ABSTRACTS 677 



The Effect of Some Manganese Salts on Ammonification and Nitrifi- 

 cation. P. E. Brown and G. H. Minges. Soil Science, 1916, 2, 

 67-85. 



The effect of the application to soils of manganese chloride, manga- 

 nese sulfate, manganese nitrate and manganese oxide, upon ammonifi- 

 cation and nitrification, is given, with the following conclusions: 



If manganese salts in small quantities increase crop yields on a 

 soil, that increase may be due, in part, at least, to a beneficial effect on 

 ammonification and nitrification, with a consequently greater produc- 

 tion of available plant food. 



On the other hand, if manganese salts when applied to the soil 

 restrict crop growth, that restriction may be due in part to a depres- 

 sion of bacterial activit3^ The amounts of manganese salts which 

 may be applied to any one soil without danger of depressing ammoni- 

 fication and nitrification are exceedingly variable. — Z. N. 



Environmental Factors Infiuencing the Activity of Soil Fungi. D. A. 



Coleman. Soil Science, 1916, 2, 1-65. 



The type of soil as well as the quality of the organic matter were 

 found to regulate the activities of the organisms used in the tests. 

 From the standpoint of pure cultures, every organism will do best 

 with a definite combination of soil and organic matter. As a general 

 rule, vegetable matter of high quality was conducive to greatest 

 activity. 



Different species of fungi respond with a very wide divergence to 

 the mechanical composition of the soil by which the oxygen sup- 

 ply is determined. Chemicals beneficial to one group or species 

 may be detrimental to other groups of organisms, suggesting a pos- 

 sible alteration of group relations among the microbes in the soil. 

 This is also true of the moisture content of the soil. 



The organisms employed were observed to have a very narrow tem- 

 perature range with an optimum of about 30°. — Z. N. 



The Yield and Nitrogen Content of Soy Beans as Affected by Inocula- 

 tion. J. G. LiPMAN AND A. W. Blair. Soil Science, 1916, 1, 579- 

 584. 



Soy beans were used for this experiment as they are less likely to 

 become inoculated spontaneously than other legumes which may be 

 used in tests of the value of commercial cultures for soil inoculation. 

 Moreover, the plants are rather hardy and may be made to grow with- 

 out difficulty under a wide range of soil and climatic conditions. 



Seven commercial cultures from different firms, and soy bean and 

 cow pea soil were compared with uninoculated checks. Nitrogen 

 accumulated was determined by the Kjeldahl method. 



The authors conclude that the use of inoculating material may be 

 very desirable in the growing of soy beans and perhaps other legumes. 

 It appears that where the soil is lacking in the right type of Ps. radi- 



