122 EXPERIMENT STATION EECORD. 



more widely distributed than tlie otliers. Sulpliates are generally found in 

 large quantities in the areas tliat can not be cultivated, but are often absent, 

 except in small amounts, iu tlie cane areas. Clilorids are found in all samples, 

 but often iu sucli small quantities as to be negligible. . . . 



" Wlaere the soil contains from 0.1 per cent to 0.2 per cent of bicarbonic acid 

 unaccompanied by any large quantity of other acids the cane is affected in its 

 growth; beyond this point it rnrely thrives. ... In most cases 0.?> per cent of 

 total acid radicles is veiy injurious or fatal to the cane, depending somewhat 

 on the relative proportion of the various radicles and upon the frequency of 

 irrigation." 



The analyses of irrigation waters show most of these to be excellent for 

 irrigation purposes. The chlorin content is small. 



It is concluded that the three chief factors influencing the purity of cane 

 juices from the south coast are root grubs, cane borers, and the salts of the 

 soils. 



The application of fertilizers to the soil, and losses by leaching, J. T. 

 Cbawley ;md W. B. Cady {Porto Rico Bd. Agr. Expt. Sta. Bui. 8 {1015), pp. 

 17-23). — Experiments with a lowland clay loam soil, a red clay hill soil, and 

 a sandy clay soil with reference to their absorptive powers for fertilizers are 

 reported. 



The results as a whole indicated that phosphoric acid is very quickly and 

 firmly fixed by all the classes of soils, but that there is an appreciable loss from 

 the light sandy soils when the fertilization is followed by repeated irrigations. 

 The nitrogen losses, while the greatest, were of material consequence only in 

 the sandy soils. The clay soils fixed the nitrogen quickly and held it firmly. 

 Potash was lost from all the soils, but in small quantities except in the case 

 of the sandy soils. It is stated that heavy rainfalls or irrigations may wash 

 the potash out before it is fixed, especially frcm sandy soils, but after becoming 

 fixed it is washed out only in small quantities. There was very little loss of 

 fertilizers from clay soils even after very heavy rains or irrigations. It is 

 thought that there is not the same reason for thoroughly mixing the fertilizers 

 with sandy soils as with clay soils, owing to the tendency for moisture to diffuse 

 the ingretlients. It is suggested also that fertilizers should be applied in small 

 and frequent doses to sandy soil rather than iu large doses at long intervals. 



The effect of fertilizers on the physical properties of Hawaiian soils, W. 

 McGeoege {Haioaii Sta. Bui. 38 {1015), pp. 31, figs. 3). — This bulletin reports 

 data obtained from an extensive study of tho physical properties of Hawaiian 

 soils and the effect of different fertilizers on these properties. Soils of widely 

 differing chemical and physical characteristics and about 40 salts, fertilizer 

 materials, aud mixtures were used in the experiments. 



It was found that withiu certain limits the effect of adding a larger applica- 

 tion of a salt only magnifies that of a smaller application. Capillarity was 

 diminished in clay soils by the addition of salts but increased in sandy soils. 

 This property was more active in silts than in sandy or clay soils, being slowest 

 in the latter. The percolation of water was most rapid in sandy soils and slow- 

 est in types the particles of which are most likely to swell. Fertilizers consid- 

 erably increased the resistance to percolation. It was found that the theory 

 that soils of greater capilh-a-y activity offer the least resistance to percolation 

 of water does not applj^ to Hawaiian soils. 



The results as regards flocculation indicated a relationship between the 

 valency of the salt and its flocculating power. " The most active salt is alumi- 

 num sulphate, a trivalent salt. . . . The divalent calcium and magnesium salts 

 of nitric, hydrochloric, and sulphuric acids are next, while the monovalent salts 



