SOILS FERTILIZERS. 221 



an effective fertilizer ou all other soils, particularly on fine clay soils of high 

 absorptive povi'er and rich in lime, especially when such soils are regularly 

 treated with stable manure. Under favorable conditions the cyanamid is con- 

 sidered to be equal to ammonium sulphate in fertilizing efficiency when used 

 at rates of 133.6 to 267.2 lbs. (2G.7 to 53.4 lbs. of nitrogen) per acre. It should 

 be applied 2 to 8 days before seeding and well mixed with the soil immediately 

 after application. It should never be applied as a top-dressing and should not 

 be mixed with superphosphates, but may be mixed with potash salts and 

 Thomas slag. The material should be kept dry in storage, otherwise there will 

 be decomposition and loss of nitrogen. If applied with a drill some device 

 should be used which will prevent scattering by the wind. If applied by hand 

 the material should be mixed with double its weight of moist soil. 



Results of experiments with calcium cyanamid on horticultural crops and 

 on wheat, K. de Polo {A.soc. ^'«/. Propayada, Circ. Trbncat. J/S, 1908, pp. 151- 

 159). — The results of a number of experiments made during 1905-6, mainly 

 in Italy, are summarized. 



Calcium, nitrate and calcium cyanamid, L. Grandeau (Jour. Agr. Prat., n. 

 scr., 15 (1908), A'o. S, pp. 229-231). — The more important practical informa- 

 tion regarding the value and use of these materials as fertilizers is summarized 

 and a brief account is given of tests of the calcium nitrate on potatoes and 

 wheat during the season of 1906-7. The nitrate gave favorable results in both 

 cases. 



A danger in the use of nitrogenous fertilizers in the cultivation of grain, 

 D. Cavazza and L. Zerbini (Ann. Uffic. Prov. Agr. Bologna, IS (1906), pp. 

 91-103). — From the experiments reported the authors conclude that nitrog- 

 enous fertilizers, especially the soluble forms, should be used with caution, 

 otherwise there may be great waste. 



On the potash fertilizing of tropical and subtropical plants, P. Vageler 

 [TropcHpfldnzcr, 12 (190S), A'O. 2, pp. 69-83). — This article reviews various 

 investigations which have been made on the potash requirements of tropical 

 and subtropical soils and crops, including a number of references to work by 

 experiment stations of the southern United States. The crops which receive 

 attention include barley, wheat, rice, sugar cane, sweet potatoes, oil plants, 

 tobacco, coffee, cacao, tea, cotton, sisal, and cocoanuts. 



The general conclusion reached is that soils of tropical and subtropical 

 regions are frequently deficient in potash and that good results generally fol- 

 low the use of potash fertilizers on the crops ordinarily grown in such regions. 

 The best forms and methods of use and the profitableness of potash fertiliz- 

 ing depend upon varying conditions which have not yet been thoroughly 

 investigated. 



Potash fertilizers, D. Cavazza (Ann. Uffic. Prov. Agr. Bologna, 13 (1906), 

 pp. 150-159). — Experiments are reported which indicate that on certain clay 

 soils potash fertilizers are not needed. 



The farming of light soils with special reference to the use of potash salts, 

 KiTziNGER (Jahrb. Dent. LandiD. GescU., 22 (1907), Ao. J,, pp. 741-752). — This 

 is a popular statement of practical experience in improving light sandy soils, 

 by proper rotations and methods of fertilizing, particularly with legumes and 

 potash salts as proposed by Schultz-Lupitz. 



The solvent action of soil bacteria upon the insoluble phosphates of raw 

 hone meal and natural raw rock phosphate, W. G. Sackett, A. J. Patten, and 

 C. W. Brown (Michigan Sta. Spec. Bui. J/S, pp. 3-30). — This is a preliminary 

 rei)ort covering 2 years' work and over 500 determinations, the purpose of 

 which was " to demonstrate quantitatively, if possible, the extent to which the 



