222 EXPERIMENT STATION RECORD. 



The consumption of nitrate of soda in the United States, C. E. Munroe 

 (Jour. Indus, and Eufjin. CJiem., 1 {1909), No. 5, pp. 2.97-299 ) .—This article 

 gives data regarding the total consumption and principal uses of fertilizing ma- 

 terials in 1905, based upon census figures compiled in that year (E. S. R., 20, 

 p. 825). The total consumption of nitrate of soda in the I'nited States in that 

 year is given as 254,772 short tons. Of this amount, 42,213 tons was used for 

 fertilizing purposes as compared with 19,518 tons in 1900. 



Contribution to the study of phosphates, of their isomerism, and of the 

 transformations which they undergo in the soil, A. Quartaroli (Staz. K/kt. 

 Agr. ItaL, Ji2 {1909). No. 1-2, pp. 121-160). — From chemical studies and experi- 

 ments the author concludes that there can be two forms of dibasic phosphates, 

 one transformable by the addition of strong acids into monobastic phosphate 

 and the other not so transformable; and two forms of tribasic phosphate, one 

 transformable into dibasic phosphate and the other not. In the form of tri- 

 basic phosphate not transformable into dibasic, there is no hydrolytic decom- 

 position. 



The author considers that the usual opinion that in the soil monocalcium 

 phosphate passes for the most part into an insoluble form as dicalcium or tri- 

 calcium phosphate is erroneous. When monocalcium phosphate is diffused in 

 the soil, by the action of water, it is decomposed, forming a more or less con- 

 centrated solution of monocalcium phosphate. This begins to change, giving 

 crystallized dicalcium phosphate, while the phosphoric acid set free unites with 

 the calcium carbonate in the soil, or, eventually, even with the compounds of 

 iron and aluDiinum. When this process has gone on till the solution of mono- 

 calcium phosphate is sufficiently diluted, no further change takes place. 



When dicalcium phosphate is used as a fertilizer the distinction between the 

 two forms is no longer made. These two forms the author calls symmetric and 

 asymmetric, the latter being the amorphous and the former the crystallized form. 



Carriers of phosphorus in fertilizers, C. E. Thorne {Ohio Sta. Circ. OS, 

 pp. 8). — This circular briefly describes different sources of phosphoric acid and 

 gives the results of experiments extending over about 20 years at different 

 places in Ohio on the effect of dissolved boneblack, acid phosphate, basic slag, 

 and bone meal on a 5-year cereal rotation of corn, oats, wheat, clover, and 

 timothy, and a 3-year rotation of potatoes, wheat, and clover. 



The results of the 20 years' experiments seem clearly to indicate that acid 

 phosphate is the most effective of the carriers of phosphorus used in these 

 experiments for cereal crops, but that bone meal and basic slag are preferable 

 for clover on acid soils. 



" When, however, the matter is considered from the standpoint of a complete 

 rotation, embracing both cereal crops and clover, it appears that on these acid 

 soils the utmost that can be claimed for basic slag is that its total phosphorus 

 has been of equal effect with the available phosphorus in acid phosphate, or the 

 phospliorus in fine bone meal, pound for pound, and that no additional value can 

 be ascribed to the basic slag because of the lime or other substances which it 

 may have contained; \vhile on soils that have been limed the pound of total 

 phospliorus in basic slag has been less effective than the pound of available 

 phosphorus in acid phosphate or in fine bone meal." 



The different phosphates were used in combination with other essential fer- 

 tilizing constituents, the nitrogen in all cases being supplied in the form, of 

 nitrate of soda. It is suggested that possibly the basic slag would have been 

 relatively more effective on acid soils if it had not been used in connection with 

 nitrate of soda. In any case, the indications are that the use of the slag to 

 correct soil acidity would be an expensive method as compared with the use of 

 quicklime. 



