548 



EXPERIMENT STATION RECORD. 



acre while B received 340 lbs. The potash was applied in the form of 

 cotton-hull ashes. The results of the 4 years are tabulated below : 



Effects of different quantities of potash. 



"In this experiment about 900 lbs. of cotton-hull ashes per acre, or 190 lbs. of 

 potash, was annually put on the land in excess of the crop requirements. 



"As has been shown in previous reports, an average tobacco crop of 1,800 lbs. per 

 acre, takes from the bind not more than 150 lbs. of potash in stalks and leaves. 

 When land has been fertilized for some years, it is probable that 150 lbs. of water- 

 soluble potash annually applied is enough to secure a full crop of tobacco. 



"An excess of potash, however, tends to neutralize the otherwise iujurious effects 

 of an excess of chlorids in the soil." 



A test of mixed fertilizers supplied by manufacturers is reported 

 and the results tabulated. 



A study of the effects of all these fertilizers on the composition of 

 wrapper leaf tobacco was made and the results of analyses are given 

 in tabular form. The preparation of the samples and the methods of 

 analyses are described and the results are discussed. The author sum- 

 marizes his observations as follows: 



"(1) The analyses represent the cumulative effects on the composition of the 

 tobacco leaf of fertilizers applied for 4 and 5 years in succession. 



"(2) The short wrappers have a somewhat larger percentage of ash, ether extract 

 and nitrogen-free extract than the long wrappers and correspondingly less fiber, 

 nicotin, nitric acid, and protein. 



"Of ash ingredients the short wrappers contain a somewhat larger percentage of 

 silica, soda, lime, magnesia, and oxid of iron, and a correspondingly smaller per- 

 centage of potash, phosphoric acid, sulphuric acid, and chlorin. 



"(3) There are no differences in the percentages of ether extract, liber, and nitro- 

 gen-free extract traceable to the different fertilizers used. 



"Where fertilizer-nitrogen was applied in large excess of the probable crop require- 

 ments, a much larger percentage of nitrates was found in the leaf, amounting in one 

 case to 3.78 per cent of nitric acid (N. 2 O r ,), than where smaller quantities of fertilizer- 

 nitrogen were applied. 



"The percentages of protein and of nicotin were also above the average in tobacco 

 to which the larger quantities of fertilizer-nitrogen had been applied. 



"(4) The fertilizers used have had striking effects on the composition of the ash. 



"(a) The largest percentage of potash was in tobacco to which most fertilizer- 

 potash had been applied. 



" The percentage of potash is least in the ash of tobacco from the plats dressed 

 with potash in form of sulphate. The percentage of potash in the ash of the tobacco 



