206 SOIL SCIENCE [BoT. Absts., Vol. VII, 



lar need abundant water and organic matter. The part played by capillarity in the upward 

 moving of water has been overestimated. It is held that gravity acts upon capillary as well 

 as free water. The writer concludes in pointing out the relative advantages and disadvan- 

 tages of the basin method and furrow method of irrigation of fruit trees. — E. L. Overholser. 



1393. Headley, F. B. Unreliable experimental methods of determining the toxicity of 

 alkali salts. Science 51: 140-141. Feb., 1920. — The method frequently used by investigators 

 of adding certain percentages of salts to soils, planting them to crops, and estimating the 

 toxicity by depression of crop growth, has led to erroneous conclusions. It has been shown 

 that soils absorb a part at least of salts added, and that the crop growth is much more closely 

 related to the proportion of alkali salts recoverable from the soils than to the proportion of 

 salts that have been added. The conclusions in two papers on the subject, published by 

 Harris, and Harris and Pittman, respectively, are criticized as unjustified, on account of the 

 fact that the salts recoverable by analysis after the treatments were made were not taken 

 into consideration. — A. H. Chivers. 



1394. MocKERiDGE, FLORENCE Annie. The occurrence and nature of the plant growth 

 promoting substances in various organic manurial composts. Biochem, Jour. 14: 432^50. 

 1920.— See Bot. Absts. 7, Entry 1318. 



1395. R., E. J. A standard book on soils. [Rev. of: Hall, A. D. The soil: an intro- 

 duction to the scientific study of the growth of crops. 3d ed. XV + 352 p. John Murray: 

 London, 1920.] Nature 105:384, 1920. — "Its distinguishing feature is its clear recognition 

 of the complexity of the soil problem." — 0. A. Stevens. 



1396. Stead, Arthur. The agriculture and soils of the Cape Province. I. Witkop-Burg- 

 hersdorp. Jour. Dept. Agric. Union of South Africa I: 429-441, 660-670. 1920. 



1397. Williams, C. B. Report of the Division of Agronomy, North Carolina Agric. Exp. 

 Ann. Rept. 42: 21-39. 1920.— See Bot. Absts. 7, Entry 677. 



SOIL ACIDITY 



1398. JoFFE, Jacob S. The influence of soil reaction on the growth of alfalfa. Soil Sci. 

 10: 301-307. Fig. 1. 1920. — Pot experiments with alfalfa were carried out in soil to which 

 varying quantities of sulfuric acid or calcium carbonate were added. The hydrogen-ion 

 exponent of the soil was determined by Gillespie's method at the beginning, during, and at 

 the end of the experiment. The germination of alfalfa seed was practically the same in soils 

 varying from Ph. 4.5-7.0 but was greatly reduced in soils below Ph. 4.5. The yields of tops 

 showed a gradual increase with an increase of Ph. from 3.8-7.0. The nodule production and 

 nitrogen content of the plants increased with decreasing hydrogen-ion concentration. — 

 W. J. Robbins. 



1399. Knight, H. G. Acidity and acidimetry of soils. I. Studies of the Hopkins and 

 Pettit method for determining soil acidity. Jour. Indust. Eng. Chem. 12 : 340. 1920. — A de- 

 tailed account of cation and anion absorption by soil is presented. — Henry Schmitz. 



1400. KmoHT, H. G. Acidity and acidimetry of soils. II. Investigation of acid soils by 

 means of the hydrogen electrode. Jour. Indust. Eng. Chem. 12 : 457-464. 1920.— A new 

 hydrogen electrode has been designed which has proved satisfactory for certain types of soil 

 investigation. Various reactions and effects of acid soils are discussed. — Henry Schmitz. 



1401. Knight, H. G. Acidity, and acidimetry of soils. III. — Comparison of methods for 

 determining lime requirements of soils with hydrogen electrode. IV. — Proposed method for 

 determination of lime requirements of soils. Jour. Indust. Eng. Chem. 12: 559-562. 1920. — 

 A method is proposed for determining the power of a soil to decompose calcium carbonate 



