Steam Sterilizatiox on WATER-SoLUiiLE Matti:k ix Soils. 255 



Fig. 68 — Showing better growth on Soil i\o. i seven months after steaming 



G A S — Soil No. I, steamed 

 G A O — Soil No I , unsteamed 

 P A O — Soil No 2, unsteamed 

 P A S — Soil No. 2, steamed 



Soil productiveness as affected by steaming. 



Wheat was planted in the unsteamed and the steamed soils, and a moist- 

 ure content of about twenty-five per cent, was maintained during the 

 period of growth. The efTcct of steaming was to loosen the structure 



