MAINTAINING FERTILITY 41 



receive a dressing of manure once a year. In addi- 

 tion to this, the summer crops especially should be 

 well supplied with phosphoric acid and potash. 



At the New Jersey Station, nine acres were 

 devoted to the growing of soiling crops, during a 

 period of nine years, crops succeeding each other 

 immediately, and the soil, instead of becoming 

 less fertile, increased in productiveness, notwith- 

 standing the continuous drain on the land and actual 

 removal of large quantities of fertility constituents. 

 This was undoubtedly due to extra cultivation, to 

 manure applied once each year, to commercial 

 fertilizers applied with the other crops, and to the 

 further fact that the land was covered with some 

 crop in winter. This practice of cover -cropping 

 not only provided abundance of food, but prevented 

 losses of constituents, as the land was not left bare 

 in fall and winter. 



PREPARATION OF LAND 



In the growing of soiling crops under intensive 

 systems, it is better, as a rule, to plow but once a 

 year, preferably in spring. In the preparation of 

 land for the other crops, it is advisable to use a 

 cutaway harrow, thoroughly pulverizing the soil 

 at a depth of three to four inches. The advantages 

 of this method are that the cultivation conserves 

 moisture should the weather be dry; while the 



