THE ROTHAMSTED EXPERIMENTS 



399 



TABLE 71. ROOT CROPS ON BARN FIELD, ROTHAMSTED 

 Yield per Acre of Roots, in Long Tons (2240 Ib.) 



does not suggest that the principal office of farm manure and rape 

 cake is to destroy toxic excreta from the roots of sugar beets. 



In Table 716 are recorded the yields of mangel roots since 1876, 

 in averages of 5-year periods for 30 years, and for single years 

 subsequently. (Swede turnips were grown in 1908, after the man- 

 gels failed, the yield of turnips varying from 1.34 to 13.01 tons.) 



