622 EXPERIMENT STATION RECORD. [Vol 40 



The use of ammonium nitrate as a fertilizer, E. J. Russell (Jour. Bd. Agr. 

 [London], 25 (1919), No. 11, pp. 1332-1339). — Experiments on potatoes, man- 

 golds, and wheat, at Rothamsted and other places, to determine the fertilizing 

 value of ammonium nitrate are reported. 



The results of these experiments agree in showing that ammonium nitrate is 

 a very useful fertilizer. It was more effective than ammonium sulphate on 

 mangolds and equally effective on wheat. It appeared to be somewhat inferior 

 to ammonium sulphate for potatoes. It has the general advantage of being 

 a very concentrated material. The fertilizing value of this material is receiving 

 particular attention in England, because with the cessation of hostilities large 

 quantities of it are being released for agricultural purposes. 



Conversion of quicklime in soil, G. Hagek (Jour. Landic, 65 (1917), pp. 

 245-311; abs. in Jour. Chem. Soc. [London], 114 (1918), No. 661. I. p. 2-/7: 

 Chem. Abs., IS (1919), No. 2, p. 156). — It was observed that of quicklime added 

 to the soil only a small proportion reappeared as calcium carbonate. The re- 

 mainder is adsorbed by the soil, and the presence of free calcium hydroxid can 

 not be detected after even a very short period of digestion. 



"The power of a soil for adsorption appears to be related to its content of 

 clay and the presence of unsaturated compounds, and under normal conditions 

 an equilibrium between the absorptive and adsorptive power of the soil carbon 

 dioxid and the soil compounds, respectively, Is soon reached. Tin- action of cal- 

 cium carbonate is stated to be less rapid than that of calcium ox id. and some 

 months may elapse before an equilibrium is obtained." 



The influence of calcium oxid on the physical character of the soil is also 

 discussed. 



Inspection of commercial fertilizers, 1918. L. P. Haigtt (Missouri Sta. Bui. 

 160 (1919), pp. 3-31). — This reports tlie results of the actual and guarantied 

 analysis of 253 samples of fertilizers and fertilising material collected in Mis- 

 souri during 191S, together with observations on the relative value of 42 samples 

 of limestone and similar material for correcting soil acidity. A list of the 

 brands and guarantied analyses of fertilizers registered and offered for sale 

 in the State in 1919 is also included. 



FIELD CROPS. 



Field crops, A. D. Wit. son and < \ W. WAHBUBTOM (St. Paul. Minn.: Webb 

 Pub. Co., 1918, rev. ed., pp. 515, pi. l, flee. 166). — This book, an earlier edition 

 of which lias been noted (E. S. R., 28, p. 493), deals with the peculiarities of 

 each of the various classes and varieties of farm crops, the handling of the 

 soil, selection of seed, general en>p management, the theory and practice of 

 crop rotation, and weeds and their eradication. "A thorough revision has been 

 made of all those parts of the text where experience has suggested improvement 

 or changes of statistics, or conditions have made it necessary. It is now be- 

 lieved that It contains the latest available Information and practice with refer- 

 ence to the subjects treated." 



Practical guide to tropical agriculture. — I, General principles, A. Faxtchsbs 

 (Guide Pratique <T Agriculture Tropicalr. — /, Fr i mei pe e Oeue'remx. Porte: 

 Augustin Vhallamcl, 1918, pp. 159). — This treatise has to do primarily with the 

 development of agriculture in the French colonial possessions. The present 

 volume deals with factors of agricultural production, including the soil, climate, 

 capital, personnel, and agricultural equipment; the preparation of the land for 

 cultivation, including clearing, draiidng, and plowing, and the construction of 

 roads and buildings; and the continuance of cultivation, embracing the main- 



