Treatment of Sick Soils 43 



When the second bed is ready for sterilization 

 (it is directly on top of the one first sterilized)^ one 

 has a pit already dug to set the framework in for 

 the third batch, and from hence on, a pit will always 

 be in readiness for the framework. It will be seen 

 by this process and by such procedure that it be- 

 comes necessary to return one batch of sterilized 

 soil to the opposite end of the greenhouse, after the 

 whole house has been sterilized. This is the second 

 batch, which was sterilized and sets on top of the 

 first. This cannot be avoided, but the soil can easily 

 be carted back by means of wheelbarrows. 



Many greenhouses are irregularly constructed, 

 with uprights and other obstructions more or less 

 promiscuously scattered; therefore, the pan method 

 is often difficult to use and it is less easy with the 

 other unadjustable apparatus, but with the method 

 just described these obstructions are much less seri- 

 ous, since they can be allowed to come in any part 

 of the bed without hindrance to sterilization. 



There is a little more expense connected with this 

 method, on account of extra labor which is neces- 

 sary, but this method is not being advocated as a 

 superior way of steaming the soil, but rather to do 

 the work where situations arise that cannot be han- 

 dled otherwise. 



Effect of Soil Sterilization on Seed Germination, 

 The main object in sterilizing soils is to destroy the 

 harmful fungus flora. Of all the methods here 

 recommended, steaming is the most effective. Not 

 all soils, however, are alike benefited by this treat- 



