Tub Bulletin. 21 



more than plat 4 ; plat 8 at the rate of 9 bushels more than plat 5, 

 and plat 10 at the rate of 12.6 bushels more than plat 9. The average 

 of these four is 10.3 bushels as given in the table. The average 

 gain for phosphoric acid, potash and lime is obtained in the same 

 manner. 



A glance at these averages shows that phosphoric acid gave over 

 twice the increase in grain that any other element did, but that the 

 increase in stover was less than that produced by nitrogen. The 

 average of the four cases where potash forms the only difference in 

 treatment shows a decrease of nearly 1 bushel of corn per acre and a 

 small gain in stover due to this element. 



While it is not safe to draw definite conclusions from one season's 

 work, the marked benefit of phosphoric acid and nitrogen compared 

 to potash certainly justifies the assumption that the phosphoric acid 

 and nitrogen supply must be increased in order to produce large crops 

 permanently. Such an assumption is in accord with the chemical 

 analysis of this soil which shows it to be abnormally high in potash. 

 The surface 6f inches contains enough of this material for nearly 

 375 one hundred bushel corn crops, while it is deficient in both phos- 

 phoric acid and nitrogen. Twenty-five such crops would require an 

 amount of phosphoric acid equal to the total existing in the top 6| 

 inches, while half this number would use up all the nitrogen. 



RESULTS ON THE HENDERSONVILLE FIELD;, POIlTER''s SANDY LOAM. 



The Hendersonville field is located on typical Porter's sandy loam 

 and is exceptionally uniform throughout. It is adjacent to the public 

 road loading northeast from the town and is not over a twenty- 

 minutes walk from the station. There are eleven plats in this field, 

 the nine fertilized ones receiving the same treatment as the corre- 

 sponding ones on the Blantyre field. This field, too, was established 

 in the spring of 1910, and corn grown the first year. The same three- 

 year rotation of corn, wheat and red clover will be followed on this 

 farm. 



