280 Further Studies on the Soils of North Wales 



appearance of prosperity which suggests Shropshire or Cheshire rather 

 than Wales. Good crops of wheat and beans are grown and the grass 

 is frequently of excellent quality. The type of rotation is not greatly 

 different from that in other parts of the area, but there is probably a 

 greater proportion of permanent grass land than elsewhere, where much 

 of the grass land comes at some period under the plough. 



The results are assembled in the general table, which is the average 

 of nine analy.ses. It will be seen that there is a fair but not large pro- 

 portion of clay, although some soils greatly exceed the average. 



There is usually a small proportion of calcium carbonate. In this 

 respect the Clwyd soils differ from most of the soils of N. Wales and from 

 the other heavy drift soils, which are deficient in this constituent. Potash 

 is high, as might be expected, and phosphoric acid is somewhat low. 

 It should be added that the subsoil i.s generally very stiff' and, at great 

 depths, has a bluish colour owing to the presence of ferrous iron com- 

 pounds. 



The proportions of organic matter are low considering that the soils are 

 heavy. We may attribute this mainly to the climate and indirectly to 

 the presence of small quantities of calcium carbonate which, however, 

 would speedily be washed out if the rainfall were as high as that of the 

 surrounding uplands. Of all the types studied this is the lowest in phos- 

 phoric acid. The figures for available phosphoric acid are also low. In 

 view of the well-known fertility of the Vale, it would seem that we must 

 take careful account of the climate in judging as to what are insufficient 

 proportions of soil constituents. From a mere inspection of the analytical 

 figures it would seem that these soils are suffering from phosphorus 

 starvation, yet the facts in practice show that this is extremely unlikely. 



6. Alluvial Soils. 



Considerable stretches of river alluvium are found in the Vale of 

 Clwyd and form rather stiff' soils. Estuarine alluvium is found at the 

 mouth of the Clwyd near Rhyl and in the reclaimed portions of the 

 Dee estuary. These alluvia must be regarded as distinct sub-types. 



(d) Fliiviatile alluvia. 



A tract of this type occurs in the Vale of Clwyd between Denbigh 

 and Ruthin. It is a light grey soil and often very heavy. Much of it is 

 badly drained and is in consequence uncultivated. Smaller patches of 

 alluvium are also found along the banks of the Alyn and the Dee. The 

 single sample, from Lleweni near Denliigh, typical of that area, is 



