33G 



in regions where the cultivation of these plants has been carried on for 

 many years the soil is full of lupine bacteria. 



In such a region a quantity of surface soil was jTocured fr<»in a field 

 where lupines had been raised, carried to Bernburg, and used for 

 inoculation in the field trials. For these latter a number of nar- 

 row strips of the experimental fields of the station were i>lanted with 

 yelh)w, bhie, and white lupines. On some of these strips the lni»ine 

 soil Avas applied in diflerent quantities and plowed under to ditterent 

 depths, while other strips received none of the lupine soil. Tlie quan- 

 tities of inoculating soil used on the diflerent strips were 10, -."». .">(». 1(M». 

 and liOO Centner per hectare, or from 440 to 8,025 pounds av<»ir(liii)ois 

 l>er acre. Similar experiments were made with serradella. 



Tlie field was in pretty fjiir condition as to manuring, so that even 

 the i)laiits which were not inoculated could develop tolerably well by 

 feeding on the nitrogen of the soil. Nevertheless the efte*^t of the 

 inoculation was ]dainly manifest on all the strii)s. At the time of 

 blooming all i»lants which had been treated with lui)ine soil were easily 

 distinguishable to the eye, even at a distance, by their greener color 

 and better develoi)ment. The differences in the ])lants with the difler- 

 ent (plant it ies of inoculating soil were likewise jilainly visible, tlu' ettect 

 increasing with tin* amount ai)plied; in<leed with the largest (piautity 

 the eflect was excessive, so that in some places the plants lo<lged. The 

 inoculation was equivalent in effect to the addition of nitrogenous 

 manure. 



In Older to compare the ])lants, and especially the roots, pi»'ces 1 

 squiire meter in size were dug out of the diflerent strips. Here again 

 the ('fleet of th«' inoculating soil was jdaiu. In strips without ino<'ula- 

 tion there were some ]dants, espe«ially among the yellow lupines, which 

 had root tubercles, but the tubert-les Avere generall.\ on the braui-h 

 ro<tts ;iml not very well develojied. The inoculated plants, however, 

 had large, healthy tubenles on the immIu roots, and the nundx'r of 

 tub.M'cles increased with the incn'ase in the (|uantity of soil used lor 

 inoculation. lJi)on tin- strips which h:id not been imiculated from 1M> to 

 liKi per cent (jf the i>lants of the blue an<i \\hit<*, lujiines were foun<l to 

 be \\ilii(Mit tubercles, while on the inoculated strips from 74 to HM» per 

 cent had tubercles, the number varying witii the amount of inoculat- 

 ing soil. There is no doubt that when the (piautitative yields of the 

 ])lants iire determined tliey will show nutal)Ie increase with the im>cu- 

 latiiui. 



These exiieriments of the last few years, biken altogether, comjdet^^ly 

 confirm the i>iopositions set forth as the result of the earlier investiga- 

 tions by the station.— fW. O. A.] 



Experiments in the assimilation of nitrogen by leguminous 

 plants, F. Nobbe, E. Schmid, L. Hiltner, and E. Hotter [L<in<lic. 



\'t IS. stilt., v. /(/*. ..'.T- .'"<''). — 'i'lie e\|ieriMients heie lejioited were car- 

 ried out duiing l.S!K» at the expeiinient station at Tharaud, Saxony. 



