CHAPTER III. 



MANURES AND FERTILIZERS. 







Composition of Plants Plant Foods in the Soil Farmyard Man- 

 ureGreen Manure Compost Heaps. NITROGENOUS FERTILIZERS 

 Sulphate of Ammonia Nitrate of Soda Nitrolim Dried Blood 

 Soot Rape Dust Castor Seed Meal Shoddy. PHOSPHATIC FERTIL- 

 IZERS Superphosphate Limphos Basic Slag Bone Meal Bone 

 Flour Dissolved Bones Phosphatic Peruvian Guano. POTASSIC 

 FERTILIZERS Sulphate of Potash Muriate of Potash Kainit. 

 COMPOSITE FERTILIZERS Peruvian Guano Dissolved Peruvian 

 Guano Fish Guano Meat Guano. NOTES ON THE USING OF FER- 

 TILIZERSVALUING FERTILIZERS TABLE OF UNIT-VALUES. 



Composition of Plants. Every plant has a living, organised 

 body, built up of materials extracted partly from the air and 

 partly from the soil. All are composed of the same ingredients, 

 but in varying proportions. Nineteen parts out of twenty of 

 these ingredients consist of water and carbon. The supply 

 of water needs no explanation. Carbon is derived from the 

 carbonic acid gas of the atmosphere, absorbed through the 

 agency of the leaves. The remaining twentieth part is made 

 up of ingredients taken from the soil. Most of these in- 

 gredients are present in almost all soils in more or less abund- 

 ance, and need give us no further concern, but there are a few, 

 absolutely essential to healthy growth, one or more of which 

 are seldom present in available form in sufficient abundance 

 to produce profitable crops. These exceptions are nitrogen, 

 phosphoric acid, and potash, sometimes lime, and on rare 

 occasions magnesia. It is the knowledge of how to make 

 good any deficiency of these materials, in a way most likely 

 to secure full crops economically, without impairing the con- 

 tinued productiveness of the soil, which constitutes the true 

 science of manuring. 



Plant Foods in the Soil. Although it is necessary for the 

 cultivator to supplement certain plant foods, it must not on 

 that account be supposed that the soil is comparatively 





