THE SOILS OF THE CANE-GROWING REGIONS 75 



Lime Potash Phosphoric acid Nitrogen 



Oahu 

 Kauai 

 Maui 



Hawaii . . 

 Whole group 



o 



0-411 0-348 0-269 0-119 



0-504 0-358 0-237 0-246 



0-691 0-401 O-2OO 0-222 



0-833 0'353 0-321 0-338 



0-693 0-366 0-268 0-290 



Maxwell also determined the solubility in I per cent, citric acid (Dyer's 

 method) of a number of typical soils. His results, as calculated by the 

 writer, are as below : 



Lime Potash Phosphoric 



% % acid % 



Highest .. 0*281 0-084 0-0125 



Lowest .. 0-030 0-009 0-0012 



Average .. 0-113 *33 0-0043 



The small amount of available phosphoric acid in proportion to the un- 

 usually high total amount present is due to the accompanying ferric oxide. 

 Hilgaid 20 , in examining Hawaiian soils, calls attention to this point, and also- 

 emphasizes the action of the ferric oxide. A similar condition has also been 

 observed in the red soils of Cuba, which are not dissimilar from these. 



Other Hawaiian soils examined by Hilgard 21 , while containing large 

 quantities of nitrogen, were yet " nitrogen hungry." The percentage of 

 nitrogen in the humus was, however, very low, and he is inclined to attribute 

 more importance to the nitrogen in the humus than to the total quantity. 

 Mr. C. F. Eckart, however, has pointed out to the writer that, as many 

 Hawaiian soils are acid, this " nitrogen hungry " condition may have been 

 due to lack of nitrates, a condition which could be corrected by proper 

 treatment. 



Java Soils. The soils of Java have been derived from fairly recent 

 volcanic rocks, mainly of the andesite type, though basalts are not infre- 

 quent. Interspersed throughout the island are also upheavals of cretaceous 

 limestones. Generally, the soils would be classed as clays or clay loams, 

 though laterite formations especially near Pekalongan and Moeria on the 

 mid-north coast are to be found. 



The island of Java being mountainous and subject to heavy rains, a 

 great part of the soil formation has resulted from alluvial deposits. This 

 process continues up to the present day consequent on the extensive flooding 

 of the land used for growing rice, following on which a cane crop is grown. 



In the development of Java civilisation, the cultivation of rice became 

 the dominant industry, and for this land capable of flood irrigation was neces- 

 sary. Land thus situated is known as " sawah," in distinction from land 

 incapable of irrigation, which is known as "tegal," or "gaga; " land partly 

 capable of irrigation is known as " sawah tadanah." 



A native Javanese term which often occurs in the literature is " tana,"" 

 which roughly indicates " soil " ; there thus appear such terms as " tana 

 tadhu," referring to land along river banks ; " tana tinchad," referring to the 

 central plain, and "tana pasir," referring to maritime alluvial deposits; 

 " tana ladoe," indicates a mixed clay and sand, whilst "tana linjad" des- 

 cribes a heavy clay. 



Another type of soil of frequent mention in the descriptions of Java 

 is " padas." This term refers to a peculiar surface formation a few inches 



