138 MASS. EXPERIMENT STATION BULLETIN 212. 



Table 6. — Relationship between Increase from Fertilizer Nitrogen, Place 



in Rotation, and Weather Conditions — Concluded. 



Corn, Yields per Acre, North Soil Test. 



I. Following Legume or Sod. 



In the year following a legume there has been no consistent response of 

 the crop to the use of fertilizer nitrogen, and this almost without regard 

 to the condition of the weather. The second year after a legume, how- 

 ever, there has been such response, — in one case in a marked degree. 

 In the two cases where corn was planted three years after the legume, 

 one showed an apparent increase rather significant in size, the other an 

 apparent decrease. 



For comparison, the results of the three com crops grown on the North 

 Soil Test are presented. All of these were grown after sod or legume. 

 On the limed section or on the undivided plot, nitrogen brought a crop 

 increase in one case out of three. On the unlimed section, in the two years 

 of record, there was a definite increase. This result may trace back to the 

 poor growth of the clover on the unlimed land. 



The Last Three Corn Crops. 



Cultural methods from 1909 on departed widely from the normal. 

 In 1908 a catch crop of crimson clover was turned under as a green manure. 

 In 1909 a partial crop of buckwheat was turned under. In 1911 there was 



