THE SOILS OF THE CANE-GROWING REGIONS 69 



obtain the maximum cultural and industrial return, promoting the size of the cane 

 and its leaf development in the first stages of its growth and without intermission, 

 until the time arrives when it is necessary to develop the juices formed at an early 

 stage." 



The various points in question are here very ably stated by Boname, and 

 briefly it may be said that the cane will succeed on anj' fertile soil, and that 

 the success will be measured b\- the extent to which those principles common 

 to all agriculture are carried out. The consensus of opinion that calcareous 

 soils are especially suited to the cane may best be looked at in the Ught of the 

 knowledge that generally soils thus derived are amongst the most fertile 

 known. 



In the course of the soil studies that have been extensively pursued in 

 all parts of the tropics, one or two points of special interest have arisen. 

 Thus Kelly^ has observed that the large quantities of manganese present in 

 many Hawaiian soils are without any harmful action on the cane, though 

 these soils prevent pineapples from making a normal growth. The cane is 

 able also to grow normally on soils containing a larger proportion of salt, and 

 this property is reflected in some of the ash analyses quoted in Chapter II. 

 Soils of this nature occur in Demerara and the Straits Settlements, and Du 

 Beaufret has recorded that in French Guiana periodic renovation of the cane 

 fields is obtained by flooding them \rith sea water. The matter has been 

 discussed by Geerligs^^, who inclines to the opinion that, while the cane is 

 not halophUous or benefited by the presence of chlorides, it can still give 

 a normal growth on soils containing considerable quantities of salt. 



A type of soil of not infrequent occurrence in the West Indies is the 

 outcrop of limestone, in which the calcium carbonate ma}' reach as much as 

 40 per cent. Cane grown on these soils exhibits chlorosis indicated by the ap- 

 pearance of longitudinal yellow stripes in the leaves. The appearance 

 is similar to that found in the yeUow stripe disease {cf. Chapter IX). The 

 condition is caused by disturbance in the mineral nutrition of the plant, and 

 can be remedied by spraving with iron salts'^, though this scheme is not 

 commercially feasible. 



Apart from the cane generally but considered only in its varietal aspect, 

 many observations have been made indicating that certain varieties are 

 specific in their choice of soils. Thus the varietj' B 208 fails in hea\'y clays 

 but succeeds in lighter soils. On the other hand, D 625 has been found 

 specifically suited to heavy and moderately heavy clays. In Java also 

 similar peculiarities are known ; the cane P.O.J. 100 growing best on Ught 

 friable soils, a second great Java variety, Bouricius 247, preferring a stiff 

 clay. Man\- other instances of this nature can be quoted. 



The Soils of some Sugar-Producing Districts. 



Studies, general and specific and in greater and less detail, have been 

 made of the soils of many sugar-producing districts. Some account of 

 these is given below. 



Argentina SoUs. — The soils of this locahty belong to the acidic type. 



The following analyses of thirteen soils under cane cultivation are due to 

 HaU.i2 



