SOILS FERTILIZERS. 621 



The conservation of our natural resources, especially with reference to 

 the soil, C. R. Van Hise (P)-oc. Ann. Conv. Farmers' Nat. Cong. U. 8., 28 

 (1908), pp. .'iS~50).— The causes of declininf,' fertility are briefly discussed and 

 the sources of supply of fertilizing materials are described. 



Fertilizers and milk production, P. Pipeks (Ciiltura, 21 (1909), Wo. 250, 

 pp. 332-S.'/7). — Experiments with cliemicnl fertilizers on grass land in nine dif- 

 ferent localities in Holland \ver<' made to determine the effect of such fertilizers 

 on the quantity and quality of tlio crop. The fertilizers used were 44,5 lbs. 

 of superphosphate and a like amount of potash salt per acre, and one plat 

 received in addition i;>4 lbs. of nitrate of soda per acre. 



It was found that nitrate of soda produced a greater increase in the amount 

 of hay than the superphosphate and potash. Not only was tbe total amount 

 of raw and digestible protein increased by the use of chemical fertilizers but 

 also the percentages of protein, fat and mineral constituents in the hay. The 

 percentage of carbohydrates was practically unchanged. The percentage of fiber 

 was slightly increased, but the proportion between the fiber and the protein 

 and fat was lowered. 



General conclusions are drawn as follows : In Holland and Belgium grass lands 

 occupy an important place ; the use of chemical fertilizers increases iind im- 

 proves the crop from these lands; the milk production is increased and improved 

 by the increase and improvement of the hay crop ; therefore, the national wealth 

 would be increased by the pi'oper use of chemical fertilizers. 



Investigations on the fertilizer requirements of different soils, O. Kellner 

 (Sachs. Laiulii: Ztschr., 57 (1909). Xo. 25, pp. J,68, -'/6\0).— This article gives in 

 brief the results of systematic pot experiments to determine the fertilizer 

 i-equirements of samples of soil from different parts of the Kingdom of Saxony. 



The diffusion of saline fertilizers in the soil, A. Muntz and H. Gaitdechon 

 (Ann. Sci. Agron., 3. ser., J, (1909), I, Xos. 5, pp. 319-1,00, figs. 22; 6, pp. J,01-J,ll, 

 figs. 8). — This has already been noted from other sources (E. S. R., 21, p. 23). 



Some improvements in sand culture, T. Takeuchi (Jour. Col. Agr. Imp. 

 Univ. Tokyo, 1 (1909), No. 2, pp. 197-202, pis. 3).— Comparative tests with rice, 

 oats, barley, and wheat, of Hellriegel's culture solution and of modifications pro- 

 posed by the author are reported. With a view to decreasing the amount of 

 soluble salts, supplying insoluble ingredients readily available to plants, and 

 securing a neutral reaction as far as possible during the period of growth, the 

 author uses nitrogen in the form of ammonium nitrate, phosphoric acid as a 

 mixture of monopotassium and dipotassium phosphate, lime and magnesia 

 as finely gi'ound natural carbonates in a favorable ratio for common cereals, a 

 small amount of gypsum and sodium chlorid, and iron as ferric hydroxid. 



The fixation of atmospheric nitrogen, P. Vageler (Die Bindung dcs atmos- 

 phUrischen Stickstoffcs in Natur intd Technik. Brunswick, 1908, pp. 132, pis. 5, 

 figs. 11). — This book treats briefly of the principal sources of combined nitrogen, 

 the fixation of nitrogen without the intervention of organisms, the fixation of 

 atmospheric nitrogen by free living bacteria, the fixation of nitrogen by bacteria 

 and other micro-organisms in symbiosis with green plants, inoculation of the 

 soil with tubercle bacteria, leguminous plants as nitrogen collectors in practice, 

 and the fixation of atmospheric nitrogen by technical processes. 



The technical utilization of atmospheric nitrogen, E. Donath and K. 

 Frenzel (Die technische Ausnulzung dcs atmosphdrisvhcn Stickstoffcs. Lclpsic 

 and Vienna, 1907, p. V+250, figs. 69).— This book treats of the chemical and 

 physical methods of preparing nitrogen compounds from the air, the theory and 

 practice of nitrogen combustion, the synthesis of ammonia from its elements, 

 nitrids and their use in making ammonia, and cyan compounds from the air. 



