930 



EXPERIMENT STATION RECORD. 



This fact is brought out iu the following results of experiments with 

 artificial soils: 



Nitrification in artificial soils of different composition and water content. 



First series, Jan. 14 to Mar. ,.\\ tern 

 perature 26°-27° C. 



SoilNo.l 



Soil No. 2 



Soil No. 3 



Soil No. 4 



Soil No. 5 



Second series, July 17 to Nov. 1. tern 

 perature <>( laboratory. 



Soil No. 6 



Soil No. 7 ■ 



SoilNo. 8 



SoilNo.9 



SoilNo. 10 



SoilNo. 11 



Third series, April 1 to June IS, tern 

 perature 26 t '. 



Soil No. 11! 



Soil No. 13 



Composition of the soil. 



Sand. ( 'lay. 



Chalk. 



Grams, drams. Grams. Grams 

 10 

 10 

 10 

 10 

 10 



9.5 

 9.5 

 9.5 

 9.5 

 9.5 

 9.5 



10.6 

 11.5 



Sulphate 

 of am- 

 monia 

 added 

 = nitric 

 nitrogen. 



Mg. 



40.9 

 40.9 

 40.9 

 40.9 



40.9 



81.8 

 .81.8 

 81.8 

 81.8 

 81.8 

 81.8 



54.5 

 54.5 



Nitric 

 nitrogen ; Percent- 



at end I age 

 ofexper- nitrified. 



iment. 



Mg. 



34.1 

 38.5 

 36.2 

 23.5 

 4.23 



51.2 

 54.1 

 77.1 

 81.9 



17 



43. C 

 55.9 



Per cent. 

 83 

 94 

 89 

 56 

 10 



63 

 66 

 94 



100 



21 

 2.7 



80 

 100 



It will be observed that in case of soil No. 11, in which the nitrifica- 

 tion was lowest (2.7 per cent), it was only necessary to increase tlie 

 water content from 9.5 gm. to 11.5 to render nitrification complete. It 

 is evident that it was not air but water which was deficient in the soils 

 containing 25 per cent or more of clay. A very slight increase of water 

 was sufficient to convert almost absolute inactivity into complete nitri- 

 fication. 



Influence of light, humidity of soil, and depth of cultivation on 

 the position of the stooling node of winter rye, D. 1ST. Pryanish- 

 nikov and E. Boarlyuk (Izv. Moscow SelsJcoJchoz. Inst., 3 {1897), 77, 

 l>l>. 17-19). — The experiments were made in 18 cylindrical glass vessels 

 filled with field soil. One half of the vessels had full illumination, while 

 the other half was shaded. Three degrees of humidity were maintained, 

 30, 55, and 80 per cent of the maximum water capacity of the soil, and 

 the depth of cultivation was about 0.8, 2, and 3 in. In each vessel 10 

 grains of rye were planted. The results obtained led to the following 

 conclusions: The deeper the grain is seeded the deeper the stooling 

 node, but not in the same degree, since the lowering of the node does 

 not keep pace with the increase of depth of the seed. Shading brings 

 the stooling node nearer to the surface. 



These two conclusions relate to the first stooling node. The tend- 

 ency to form a second node increases with the depth of planting. The 

 position of this second node is strongly intiuenced by the conditions of 

 illumination, but not by the depth of plan tin g. In regard to the influence 



