SOILS — FERTILIZERS. 213 



Maintenance of soil fertility: Plans and summary tables (Ohio Sia. Circ. 

 131, pp. ll-JfO, figs. 6). — This is one of tlie annual statements on the subject 

 (E. S. R.. 27, 1). 124), bringing the data for the experiments up to the end of 

 1912 and summarizing the results for 19 years (1894-1912). 



The relation of fertilizers to soil fertility, F. B. Guthrie (Agr. Gas. N. 8. 

 Walcfi, 2Jf (1913), No. 3, pp. 217-233) .—The present state of knowledge on this 

 subject is reviewed, the general conclusion being " that the action of fertilizers 

 is not confined to supplying the crop with food, but that it is far more complex, 

 and that fertilizers influence the physical structure of the soil, and also its 

 bioiogical and chemical condition in a great variety of ways; further, that we 

 have to take into account a large number of factors which affect the fertility 

 of the soil and which are quite independent of its supply of plant food." 



The importance of the place in the rotation at which fertilizers are applied, 

 G. F. Wareen (Proc. Amer. Soc. Agron., 4 (1912), pp. 58-62). — This article em- 

 phasizes the importance of studying the requirements of the plant, as well as 

 the soil, in fertilizer experiments. 



Some business questions involved in the interpretation of fertilizer tests, 

 G. F. Warren (Proc. Amer. Soc. Agion., J^ (1912), pp. 62-66). — In this article 

 the importance of considering the most profitable, as contrasted with the maxi- 

 mum, increase of yield which can be produced by the use of fertilizers is em- 

 phasized. 



Practical suggestions about the purchase of commercial fertilizers, J. H. 

 VooRHEES (Tribune Farmer [N. Y.I, 12 (1913), No. 503, pp. 1, 2). — The purchase 

 of unmixed materials containing in cheapest form the fertilizing constituents 

 which practical experience has shown to be actually needed is advised, the 

 materials to be either applied separately or mixed on the farm as required. 



Statistical yearbook of fertilizers and chemical products used in agricul- 

 ture, E. and M. Lambert (Annuaire Statistique des Engrais et Produits C'hi- 

 miques Destines a V Agriculture. PaHs, 1912, pp. 328; rev. in Jour. Agr. Prat., 

 n. ser., 2^ (1912), Nos. 46, pp. 619, 620; 47, pp. 660, 661; Bui. Soc. Nat. Agr. 

 France, 72 (1912), No. 8, i)p. 765-774; Rev. G^n. Sd., 23 (1912), No. 18, pp. 

 707-709; Econ. Frang., 40 (1912), II, No. 50, pp. 864-866; G6nie Civil, 62 

 (1913), No. 10, pp. 192, 193, 200). — ^This yearbook gives very complete statistics 

 up to the end of 1911 of the world's production and consumption for agricul- 

 tural purposes of sodium nitrate, calcium nitrate, calcium cyanamid, ammonium 

 sulphate, Peruvian guano, potash salts, phosphates, sui>erphosi)hates. and 

 Thomas slag, and of pyrites and sulphuric acid used in the manufacture of 

 fertilizers. 



Importance of the South in the production and consumption of fertilizers 

 (Manfrs. Rec, 63 (1913), No. 12, pt. 2, p. 82; Amer. Pert., 38 (1913), No. 8. 

 pp. 34-36). — This article reports and discusses statistics which show that the 

 consumption of fertilizers in 12 Southern States increased from 1,683,964 tons 

 in 1901 to 3,954,468 tons in 1912. In the 10 years 1900 to 1910 the expenditures 

 for fertilizers in 17 southern States increased from $29,277,000 to $75,391,000, 

 while the total expenditures for this purpose in the whole United States in- 

 creased from $53,030,000 to $114,273,000. Among the larger increases were 193 

 per cent in Alabama, 245 per cent in Arkansas, 378 per cent iu Florida, 193 

 per cent in Georgia, 190 per cent in Mississippi. 173 per cent in North Carolina, 

 237 per cent in South Carolina, and 371 per cent in Texas. 



Tests with four nitrogenous manures (Dept. Agr. and Tech. Insitr. Ireland 

 Jour., 13 (1913), No. 2, pp. 294-299). — Comparative tests were made of sodium 

 nitrate, ammonium sulphate, calcium nitrate, and calcium cyanamid in field 

 experiments with oats, potatoes, turnips, and mangels. 



