Vlll CONTENTS 



CHAPTER VII 



Phosphate Fertilizers. Importance of phosphorus as plant food ; 

 Amount removed in crops ; Amount and source of phosphoric acid 

 in soils ; Commercial forms of phosphoric acid ; Phosphate rock ; 

 Calcium phosphates ; Reverted phosphoric acid ; Available phos- 

 phoric acid; Manufacture of phosphate fertilizers, 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 164-176. 



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 ; Muriate of potash ; 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 alka- 

 linity of ashes; Coal ashes; Miscellaneous ashes; Commercial 

 value of potash ; Use of potash fertilizers ; Joint use of potash 

 and lime. Pages 177-186. 



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 ; Pul- 

 verized lime rock ; Marl ; Physical action of lime ; Judicious use of 

 lime ; Miscellaneous fertilizers ; Salt and its action on the soil ; 

 Magnesium salts ; Soot ; Sea-weed ; Strand plant ash ; Wool wash- 

 ings ; Street sweepings. Pages 187-195. 



CHAPTER X 



Commercial Fertilizers. History of development of industry; 

 Complete fertilizers and amendments ; Variable composition of 

 commercial fertilizers ; Preparation of fertilizers ; Inert forms of 

 matter in fertilizers ; Inspection of fertilizers ; Mechanical condi- 



