SYSTEMS OF CROPPING 277 



arranged when the work is begun. After a systematic 

 rotation is established, it simplifies the farming. Figs. 142 

 and 143 show how the re-arrangement of fields and the 

 establishment of a rotation have simplified a farm lay-out. 

 Formerly there were more fields, and each year the crop- 

 ping scheme had to be worked out. 



246. Profits from Rotation. Crops differ in necessity 

 for rotation. At Rothamsted, England, 1 where experi- 

 ments have been conducted for fifty years, it has been 

 found possible to grow good crops of roots, turnips, mangels, 

 etc., without rotation, if the land is properly fertilized. 

 Wheat and barley were improved by rotation. Legumi- 

 nous crops failed entirely if grown continuously on the 

 same land. 



Wheat was grown in a four-year rotation for forty- 

 eight years, giving twelve crops of wheat and thirty-six 

 crops of other kinds. The average yields of wheat for the 

 twelve years compared with the yields for the same years 

 on land continuously in wheat, were as follows: 



Continuous wheat, average yield, 12 crops, 12.4 bushels per acre. 

 Wheat, in 4-year rotation, average yield, 12 crops, 28.6 bushels 

 per acre. 



A similar experiment with barley gave the following 



results: 



Continuous barley, average of 12 crops, 1,735 pounds per acre. 

 Barley in rotation, average of 12 crops, 2,960 pounds per acre. 



247. Crop-Rotation and Crop-Failure. Sometimes the 

 grass seeding may fail, or frosts or rains may spoil a crop. 

 These emergencies can be met without interfering with 

 the rotation. If a grass seeding in grain fails, it may be 



* The Book of the Rothamted Experiments, by A, D. Hall. 



