SOILS — FERTILIZERS. Yl? 



(lie Ki'owiiif: i)(>rio(l of various crops. The crops were wheat, medic, and fall- 

 sovvu rai»e followetl by corn. Samples of soil were taken from to 10 in. and 

 from 10 to 20 in. 



It was observed that the average amount of nitrates found in the case of 

 wheat and of rape and corn was greater in the lower stratum, l)ut with medic, 

 esiK'cialiy in summer and autumn, the average amount was greater in the 

 upper stratum. For all crops named the smallest quantity was found in Febru- 

 ary, Marcii, and .Tune, and the largest quantity from July to December. The 

 author tliinks the greater amount in the upper stratum in the case of medic 

 is due to the fact that the roots of this plant have tubercles which absorb less 

 nitrates in the upper stratum of the soil, while wheat, rape, and corn have 

 abundant absorbing roots near the surface. 



Determinations were also made of the nitric nitrogen in the soil moisture 

 with the result that the least was found in March and .Tune and the most in 

 August, that is, at the time when the soil has least moisture. 



These experiments were terminated at the end of the third year, so that 

 sutlicient data were not obtained to warrant definite conclusions. 



White mustard in its relation to nitrogen assimilation, O. Lemmermanx 

 and E. Blanck {Lnndw. Vcrn. Stat., 69 (1908), No. 1-2, pp. 1 -',5-1 60). —The 

 e.\i)eriments reported were conducted for the purpose of determining more 

 definitely the influence of white mustard on the nitrogen content of the soil. 

 The results and views of different investigators are briefly noted and the 

 authors' own work is described. 



Tlie results of soil analyses made showetl that during the period of vegeta- 

 tion a soil growing peas had a higher nitrogen content than the same kind of 

 soil gi'owing l)arley and nuistard. It was further found that if during the 

 l>eriod of growth any nitrogen assimilation in the soil took place the ipiantlty 

 assimilated in the soil growing mustard was not greater than that in the soil 

 Itnulucing l)arley. 



To samples of soil from these different iilats weighing 1,000 gni. was added 

 20 gm. of sugar as a source of energy to the soil bacteria. Analyses of these 

 sjunpies were ma<le 4fi and 02 days after this treatment. Analyses of the soils 

 from the diflereut i)lats without the sugar treatment showed that under the 

 inHuence of mustard roots no nitrogen increase in the soil had taken place. 

 (Ml the other hand, the samples treated with sugar showed marked differences 

 ill the nitrogen assimilated, from which the authors conclude that in all these 

 soils iiitntgen-assimilating organisms were present. After 40 days the barley 

 soil siiowed 1.4r).S nig. of nitrogen per 100 gm. of soil, the mustard soil .3.232 

 nig., and the pea soil 1(5.402 nig. For the 92-day period the figures were G.SSG, 

 !».i:!2, and 14.!)2(; mg., resiiec-tively. 



Work of the chemical laboratory of the Ploti Experiment Station, 1907, 

 r.. WKi.iua. and A. Winkj.er ((ihodlchnni'i Otclict I'lotj/. Sclsk. Klio.::. Opuitu. 

 Stanlzi'i. l.i (/.W7), pp. 1().',-Ui0, /7J-/.'*/ ).— Tlie work here reported followed 

 ill the main the same lines and confirmed in large measure th<» results of |)re- 

 vioiis invt'stigalions (F. S. R., 10, ji. 02.*i), but in view of the fact that condi- 

 tions are more or less abnormal in lysimetors the field studies on nitrification 

 were exteiuh'd during the year and were supplemented by pot and box experi- 

 ments on (he same soils. This rejtort de.-ils more particularly with the results 

 of studies of nitrification in plats occuiiied by spring and winter wheat and by 

 fallow. On the spring wheat plats the intluence of previous crojts of leguminous 

 plants, cereals, or (hret; years' bare fallow was studie<l, and on the winter 

 wlieat plats the iiiHueuce of difl'erenl kinds «)f fallow (black and green) and of 

 farm nianm-e. 



