CONTENTS. ix 



Fermentation of farmyard manure 



Action of micro-organic life in producing fermentation 30 

 Two classes of bacteria active in this work, aerobies and 

 anaerobies . . . . . . . .31 



Conditions influencing fermentation 



Temperature ........ 32 



Openness to the air . . . . . . .32 



Dampness ........ 33 



Composition of manure . . . . . .33 



Products of fermentation . . . . . .34 



Analyses of farmyard manure 



Dr Voelcker's experiments . . . . ... 36 



Variation in composition . . . . . .36 



Amounts of moisture, organic matter (containing nitro- 

 gen), and mineral matter . . . . . .36 



Its manurial value compared with nitrate of soda, sul- 

 phate of ammonia, and superphosphate . . .37 

 Comparison of fresh and rotten manure 



The nature and amount of loss sustained in the pro- 

 cess of rotting . . . . . . .37 



Ought manure to be applied fresh or rotten ? . .38 

 Relative merits of covered and uncovered manure-heaps . 39 

 Methods of application of farmyard manure to the field 



Merits and demerits of the different methods . . 41 

 Setting it out in heaps ...... 42 



Spreading it broadcast, and letting it lie . . 42 



Ploughing it in immediately ..... 43 



Value and function of farmyard manure 



As a supplier of the necessary elements of plant-food . 44 

 As a " universal " manure ...... 44 



Proportion in which nitrogen, phosphoric acid, and 

 potash are required by crops . . . .45 



Proportion in which they are present in farmyard 

 manure ......... 46 



Farmyard manure poor in nitrogen . . . .46 



Lawes' and Gilbert's experiments . . . .47 



