CONTENTS 



PAGE 



CONTENTS , . .,',.., , . . , . . xi 



INTRODUCTION 



Brief view of authorities. . . . . . . . , I 



The Sun as a source of energy. The vegetable leaf as an absorptive 

 agent to convert Solar energy into Chemical energy. The soil as a 

 medium for vegetable growth. The chief factors determining 



vegetable growth 3 



Need for fertilizers. Virgin soils. Barren soils. Exhausted soils. 



Losses and gains in Nature. Losses and gains in practice . . 3 

 The balance of life ......... 8 



References 9 



PART I. FERTILIZERS. 



SECTION i. NITROGEN GROUP OF 

 FERTILIZERS. 



General properties ...... . 10 



(a) Sulphate of Ammonia. Origin. Useful and impracticable mixtures. 



Application to the land. Physical and chemical properties. Time to 

 apply. Secondary effects on the soil. Effects on crops. Crops most 

 suited for sulphate of ammonia . . . . . . . n 



(b) Ammonium Chloride, Nitrate, and Carbonate . . . . -17 



(c) Nitrate of Soda. Origin. Mixtures. Application to the land. Physical 



and chemical properties. Time to apply. Methods of application. 

 Ultimate effect on the soil. Effect on the crop grown. Crops most 

 suited to nitrate of soda . . . . . . . .18 



(d) Nitrate of Lime. History. Crops best suited. Difficulties of applica- 

 tion. Suitable mixtures ........ 20 



(e) Nitrate of Potash. History. Indian and Egyptian methods of manu- 



facture. Local agricultural uses. Nitre earths. Nitre wells. Manu- 

 facturing wastes , . . . . v 21 

 (/) Calcium Cyanamide. Nitrolim. Storage. Properties. Difficulties of 

 application to soil. Times to apply. Crops most suited. Secondary 



effects on the soil * .21 



xi 



