126 



HATCH EXPERIMENT STATION. 



[elan. 



given here we made use of a similar soil, namely, a yellow 

 subsoil loam, containing little organic matter. Eight i)ots 

 were selected, four of which contained loam and four sub- 

 soil. Of these, two each of the loam and subsoil pots were 

 sterilized, and two each of the remaining pots were left un- 

 sterilized. The results follow. 



Table shoiving Orowth of Soy Bean in Sterilized and UnsLerilized Loam 



and Subsoil. 



Loam, 

 Subsoil, 



Total 

 Number 

 of Pots 



used. 



Average Length (cm.) of 

 Stems in — 



Unsterilized 

 Soil. 



Sterilized 

 Soil. 



9.53 

 9.79 



10.87 

 4.14 



Gain (+^ or 



Loss ( — ) in 



Sterilized 



Soil (Per 



Cent.). 



+ 14.05 

 — 57.70 



The number of seeds o-erminated in unsterilized loam and 

 soil was 30, that for the sterilized 34, showing a slight gain 

 in favor of sterilization, which is unimportant, considering 

 the small number of seeds used. There is also a gain in 

 height of loam plants of 14 per cent, in favor of steriliza- 

 tion, while in the subsoil series there is a loss of 57 percent, 

 due to treatment. The subsoil pots also showed a poor, 

 sickly development. This corresponded in every way with 

 the results obtained by Mr. Parker in his experiments. 

 This experiment shows, among other things, that extreme 

 precaution is necessary in drawing deductions from experi- 

 ments in which the soil is sterilized, especially where inocu- 

 lation work is undertaken in connection with soil organisms. 



Influence of Soil Sterilization ox Seed Germination. 



In a previous report ^ the results of a similar series of ex- 

 periments were described, and this pajier is a continuation 

 of the earlier one. As in the preceding series, the seeds 

 selected were in most cases from an old lot, which possessed 

 a rather low germinating capacity. The object of these 

 experiments was to ascertain the degree of acceleration in 

 germination which would result from ])lant scred in steril- 



* Fifteenth annual report of the Hatch Experiment Station, p. 41, 1903. 



