lOO 



ment of any agricultural territory that there will be a decline 

 from a higher to a lower state of production. There must come 

 a time when the fruit grower, dairyman or any other type of 

 farmer will have to think of ways and means to maintain the fer- 

 tility of the soil and to improve the fertility of the soil, and when 

 he reaches this point he will be confronted with certain questions 

 he must answer if he is to accomplish the purpose which is before 

 him. He must answer the question as why soils deteriorate. They 

 deteriorate because they lose a larger or smaller portion of 

 their available plant food, and therefore, cannot furnish the grow- 

 ing crop with building material as fast as the crop may need it 

 for profitable production. 



Soils may also deteriorate not because they lose too much 

 plant food for profitable production, but because the texture of the 

 soil itself has deteriorated. Instead of being open and mellow, 

 permitting conditions that would favor the circulation of air and 

 moisture, the soil has become compact and the moisture does not 

 penetrate as it should. The farmer w^ho is able to answer these 

 questions is also able to find the causes that lead to soil deteriora- 

 tion, and he is ready to seek then for remedies that will enable him 

 to counteract these tendencies. If you examine one hundred soils 

 from any territory that has been under cultivation for a generation 

 or more, and try to inquire into the deficiencies of these soils, you 

 will find most of them deficient in the element nitrogen. The next 

 largest proportion will be deficient in phosphoric acid, some will be 

 deficient in potash and there might be many deficient in lime. 



In a soil deficient in nitrogen, a cover crop could be used to 

 restore the nitrogen, hence it behooves the fruit grower to use 

 cover crops that will restore this element. If the soil has deterior- 

 ated in texture because it has lost too much of its vegetable matter, 

 he must use cover crops to restore the vegetable matter that has 

 been lost. These points are recognized well enough in the use of 

 cover crops, but there are two or three other facts that are not as 

 readily recognized. 



Why is it that a soil left to itself tends to grow more pro- 

 ductive? It has been the impression in farming districts in Europe 

 and elsewhere, that soils must rest, that soils that are allowed to 

 rest will regain a portion of their fertility. 



Indeed, there are still localities in Europe where the land is 

 allowed to grow up with weeds for a few years so as to recover 

 some of its lost fertility. 



Why is it that some of our best soils are prairie soils? The 

 vegetable matter accumulating, plants growing and dying, and 

 growing again, produce in time a deep layer of vegetable mold. 

 Why is it that some of our best soils are forest soils? These for- 

 est soils when cleared of their timber growth, are able to pro- 

 duce large and profitable crops for some years, as shown in Penn- 

 sylvania. Why is it that when we analyze any cultivated soil, we 

 find certain forms of plant food concentrated in the surface soil? 



