814 EXPERIMENT STATION RECORD. [Vol.43 



phosphorus in the surface and one-tifth of that in the subsurface samples of both 

 virgin and cultivated soils were found to be in the organic form. 



The organic phosphorus and humus soluble in ammonia were shown to be 

 closely related to each other, to total nitrogen in the soil, and, to a less extent, 

 to the color of the ammonia extract. It was found that if 100 represents the 

 percentage of ammonia-soluble humus obtained from a soil, the total nitrogen in 

 the .soil is 10 and the organic phosphorus in the ammonia extract 1. Except as 

 noted, there did not appear to be any connection between other soil constituents 

 and organic phosphorus present. 



The soil reaction appeared to be without influence upon the quantity and 

 nature of the organic phosphorus present. Some evidence was obtained that 

 the organic phosphorus compounds of cultivated soils are decomposed slightly 

 •more readily than are those of the virgin soils examined. From general con- 

 siderations it is thought that the phosphorus in organic combinations in the 

 .soil is not of a very high order of availability. 



Deficiency of iilant-food calcium in soils (Kentucky Sta. Rpt. 1919, pt. 1, 

 pp. 29-31). — Studies by O. M. Shedd of six different Kentucky soils of relatively 

 low calcium content and varying from slightly to strongly acid, to determine 

 whether they were capable of supplying sufficient calcium for plant growth, 

 are reported. 



Calcium nitrate, calcium oxalate, and a calcium-sodium citrate were applied 

 to the soils. The results showed marked differences in the response of the 

 several soils to the application of calcium compounds. In some the crops were 

 increased and in others decreased. The response was greater in the growth 

 of the plant than in the seed, and the plants grown in the presence of calcium 

 contained more of this element than those grown in soils to which none was 

 applied. 



This work is being continued. 



Unreliable experimental methods of determining the toxicity of alkali 

 salts, F. B. Headley (Science, n. ser., 51 (1920), No. 1810, pp. 1^0, i^i).— The 

 author reviews the conclusions of others, drawn from investigational work 

 on the toxicity of alkali salts, notably those by Harris and Pittman (E. S. R., 

 40, p. 315), and is of the opinion that such results and conclusions should be 

 based upon the amounts of salts recoverable from the soil by analysis instead 

 of on the amounts of salts added. 



The management of Palouse soils, P. P. Peterson (Idaho Sta. Circ. 12 

 (1920), pp. [5], fig. 1). — This is a summary of Bulletin 118 of the station, pre- 

 viously noted (E. S. R., 43, p. 227). 



Agricultural value and reclaiiiation of Minnesota peat soils, F. J. Axway 

 (Minnesota Sta. Bui. 188 (J.920), pp. 7-136. figs. 111).— The first sentence in the 

 second paragraph of the abstract of this bulletin (E. S. R., 43, p. 420), should 

 be corrected to read : Drainage is the first essential step in the reclamation of 

 these soils, followed by liming as an indispensable step on the low-lime peats. 



The best methods of laying doAvn and improving grass laud, D. A. Gn.- 

 CHRiST (Jour. Farmers' Club [London], 1920, pt. 4, pp. 65-88). — This is a very 

 popular discussion on the use of fertilizers, lime, and seed mixtures in the im- 

 provement of pasture soils. 



Soil fertility (Kentucky Sta. Rpt. 1919, pt. 1, pp. 21, 22).— Data on the effect 

 of a four-year rotation of corn, soy beans, wheat, and clover on a field on 

 which tests of various fertilizing materials were made are given, showing that 

 the application of fertilizers has not produced any significant increase in crop 

 but that the use of legumes has increased the corn crop. 



Soil fertility iuA^estigations, O. I. Bergh (Minnesota Sta., Rpt. Grand Rapids 

 Substa., 1915-1919, pp. 34-50, figs. 4). — In a manui'e and phosphate experiment 



