348 EXPERIMENT STATION RECORD. 



1819 is briefly reviewed, and experiments in glass cylinders filled with successive lay- 

 ers of fine soil (1 ram. particles) separated l>y filter paper to test the rate of absorp- 

 tion and depth of penetration of phosphoric acid in superphosphate solution, and 

 potash in chlorid solution, are reported. The surface of the soil in the glass cylin- 

 ders was covered with a filter paper and the solutions were poured on slowly, followed 

 by distilled water, until a given amount had run out through the tube at the bottom 

 of the cylinder. 



After a period of a month the successive layers of soil were removed, dried, and 

 analyzed. In the experiments three soils -siliceous clay, calcareous clay, and peat — 

 were used. Phosphoric acid was applied at the rate of 3,410 kg. per hectare, the 

 potash at the rate of 2,050 kg. per hectare. The phosphoric acid descended to a 

 greater depth and a larger amount passed through in case of the peat than in case of 

 the other soils, the siliceous clay standing next in these respects and calcareous clay 

 last. In the latter all of the phosphoric acid was retained comparatively near the 

 surface and none passed through. 



The potash was more uniformly distributed through the different layers of the soils 

 and in case of peat was to a large extent removed by repeated washing. 



The results indicate in general that'96.6 per cent of the phosphoric acid and 72 per 

 cent of the potash applied on the surface of soils is rendered insoluble before a depth of 

 8 cm. is reached. 



Influence of the humidity of the soil at various periods of development of 

 buckwheat on the yield of grain, I. A. Pulman ( Zhur. Opuitn. Agron. [Jour. Krjjt. 

 Laudw.~\, 5 {1904), No. 1, pp. 68-72). — Phenological observations by the author on 

 the growth of buckwheat during 20 years have led to the conclusion that good yields 

 of grain were obtained only when there was a sufficient rainfall during the period 

 between blossoming and fruit forming. 



To test the validity of this conclusion he made the following vegetation experi- 

 ments in 1903: Four pots were used and in all the optimum humidity, 34 per cent, 

 was at first maintained. The buckwheat plants (six in each pot) developed uni- 

 formly until the period of blossoming, at the beginning of which the humidity in 

 one pair of the pots was maintained as before at 34 per cent, while in the other it 

 was reduced to 24 per cent. As soon as the seed began to form, the humidity content 

 was again altered; in one pot of the pair with 34 per cent the humidity was reduced 

 to 24 per cent, while in one vessel of the pair with 24 per cent the humidity was raised 

 again to 34 per cent. 



The larger total yield and the greater number of good seeds were obtained where 

 the abundant supply of water was maintained, and in the author's opinion furnishes 

 a complete corroboration of his conclusion that for the yield of buckwheat seed the 

 humidity of the soil during fruit-building is of primary importance. — p. fireman. 



On the moisture of the soil, N. A. Dimo (Pochvovyedenie [Pidohgie], 6 (1904), 

 No. 1, pp. 45-58). — Observations were made by the author simultaneously on meadow 

 and forest soils of the same character, viz, heavy clay alluvium which becomes more 

 friable at a depth of 65 to 85 cm. and then passes into a yellowish-white river sand. 

 The surface is quite level, and the underground waters are rather near the surface. 



Twenty-eight observations made during a period of 103 days (from May 21 to Sep- 

 tember 1) at depths varying from 10 to 140 cm. are reported. The mean percentages 

 of moisture to a depth of 25 cm. was in meadow soil 18.32 per cent, in wood soil 21.51 ; 

 in the soil layer at depths of 50 to 140 cm., 18.63 in meadow soil, 14.29 in forest soil; 

 the average for all depths 18.53 in meadow soil, 17.30 in forest soil. 



From these data the author concludes that (1) the mean values of the moisture of 

 the soil for the entire depth and during the whole period are very close for both the 

 meadow and the woods soil; (2) the surface layer from to 25 cm. is more moist in 

 the woods than in the meadow; (3) the deep layers, on the contrary, are more moist 



