216 EXPERIMENT STATION EECOED. 



soil surveys which have been carried on since 1872. A list of apparatus and 

 ^instructions for simple tests of soils are appended. 



Soils in relation to geology and climate, H. I. Jensen (Dept. Agr. N. 8. 

 Wales, 8ci. Bui. 1, 1911, pp. 3-30).— "In this paper the soils of New South 

 Wales have been classified and cross classified on a meteorological and geo- 

 logical basis. The results are based on the comparative study of over 2,300 

 analyses of farmers' soils and type soils. 



" The compilation clearly shows that a soil survey can be made more satis- 

 factorily by geological and physiographic work than by chemical analyses. 

 The results obtained by analysis only confirm what one would expect from 

 geological considerations. Soil mapping is therefore essentially the work of 

 the geologist and physiographer, who at the same time has devoted attention to 

 the origin of soils and the agricultural needs of the State, or whose work is 

 interpreted by an expert in agriculture." 



The author believes that the most effective way of aiding the farmer would 

 be the establishment of an experiment station on each important soil type to 

 determine the strength and quality of the soil by growing test crops. 



The effect of soluble salts on the physical properties of soils, R. O. E. 

 Davis {U. 8. Dept. Agr., Bur. Soils Bui. 82, pp. 3S, pis. 6, figs. 2i).— In this study 

 of the effect of soluble salts on the physical properties of soils determinations 

 were first made of penetration by the method proposed by Cameron and Gal- 

 lagher (E. S. R., 19, p. 818), but it was found "that while the penetration 

 method is of value in determining the general curve and the optimum water 

 content for a soil, it can not be relied upon to detect small differences in the 

 physical properties of a soil due to the addition of small amounts of soluble 



Tests were therefore made of the effect of the salts upon the apparent specific 

 gravity by weighing full of soil a vessel of known volume, determinations being 

 also made of the percentage of moisture in the soil. The soils used were Cecil 

 clay loam, Volusia silt loam, Norfolk sand, and Susquehanna clay. The salts 

 added included potassium chlorid, carbonate, and bisulphate, calcium sulphate, 

 nionocalcium phosphate, phosphoric acid, and ammonium nitrate singly and in 

 various combinations in amounts varying from 0.006 to 1.33 per cent. The 

 results showed that the addition of the soluble salts brought about changes in 

 volume. 



To determine the effect of the salts upon the movement of moisture, measure- 

 ments were made of capillary movement in soil in a tube which was maintained 

 in a horizontal position to eliminate the effect of gravity. The tubes were of 

 glass " 1 in. in diameter, with a scale in millimeters pasted along their length. 

 These tubes were connected by strong rubber tubing to brass elbows, the lower 

 end of which dipped into water. The water supply was kept at constant level. 

 In filling the tube the end was closed by a sheet of filter paper and the tubes 

 filled to the same distance in each case and then tapped until the loose soil 

 had subsided a determined number of centimeters (usually 5). The brass 

 elbows were all filled with the same soil, rubbed up in a mortar with a rubber- 

 tipped pestle, and as nearly as possible given the same packing in the tubes. 

 The lower ends of the brass tubes were closed by perforated corks, with glass 

 wool in the perforations and fine copper gauze over them. The ends were 

 submerged in the water about 3 cm. and allowed to stand there for 24 hours 

 before the soil columns in the glass tubes were attached." 



Observations on the capillary movement of water in the tubes during 24 

 hours showed that this was influenced to varying degrees by the soluble salts, 

 which were the same as in the specific gravity tests. 



