SOILS FKRTILIZKRS. 819 



soil is I'iirrii'd dnwii into tiic sui)soiI wiicn' it is l)n)uj;lit into contact \vitli 

 ;.'yi»siini and converted into sodinni sulphate. In the warmer and drier portion 

 of th<> year the water containinij: this sulphate rises to the surface soil and 

 the sulphate is there again converted into carhonate. It thus hapi)ens that the 

 (•oniiK)sition of tlie alkali salts in tlie same soil is v«'ry variable at different 

 seasons of the year. 



Lime and phosphates in Khodesian soils, ,1. Caaikkon { JflKjdcsian Agr. Jour., 

 r> (IHOfO, .\o. .1. PI). I.',:, I. ',<!). ^It is slated that tlu' most marked feature of 

 UhiidesiaM soils is the low eonleiit of lime wjih ;i r.iflier sm.ill supply of phos- 

 iihates. Attention is al.so called to the calcareous and |)hosphatic deposits 

 which are found in ant heaps occurring on the soils. The core-lilve material 

 occurring in tliese heaps was found to contain .'is in>r cent of carbonate of 

 lime, 3.5 per cent of plio.sphoric acid, L' jier cent of majiuesia, and 3 per cent of 

 iron. It is believed that this material lias been fornie<l at the expense of the 

 lime and pliosplioric acid of the surrounding soils. When these moimds are 

 liroken up and scatten'd over the soils tlieii' fertility is greatly increase<l. 



Investigations on the fertility of noncalcareous soils, (1. Vatvhki/ {Prog. 

 A(jr. it \ it. (Ed. VEst-Vcntrc), 2'J {t'JOS), \o. .',(). ///». '//•'-'/~^)— This article 

 calls atteiitioji to certain soils which do not contain any calciinn carbonate and 

 yet are in many cases abundantly supplied with lime, generally in the form of 

 huuiate, which is easily soluble and assimilable by the roots of plants. 



Analyses of ."> sam]tles of such soils, containing from 0.;>2 to 1.15 per cent of 

 lime, are reported, as well as fertilizer experiments with one of the soils. A 

 .'sample of one of the soils containing 0.4!) per cent of lime yielded one-Hfth of 

 its lime (tn extraction with distilled water and 40 i)er cent on extraction with 

 1 per cent citric acid. 



10xi)eriments have shown that these soils are benefited by applications of lime 

 to only a slight extent, but that applications of phosphates produce marked 

 results. It is thought that superphosphates are likely to prove more etiicieut 

 on these soils than Thoiuas slag. 



The status of soil fertility investigations ( lUUiois Sta. Circ. t,i,i. pp. 3-.')6). — 

 This is a collection of documents relating to the controversy in connection with 

 the theories of soil fertility of the Uiu'eau of Soils of this Department. 



Chemical principles of soil classification, ('. G. Hopkins (Science', n. ser., 

 2S ( t;)08), \i). 12!), pp. 6'J7-.S(;.S).— This is an address delivered before the Ameri- 

 <"in Society of Agronomists at Cornell University in July, 1908, discussing the 

 (heories of the Hureau of Soils of this Department regarding soil fertility. 



Chemical principles of soil fertility, ('. (J. IIopki.ns (Nliiioix Sta. Circ. 12.'i, 

 Pl>. III). See abstract above. 



Bacteria for enriching the soil and for increasing the production of crops, 

 .\. .\. r.ANKK.iKi {Itrpt. .\tir. liciujiil. (^uiirl..l(ittr.. I ( I'lOS), .\o. }, pp. 22I-22S). — 

 This is a l»rief account of exiterinients in inoculating seed and soil with dry 

 iMilinres prep.-ired by this De|iartment and licpiid cultures |)repared in (Jermany 

 for the pr< dnction of cowpeas. The results, while not conclusive, indicate that 

 in certain cases decided benefit was derived from the use of the inoculating 

 Ujaterial. 



Notes on inoculation with Nitragin and inoculated soil in the culture of 

 leguminous plants and its importance in fruit and garden culture. H. IIkinzk 

 i I'rushiiH. (fftslhiiii /.III.. I.i UUIIS), .Vo.s. (/, pp. .S7-.'/,J.- 7. /)/'. tOd-lDU). Inocula- 

 tion by means of Nitragin or infeded soil is considered advisable in many ca.ses. 



Inoculation of gram seed with the tubercle-forming bacteria. .1. .M. IIayman 

 ' /I'y-/. Cnunpuri [hnliii] .\ijr. Stu., lUdl, pp. (JJ, 0"}).— I'ut and Held experimeuts 



