CROPS AND SOIL IMPROVEMENT 



which become available slowly, and upon commer- 

 cial fertilizers. 



There has been a disposition on the part of 

 many farmers to regard fertilizers only as stimu- 

 lants, due to the irrational use of certain materials, 

 but a good commercial fertilizer is a carrier of 

 some or all of the necessary elements that we find 

 in stable manures. They may carry nitrogen, 

 phosphoric acid, or potash, any one or two or 

 the three, and the three are the constituents 

 that usually are lacking in available forms in our 

 soils. Examples of the best modern skill in farm- 

 ing may be found in the rational selection and use 

 of commercial fertilizers. 



Tillage. Man's ability to assist nature in the 

 work of production finds a notable illustration in 

 the matter of tillage. Its purpose is to provide 

 right physical condition of the soil for the par- 

 ticular class of plants that should be produced, 

 while destroying the competition of other plants 

 that are for the time only weeds. Most soils 

 become too compact when left unstirred. The 

 air cannot enter freely, plant-roots cannot extend 

 in every direction for food, the water from rains 

 cannot enter easily, there is escape of the moisture 

 in the ground, and weathering of the soil proceeds 



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