SOILS 93 



there are fields that have never grown any crop but 

 cotton; others, nothing but wheat. This is bad for 

 the land, and the thoughtful farmer does not prac- 

 tice it. 



Good Reasons for Rotation. By rotating and 

 having several different crops, the laborers and 

 teams are kept busy. The farmer has some crops 



Courtfcby of Agricultural Experiment Station, Wisconsin 



Fio. 53. Clover sod with potash and phosphorus fertilizer yielded 26 

 bushels of corn per acre, shown at the left, as compared with 13.5 

 bushels where potash and phosphorus were used without clover, 

 shown in the center, and S8.5 bushels where peat, potash, and phos- 

 phorus were used, shown on the right. This shows the importance 

 of adding nitrogen and organic matter to sandy soils. 



to sell and some to feed. He also escapes a total 

 crop failure, and he keeps his soil in better condi- 

 tion. By growing the same crops on the same fields 

 year after year, certain weeds get the upper hand. 

 By changing crops, these weeds are checked, be- 

 cause the crops are worked at different times and 

 in different ways. Then, too, there are some plant 



