514 



EXPERIMENT STATION EECORD. 



Baltic provinces in continuatiou of studies, a report of which has ah^eady 

 been abstracted (E. S. R., 5, p. 418). During the first of these tours, 

 which lasted from June 15 to 25, 1893, 13 samples of soil from different 

 localities were collected; and in the second, extending from June 23 to 

 July 7, 1894, 13 other samples were collected. 



The soils were all separated on the basis of their actual productive 

 l)Ower into 3 classes — best, medium, and poor — before analyses were 

 made. To what extent chemical analysis bore out the agricultural 

 estimate is shown in the following table: 



Average compoHxtion of Courland soils. 



The variations in the percentages of water are so irregular that no 

 definite relations can be traced between the water content and the 

 quality of the soil, except that the proportion of moisture is generally 

 more uniform iu the good soils than in the medium and poor soils. 

 Another point illustrated with more or less clearness iu these investi- 

 gations is that clay soils retain moisture so much more tenaciously than 

 sandy soils that on the former plants suffer from drought when the 

 amount of water is not more than 10 to 14 per cent, while on the latter 

 they thrive with jjercentages of water ranging between 6 and 9. 



A.S in previous investigations, the percentages of phosphoric acid iu 

 both soil and subsoil stand in direct relation to the agricultural value. 

 The percentages of phosi)horic acid are invaribly lower in the subsoil 

 than iu the surface soil. This is due to the continuous fertilizing with 

 phosphatic manures to which these soils have been subjected. The 

 recommendation made in former articles that soils containing less than 

 0.15 per cent of phosphoric acid should be treated with phosphatic 

 manures holds good for the soils examined in this case. 



As regards nitrogen, the results of analyses appear to contradict the 

 estimate based upon the actual productiveness. It will be observed 

 that percentages are much higher for the surface soil than for the sub- 

 soil. This is ascribed to the system of culture pursued by which nitrog- 

 enous organic matter is accumulated in the upper layers of the soil. A 

 study of the individual analyses shows that in many cases a high per- 

 centage of nitrogen accompanied a high water content. It is suggested 

 that those soils which show a high percentage of nitrogen but are com- 

 paratively unproductive may be greatly improved by drainage or by 

 heavy liming. 



The percentages of potash seem to bear no definite relation to the 

 quality of the soil, but it is interesting to observe that the subsoils 

 are invariably richer in this element than the surface soils. 



