soils FERTILIZERS. 17 



described in detail. These met lux is involve 2 series of operations, I l | i In- separation 

 of tin- unaltered sand by means of chemical reagents, ami (2) tin- separation of the 

 differenl minerals which are present. 



Denitrifieation of soil, III, <.. A.MPOLA (Gaz. Chim, liul. , .;; [1904), //, pp. 

 SOI 815; abs. in Jour. Chem. Soc. | London], 88 \ 1905), No. 509, II. p. 194). Studies 

 are reported w hich lead to the follow ing conclusions: 



Applications of calcium and sodium nitrates give better results than no uitrate, the 

 calcium nitrate being more effective than the sodium nitrate. Green manures give 

 Letter results than well-rotted Btable manure, the latter better than fresh stable 

 manure, and fresh stable manure better than straw. The general conclusion, con- 

 firming results previously obtained, is thai calcium nitrate, a natural producl of 

 nitrification, is a better fertilizer than sodium nitrate. The calcium salt, moreover, 

 offers greater resistance to the action <>f the denitrifying organisms than the sodium 

 salt, denitrifieation depending mainly upon the character of the organic matter of the 

 manure. 



The author believes thai danger from denitrifieation in the soil may be wholly or 

 partially obviated only when the organic substances have been decomposed that is, 

 when the denitrifying organisms have been reduced to a state of inactivity. 



Experiments on the accumulation and utilization of atmospheric nitrogen 

 in the soil, E. I>. Voorhees and .1. <i. Lipman (Jour. Amir. Chem. Soc, <; \ 1905), 

 No. 5, />/>. 556-589).— A series of pot experiments are reported which were designed 

 to show the relation of leguminous crops, such as cowpeas, to soil nitrogen and to 

 determine as far as practicable the value of such crops as a source of nitrogen to ,ul,- 

 sequenl nonleguminous crops. 



"The facts established in this experiment are of very considerable practical impor- 

 tance, even though the experiment itself was carried out under conditions more or 

 less artificial. They demonstrate, in no uncertain manner, that the bacterial activi- 

 ties that concern the gain and loss of nitrogen in the soil are manifold and complex, 

 and yet susceptihle of differentiation. Evidently there was a gain of nitrogen in the 

 box soils by means of symbiotic fixation where the cowpea crop was grown." 



Substantially the same matter has been published as Bulletin 180 of the New Jersey 

 Stations | E. S. R., Hi, p. L063). 



The absorptive property of th.3 leaf cover of the soil of forests, E. Henry 

 (/>'/>/. Soc. Sci. Nancy, 8. ser., 5 I 1904), No. 2, pp. 105-115). — Studies by Calas's method 

 of the absorptive capacity for water of the undisturbed leaf cover of one square meter 

 of forest soil showed that a cover of pirea needles absorbed 418 gm. of water per 100 

 gm. dry weighl of cover, and beech leaf cover absorbed 538 gm. 



The varying absorbent power of soils for bone superphosphate and mineral 

 superphosphate, ('. Montanari (Staz. Sper. Agr. Ttal., 88 { luor,), No. 8, pp. ?58- 

 958). 



Agricultural phosphate, Bachmann (Fuhling'& Landw. Ztg., 54 (1905), No8. .', 

 pp. .;.'>-•'/; 8, pp. 84^-90; 4, pp- 186-142; 5, pp. /:; 1&5). — A series of comparative tests 

 of this phosphate and Thomas slag on a variety of crops grown on loam and sandy 

 soils are reported. 



The "agricultural phosphate" used was a crude phosphate containing 22 to 24 per 

 cent of total phosphoric acid. The Thomas slag contained about 20 per cent of total 

 phosphoric acid, of which about 1<> percent was soluble in citrate solution. The 

 results show that the two phosphates were aboul equally effective on the loam soils, 



hut that the " agricultural phosphate" was somewhat less effective than Thomas 

 Blag on the Bandy soils. 



Fertilizer experiments with calcium cyanamid on common soils and on 

 moorland, II. vo.x Feilitzen {Sm^hn Mosftkulturfdr. Ttdskr., 19 (1906), No. £, />/>. 

 100-iw, figs, j). — Experiments conducted during the season of 1904 with barley, oats, 

 wheat, and potatoes indicated that this fertilizer on certain soils, like clayey and 



