WATER SOILS. 459 



depends mainly, under favorable climatic conditions, upon tlie cultural methods and 

 suitable crop rotation, a conclusion strictly in accord with the experience of good 

 farm practice in all countries, and that a chemical analj'sis of a soil, even by these 

 extremely delicate and sensitive methods, will in itself give no indication of the 

 fertility of the soil or of the probable yield of a croji, and it seems probable that this 

 can only be deternnned, if at all, by physical methods, as it lies in the domain of 

 soil physics." 



The influence of climate, texture of the soil, rotation, and variety of croj"* on the 

 yield of crops, as well as the role of commercial fertilizers, are discussed. It is 

 claimed that in view of the results reported in this bulletin " the role of fertilizers 

 requires other explanations than those now generally accepted. There is no ques- 

 tion that in certain cases, and in many cases, the application of commercial fertil- 

 izers is l)eneticial to the crop, . . . but whether [the] increase is due to an actual 

 increase of the plant food in the soil, to an early stimulation of the plant to enable 

 it to get its roots out into a sufficient volume of soil, or to some jihysiological or 

 physical effect is not altogether clear." 



The authors conclude " that on the average farm the great controlling factor in the 

 yield of crops is not the amount of plant food in the soil, but is a physical factor the 

 exact nature of which is yet to be determined." 



Pineapple culture. I, Soils, H. K. Miller and H. H. Hume {Florida Sta. 

 Bui. 68, pp. 669-<j9S, plx. u). — Chemical and mechanical analyses of 21 samples of 

 soils, with corresponding subsoils, collected in different localities in Florida where 

 pineapples have been successfully grown, are reported in this bulletin, with descrip- 

 tions of the soils and of the local conditions and characteristic vegetation of the 

 regions from which they were obtained, notes on sampling, and a general discussion 

 of the requisites (,)f a good pineapjile soil. Comparing the results of the chemical 

 analyses with the average figures given by Hilgard, it is shown that the pineapple 

 soils are generally deficient in plant food. 



"Few of the soils would be able to produce more than two or three crops of pine- 

 apples if all the plant food present were available. And when we consider that only 

 a small proportion of this is actually in a condition to be taken up by the plants, we 

 can readily understand Avhy it is impracticalile to pro<luce pineapples on such soils 

 without making liberal apiilications of a complete fertilizer. 



" In a general way all our jiineapple soils are shown to belong to the same type, a 

 type which is marked by the absence of any appreciable amount of very fine sand, 

 silt, and clay. The capacity of these soils for holding water is not great, inasmuch 

 as the interstitial spaces are relatively large and are not altogether caiiillary, but are 

 only such near the points of contact of the soil grains." 



The sugar-cane soils of Jamaica, H. H. Cousins [Ihil. Dept. Agr. Jamaint, 1 

 {I'JOS), Nus. 4, pp- 76-9S; 5, jjp. 97-109). — Mechanical and chemical analyses of 31 

 samples of sugar-cane soils and 23 subsoils from different districts of Jamaica are 

 reported, together with the results of fertilizer experiments on some of the soils. 

 The wide variation in the character of the soils successfully used in sugar-cane pro- 

 duction is noted. They vary from light gravelly sands to stiff clays and from soils 

 containing almost no lime to those containing 50 per cent of calcium carbonate. All 

 soils on which sugar-cane cultivation is normally successful present, however, on the 

 whole a very high standard of fertility, the proportion of phosphoric acid being 

 particularly high, while potash is the constituent of which there is the smallest 

 availal)le supply. 



Reclamation of alkali land at Fresno, Cal. , T. H. Means and W. H. Heile- 

 MAN ( 11. S. Dept. Agr., Bni-cmi of Soils Circ. 11, pp. 9). — A brief account is given of 

 experiments in drainage and flooding to remove alkali from a 20-acre tract of land 

 2i miles south of Fresno. "Three-inch, 4-in., and 6-in. tile were laid over the tract 

 at an average depth of a little over 3 ft. and 150 ft. apart. . . . The work of ditching 



