EFFECT OF TREE PRODUCTS ON BACTERIOLOGICAL ACTIVITIES IN SOIL

Publisher Website
Google Scholar
Abstract
One hundred and six samples of forest soils were collected aseptically. Azotobacter was found in 24.5%. There was no direct correlation between crop history or pH and presence of Azotobacter. It was found to remain in 47 out of 60 samples inoculated for over 18 months. Longer tests were not made. Five of the 24 samples tested for ability to fix N when inoculated and supplied with mannite as a source of energy fixed definite amounts of N. Sawdust, leaves, and needles were tested for effect on N fixation in solution. Sawdusts exerted very little inhibiting action, with the exception of cedar. Leaves and needles exerted a retarding influence. The retarding effect of these products on N fixation was not marked in soil, and applications of 1-2% sawdust resulted in stimulation. Thirty-one of the samples were tested for NH3 and nitrate accumulating ability. All showed ability to accumulate NH3 and all were decidedly lacking in ability to form nitrate from (NH4)2SO4 or blood. Sixteen of the soils were not benefited in this respect by addition of CaCO3, whereas 15 were greatly benefited. Soils not able to form nitrate were largety soils bearing virgin timber; those which formed nitrate were largely soils long under cultivation.

This publication has 0 references indexed in Scilit: