17 



Miss. The Nitrifying Capacity of Some Mississippi Soils During 



Various Seasons* To learn (1) nitrifying capacities of rep- 

 resentative soils by seasons; (2) effect of addition of various 

 sources of NH/^ nitrogen and organic residues on rate of nitri- 

 fication; and (3) effect of soil pH on nitrification. 

 Agron. HD-9 



Miss. Factors Affecting Microbiological Break-Down of Organic 



Matter and Nitrogen Transformations in Southern Soils. Learn 



(1) rate and nature of microbial deccaposition of various plant 

 residues in soils and resultant effect on N status of the soil; 



(2) effects of the principal biological factors on mineraliza- 

 tion, iamobiliaation, and loss of N under diverse environmen- 

 tal and climatic conditions; (3) rate and extent of biological 

 oxidation of ammonia from varying sources at different depths 

 as affected by temperature, aeration, and moisture; and (4) 

 rate and magnitude of biological release of chemically fixed, 

 non-exchangeable ammonia in Southern soils. 



Agron., Soils RRFD-1 (S-35) 



N.J, Control of the Processes of Microbial Nitrification. 



Learn how rate of nitrate formation can be increased or de- 

 creased in soil. Learn if bacterial growth is limited by de- 

 ficiency or excess of medium constituents or by products of 

 growth, using chemostat to continuously supply new and remove 

 old medi\im. Test effects of cyanamide, dicyanodiamide, thiourea 

 and related compounds, mercapto compounds, chroma tes, and sul- 

 fite in inhibiting growth of nitrifying bacteria. 

 Agr. Microbiol. 402 



N.T. Biochemical Transformations of Soil Nitrogen. To determine 



(Cornell) effect of low temperatures on biochemical N transformations, and 

 make experiments on nitrification using a modified soil per- 

 fusion apparatus which maintains both temperature and pH. 

 Agron. 45 



N.Y. Biological Nitrogen Fixation. Critical tests of cytochrome 



(Cornell) hypothesis and nature of N fixation inhibition by CO. 

 Bot. 78 



N.C. Soil Transformation of Nitrogen Which Influence Availa - 



bility to ^rop Plants, (l) Study nature, magnitude, and fac- 

 tors controlling microbiological immobilization, mineraliza- 

 tion, nitrification, denitrification, volatilization of 

 ammonia, ammonia fixation, hydrolysis of urea and C3ranamide, 

 movement of inorganic ions, etc.; and (2) learn influence 

 of above soil transformations of N on availability of N to 

 Southern crops. 

 Soil 131 



