SOILS — FERTILIZERS. 517 



These investigations have already been noted from another source (E. S. R., 

 29. p. 621). 



Nitrification in acid or nonbasic soils, J. C. Temple {Oeorgia Hta. Bid. 103 

 (1914), PP- 1^)- — This is a fuller account of investigations briefly reported else- 

 where (E. S. K., 20, p. 722). 



The fertility of the soil, E. J. Russell (Camhri-dgc, England, 1913, pp. VI+ 

 128, pU. 10). — This is one of the Cambridge Manuals of Science and contains 

 "the substance of tallis, lectures, and other discourses delivered before all 

 sorts and conditions of men and women and in all Icinds of meeting places." 



Different chapters treat of the natural history of the soil, how plant food 

 is made in the soil, what soil fertility is and how it may be attained, soil fer- 

 tility and systems of husbandry, the raising of the fertility limit, the checlcered 

 career of the clays, the rise of the sands, and the moor and its management. A 

 brief concluding chapter sums up the general conclusions to which the pre- 

 ceding chapters lead. Here it is shown that while the main purpose of this 

 book is to deal with the problem of making the soil fertile by modifying it to 

 suit the needs of crops, the author is not unmindful of the great importance of 

 modifying crops (by breeding) to suit the soil or of selecting crops especially 

 suited to the soil and climatic conditions. 



The increase of plant food in soils, C. T. Gimtngham {Cliem. World, 2 

 (li)lS), No. 12, pp. 376, 377). — On the basis of previous investigations by Rus- 

 sell and Hutchinson (E. S. R., 29, p. 122), it is stated that without doubt the 

 harmful factor which limits the number of plant-food producing soil bacteria, 

 is living, and " the assumption that it is the active soil protozoa fits in with all 

 the known facts." 



Preliminary tank experiments on the movement, changes in composition, 

 and toxic effect on wheat of certain salts in sandy loam and adobe soils, 

 R. F. Hare et al. {New Mexico 8.ta. Bu i. 88 {1913), pp._32, ^^s. 7).— The ex- 

 periments reported were made in tanks filled with sandy loam and heavy 

 adobe soils. Galvanized iron cylindrical tanks 8 ft. high and 8 in. in diameter 

 with 15J in. holes 6 in. apart from top to bottom were used. The cylinders 

 were filled to wathin about 4 in. of the top wnth the soils mixed wath varying 

 proportions and combinations of sodium chlorid, sulphate, carbonate, and 

 bicarbonate. The tanks were irrigated from time to time and samples of soil 

 taken for examination at different depths through the holes in the sides of the 

 tanks, the space left by the removal of the sample being filled with the original 

 mixture of soil and salt and the holes kept tightly closed. Some of the tanks 

 were left bare and others cropped to wheat. 



The results are discussed in detail. They indicate in general " that the same 

 treatment of sodium chlorid and sodium sulphate in adobe soil leached the 

 chlorid to a crop tolerance limit of 32 in., while the sulphates were not carried 

 beyond 2 in. On sandy loam the chlorids were leached to SO in. and the sul- 

 phate to 38 in. In other words, nearly as much water was necessary to leach 

 the sulphates from sandy loam as was required to remove the chlorids to the 

 same depth in adobe. 



" [Apparently sodium carbonate and bicarbonate] may move with the water 

 by capillarity more than the other two salts. The possible change of either one 

 of the salts into the other, as w^ell as the neutralizing effect of gypsum in both 

 soil and water, makes it diflicult to compare the leaching action of water on 

 these salts with those of sodium sulphate and sodium chlorid. At the end of 

 the experiment the crop tolerance line of the carbonates and biearbonates had 

 apparently moved down 20 in. in the adobe soil and to 38 and 44 in., respectively, 

 in the sandy loam. 



