1024 EXPERIMENT STATION RECORD. 



addition to analyt^es of various rocks and minerals, detailed mineral analyses of clays, 

 soils, etc. 



On the examination of soils -with reference to assimilable plant food, O. 

 Kellner (Fi'tlilliK/s Lidnlir. Ztg., 50 {1901), No. i^,p}>. 71, 7-'). — Referring to Meyer's 

 recommendation (see p. UI20) that ammonium cblorid solution he used for the deter- 

 mination of the assimilable lime in soils, the author calls attention to his eariier 

 exiperiiiients with the same method which were Tvjported in 1887.' 



The determination of assimilable lime in soils, 1). Meyeh ( Fi'di/iiif/'s Ldinhr. 

 Ztg., 50 ( 1901), No. S, pp. 128, 129). — A reply to Kellner's claim of priority reirardincr 

 the method used by the author (see alK)ve). 



Need for humus in soils of Asrestern Kansas, K. W. Clothier {Indudrkdist, 27 

 (1901), No. 19, pp. 241-24.!). — A brief explanation of the causes of the decrease of 

 luunus in these so\\s and the urgent need of restoring it. 



What role does humus acid play in nature? H. Borntraoer {Oenterr. Cliem. Zty., 

 .)' {1900) , No. 21, p. 516). — The action of hunuis acid in absorbing moisture and fertiliz- 

 ing constituents and giving them out again as recjuired by the growth of plants is 

 briefly explained. • 



The cultivation of the soil in warm regions, G. Paturel [Ann. Agron., 'i7 

 {1901), No. 1, pp. 45-62, fig. 1). — This article describes the climatic conditions in 

 Tunis and reports results of experiments on the influence of cultivation on the con- 

 servation of moisture in the soil of the southern or arid portion of this country. The 

 results of these experiments show that by deep and thorough cultivation the rainfall 

 of the period from November to April may be stored and conserved to such an extent 

 that the growth of crops during the dry months, May to October, may be decidedly 

 promoted and the amount of irrigation required materially reduced. 



New problems in soil inoculation, J. S. Stoklasa, F. Duchacec, and J. Pitra 

 {Ztxchr. Lundw. Versuchaw. Oederr., 4 (1901), pp. 10-29; abs. in Cliem. Centbl., 1901, 

 r, No. 5, p. £69).— See E. S. R., 12, p. 325. 



FERTILIZERS. 



Phosphorite and green manuring, A. N. Engelhardt {Ztschr. 

 Lundir. Vei'-sac/mw. Ovftterr.^ J {1900)., pp. 6Sl-6Jfj8,' abd. in Cheni. 

 CentU.^ 1901, /, No. ^, p). '2S2).—Yxow\ 3 j^ears' field experiments the 

 author conchide.s that the soils which responded to applications of 

 tine-grotmd phosphorite were those in which the phosphoric acid was in 

 form of apparently unassimilable organic compounds not set free by 

 calcium carbonate (chalk). The fine-ground tmtreated phosphate was 

 especiall}' efiectivc on cereals, the efl'ect depending upon the percent- 

 age of calcium phosphate in amorphous form. The finer the meal the 

 more efl'ective the phosphate. The best restilts were obtained with 

 rye, but the following crop of oats was also benefited. When the 

 phosphorite was applied to r^e, oats, or flax, and these crops were fol- 

 lowed by a ci'op of rye to which barnyard mantire was applied, the 

 yield of the latter was much greater than that of rye which had received 

 onl}^ an application of barnyard manure. The ground phosphorite 

 can be profita})ly tised to supph' a deficiency of assimilable phosplioric 

 acid on all soils which contain a sufiicient amount of nitrogen, potash, 



iLandw. Vers. Stat., 33 (1887), p. 359. 



