are 

 sometimes sown in the fall and left to lie over winter and 

 germinate in the spring a practice not to be commended, 

 however. On the other hand, late seeding renders the 

 crop liable to injury by early drought, which the earlier 

 sown crop may escape. Spring seeding begins in the 

 South about February 1, and is not completed in the 

 North until in May. In the latitude of Kansas and Ken- 

 tucky, it ranges from March 10 to March 25. From 

 Pennsylvania to Iowa, the period is from March 25 to 

 April 15. In the states still further north, the latter half 

 of April is usually best, though earlier seeding in favor- 

 able seasons may be an advantage, while seeding in May 

 will sometimes be necessary in a late spring. 



.355. The rate of seeding the same cereal crop depends 

 on the locality, condition and fertility of the soil, method 

 of seeding, and size of seed. Always more seed is required 

 in the Eastern area than in the Great Plains and Western 

 areas. Drilling requires less seed than sowing broadcast. 

 More seed is needed on poorly prepared or weedy land. 

 On rich land the plants grow larger and tiller more than 

 on poor land, hence the former requires less seed than the 



