SOIL IMPROVEMENT 85 



The old sandy fields were almost destitute of humus, 

 but the cowpea and the crimson clover have restored it, 

 and hence there has been success attending the efforts of 

 the farmers. 



Through growing legumes and feeding them to stock 

 and returning the manure to the ground, we can profitably 

 restore the new soil conditions. 



The cowpea will grow on the poorest of soils and over 

 all the south is the most valuable of legumes, and in the 

 north it can be profitably used to get the moisture-retain- 

 ing humus in the soil and thus help in the restoration of 

 the conditions that formerly existed when clover did 

 flourish and where it now fails. 



After a crop of rye or oats is taken off in the early 

 summer there is plenty of time to disk or plow the field 

 and sow soy beans for a late summer crop. It can be 

 used as pasturage or for hay. 



Plants in their growth make use of thirteen chemical 

 elements, nine of which they secure directly from the soil. 

 These are called the mineral plant foods ; they are phos- 

 phorus, potassium, calcium, magnesium, sodium, iron, 

 silicon, chlorin and sulphur. 



