SI 



accomplish this he states that it is necessary to have a boiler of some 

 25-horse power carrying at least 50 lbs. pressure of steam continually. 

 These are the only methods for sterilizing soil, so far as we are 

 aware, that have been described, and all of these methods have been 

 described within two or three years. 



In our experiments' relating to soil sterilization we have tried 

 many methods and found the tile system as used by Galloway cheap, 

 and satisfactory for many purposes, especially when w'e wish to ster- 

 ilize the soil in the bed in which the crop is to be grown. Another 

 advantage which it possesses is that it can be . used for subirri- 

 gating purposes. To ascertain the best method of using tile we 

 arranged them in beds of equal size containing the same amount of 

 similarly prepared earth. The beds were iS ft. long, 30 in. wide 

 and I ft. deep and each contained 45 cu. ft. of soil suitable for grow- 

 ing cucumbers. Part of the soil had been used 43reviously for 

 cucumbers and tomatoes and was well infested with nematodes, and 

 previous to sterilization it was mixed with fresh horse manure. The 

 beds contained a different number of feet of pipe which w^ere laid in 

 various ways and in each case they were placed about 2 in. from the 

 bottom. For details concerning the manner of piping see fig. I., 

 a, b, c, d, e. Bed (a) was piped with two lengths of tile without any 

 end connection. Bed (b) was piped with three lengths of tile with 

 end connections, thus forming a continuous circuit. Bed (c) was 

 piped with two lengths of tile with end connections and cross tile 

 every two feet. Bed (d) was piped with three lengths of tile as in 

 (b). Bed (e) was not piped at all. Each bed was treated separately 

 from a 4-horse power portable boiler having a pressure of steam 

 varying from 40 to So lbs. The steam was conducted from the 

 boiler through a half-inch pipe provided with a valve, and this led 

 into a I in. pipe, (tig. I., 1), which had a four way connection, the ends 

 of which were inserted into the free open ends of the tile. The con- 

 nections were easily made with the boiler and when one bed was ster- 

 ilized it was disconnected and the pipe attached to another bed. The 

 steam was confined by means of boards placed over the top, although 

 straw mats or blankets would have served the purpose better. The 

 valve regulating the amount of steam from the boiler was never 

 turned on more than half way, this being found sufficient to supply 



I. See Nematode Worm and Root Gall on Cucumbers and Tomatoes, New England 

 Farmer, Feb. 26, 189S. 



