SOILS FERTILIZERS. 25 



The results of these experiments are discussed in their relation to the results 

 of similar experiments by other investigators. They show .that soluble phos- 

 phoric acid aiiplied to the soil in the form of superphosi)liate is tixed in the 

 upper layers of calcareous soil as well as in soil poor in lime in a form insoluble 

 in water, but still readily available to i)lants. The fixed phosphoric acid tends 

 constantly to become more ditlicultly soluble. There is no danger of phosphoric 

 acid as applied in the usual way in fertilizers being washed out of the soil by 

 atmosjiherlc precipitation. In order to secure the best results superphosphate 

 should be applied in as finely divided condition as possible. Deep harrowing or 

 plowing in increases the effect. Very small amounts of the phosphoric acid 

 aiiplied on the surface sink deei)er than 30 cm. (11.82 in.) in the soil. 



The i)ot experiments showed that in certain cases in which there was no 

 increase of yield following the ai)plication of superphosphate there was, how- 

 ever, an influence upon the amount of phosphoric acid taken up by the plant. 



The content of phosj^horic acid in the drainage water was lower than the 

 solubility of tricalcium phosi)hate would indicate. It was about o mg. per liter 

 in calcareous soils and 2 mg. in granitic soils. 



Mineral resources of the United States, calendar year 1908. — Part II, Non- 

 metallic products (U. <S'. (icol. tiiirrcij, 1009, />/>. S9[K pi. 1, pys. U). — This is the 

 usual detailed report on this subject. The chapter of greatest agricultural in- 

 terest is that relating to phosphates (E. S. K.. 22, p. 227). In this article the 

 statistics are brought up to the close of the year 1908. 



Peat resources of the United States exclusive of Alaska, C. A. D.wis (Nat. 

 Conserv. Com. RiJt., 1909, vol. 3, pi>. -)Tb'--'/S2). — This article gives substantially 

 the same data as that contained in an article already noted (E. S. R., 21, p. 187). 



Lime and limestones, B. C. Aston {'Ncio Zeal. Dept. Ayr. Ann. Rpt., 17 

 (1909). up. 190, 191). — Analyses of a number of samples are reported. 



Seaweed as a manure (Field [London], 11.) (1910), \o. 2979, p. 16.5; Mark 

 Lane Expres.^ 103 (1910), A>j.s', .',093, p. 269; -',096, p. 369 ) .—Attention is 

 called to the importance and methods of use of seaweed in the production of 

 early potatoes in Ayrshire and Jersey, and evidence as to the fertilizing value 

 of inshore ware and tangle collected on the shores of the Firth of Forth is 

 sunnnarized. This evidence was submitted in a suit brought by farmers to 

 determine the compensation due them for deprivation of rights to collect this 

 seaweetl for fertilizing purposes. 



Analyses are reported which show thiit the inshore ware contains about 70 

 per cent of water, 0.43 per cent of nitrogen, 0.09 per cent of phosi»horic acid, 

 0.9 per cent of potash, and 0.5 per cent of lime; the tangle contains 85 per 

 cent of water, 0.26 per cent of nitrogen, 0.13 per cent of phosphoric acid, 1.58 

 per cent of potash, and 0.34 per cent of lime. The evidence tended to show 

 that the seaweed was fully equal, if not superior, to barnyard manure. 



The garbage question at Paris, Maurecours (Engrais, 25 (1910), Nos. 7, 

 pp. hS2-]S.'j; s, pp. 213-216). — The methods of handling and using Paris gar- 

 bage are briefly described, particular attention being given to the relative merits 

 of methods of incineration and rendering. It is pointed out that hygienists as 

 a rule favor incineration, while farmers prefer methods of rendering by which 

 the larger part of the fertilizing value of the garbage is made available for use. 

 The author is inclined to favor a combination of the two systems of disposal. 



Analyses of the fine powder obtained by systems of rendering which are now 

 in use show fertilizing constituents as follows: 0.6 to 1 [ler cent of nitrogen. 

 0.5 to o.S per cent of phosphoric acid, 0.4 to 0.6 per cent of itotash, and 4 to 6 

 l)er cent of lime, indicating that this material is superior in fertilizing value to 

 barnyard manure. 



