MAINTAINING SOIL FKRTILITV 29 



without the return of any fertility. On most of these one crop 

 farms no fertility is put on the soil and the farm is abandoned 

 or else artificial (commercial) fertilizers are used. Most of our 

 soils in the United States were formerly fertile but the prac- 

 tice of growing crops without returning organic matter has re- 

 sulted in decreasing the yields on our older cultivated lands. 

 Under the subject "fallowing" we learned that it was poor pro- 

 cedure to allow the land to lie idle except in dry regions, and 

 the best farmers to-day are those that utilize their land con- 

 tinually and to the fullest extent. When we visit some of the 

 European countries where land has been in cultivation for cen- 

 turies,-we find that these lands are still producing valuable crops, 

 and that the yields are as large, if not larger now, than they were 

 two centuries ago. This condition exists in Europe because 

 fertility has been returned to the soil every year to sustain crops. 



Fortunately, land has been comparatively cheap in the United 

 States and when a farm failed to produce paying crops another 

 piece of land was secured, and so on. The time has arrived 

 when the acquiring of new land for one crop farming is hard to 

 obtain at a price within the bounds of such farmers. So it is 

 now necessary and more profitable for the farmer to grow other 

 crops in conjunction with his money crop. This growing of 

 other crops is called diversifying or rotating. 



Diversification and Rotation of Crops. — Diversification is the 

 growing of different crops without any regular or definite sys- 

 tem. Rotation of crops is spoken of as growing a certain num- 

 ber of crops, in regular order, on the same piece of land. For 

 example, a rotation may consist of four crops, corn, oats, wheat 

 and clover, and will be called a four year rotation because these 

 crops will be grown in order on the same piece of land and take 

 four years to complete. A farmer may have 160 acres in his 

 rotation, and each year 40 acres will be allowed for each of 

 the four crops mentioned. Each 40 acres will grow the same 

 crop every fifth year and one of the crops every year. The 

 terms six-year, five-year, four-year, three-year, two-year, etc., 

 are applied to rotations depending upon the time it takes to 

 complete them. Rotations taking 15 years to complete are known 



