SOILS FERTILIZERS. 23 



plowed under ou the field where they grew and those grown in one field and 

 taken to another to be ptowed under. 



From the results of quite extended experiments the conclusion is drawn that 

 the green manure grown elsewhere is more effective than that grown on the 

 field itself. This greater effectiveness varies with climatic conditions, with the 

 nature Qt the soil, and the species of plants used, and is due to the fact that the 

 water taken up by the green manure crop is saved for the soil which is ma- 

 nured. This is important in dry regions and in periods of drought. 



Experiments with, certain fertilizer salts, S. de Grazia (Ann. R. St as. 

 Cliini. Agr. Six'i: Roma. 2. scr.. 2 [1907-S). />/>. ^7--'i9). — Experiments have been 

 carried on since 1903 to determine the effect of different quantities of the com- 

 moner kinds of fertilizer salts (muriate of potash, sulphate of potash, sulphate 

 of ammonia, and nitrate of soda) on the concentration of water solutions in the 

 soil and on the quality of the products obtained. Results for the current year 

 only are given. Large applications of these salts did not cause any great 

 decrease in the product. Muriate of potash did not cause a greater decrease 

 than sulphate of potash. Flax and wheat were almost equally responsive to 

 the kind of salt used. 



The difEusion of fertilizer salts in the soil, A. MiJNTZ and H. Gaudechon 

 (Ann. Inst. Nat. Agron., 2. sen, 7 (1908), No. 2, pp. 205-238, figs. 30; Compt. 

 Rend. Acad. Sci. [Paris], 148 (1909). No. 5, pp. 253-258, figs. 3; abs. in Rev. 

 Sci. [Paris], 47 (1909), I, No. 7, p. 219; Rev. Q6n. Set., 20 (1909), No. .',, pp. 

 151, 152; Jour. Chem. Soc. [London], 96 (1909). No. 557, II, p. 259; Cheni. 

 ZentM., 1909, 1. No. 11. pp. 936, 937; Chem. Abs., 3 (1909). No. 10. p. 1197).— 

 Obsei-vations on the rate of diffusion of soluble salts in different kinds of soils 

 under varying conditions of moisture, etc.. are reported, and the conclusion is 

 drawn from the results that the soil may be regarded as a discontinuous me- 

 dium in which even the most soluble substances diffuse only with extreme slow- 

 ness and in which there may exist simultaneously and for a long period zones 

 of very different composition unless uniformity is brought about by cultivation 

 or increase of moisture. 



The difEusion of fertilizer salts in the soil, P. Krische (IUus. Landw. Ztg., 

 29 (1909), No. 27. pp. 277-279. figs. 6). — A German translation of the above 

 article. 



Box experiments with fertilizers, Gi.ausen (Landw. Wchnbl. ScJilcs. Hoist., 

 59 (1909), No. 9. pp. 138-141). — Experiments with sulphate of ammonia. 40 

 per cent potash salt, and superphosphate on oats, clover, wheat, and beets in 

 boxes 1 meter square and sunk in the soil to a depth of 80 cm. are reported. 

 The boxes were surrounded by strips of soil cultivated and planted as in case 

 of the soil in the boxes. The value of this method of experimenting is dis- 

 cussed. 



Experiments with commercial fertilizers, especially kainit. on the Peter- 

 hof experiment farm, W. von Knieriem (Bait. Wchnschr. Landw.. 46 (1908), 

 JVo. 12, p. 109; abs. in Zentbl. Agr. Chem., 38 (1909), No. 1, pp. 17-20).— Expevi- 

 ments with superphosphate. Thomas slag, and potash salts on clover, potatoes, 

 and grain during a number of years are reported. 



The potash fertilizer was found to be especially beneficial to potatoes. It 

 was necessary, however, to apply it a sufficient time in advance of planting in 

 order that the injurious effects of the associated salts might be overcome. 

 Thirty per cent potash salt was better suited to potatoes than kainit. Next to 

 potatoes, clover was the crop most benefited T)y potash fertilizer. The highest 

 yields were obtained with a combination of kainit and Thomas slag. 



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