750 SUBANTARCTIC ISLANDS OF NEW ZEALAND. [Soils and Soil-formers. 



Vogeler (34) found that the average analyses of cultivated Bavarian moor soils 

 showed a variation in potash content from 0-0544 to 0*089 per cent., the average 

 amount being 0-033. In spite of the fact that these soils are well supplied with 

 this ingredient, it is apparently in a very unavailable form, as they are much 

 benefited by liberal applications of potash fertilisers. 



All authorities agree on the advisability of applying lime to peaty soils to obtain 

 the best results. Woolney has shown that calcium-humate will oxidize much more 

 rapidly than uncombined humic acid placed under similar conditions. To the 

 absence of calcium-carbonate and mineral salts generally Hall (13) thinks may be 

 ascribed the tendency of humus to accumulate and persist in very light sandy 

 heaths. 



The simplest treatment* of peat and humus soils for agricultural purposes 

 depends on the following principles : (a) Drainage, to take away the surplus water ; 

 (6) removal of the peat or humus layer, and exposing the underlying clay or 

 sand ; (c) mixing the sandy or clayey base of the bog with a certain amount of 

 humus. 



This procedure may be considerably modified, and, instead of exposing the 

 base of the deposit, large applications of gravel (350 tons of gravel per acre) 

 or marl (carbonate of lime with clay) were recommended in the report of 

 the Eoyal Commissioners, 1809-14). Thomas phosphate (basic slag), and on 

 Irish bogs potash-salts, are the most efficacious fertilisers to apply. Farmyard 

 manure, itself an organic manure, and green manure are also similarly success- 

 ful on humus soils — King (36) and Whitson (37). Burning peat in heaps and 

 spreading the ashes on the soil is also a well-known treatment to render such 

 soils fertile. 



Other uses to which peat is put are the manufacture of — (a) alcohol ; (6) fuel ; 

 (c) peat wool for clothing ; (d) products of destructive distillation (oil, tar, paraffin, 

 and pitch) ; (e) peat mull or powder for litter, absorbent for food mixtures, molasses ; 

 (/) paper ; {g) building-materials, roofing-material ; {h) brown dye ; (i) tanning- 

 material ; (j) manure ; {k) packing- materials ; and (l) ammonia. 



Different grades of peat have different uses, and thus the upper layers of a peat 

 bog, and layers containing much cellulose and unaltered plant-remains, would be 

 more suited for use as absorbents, manufacture of alcohol, paper, peat clothing, 

 feeding-stuffs, and packing-material, while the well-humified layers rich in carbon 

 and nitrogen are better adapted for use as fuel, as fertiliser, or as a source of 

 ammonia. 



Paturel (31) finds that peat yields most of its nitrogen as ammonia when heated 

 by superheated steam, and may be used to promote intense nitrification in nitre- 

 beds. 



* Humus acid is said to decompose silicates (Rodzyanko, J.C.S., 1892, vol. Ixii, p. 1373), and by a 

 reaction between it and ammonia from rain-water, nitrogen from the air, and silica from the soil a series 

 of silic-azohumic acids is formed (P. Thenard, Compt. Rendus, vol. Ixx, 1412, 1870) whose alkaline 

 salts are easily soluble. Even quartz may be corroded by this class of organic solvents (E. V. Hayes, 

 Bull. Geol. Soc. Amer., 8, p. 213, 1896). See also Clarke (20). 



Note. — Recent publications are leaflet No. 203, " On the Utilisation of Peat Lands," pubHshed 

 gratuitously by the British Board of Agriculture ; and Bulletin No. 2, vol. iii, of the Imperial Institute, 

 " On Utilisation of Peat." 



