Treatment of Sick Soils 33 



bed previously contaminated. Fortunately, sick 

 soils in the greenhouse, unlike the soil outdoors, may 

 be readily treated so as to destroy all forms of para- 

 sitic micro-organisms or injurious animal life which 

 are present in it. The various methods to be men- 

 tioned make it possible to use the soil over and 

 again. Rid the soil of parasites, then all chances 

 will be in favor of good crops whether vegetables 

 or flowers. 



Soil Treatment with Formaldehyde 



When steam sterilization is not feasible, because 

 of the absence of suitable steam pressure, the for- 

 maldehyde treatment is the next best. With this 

 method we may control Fusarium, Rhizoctonia, and 

 P^thium in infected beds. It is doubtful, however, 

 if it will entirely eradicate eel worms from infested 

 soils. The method is as follows: the beds are thor- 

 oughly prepared in the usual way with all fertilizers 

 worked in and then the soil is drenched with a solu- 

 tion of formaldehyde composed of one pint of the 

 chemical (40 per cent, pure) to 30 gallons of water 

 applied at the rate of one gallon per square foot. 

 The solution should be put on with a watering can 

 and distributed as evenly as possible over the bed, 

 so as to wet the soil thoroughly to a depth of one 

 foot. It will, in most cases, be necessary to apply 

 the solution in two or three intervals, as the soil 

 may not absorb the full quantity of the liquid at 

 one time. After treatment the beds should be cov- 



