952 EXPEKIMENT STATION RECORD. 



The results of the trials corroborate those of Ivelluer and B()ttcher in showing that 

 the favorable effects of bone meal are considerably decreased by liming, viz, as much 

 as 81 per cent. They also show that a similar decrease took place in case of precipi- 

 tated calcium i^hosjjhate (66.5 per cent decrease). The results obtained differ from 

 those of the scientists mentioned in so far as the effect of the superphosphate was 

 not materially influenced by the addition of the lime, possibly because the author 

 used less lime. 



The effect of liming on the action of bone meal is discussed by the author. He 

 calls attention to the fact that the fertilizing value of neutral phosphates only was 

 reduced by the addition of lime, and suggests that the calcium bicarbonate formed 

 in soils rich in lime by the action of water containing carbonic acid in solution on 

 calcium carbonate may be responsible for the phenomenon, since the water contain- 

 ing this salt in solution does not dissolve tricalcium phosphate to the same extent as 

 does water containing free carbonic acid. 



The residuary effect of tricalcium phosphate was studied during 1901 with the 

 cylinders used in the experiments of the preceding year. Although the j^hosphoric 

 acid in the tricalcium phosphate only slightly improved the crop harvested during 

 the first season, its effect during the following season was insignificant, and was 

 decidedly less than during 1900 and less than the residuary effect of Thomas phos- 

 phate during the season of 1901. 



As regards the value of the two electrolytically prepared phosphates, the con- 

 clusions drawn are that triphosphate on soils poor in lime produced somewhat lower 

 results than did bone meal and on freshly limed soils somewhat better results, and 

 that dicalcium phosphate proved to possess much the same fertilizer value as super- 

 phosphate, without regard to whether the soil was limed or not. — p. w. woll. 



The action of phosphoric acid in the presence of lime, Bachmann {Fuhling's 

 Landw. Ztg., 62 {190;^), No. 1, pp. 12-14). — Plat experiments with rye, oats, and 

 beets on sandy soils fertilized with superphosphate, Thomas slag, and bone meal 

 with and without the addition of lime are reported. The most profitable returns 

 were obtained with Thomas slag, the least profitable with bone meal. The results 

 showed in general that the use of lime in connection with superphosphate and bone 

 meal resvdted in little or no reversion of the phosphoric acid during the first year. 



The effect of moisture on the availability of dehydrated phosphate of 

 alumina, F. W. Morse {Jour. Amer. (1iem. Soc, 25 {190S), No. 3, pp. 2S0-2S8). — 

 It is stated that a patented process for preparing dehydrated alumina and iron phos- 

 phate for use as a fertilizer by heating to about 325° C. was described by S. L. 

 Goodale in 1893. Dehydrated phosphate shows a high solubility in ammonium 

 citrate, although pot and field tests have not borne out the laboratory indications of 

 availability. An account is here given of determinations of the progress of dehydra- 

 tion of Redonda phosphate heated to different temperatures — 100, 150, 250, 325, 560, 

 830° C. — of the absorption capacity for water of the different samples so heated, and of 

 the solubility in neutral ammonium citrate of the i:)hosphoric acid of the undehydrated 

 and dehydrated material as well as of samples which had been dehydrated at differ- 

 ent temperatures and then allowed to absorb moisture. The results indicate that 

 dehydration is not complete at 325° C, but that a temperature of 560° gives a 

 product which is completely dehydrated, absorbs water more slowly, and for this 

 reason remains soluble in ammonium citrate longer than phosphate heated to lower 

 temperatures. Whether this resistance to hydration will render the phosphate 

 actually more available to plants remains to be determined. 



The action of phosphatic fertilizers on the chemical composition of forage 

 plants, L. BoNETAT and P. Touchard {Jour. Agr. Prat., n. sn-., 5 {1903), No. 11, pp. 

 343-345) . — The results of a number of experiments with grasses and leguminous 

 plants are reported to show that the application of phosphatic fertilizers not only 



