320 EXPERIMENT STATION RECORD. 



lil/oci/iiiKiis. iinuluciHl M slijilit (IcnitriticMtioii. When the chernozem soil was 

 sterilized, however, and inoculated with the or>janisni and with soil extract 

 containing various other organisms, denitritication was quite marked, especially 

 when fertilizers were added, and the soil nitrates were completely decomposed 

 when straw was added to the extent of 4 per cent of the soil. 



Experiment in inoculation of an old cultivated soil with nitrogen bacteria, 

 N. X. ISlandov ( \!icsttilh- Hakt. AyUion. Htanlzil V. K. Ferreln, 1907, No. 13, pp. 

 lJf-16). — On one plat clover soaked with the culture was sown and on another 

 clover not so treated. Oats were used as a cover crop in both cases. The first 

 year no mark"d difference in the yield of clover was observed, but the next year 

 the yi(>l(l li-oin the treated seed exceeded by 50 per cent that from the untreated 

 seed. 



Tubercle bacteria and clover sickness, L. Budinov {Vyestnlh Bakt. Aghron. 

 Stantzil V. K. Fcrrein, 1907, No. IS, pp. 17-109, dgms. 10).— On the basis of 

 several years' observations on the subject the author describes in detail the 

 characteristics of clover from clover-sick soil as compared with that grown on 

 normal soil. 



Apparently the most characteristic difference was found in the rate of 

 development of the root tubercles, and the author concludes that clover sick- 

 ness is due to a weakening of the virulence of Bacillus radicicola in conse- 

 quence of which the organisms are unable sufflciently to infect the root system 

 of the clover plant and form the necessaiy tubercles. As a result the plant 

 is unable to fix atmospheric nitrogen with sufficient energy to develop normally. 



The beneficial effect of applying phosphatic and potash fertilizers to clover- 

 sick land is ascribed not only to the favorable action of the fertilizers on the 

 plant host but also to their action in increasing the life activity of the nitrogen- 

 fixing organisms. 



Importance of physical studies of the soil, R. Roche {Bui. Inst. Egyptien, 

 5. ser., 2 {1908), No. 1, pp. Jt7-5.'t).—A. general discussion of this subject. 



The proportion of mineral constituents in granitic soils, C. Pekret {Prog. 

 Agr. et Vit. {Ed. VEst-Ccntre), 30 {1909), Nos. J,9, pp. 691-693; 50, pp. 728- 

 732). — This paper is based upon a 9 years' study of the granitic rocks and 

 soils of the Forez Mountain region of Saint-Bonnet-le-Chateau, Loire. 



As a result of this study the author maintains, contrary to the general con- 

 clusion reached by Risler that granitic soils are rich in potash and poor in 

 phosphoric acid, that the granitic soils in question are rich in both total and 

 assimilable phosphoric acid, and in many cases are benefited by the application 

 of potash fertilizers. 



The mineral composition of the rocks and the physical and chemical prop- 

 erties of the soils are discussed. Seventy per cent of the rocks of the region are 

 granitic, consisting essentially of quartz, feldspar, and black mica. There are, 

 however, variations of the type rocks with a corresponding variation in the 

 character of the soil resulting therefrom. 



Examinations of 5 samples of typical soils are reported, showing fine earth 

 varying from 31 to 88.6 per cent, nitrogen in fine earth from 0.06 to 0.4 per cent, 

 total phosphoric acid from 0.12 to 0.79 per cent, assimilable phosphoric acid 

 from a trace to 0.36 per cent, total potash from 0.41 to 1.18 per cent, assimilable 

 potash from 0.007 to 0.04 per cent, and lime from 0.003 to 0.95 per cent. 



Analyses of typical samples of the rocks from which the soils were formed 

 showed phosphoric acid varying from 0.19 per cent in gneiss to 0.56 per cent in 

 basalt. 



The results show beyond question that these granitic soils are well supplied 

 with phosphoric acid as well as potash. Fertilizer experiments with various 

 crops indicated that the phosphoric acid was to a large extent readily assiiaila- 



