852 



HOTANiCAL SURVEY OK DISMAL SWAMP ItKOION. 



retardation of I lu- drainage. Aeration of the soil is necessarily very 

 imperfect under such conditions. It is the experience of farmers in 

 the region that new fields when brought under cultivation are much 

 benefited by liberal applications of lime. Even after being cultivated 

 for twenty years the soils are still slightly acid and would doubtless 

 be improved by further treatment with lime. Lime neutralizes the 

 aeids, and this is undoubtedly the principal advantage of its use on 

 swamp soils. It is usually applied here in the form of burnt shells, 

 about one ton per acre being the amount used on the swamp soils. 

 The total cost of adding to the land this quantity of lime is estimated 

 at about 14.50 per ton. 



Portions of the swamp on which "juniper" abounds are of very 

 little value agriculturally, and since even the waters flowing from 

 these parts of the swamp are strongly acidified it may be that the 

 presence of large amounts of acid is one of the causes of this non- 

 productiveness. Whatever the cause of the acidity, it is gradually 

 reduced when the soil is drained and exposed to the air, so that 

 decomposition can proceed. 



CLAY CONTENT. 



The distribution of the clay content of these soils, as shown by the 

 following table, is very interesting: 



Per cent of clay in .soils. 



Depth. 



Virgin 

 soils. 



Soil culti- 

 vated 20 

 yoars. 



Soil culti- 

 vated 50 

 years. 



Mean. 



10.17 

 20.13 

 15.17 



cm. 0- 50 

 in. 0- 20 



cm. 50-100 

 ♦ in. 20- 40 



cm. 100-150 

 in. 40- «0 



Moan 



| 11.00 



33.35 



i- 16. 65 



11.10 



18.65 

 Hi. 50 



7.80 

 18.40 



12.:*-) 



17.20 



15. 42 



13. 85 











It will be seen that the per cent of clay at to 50 centimeters (20 

 inches) is in each soil less than at either of the other depths, while at 

 20 to 40 inches it is greatest. This is a very fortunate distribution of 

 the clay content, for this particular region. The mean clay content 

 of 10 per cent at to 50 centimeters gives a texture that is very easy 

 of cultivation and one that can be cultivated very soon after rains 

 without injury to the structure of the soil. On the other hand, when 

 taken in connection with its high per cent of organic matter and the 

 character of the succeeding 20 inches in depth, it is sufficiently heavy 

 to be adapted to a fairly wide range of crops. 



The mean clay content of 20 per cent at 50 to 100 centimeters (20 to 

 40 inches) is just twice that, of the surface 20 inches and gives a texture 

 sufficiently heavy to be subject to but little leaching. This will pre- 

 vent any considerable loss of plant food that is now present or that 



