1110 The Improvement of Peaty Soils. [Mar., 



sea level, and it has a rainfall of 85 to 95 inches. While some- 

 what warmer than the northern moors it is distinctly cold ia 

 spring and autumn. The peat is strongly acid and consists of 

 two layers; the upper about 4 in. in thickness formed of partially 

 decayed vegetation (the heather breaking down more easily 

 and the sedges taking longer) ; the whole however is difficult to 

 plough; the lower layer is composed of black decomposed 

 material. Below this again comes a dark brown or chocolate 

 coloured layer of earth several inches in thickness, probably 

 at one time the original surface soil until it became covered' 

 up by a deposit of peat. It is gritty and stony, but usually it 

 has not formed a continuous hard layer of rock or " pan." 

 It must, however, be broken so as to allow full liberty to plant 

 roots. Underneath lies a considerable depth of reddish brown 

 or yellowish earth with occasional patches of white clay. This 

 is so gritty and contains so many pebbles that it is not likely 

 to prove hopelessly retentive of water; further, it is deep in 

 many places. The lowest layer of all is the granite, from which 

 the whole formation arises. Much of the granite is light 

 coloured. It disintegrates very readily on exposure to weather 

 as is well seen in the little quarry near Two Bridges at the 

 junction of the Tavistock and Princetown Roads. 



Assuming the land to remain in arable cultivation the 9 in. 

 of peat now covering it would gradually oxidise and disappear, 

 bringing more and more into prominence this old surface soil; 

 its composition is as follows; — 





Blank 



or chocolate 



Reddish earth (original 





coloured layer (probably 



subsoil under! 



ving 





original surface soil), 



black layer"*, 15 in. to 





9 in. to 15 in. 



from 



24 in. from present 





present surface. 





surface. 







1 



2 



3 (8 



1 



2 



3 









11 >>,.) 









Fine gravel 



17-1 



7-9 



9 2 



18-2 



13-8 



10 8 



Coars^ sand 



16-5 



19-5 



32-1 



17-1 



1P.-4 



27-0 



Fin'^ sand ... 



233 



241 



2(1-9 



19 5 



18 5 



209 



Silt 



147 



1S-4 



11-8 



170 



19-4 



17-1 



Fine silt 



9-7 



11-5 



10-5 



11-6 



106 



7-7 



Clay 



24 



2-8 



2-6 



4-4 



. 74 



4-6 



Loss on ignition ... 



12-4 



12-7 



10-3 



7-8 



9-8 



8-4 



Phosphoric acid 















(P a O,) Total ... 



003 



0-05 



003 



0-04 



006 



00-2 



Potash (K 2 0) Total 



023 



023 



0-28 



0-41 



0-41 



0-44 



Nitrogen 



022 



0-26 



0-22 



o-ii 



0-15 



012 



Carbonates... 



Nil 



Nil 



Trace 



Nil 



Nil 



Trace 



