40 EXPERIMENT STATION. [Jan. 



The results shown hy this table tell quite a different story 

 than do the analyses in the first table. Note the comparatively 

 small amount of total solids, nitrogen, potash and, in fact, of 

 most all of the water soluble constituents in soil No. 4, which 

 showed a normal growth of tobacco, and No. 5, taken from 

 tobacco bed. The soils giving abnormal results showed an 

 increase of over 70 per cent, in total soluble solids, over 85 

 per cent, in water soluble nitrogen, and over 219 per cent, in 

 water soluble potash. To have supplied the water soluble 

 nitrogen found in soil No. 2, it would have required an appli- 

 cation of 3,445 pounds of nitrate of soda per acre ; to have 

 supplied the w^ater soluble potash found in soil No. 1 it would 

 have required an application of 1,112 pounds of high-grade 

 sulfate of potash per acre. 



It was subsequently discovered that the field was underlaid 

 with a hard impervious subsoil furnishing very poor drain- 

 age facilities, the soil had been used for the cultivation of 

 tobacco continuously for more than thirty years. These facts, 

 taken in connection with the very large amount of soluble 

 plant food present, seemed to indicate strongly that the trouble 

 was due to the accumulation of soluble saline constituents, 

 probably originating in the fertilizers which had been applied 

 in very liberal quantities for many years. It is a reasonable 

 assumption that, had the soil been underlaid by an o}^en 

 porous subsoil, the condition would never have occurred, as the 

 soluble salines would have passed out in the drainage water. 

 This is borne out by the fact that all of the soils which have 

 given this trouble have had imperfect drainage. In this con- 

 nection it seemed of interest to procure several tyj^ical, well- 

 drained tobacco soils which had been used continuously for 

 thirty or forty years for tobacco culture. Three samples of 

 soil and subsoil were, therefore, carefully taken from the farms 

 of well known tobacco growers in various parts of the Con- 

 necticut valley. The soil was taken to a depth of 1 foot, the 

 subsoil to a depth of 1 foot l>elow the surface soil. 



The following table shows the composition of the several 

 soils and subsoils. Hydrochloric acid, specific gravity 1.115, 

 was used as a solvent. The results are expressed on a 20 per 

 cent, moisture basis, also in pounds per acre. 



