Vlll CONTENTS 



piles of manure in fields objectionable ; Rate of application ; Most 

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

 Comparative value of good and poor manure ; Summary of ways in 

 which manures may be beneficial. Pages 141-171. 



CHAPTER VII 



Phosphate Fertilizers. — Importance of phosphorus as plant food ; 

 Amount of phosphoric acid in soils, amount removed in crops ; 

 Source of soil phosphoric acid ; Commercial forms of phosphoric 

 acid ; Phosphate rock ; Calcium phosphates ; Reverted phosphoric 

 acid ; Available phosphoric acid ; Manufacture of phosphate fertil- 

 izers, acid phosphates, superphosphates ; Commercial value of 

 phosphoric acid ; Basic slag phosphates ; Guano ; Bones ; Steamed 

 bone ; Dissolved bone ; Bone black ; Use of phosphate fertilizers ; 

 How to keep the phosphoric acid of the soil available. Pages 172- 

 185. 



CHAPTER VIII 



Potash Fertilizers. — Potassium an essential element ; Amount of 

 potash removed in crops ; Amount in soils ; Source of soil potash ; 

 Commercial forms of potash ; Stassfurt salts, occurrence of ; 

 Kainit ; Sulphate of potash ; Other Stassfurt salts ; Wood ashes, 

 composition of ; Amount of ash in different kinds of wood ; Action 

 of ashes on soils ; Leached ashes ; The alkalinity of ashes ; Coal 

 ashes ; Miscellaneous ashes ; Commercial value of potash ; Use of 

 potash fertilizers; Joint use of potash and lime. Pages 186-195. 



CHAPTER IX 



Lime and Miscellaneous Fertilizers. — Calcium an essential ele- 

 ment ; Amount of lime removed in crops ; Amount of lime in soils ; 

 Different kinds of lime fertilizers ; Their physical and chemical 

 action ; Action of lime upon organic matter and correcting acidity 

 of soils ; Lime liberates potash ; Aids nitrification ; Action of land 

 plaster on some "alkali" soils; Quicklime and slaked lime ; 

 Marl ; Physical action of lime ; Judicious use of lime ; Miscel- 

 laneous fertilizers ; Salt and its action on the soil ; Magnesium 

 salts ; Soot ; Sea-weed ; Strand plants ; Wool washings. Pages 

 196-204. 



