CONTENTS Vll 



tivation upon these conditions ; Nitrous acid organisms, ammonia- 

 producing organisms, denitrification, number and kind of organ- 

 isms in soils ; Inoculation of soils with organisms ; Chemical pro- 

 ducts produced by organisms ; Losses of nitrogen by fallowing rich 

 prairie lands; Influence of plowing upon nitrification ; Nitrogenous 

 manures ; Sources ; Dried blood, tankage, flesh meal, fish scrap, 

 seed residue, and uses of each ; Leather, wool waste and hair ; 

 Peat and muck ; Leguminous crops as nitrogenous fertilizers ; Sod- 

 ium nitrate, ammonium salts ; Cost and value of nitrogenous fer- 

 tilizers. Pages 97-130. 



CHAPTER V 



Farm Manures. Variable composition of farm manures ; Average 

 composition of manures ; Factors which influence composition of 

 manures ; Absorbents ; Use of peat and muck as absorbents ; Rela- 

 tion of food consumed to manures produced ; Bulky and concen- 

 trated foods ; Course of the nitrogen of the food during digestion ; 

 Composition of liquid and solid excrements; Manurial value of 

 foods; Commercial valuation of manure; Influence of age and 

 kind of animal; Manure from young and old animals ; Cow ma- 

 nure ; Horse manure ; Sheep manure ; Hog manure ; Hen manure; 

 Mixing manures ; Volatile products from manure ; Human excre- 

 ments ; Preservation of manures ; Leaching ; Losses by fermenta- 

 tion ; Different kinds of fermentation ; Water necessary for fermen- 

 tation ; Heat produced during fermentation ; Composting manures; 

 Uses of preservatives ; Manure produced in sheds; Value of pro- 

 tected manure ; Use of manures ; Direct hauling to field ; Coarse 

 manures may be injurious ; Manuring pasture land ; Small piles of 

 manure in fields objectionable ; Rate of application ; Most suitable 

 crops to apply to ; Comparative value of manure and food ; Lasting 

 effects of manure ; Comparative value of good and poor manure ; 

 Summary of ways in which manures may be beneficial. Pages 



I3I-I59. 



CHAPTER VI 



Fixation. Fixation a chemical change, examples of ; Due to 

 zeolites ; Humus and fixation ; Soils possess different powers of fix- 

 ation ; Nitrates do not undergo fixation ; Fixation of ammonia ; 

 Fixation may make plant food less available ; Fixation a desirable 

 property of soils ; Fixation and the action of manures. Pages 

 160-163. 



