ANNUAL REPORT, 1932 , 13 



Effect of Varying Amounts of Moisture and Organic Materials on Soil 

 Nitrates. (M. H. Cubbon.) Nitrate nitrogen was produced in large quantities 

 in potted soils which had been treated with different (and large) amounts of 

 domestic peat and manure. The moisture content was purposely varied in differ- 

 ent pots. Nitrates increased with increase of moisture up to about 35 per cent. 

 Nitrate nitrogen disappeared from the soil, or was greatly reduced, when turnips 

 began to grow vigorously. Soils which received excessive amounts of manure 

 (80 tons), or peat equivalent to 20 tons of manure, maintained a relatively high 

 nitrate nitrogen content throughout the growing season. (This is part of a study 

 of factors affecting "dark center" of turnips, in cooperation with the Department 

 of Olericulture.) 



Fine Turf Grasses. (L. S. Dickinson.) Further studies have been made 

 regarding the desirability of pre-seeding fertilization of newly built or newly seeded 

 turf areas, and a check experiment has been conducted to verify the results ob- 

 tained in 1931. Nitrogen, phosphorus, and potash were applied singly and in 

 combinations prior to seeding with Kentucky bluegrass and Colonial bent. The 

 check experiments were conducted in deep boxes, placed out of doors and unpro- 

 tected. The results obtained again indicate that on normal soils pre-seeding 

 fertilization with anything but superphosphate or a single phosphorus carrier is 

 unnecessary'. Also, that stronger young plants are obtained without pre-seeding 

 nitrogen and potash, and that the plants will more economically use fertilizer 

 applied as a top-dressing when they are from 60 to 70 days old. This project was 

 made possible by the New England Greenkeepers' Association. 



The plots maintained in cooperation with the United .States Golf Association, 

 and the nine-year-old lawn plots on one of the regular campus lawn areas, are the 

 only plots that are now being maintained, due to the decrease in funds. 



A new project, made possible by Brague Inc., has been started to determine the 

 advisable amounts of peat to be mixed with various types of soil to improve the 

 physical condition. This involves a study of methods of determining, easily 

 and quickly, yet with practical reliability, the physical strength of soil samples. 

 A study is being made, also, of methods of establishing definite soil standards to 

 use in comparative work. 



DEPARTMENT OF BACTERIOLOGY 

 Leon A. Bradley in Charge 

 Nitrogen Fixation in the Presence of or as a Result of Legumes Versus 

 Non-Legumes. (J. E. P'uller.) Additional studies have been made to deter- 

 mine the activity of nitrification and carbon-dioxide evolution, for the purpose 

 of comparing these activities with nitrogen fixation in the same field in which pre- 

 vious studies have been made. Dried blood and ammonium sulfate respectively 

 were added to the soil, and the rate of nitrification of these substances was deter- 

 mined. Carbon-dioxide evolution was determined from soil samples to which oat 

 straw had been added. All of the experiments were carried out in pots in the 

 laboratory. The soil samples studied represented two lots, one lot having been 

 collected before the field was plowed in the spring, and the other in the fall after 

 the crops had been harvested. No infiuence was observed, on the part of the 

 legume crop as compared with the non-legume crop, on nitrification or cellulose 

 decomposition. A paper describing the study in detail has been accepted for 

 publication in Soil Science, 



Influence of Temperature on the Nitrate Content of Soil in the Presence 

 of Decomposing Cellulose. (J. E. Fuller and L. H. Jones.) This study was 



