374 



are cliaracterizcd by a high percentage of exceedingly fine gran- 

 ules ; in some places this fineness conii)aring with that of pre- 

 cipitated chalk, being an almost impalpable powder. The more 

 granular types are known as "shotty soils." Most of the soils 

 become quite stick)- when wet, but readily disintegrate upon 

 drying. 



Iron and manganese are often so abundant that the soil con- 

 taining them resembles a low-grade ore in composition. In gen- 

 eral the soils are characteristically acid, with high percentages of 

 iron (15%-607r), and nitrogen. The average nitrogen content 

 exceeds 0.3%, or six tons per acre-foot. Most of the soils are 

 also rich in phosphoric acid and potash, but these are not always 

 in available forms. The soils are, in general, exceedingly fer- 

 tile, due partly to the abundant store of plant-food in them, and 

 to the relatively short period in which they have been subjected 

 to leaching. 



Hawaiian soils respond quickly to the application of fertilizers, 

 and like all other new soils improve rapidly under rational culti- 

 vation. Many of the soils are deficient in lime, but this is easily 

 supplied in the form of coral sand, an excellent form for soil 

 improvement. Dr. Wilcox, special agent in charge of the Fed- 

 eral Experiment Station in Honolulu, says: "When plowed 

 deeply our soils are exceedingly retentive of moisture, as evi- 

 denced by the fact that cotton and various other plants thrive in 

 a wind condition where no rain falls except once or twice j^er 

 year, and then only to the extent of one or two inches. More- 

 over, good crops of alfalfa and forty bushels of corn per year 

 have been produced with two inches of rainfall without irriga- 

 tion. One of the most important points in soil cultivation, wliich 

 has been demonstrated by the sugar planters, is the great value 

 of deep plowing. Some of our soils are commonly plowed to a 

 depth of two or three feet, and are thus put in condition to hold 

 and store the rainfall, for the benefit of the cro]). The soils are 

 easily kept in good tilth and great fertility by deep plowing, suit- 

 able crop rotation, and the application of fertilizers to replace 

 special elements of plant-food removed by the crops." 



The desirable conditions, specified above, find their best and 

 most complete development, in Hawaii, in valley floors or bot- 

 toms. 'I'he mouths of the valleys are es])ecially adapted to kalo 

 farnn'ng. There the valleys widen, giving broad stretches of 

 l(»\v-l)ing land. Thr kalo lands in such valleys as .Manoa and 

 Kalihi. (m ()alui, haw doubtless been cultivated contiiuiously for 

 a jjcriod of several hnndrcd years. In former times the lei were 

 situated chiefly in the midflle and upper i)orli(Mis of the valleys. 

 "The development of artesian wells on < 'ahn in 1X7'*," accord- 

 ing to Sedgwick, "made it possible to throw opin greater low- 

 land areas to taro culture." .As a matter of fad. this land was 

 utilized mainly for rice Tliis soil is ferlile mountain w.isli. line 

 textured and very deep. 



