64 



FIELD CROPS 



reasons, be plowed in the spring. To get the best results 

 from spring plowing, the conditions obtained by fall plow- 

 ing must be duplicated as nearly as possible. One of the 

 chief difficulties with spring plowing is that the soil does not 

 have a chance to settle; it is therefore likely to be so loose 



Fig. 17. Hills of corn eleven weeks from 

 planting. The roots have now penetrated to a 

 depth of 2% feet. Compare with Figs. 16 and 18. 



that it dries out readily, while, at the same time, the move- 

 ment of moisture from the subsoil up through the furrow 

 slice is somewhat retarded. One of the most common ways 

 of putting spring-plowed land in the desired condition is to 

 harrow and disk it several times after plowing to aid in 



