78 



The Principles of Fruit-growing 



tains potassium and phosphorus and nitrogen, and yet 

 nothing grows upon it until it begins to decay. A hundred 

 pounds of potash in a stone-hard lump is worth less to a 

 given plant than an ounce in a state of fine division. Soils 

 that the chemists may pronounce rich in plant-foods 

 may grow poor crops. In other words, a chemist cannot 

 tell what a soil will produce; he can tell only what it 

 contains. 



FIG. 12. A fruit-plantation in New Mexico, 'under tillage. 



Every good farmer knows that a hard and lumpy soil 

 will not grow good crops, no matter how much plant^food 

 it may contain. A clay soil that has been producing good 

 crops for any number of years may be so seriously injured 

 by one injudicious plowing in a wet time as to ruin it for 

 the growing of heavy crops for two or three years. The 

 injury lies in the modification of its physical structure, 

 not in the lessening of its natural fertility. A sandy soil 

 may also be seriously impaired for the growing of any crop 



