No. 1, July, 1920) SOIL SCIENCE 249 



vary so that the condition of a soil at any time can be considered but a stage in its progress 

 toward a constantly shifting equilibrium in accordance with the principle of Le Clatelier. — 

 Henry Schmitz. 



1G57. RABATB, E. Recherches sur la reaction des terres. [The reaction of soils.] Compt. 

 Rend. Acad. Agric. France 5: 854 858. 1919. — Discusses methods of demonstrating alkalinity 

 or acidity of soils and the cultural practices to be followed in consequence. — E. .1. Bt 



1658. Stephenson, R. E. Activity of soil acids. Soil Sci. 8: 41-59. 1919.— Soil arid- 

 capable of giving a toxic hydrogen ion concentration react rather quickly (2 weeks in the ex- 

 periment reported) with calcium carbonate but soils may contain a large reserve of acidity 

 which is capable of decomposing calcium carbonate slowdy for a considerable period of time 

 (21 weeks in the experiment noted). — William J. Robbins. 



1659. Truoo, Emil, and M. R. Meacham. Soil acidity: II. Its relation to the acidity 

 of the plant juices. Soil Sci. 7: 469-474. 1919. — The hydrogen ion concentration of juice 

 pressed from plants grown in strongly acid soils is generally greater than that of the juice of 

 plants grown on the same soil limed. Lupines were an exception. The juice of plants cut in 

 the morning is more acid than that of plants cut in the afternoon. A difference between the 

 acidity of the juice of tops and roots of the same plant is noted. — William J. Robbins. 



FERTILIZATION 



1660. Cruickshank, Robert B. Orchard fertilization. Trans. Indiana Hortic. Soc. 

 1918: 121-137. 1 pi, 3 fig. 1919— See Bot. Absts. 4, Entry 915. 



1661. Hartwell, Burt L. The manurial value of a modification of orthoclase-bearing 

 rock where only potassium was deficient. Jour. Amer. Soc. Agron. 2: 326-329. 1919. — The 

 paper reports the results of an inextensive field trial conducted at the Rhode Island station 

 during six years. — F. M. Schertz. 



1662. Hedrick, U. P., and R. D. Anthony. Twenty years of fertilizers in an apple orch- 

 ard. New York Agric. Exp. Sta. [Geneva] Bull. 460: 71-96. Fig. 1. 1919.— See Bot. Absts. 4, 

 Entry 931. 



1663. Johnson, M. O. [Soil Investigations.] Hawaii Agric. Exp. Sta. Rept. 1918: 23-26. 

 PI. 5. 1919. — A rapid approximate method of determining the lime requirements of Hawaiian 

 soils as developed at this station is referred to. Fertilizer experiments with rice, bananas, 

 and pineapples are reported, with special attention given to the application of iron sulphate 

 in the form of spray to overcome the deleterious effect of abnormal quantities of manganese 

 in pineapple fields. Burnt lime has proved partially effective in controlling pineapple wilt 

 but can not be considered entirely successful. — J. M. Westgate. 



1664. Iversen, Karsten. Lokale Forsog med Kunstgodning til Korn og Rodfrugt. Vd- 

 forte paa Fyn i darene 1901-1915. [Local experiments with fertilizers for cereals and root crops. 

 Performed in Fyn in the years 1901-1915.] Tidsskr. Landbrug. Planteavl 26: 193-297. 1919 — 

 The objects of the experiments were to determine (1) the fertilizer needs of the soil in each 

 locality and (2) the effects of fertilizers on various crops under varying conditions. — Similar 

 plans were used for each set of experiments, which were performed on 4 to 8 replicate plots. 

 Differences between crops on fertilized and unfertilized plots were noted on the following num- 

 ber of experiments; 126 with barley, 49 with oats, 191 with mangolds, 41 with sugar beets. 

 Stable manure was used in the experiments with mangolds and sugar beets, but not with oats 

 and barley. — It was found that the effect of sodium nitrate, superphosphate and potassium 

 is greater when used three together than when used singly or in pairs. The needs of the crop 

 for fertilizer depended largely on the chemical composition of the crops, as determined by the 

 average analysis for the four species. — The assimilation of the fertilizer and the effect of 



