70 



CHAPTER V 



British Guiana Soils. — The soils of this colony have been critically 

 examined by Harrison.^ He distinguishes eight types of soil, of which only 

 three occur within the part where the cane is cultivated. These three are : — 

 I. The clay soils of the alluvial coast lands. 

 n. The sand reef soils of the alluvial coast lands. 

 in. The peaty or " pegass " soils of the alluvial coast lands. 

 Of these soils he writes : — 



" Experience has indicated to us that in Class I we find soils of marked 

 fertility : soils which, with careful cultivation and tillage, should not alone retain 

 their fertility for long periods, but give gradually increasing returns. These are 

 the sugar cane and rice lands of the colony. 



" In Class II we have the soils which are not infrequently met with in belts 

 known as sand reefs crossing sugar estates. They are to a great extent practically 

 useless for economic cultivation. 



" Class III consists of soils frequently characteristic of parts of the sugar 

 estates, and of which much of the swamps and wet savannahs of the back parts of 

 the alluvial coast lands consists. They also are found very commonly at short 

 distances back from the banks of the lowei parts of our rivers and creeks. As 

 indicated earlier in this report, they are essentially peat soils, and as such are 

 unsatisfactory and difficult to work. But given tillage, diainage, and amelioration 

 of their textuie by admixture with the underlying clays, they offer mines_of wealth 

 in plant food for future agriculturists in this colony." 



Harrison states that : — 



" The alluvial soils of British Guiana are largely derived from sea-borne mud 

 from the Amazon river, and are not delta soils of the Guianan rivers. 



The mean composition of the coast soils included in Class I he gives as : — 



Per cent. 

 Nitrogen .. .. 0-209 



Lime .. .. o-2i2~j Soluble in 20 per cent, hydrochloric acid at 



Potash . . . . 0-425 V the temperature of boiling water over 



Phosphoric Acid .. 0-072 J five working days. 



A tract of virgin savannah land, situated six miles west of the Berbice 

 river and four miles from the coast, was found by the writer to be of the 

 following average composition : — 



Total quantities 



per cent, on 



air-dry soil.* 

 Lime .. .. .. 0-153 



Magnesia .. .. 0-539 



Potash . . . . . . I • 467 



Phosphoric Acid . . o- 093 



Humus . . . . 6-013 



Nitrogen .. .. 0-479 



* Determined by solution in hydrofluoric acid. 



Soluble in i per cent. 



citric acid with 5 hours* 



continual shaking. 



0-0312 



0-2635, 



0-0162 



0-0034 



