Treatment of Sick Soils 



45 



Table 3 



Date 



No. of Blossoms Picked 



Unsterilieed 

 Soa 



Sterilized 

 Sou 



Percentage 

 Gain \ 



November 



December. . . . 



January 



February 



March 



April 



Total.. 

 Average 



19 

 63 



55 



39 



144 



482 



38 



lOI 



125 



72 



250 



510 



100 



63 



127 



84 



73 



5 



801 

 133 



1,096 

 182 



-36 



Not only was production of flowers increased in 

 the sterilized soil, but there was also a decided de- 

 crease in leaf spots. 



Changes in the Soil due to Sterilization. Vari- 

 ous investigators have found that by steam heat- 

 ing, the physical, chemical, and physiological prop- 

 erties of a soil are more or less changed. Through 

 chemical action there is an increase of soluble mat- 

 ter in some of the inorganic substances such as pot- 

 ash and phosphoric acid as well as in the organic 

 matter. Ammonia is also formed by the reduction 

 of nitrates to nitrites and by the decomposition of 

 organic compounds, large amounts of which are also 

 made available for plant growth. This, then, would 

 explain the reason of the stimulation of growth in 

 sterilized soils. However, steamed soils may also 

 contain injurious substances, which upon becoming 

 soluble are harmful to plant growth and to the ger- 

 mination of certain seed. This seems especially the 



