492 



In the case of plat 3, therefore, the yield, ])ro«ln»ti(»ii it\' t nlicrcles, aii<l 

 (Icptli to which tho roots reached, as well as tlic iicncial growth of the 

 l»laiits. were favoiable to the iiiocnlatiou. 



Composition of drainage waters from bare and cultivated soils, 

 P. P. Deherain {Ann. Ayron., 17 {1^91)^ pp. IH-xi'; <th.s. in Forsrh. an/ 

 d. (Jch. d. (((jr. ritysik; 11 (1891), pp. 277-^x1). — In continuation of pre- 

 vious research, exijeriments are here rei)orted on the loss of nitrogen 

 by drainajfe under varying conditions an<l with difterent soils. 



Uncnltivntcd .soils. — The amount of nitrat«'s ajipeariny; in the draiuajr*' 

 waters from different soils from Marcli 1 to November 7 was found t»» 

 be (juite variable, and these variations seeme<l not to be attributable 

 to (liHereiu-es in rainfall. The amount (»f nitrates washed out was nunli 

 the smallest in the case of the soils richer in organic matter (humus), 

 which Warington and Winogradsky have shown to be unfavorable to 

 nitriti<-ation. 



Soils mnnuri'd irith ammonium sulphate. — A soil was used which had 

 been exhausted by cultivation. Vots filled with this (30 kg. eacli) 

 received 12 grams of ammonium sulphate (7(K) pounds })er acre) in the 

 fall of 1MS!> or received no fertilizer. From danuary (5 to duly 1."), IS'.io. 

 the unmanure<l soil gave oil <iHi mg. of nitrogen as nitrates in the 

 drainage water, and the manured L',r»ll mg. TIm' change of the ammo- 

 nium salt to iiitrat*' ]>rogress»'<l far nnue ra]»idly (luring the warm sea- 

 son than during the colder, for wliile only 'u'l mg. of nilrogen were 

 washe<l out by the drainage water Irum .laiiuary (» to March 1*1, L*,U.".'.t 

 mg. were removed Ix'tween .lune .'? and -Inly lo. In tin* >» months from 

 Novend)er, ISS!», to .Inly. 1S'.»0. the larger ])art. altliough not tlie whole, 

 of the nitrogen applied in the ammonium sulphates was removed liy 

 the drainag*' water. 



CuUiratcd soils. — Oats. hemp, rye grass. ]»eas. and cloM-rwere grown 

 in pots (1) in good soil without fertilizer and (li) in worn-out soil with 

 (mt fertilizer, and with dressings of mixed fertilizer containing (>..?-! 

 gram of nitrogen per pot; an extract of barnyard manure containing 

 Ki.Tl grams of organic nnitter and 1.47 grams of nitrogen per pot: and 

 the two combined, furnishing 1.7'J grams (»f nitrogen i)er pot. 



The pots were set in the air above ground. These conditi«uis, as tlu- 

 author remarks, wi're artificial in so far as the heating of the pots on 

 the sides made tlu' s(til in them wainier and dryer than that in the 

 Held. The higher temi»erature naturally conduced to a more inten.sive 

 nitrilication. while the increased dryness of the soil ha<l just the reversi^ 

 etfect. Taking the results as they are, however, the anu^unt of nitrates 

 in the drainage water seemed to dejuMul upon the kin<l of i)lants grown. 

 The indications are that the loss of nitrogen as nitrates by draimig«' is 

 very nnuh less with graminacemis than with leguminous plants. Thus, 

 while, roughly speaking, L'(» mg. of nitrate nitrogen p«'r pot was lost 

 from the oat and rye grass cultures. 'JOO mg. per i>ot was lost from the 

 pea and clover cultures. On the other liaml the (puiutity of drainage 



