17 



tion ' in 1891 and 1892 it was found that the application of fertilizers 

 furnishing nitrogen and phosphoric acid produced the best quality of 

 leaf, while fertilizers supplying nitrogen and potash gave the best 

 results in yield and total value of crop. Potassium chlorid as a source 

 of potash was more profitable than kainit or potassium sulphate, but 

 the use of the sulphate resulted in a better quality of leaf as compared 

 with the other forms of potash. 



Field experiments with tobacco were conducted by the Massachusetts 

 Experiment Station a at three different points in the Connecticut Val- 

 ley within the State during three seasons, from 1893 to 1896. The 

 different fertilizers applied had a greater effect upon the quality of 

 the crop than upon the yield. Cotton-seed meal, linseed meal, and 

 castor pomace, when used in connection with an amount of nitrate of 

 soda or nitrate of potash sufficient to furnish one-fourth of the nitrogen 

 needed by the crop, proved equally good as sources of nitrogen. 

 Nitrate of soda applied with acid phosphate or dissolved bone black 

 produced a better quality of tobacco than nitrate of potash under the 

 same conditions. Cotton-seed hull ashes, followed by high grade sul- 

 phate of potash, were observed to be the most valuable sources of 

 potash. Nitrate of potash produced excellent results when used in 

 connection with an alkaline phosphate, such as phosphoric slag meal 

 or with carbonate of potash and magnesia. Potash-magnesia sulphate 

 as the main source of potash did not give encouraging results. The 

 author classifies the fertilizer mixtures used in these experiments as 

 follows : 



First class. 



Xitrate of soda, cotton-seed hull ashes, and castor pomace. 

 Xitrate of soda, cotton-seed hull ashes, and cotton-seed meal. 

 Xitrate of potash, cotton-seed hull ashes, and cotton-seed meal. 

 Nitrate of potash, carbonate of potash-magnesia, and phosphatic slag. 



Second class. 



Nitrate of soda, high grade sulphate of potash, cotton-seed meal, and dissolved 

 bone black. 



Xitrate of soda, high grade sulphate of potash, linseed meal, and dissolved bone 

 black. 



Xitrate of soda, high grade sulphate of potash, castor pomace, and dissolved bone 

 black. 



Third class. 



Xitrate of potash, potash-magnesia sulphate, cotton-seed meal, and dissolved bone 

 black. 



Xitrate of potash, potash-magnesia sulphate, castor pomace, and dissolved bone 

 black. 



1 North Carolina Station Bui. No. 89. 



2 Massachusetts Hatch Sta. Bui. No. 47. 

 13931— No. 03 2 



