SOILS FEBTILIZERS. 433 



Relation of phosphorus to permanent American ag^riculture, J. E. Whit- 

 church (III. Agr., llf {1910), No. Jf, pp. 22-25). — The widespread need of phos- 

 phates for the improvement of soils and the consequent importance of con- 

 serving the phosphate deposits of the country are discussed. 



Acid phosphate, C C. James (Hnicaii. Forester and Agr., 6 (1909), No. 11, 

 pp. .'il9-Ji22). — Tlie apparatus and methods employed in the manufacture of 

 acid phosphate are described as well as the chemical changes which the phos- 

 phate undergoes in the process of manufacture and in storage. 



The use of fertilizer lime, R. W. Thatcher (Washington Sta. Popular Bui. 

 19, pp. -'/). — A popular edition of Bulletin 88 previously noted (E. S. R., 21, pp. 

 224, 291). 



Concerning the influence of various relations between lime and magnesia 

 on the development of plants, II, L. Bernardini and A. Siniscalchi (Ann. 

 R. Scuola Hup. Agr. I'ortUi, 2. ser., 8 (IDOS), pp. 19). — This is a continuation of 

 work previously noted (E. S. R., 20, p. 728). The study here reported had in 

 view: (1) To determine what influence was exercised by the relation between 

 lime and magnesia u])on the assimilation of phosphoric acid by the i>lant; (2) 

 to determine if an antagonism between lime and magnesia exists in the veg- 

 etable organism. 



In the first series the cultures were made in a nutritive solution, with plants 

 of wheat, barley, and corn, germinated in pure quartz sand. The nutritive solu- 

 tion contained, per 1,000 cc, 0.5 gm. disodium phosphate, 0.5 gm. potassium 

 sulphate, and 0.001 gm. iron chlorid. In addition each flask received per 

 1,000 cc. of solution such a quantity of calcium nitrate and of magnesium 

 nitrate that, while the quantity of the anion NO3 remained constant at 0.457 gm., 

 the ratios of lime to magnesia were 4 : 1, 2.5 : 1, 1 : 1, 1 : 2.5, and 1 : 4. The con- 

 clusion is drawn that the assimilation of phosphoric acid is dependent upon the 

 ratio of lime to magnesia ; increasing this ratio decreases the phosphoric acid 

 assimilated, and conversely, decreasing the ratio increases the phosphoric acid 

 assimilated. 



In the second series lupines were used in pot cultures. The conclusion is 

 drawn that the injurious action produced by an excess of lime and the poison- 

 ous action of an excess of magnesia in the soil is not due to the absolute 

 quantity of the ions Ca and Mg absorbed by the plant but to the ratio in which 

 they are absorbed, and hence that with the appropriate application of the salts 

 of calcium and magnesium it will be possible to correct the poisonous effects 

 on plants of an excess of magnesia or of lime existing in the soil. 



On the various correlations between lime and magnesia in the nutritive 

 solution, I. KoNovALOv (Zliur. Opuitn. Agron. (Russ. Jour. Expt. Landiv.), 10 

 (1909). No. 3, pp. 303-320; abs. Chem. Ahs., 3 (1909), No. 2//, p. 299/).— The 

 experiments here reported were a continuation of earlier work (E. S. R., 19, p. 

 827) and similar methods were used. 



The results of the water and sand cultures with wheat, lupines, Set aria 

 italica, and oats confirmed in general the results of the previous experiments. 

 The growth of the plants was injuriously affected when magnesia was present 

 but lime absent in the nutrient solution, and the yield increased with the 

 increase of the proportion of lime to magnesia. The results did not confirm 

 Loew's view that there is a definite lime-magnesia ratio for each plant. 



Manganese fertilizers, H. Rousset (Ann. Set. Agron., 3. ser., Jf (1909), II, 

 No. 2, pp. 81-111). — This is a summary of investigations relating to the occur- 

 rence of manganese in nature; the physiological role of manganese; the earlier 

 Japanese experiments with manganese as a fertilizer, particularly for rice ; 

 manganese fertilizers for other cereals, sugar beets, potatoes, and miscellaneous 



